The positivists divided all meaningful assertions into two classes: analytic propositions and empirically verifiable ones. Analytic propositions, which include the propositions of logic and mathematics, are statements the truth or falsity of which depend together on the meanings of the terms constituting the statement. An example would be the proposition two plus two equals four. The second class of meaningful propositions includes all statements about the world that can be verified, at least in principle, by sense experience. Indeed, the meaning of such propositions is identified with the empirical method of their verification. This verifiability theory of meaning, the positivists concluded, would demonstrate that scientific statements are legitimate factual claims and that metaphysical, religious, and ethical sentences are factually empty. The ideas of logical positivism were made popular in England by the publication of A.J. Ayers Language, Truth and Logic in 1936.
The positivists verifiability theory of meaning came under intense criticism by philosophers such as the Austrian-born British philosopher Karl Popper. Eventually this narrow theory of meaning yielded to a broader understanding of the nature of language. Again, an influential figure was Wittgenstein. Repudiating many of his earlier conclusions in the Tractatus, he initiated a new ligne of thought culminating in his posthumously published Philosophical Investigations (1953; translated 1953). In this work, Wittgenstein argued that once attention is directed to the way language is actually used in ordinary discourse, the variety and flexibility of language become clear. Propositions do much more than simply picture facts.
This recognition led to Wittgensteins influential concept of language games. The scientist, the poet, and the theologian, for example, are involved in different language games. Moreover, the meaning of a proposition must be understood in its context, that is, in terms of the rules of the language game of which that proposition is a part. Philosophy, concluded Wittgenstein, is an attempt to resolve problems that arise as the result of linguistic confusion, and the key to the resolution of such problems is ordinary language analysis and the proper use of language.
Additional contributions within the analytic and linguistic movement include the work of the British philosophers Gilbert Ryle, John Austin, and P. F. Strawson and the American philosopher W. V. Quine. According to Ryle, the task of philosophy is to restate systematically misleading expressions in forms that are logically more accurate. He was particularly concerned with statements the grammatical form of which suggests the existence of nonexistent objects. For example, Ryle is best known for his analysis of mentalistic language, language that misleadingly suggests that the mind is an entity in the same way as the body.
Austin maintained that one of the most fruitful starting points for philosophical inquiry is attention to the extremely fine distinctions drawn in ordinary language. His analysis of language eventually led to a general theory of speech acts, that is, to a description of the variety of activities that an individual may be performing when something is uttered.
Strawson is known for his analysis of the relationship between formal logic and ordinary language. The complexity of the latter, he argued, is inadequately represented by formal logic. A variety of analytic tools, therefore, are needed in addition to logic in analyzing ordinary language.
Quine discussed the relationship between language and ontology. He argued that language systems tend to commit their users to the existence of certain things. For Quine, the justification for speaking one way rather than another is a thoroughly pragmatic one.
The commitment to language analysis as a way of pursuing philosophy has continued as a significant contemporary dimension in philosophy. A division also continues to exist between those who prefer to work with the precision and rigour of symbolic logical systems and those who prefer to analyze ordinary language. Although few contemporary philosophers maintain that all philosophical problems are linguistic, the view continues to be widely held that attention to the logical structure of language and to how language is used in everyday discourse can be oftentimes resolved through ways that are negotiably attracted by philosophical problems.
Appeased, relations to some sorted identification to logical calculus and is in addition called a formal language, and a logical system? A system in which explicit rules are provided to determining (1) which are the expressions of the system (2) which sequence of expressions count as well formed (well-forced formulae) (3) which sequence would count as proofs. A system that may include axioms for which they leave them to terminate of their proof, however, it shows of the prepositional calculus and the predicated calculus.
Its most immediate of issues surrounding certainty are especially connected with those concerning scepticism. Although Greek scepticism entered on the value of enquiry and questioning, scepticism is now the denial that knowledge or even rational belief is possible, either about some specific subject-matter, e.g., ethics, or in any area whatsoever. Classical scepticism, springs from the observation that the best methods in some area seem to fall short of giving us contact with the truth, e.g., there is a gulf between appearances and reality, it frequently cites the conflicting judgements that our methods deliver, with the result that questions of truth commence to be undefinable. In classic thought the various examples of this conflict were systemized in the tropes of Aenesidemus. So that, the scepticism of Pyrrho and the new Academy was a system of argument and inasmuch as opposing dogmatism, and, particularly the philosophical system building of the Stoics.
As it has come down to us, particularly in the writings of Sextus Empiricus, its method was typically to cite reasons for finding our issue undesirable (sceptics devoted particular energy to undermining the Stoics conception of some truth as delivered by direct apprehension or some katalepsis). As a result the sceptics conclude eposhé, or the suspension of belief, and then go on to celebrate a way of life whose object was ataraxia, or the tranquillity resulting from suspension of belief.
For many sceptics had traditionally held that knowledge requires certainty, artistry. And, of course, they claim that certain knowledge is not possible. In part, nonetheless, of the principle that every effect it’s a consequence of an antecedent cause or causes. For causality to be true it is not necessary for an effect to be predictable as the antecedent causes may be numerous, too complicated, or too interrelated for analysis. Nevertheless, in order to avoid scepticism, this participating sceptic has generally held that knowledge does not require certainty. Except for alleged cases of things that are evident for one just by being true. It has often been thought, that any thing known must satisfy certain criteria as well for being true. It is often taught that anything is known must satisfy certain standards. In so saying, that by deduction or induction, there will be criteria specifying when it is. As these alleged cases of self-evident truth, the general principle specifying the sort of consideration that will make such standards in the apparent or justly conclude in accepting it warranted to some degree.
Besides, there is another view - the absolute globular view that we do not have any knowledge whatsoever. In whatever manner,
It is doubtful that any philosopher seriously entertains of an absolute scepticism. Even the Pyrrhonist sceptics, who held that we should refrain from accenting to any non-evident standards that no such hesitancy about asserting to the evident, the non-evident are any belief that requires evidences because it is warranted.
René Descartes (1596-1650), in his sceptical guise, never doubted the content of his own ideas. Its challenging logic, inasmuch as of whether they corresponded to anything beyond ideas.
All the same, Pyrrhonism and Cartesian form of a virtual globular scepticism, in having been held and defended, that of assuming that knowledge is some form of true, sufficiently warranted belief, it is the warranted condition that provides the truth or belief conditions, in that of providing the grist for the sceptics mill about. The Pyrrhonist will suggest that something that does not exist has the value qualities that correspond with non-distinct or to prove themselves for being non-evident, and empirically deferring the sufficiency of giving in but it is warranted. Whereas, a Cartesian sceptic will agree that no empirical standard about anything other than ones own mind and its contents is sufficiently warranted, because there are always legitimate grounds for doubting it. In which, the essential difference between the two views concerns the stringency of the requirements for a belief being sufficiently warranted to take account of as knowledge.
A Cartesian requires certainty. A Pyrrhonist merely requires that the standards in case are more warranted then its negation.
Cartesian scepticism was by an inordinately persuasions and of some influence with which Descartes agues for scepticism, than his reply holds, in that we do not have any knowledge of any empirical standards, in that of anything beyond the contents of our own minds. The reason is roughly in the position that there is a legitimate doubt about all such standards, only because there is no way to justifiably deny that our senses are being stimulated by some sense, for which it is radically different from the objects which we normally think, in whatever manner they affect our senses. Therefrom, if the Pyrrhonist is the agnostic, the Cartesian sceptic is the atheist.
Because the Pyrrhonist requires much less of a belief in order for it to be confirmed as knowledge than do the Cartesian, the argument for Pyrrhonism are much more difficult to construct. A Pyrrhonist must show that there is no better set of reasons for believing to any standards, of which are in case that any knowledge learnt of the mind is understood by some of its forms, that has to require certainty.
The underlying latencies that are given among the many derivative contributions as awaiting their presence to the future that of specifying to the theory of knowledge, is, but, nonetheless, the possibility to identify a set of shared doctrines, however, identity to discern two broad styles of instances to discern, in like manners, these two styles of pragmatism, clarify the innovation that a Cartesian approval is fundamentally flawed, nonetheless, of responding very differently but not forgone.
Repudiating the requirements of absolute certainty or knowledge, insisting on the connexion of knowledge with activity, as, too, of pragmatism of a reformist distributing knowledge upon the legitimacy of traditional questions about the truth-conduciveness of our cognitive practices, and sustain a conception of truth objectives, enough to give those questions that undergo of gathering into their own purposive latencies, yet we are given to the spoken word for which a dialectic awareness sparks the flame from the ambers of fire.
It seems clear that certainty is a property that can be assembled to either a person or a belief. We can say that a person, S is certain, or we can say that its descendable alinement is aligned as of p, is certain. The two uses can be connected by saying that S has the right to be certain just in case the value of p is sufficiently verified.
In defining certainty, it is crucial to note that the term has both an absolute and relative sense. More or less, we take a proposition to be certain when we have no doubt about its truth. We may do this in error or unreasonably, but objectively a proposition is certain when such absence of doubt is justifiable. The sceptical tradition in philosophy denies that objective certainty is often possible, or ever possible, either for any proposition at all, or for any proposition from some suspect family (ethics, theory, memory, empirical judgement etc.) A major sceptical weapon is the possibility of upsetting events that can cast doubt back onto what were hitherto taken to be certainties. Others include reminders of the divergence of human opinion, and the fallible source of our confidence. Fundamentalist approaches to knowledge look for a basis of certainty, upon which the structure of our system is built. Others reject the metaphor, looking for mutual support and coherence, without foundation.
However, in moral theory, the views that there are inviolable moral standards or absolute variable human desires or policies or prescriptions.
In spite of the notorious difficulty of reading Kantian ethics, a hypothetical imperative embeds a command which is in place only given some antecedent desire or project: If you want to look wise, stay quiet. The injunction to stay quiet is only given to those with the antecedent desire or inclination. If one has no desire to look wise, the injunction cannot be so avoided: It is a requirement that binds anybody, regardless of their inclination. It could be represented as, for example, tell the truth (regardless of whether you want to or not). The distinction is not always signalled by presence or absence of the conditional or hypothetical form: If you crave drink, don't become a bartender may be regarded as an absolute injunction applying to anyone, although only activated in cases with which of those that are stated desirously.
In Grundlegung zur Metaphsik der Sitten (1785), Kant discussed five forms of the categorical imperative: (1) the formula of universal law: act only on that maxim through which you can at the same times will that it should become universal law: (2) the contractual laws of nature are as of their acts in becoming as if the maxim of your action were to change, by means of your will as a universal law of nature: (3) the formula of the end-in-itself: act of practicing ways that treat humanity in whatever manner as your own person or in the person of any other, never simply as a means, but always at the same time as an end: (4) the formula of autonomy, or considering the will of every rational being as a will which makes universal law: (5) the formula of the Kingdom of Ends, which provides a model for the systematic union of different rational beings under common laws.
Even so, a proposition that is not a conditional p. Moreover, the affirmative and negative, modern opinion is wary of this distinction, since what appears categorical may vary notation. Apparently, categorical propositions may also turn out to be disguised conditionals: X is intelligent (categorical?) = if X is given a range of tasks she performs them better than many people (conditional?) The problem. Nonetheless, is not merely one of classification, since deep metaphysical questions arise when facts that seem to be categorical and therefore solid, come to seem by contrast conditional, or purely hypothetical or potential.
A limited area of knowledge or endeavour to which pursuits, activities and interests are a central representation held to a concept of physical theory. In this way, a field is defined by the distribution of a physical quantity, such as temperature, mass density, or potential energy y, at different points in space. In the particularly important example of force fields, such as gravitational, electrical, and magnetic fields, the field value at a point is the force which a test particle would experience if it were located at that point. The philosophical problem is whether a force field is to be thought of as purely potential, so the presence of a field merely describes the propensity of masses to move relative to each other, or whether it should be thought of in terms of the physically real modifications of a medium, whose properties result in such powers that are, liken to force fields, having potentially pure characterized by their means of dispositional statements or conditionals, or are they categorical or actual? The former option seems to require within ungrounded dispositions, or regions of space that differ only in what happens if an object is placed there. The law-like shape of these dispositions, apparent for example in the curved lines of force of the magnetic field, may then seem quite inexplicable. To atomists, such as Newton it would represent a return to Aristotelian entelechies, or quasi-psychological affinities between things, which are responsible for their motions. The latter option requires understanding of how forces of attraction and repulsion can be grounded in the properties of the medium.
The basic idea of a field is arguably present in Leibniz, who was certainly hostile to Newtonian atomism. Despite the fact that his equally hostility to action at a distance muddies the water. It is usually credited to the Jesuit mathematician and scientist Joseph Boscovich (1711-87) and Immanuel Kant (1724-1804), both of whom was influenced by the scientist, Michael Faraday (1791-1867), with whose work the physical notion became established. In his paper On the Physical Character of the Lines of Magnetic Force (1852). Faraday was to suggest several criteria for assessing the physical reality of lines of force, such as whether they are affected by an intervening material medium, whether the motion depends on the nature of what is placed at the receiving end. As far as electromagnetic fields go, Faraday himself inclined to the view that the mathematical similarity between heat flow, currents, and electromagnetic lines of force was evidence for the physical reality of the intervening medium.
Once, again, our mentioned recognition for which its case value, may turn of its view, especially a view s associated with the American psychologist and philosopher William James (1842-1910), in that the truth of a statement can be defined in terms of a utility of accepting it. Communicated, so much as a dispiriting position for which its place of valuation may be viewed as an objection. Since there are things that are false, as it may be useful to accept, and conversely there are things that are true and that it may be damaging to accept. Nevertheless, there are deep connections between the idea that a representation system is accorded, and the likely success of the projects in progressive formality, by its possession. The evolution of a system of representation either perceptual or linguistic, seems bounded to connect successes with everything adapting or with utility in the modest sense. The Wittgenstein doctrine stipulates the meaning of use that upon the nature of belief and its relations with human attitude, emotion and the idea that belief in the truth on one hand, the action of the other. One way of binding with cement, wherefore the connexion is found in the idea that natural selection becomes much as much in adapting us to the cognitive creatures, because beliefs have effects, they work. Pragmatism can be found in Kant’s doctrine, and continued to play an influencing role in the theory of meaning and truth.
James, (1842-1910), although with characteristic generosity exaggerated in his debt to Charles S. Peirce (1839-1914), he charted that the method of doubt encouraged people to pretend to doubt what they did not doubt in their hearts, and criticize its individualists insistence, that the ultimate test of certainty is to be found in the individuals personalized consciousness.
From his earliest writings, James understood cognitive processes in teleological terms, as he thought that it holds some assistance in satisfactory interests. His will to Believe doctrine, the view that we are sometimes justified in believing beyond the evidential relics upon the notion that a beliefs benefits are relevant to its justification. His pragmatic method of analyzing philosophical problems, for which requires that we find the meaning of terms by examining their application to objects in experimental situations, similarly reflects the teleological approach in its attention to consequences.
Such an approach, however, sets James' theory of meaning apart from verification, dismissive of metaphysics. Unlike the verificationalist, who takes cognitive meaning to be a matter only of consequences in sensory experience. James took pragmatic meaning to include emotional and matter responses. Moreover, his, metaphysical standard of value, not a way of dismissing them as meaningless. It should also be noted that in a greater extent, circumspective moments James did not hold that even his broad set of consequences was exhaustive of a terms meaning. Theism, for example, he took to have antecedently, definitional meaning, in addition to its varying degree of importance and chance upon an important pragmatic meaning.
James' theory of truth reflects upon his teleological conception of cognition, by considering a true belief to be one which is compatible with our existing system of beliefs, and leads us to satisfactory interaction with the world.
If realism itself can be given a fairly quick clarification, it is more difficult to chart the various forms of supposition, for they seem legendary. Other opponents deny that the entitles posited by the relevant discourses that exist or at least exists: The standard example is idealism that reality is somehow mind-curative or mind-co-ordinated - that real object comprising the external world is dependently of eloping minds, but only exists as in some way correlative to the mental operations. The doctrine assembled of idealism enters on the conceptual note that reality as we understand this as meaningful and reflects the working of mindful purposes. And it construes this as meaning that the inquiring mind itself makes of a formative constellations and not of any mere understanding of the nature of the real bit even the resulting charger that we characterize with it.
Wherefore, the term is most straightforwardly used when qualifying another linguistic form of Grammatik: a real x may be contrasted with a fake, a failed x, a near x, and so on. To treat something as real, without qualification, is to suppose it to be part of the actualized world. To reify something is to suppose that we have committed by some indoctrinated treatise, as that of a theory. The central error in thinking of reality and the totality of existence is to think of the unreal as a separate domain of things, perhaps, unfairly to that of the benefits of existence.
Such that non-existence of all things, as the product of logical confusion of treating the term nothing as itself a referring expression instead of a quantifier. (Stating informally as a quantifier is an expression that reports of a quantity of times that a predicate is satisfied in some class of things, i.e., in a domain.) This confusion leads the unsuspecting to think that a sentence such as Nothing is all around us talks of a special kind of thing that is all around us, when in fact it merely denies that the predicate is all around us have appreciations. The feelings that lad some philosophers and theologians, notably Heidegger, to talk of the experience of nothing, is not properly the experience of anything, but rather the failure of a hope or expectations that there would be something of some kind at some point. This may arise in quite everyday cases, as when one finds that the article of functions one expected to see as usual, in the corner has disappeared. The difference between existentialist and analytic philosophy, on the point of what, whereas the former is afraid of nothing, and the latter think that there is nothing to be afraid of.
In the 20th century, modal versions of the ontological argument have been propounded by the American philosophers Charles Hertshorne, Norman Malcolm, and Alvin Plantinga. One version is to define something as unsurpassably great, if it exists and is perfect in every possible world. Then, to allow that it is at least possible that an unsurpassable great being existing. This means that there is a possible world in which such a being exists. However, if it exists in one world, it exists in all (for the fact that such a being exists in a world that entails, in at least, it exists and is perfect in every world), so, it exists necessarily. The correct response to this argument is to disallow the apparently reasonable concession that it is possible that such a being exists. This concession is much more dangerous than it looks, since in the modal logic, involved from possibly necessarily p, we can device necessarily p. A symmetrical proof starting from the assumption that it is possibly that such is not exist would derive that it is impossible that it exists.
The doctrine that it makes an ethical difference of whether an agent actively intervenes to bring about a result, or omits to act in circumstance in which it is foreseen, that as a result of the omission brings the same formation. Thus, suppose that I wish you dead. If I act to bring about your death, I am a murderer, however, if I happily discover you in danger of death, and fail to act to save you, I am not acting, and therefore, according to the doctrine of acts and omissions not a murderer. Critics implore that omissions can be as deliberate and immoral as I am responsible for your food and fact to feed you. Only omission is surely a killing, Doing nothing can be a way of doing something, or in other worlds, absence of bodily movement can also constitute acting negligently, or deliberately, and defending on the context, may be a way of deceiving, betraying, or killing. Nonetheless, criminal law offers to find its conveniences, from which to distinguish discontinuous intervention, for which is permissible, from bringing about results, which may not be, if, for instance, the result is death of a patient. The question is whether the difference, if there is one, is, between acting and omitting to act be discernibly or defined in a way that bars a general moral might.
The double effect of a principle attempting to define when an action that had both good and bad results are morally permissible. I one formation such an action is permissible if (1) The action is not wrong in itself, (2) the bad consequences are not that which is intended (3) the good is not itself a result of the bad consequences, and (4) the two consequential effects are commensurate. Thus, for instance, I might justifiably bomb an enemy factory, foreseeing but intending that the death of nearby civilians, whereas bombing the death of nearby civilians intentionally would be disallowed. The principle has its roots in Thomist moral philosophy, accordingly. St. Thomas Aquinas (1225-74), held that it is meaningless to ask whether a human being is two things (soul and body) or, only just as it is meaningless to ask whether the wax and the shape given to it by the stamp are one: On this analogy the sound is yet a form of the body. Life after death is possible only because a form itself does not perish (pricking is a loss of form).
And is, therefore, in some sense available to reactivate a new body, therefore, not I who survive body death, but I may be resurrected in the same personalized body that becomes reanimated by the same form, that which Aquinas' account, as a person has no privileged self-understanding, we understand ourselves as we do everything else, by way of sense experience and abstraction, and knowing the principle of our own lives is an achievement, not as a given. Difficultly at this point, led the logical positivist to abandon the notion of an epistemological foundation altogether, and to flirt with the coherence theory of truth, it is widely accepted that trying to make the connexion between thought and experience through basic sentence s depends on an untenable myth of the given
The special way that we each have of knowing our own thoughts, intentions, and sensationalist have brought in the many philosophical behaviorist and functionalist tendencies, that have found it important to deny that there is such a special way, arguing the way that I know of my own mind inasmuch as the way that I know of yours, e.g., by seeing what I say when asked. Others, however, point out that the behaviour of reporting the result of introspection in a particular and legitimate kind of behavioural access that deserves notice in any account of historically human psychology. The historical philosophy of reflection upon the astute of history, or of historical, thinking, finds the term was used in the 18th century, e.g., by Volante was to mean critical historical thinking as opposed to the mere collection and repetition of stories about the past. In Hegelian, particularly by conflicting elements within his own system, however, it came to man universal or world history. The Enlightenment confidence was being replaced by science, reason, and understanding that gave history a progressive moral thread, and under the influence of the German philosopher, whom spreading Romanticism reached Gottfried Herder (1744-1803), and, Immanuel Kant, this idea took it further to hold, so that philosophy of history cannot be the detecting of a grand system, the unfolding of the evolution of human nature as witnessed in successive sages (the progress of rationality or of Spirit). This essential speculative philosophy of history is given an extra Kantian twist in the German idealist Johann Fichte, in whom the extra association of temporal succession with logical implication introduces the idea that concepts themselves are the dynamic engines of historical change. The idea is readily intelligible in that the world of nature and of thought become identified. The work of Herder, Kant, Flichte and Schelling is synthesized by Hegel: History has a plot, as too, this is the moral development of man, only to equate with the freedom within the state, this in turn is the development of thought, or a logical development in which various necessary moment in the life of the concept are successively achieved and improved upon. Hegels method is at its most successful, when the object is the history of ideas, and the evolution of thinking may march in steps with logical oppositions and their resolution encounters red by various systems of thought.
Within the revolutionary communism, Karl Marx (1818-83) and the German social philosopher Friedrich Engels (1820-95), there emerges a rather different kind of story, based upon Hefls progressive structure not laying the achievement of the goal of history to a future in which the political condition for freedom comes to exist, so that economic and political fears than reason is in the engine room. Although, it is such that speculations upon the history may it be continued to be written, notably: late examples, by the late 19th century large-scale speculation of this kind with the nature of historical understanding, and in particular with a comparison between the, methods of natural science and with the historians. For writers such as the German neo-Kantian Wilhelm Windelband and the German philosopher and literary critic and historian Wilhelm Dilthey, it is important to show that the human sciences such, as history is objective and legitimate, nonetheless they are in some way deferent from the enquiry of the scientist. Since the subjective-matter is the past thought and actions of human brings, what is needed and actions of human beings, past thought and actions of human beings, what is needed is an ability to re-live that past thought, knowing the deliberations of past agents, as if they were the historians own. The most influential British writer on this theme was the philosopher and historian George Collingwood (1889-1943) whose, The Idea of History (1946), contains an extensive defence of the Verstehe approach, but it is nonetheless, the explanation from their actions, however, by re-living the situation as our understanding that understanding others is not gained by the tactic use of a theory, enabling us to infer what thoughts or intentionality experienced, again, the matter to which the subjective-matters of past thoughts and actions, as I have a human ability of knowing the deliberations of past agents as if they were the historians own. The immediate question of the form of historical explanation, and the fact that general laws have other than no place or any apprentices in the order of a minor place in the human sciences, it is also prominent in thoughts about distinctiveness as to regain their actions, but by re-living the situation in or thereby an understanding of what they experience and thought.
The view that everyday attributions of intention, belief and meaning to other persons proceeded via tacit use of a theory that enables ne to construct these interpretations as explanations of their doings. The view is commonly hold along with functionalism, according to which psychological states theoretical entities, identified by the network of their causes and effects. The theory-theory had different implications, depending on which feature of theories is being stressed. Theories may be though of as capable of formalization, as yielding predications and explanations, as achieved by a process of theorizing, as achieved by predictions and explanations, as achieved by a process of theorizing, as answering to empirically evince that is in principle describable without them, as liable to be overturned by newer and better theories, and o on. The main problem with seeing our understanding of others as the outcome of a piece of theorizing is the non-existence of a medium in which this theory can be couched, as the child learns simultaneously he minds of others and the meaning of terms in its native language.
Our understanding of others is not gained by the tacit use of a theory, enabling us to infer what thoughts or intentions explain their actions, however, by re-living the situation in their moccasins, or from their point of view, and thereby understanding what they experienced and thought, and therefore expressed. Understanding others is achieved when we can ourselves deliberate as they did, and hear their words as if they are our own. The suggestion is a modern development of the verstehen tradition associated with Dilthey, Weber and Collngwood.
Much as much, it is therefore, in some sense available to reactivate a new body, however, not that I, who survives bodily death, but I may be resurrected in the same body that becomes reanimated by the same form, in that of Aquinas' account, a person hasn't the privilege of self-understanding. We understand ourselves, just as we do everything else, that through the sense experience, in that of an abstraction, may justly be of knowing the principle of our own lives, is to obtainably achieve, and not as a given. In the theory of knowledge that knowing Aquinas holds the Aristotelian doctrine that knowing entails some similarities between the knower and what there is to be known: A humans corporal nature, therefore, requires that knowledge start with sense perception. As yet, the same limitations that do not apply of bringing further the levelling stabilities that are contained within the hierarchical mosaic, such as the celestial heavens that open in bringing forth to angles.
In the domain of theology Aquinas deploys the distraction emphasized by Eringena, between the existence of God in understanding the significance of justifications: They are (1) Motion is only explicable if there exists an unmoved, a first mover (2) the chain of efficient causes demands a first cause (3) the contingent character of existing things in the wold demands a different order of existence, or in other words as something that has a necessary existence (4) the gradation of value in things in the world requires the existence of something that is most valuable, or perfect, and (5) the orderly character of events points to a final cause, or end t which all things are directed, and the existence of this end demands a being that ordained it. All the arguments are physico-theological arguments, in that between reason and faith, still, Aquinas lays out proofs for the existence of God.
He readily recognizes that there are doctrines such that are the Incarnation and the nature of the Trinity, know only through revelations, and whose acceptance is more a matter of moral will. Gods essence is identified with his existence, as pure activity. God is simple, containing no potential. No matter how, we cannot obtain knowledge of what God is (his quiddity), perhaps, doing the same work as the principle of charity, but suggesting that we regulate our procedures of interpretation by maximizing the extent to which we see the subject s humanly reasonable, than the extent to which we see the subject as right about things. Whereby remaining content with descriptions that apply to him partly by way of analogy, God reveals of him, who is not actualized by and for himself.
The immediate problem availed in ethics is supported by the English philosopher Phillippa Foot, in her The Problem of Abortion and the Doctrine of the Double Effect (1967). Where a runaway train or trolley comes to a section in the track that is under construction and impassable. One person is working on one part and five on the other, and the trolley will put an end to anyone working on the branch it enters. Clearly, to most minds, the driver should steer for the fewest populated branch. But now suppose that, left to itself, it will enter the branch with its five employs that are there, and you as a bystander can intervene, altering the points so that it veers through the other. Is it right or obligors, or even permissible for you to do this, thereby, apparently involving yourself in ways that responsibility ends in a death of one person? After all, who have you wronged if you leave it to go its own way? The situation is similarly standardized of others in which utilitarian reasoning seems to lead to one course of action, but a persons integrity or principles may oppose it.
Describing events that haphazardly happen does not of itself permits us to talk of rationality and intention, which are the categories we may apply if we conceive of them as action. We think of ourselves not only passively, as creatures that make things happen. Understanding this distinction gives forth of its many major problems concerning the nature of an agency for the causation of bodily events by mental events, and of understanding the will and free will. Other problems in the theory of action include drawing the distinction between an action and its consequence, and describing the structure involved when we do one thing by; doing another thing. Even the planning and dating where someone shoots someone on one day and in one place, whereby the victim then dies on another day and in another place. Where and when did the murderous act take place?
Causation, least of mention, is not clear that only events are created by and for itself. Kant cites the example o a cannonball at rest and stationed upon a cushion, but causing the cushion to be the shape that it is, and thus to suggest that the causal states of affairs or objects or facts may also be casually related. All of which, the central problem is to understand the elements of necessitation or determinacy of the future. Events, Hume thought, are in themselves loose and separate: How then are we to conceive of others? The relationship seems not too perceptible, for all that perception gives us (Hume argues) is knowledge of the patterns that events do, actually falling into than any acquaintance with the connections determining the pattern. It is, however, clear that our conception of everyday objects are largely determined by their casual powers, and all our action is based on the belief that these causal powers are stable and reliable. Although scientific investigation can give us wider and deeper dependable patterns, it seems incapable of bringing us any nearer to the must of causal necessitation. Particular examples o f puzzles with causalities are quite apart from general problems of forming any conception of what it is: How are we to understand the casual interaction between mind and body? How can the present, which exists, or its existence to a past that no longer exists? How is the stability of the casual order to be understood? Is backward causality possible? Is causation a concept needed in science, or dispensable?
The news concerning free-will, is nonetheless, a problem for which is to reconcile our everyday consciousness of ourselves as agent, with the best view of what science tells us that we are. Determinism is one part of the problem. It may be defined as the doctrine that every event has a cause. More precisely, for any event C, there will be one antecedent states of nature N, and a law of nature L, such that given L, N will be followed by C. But if this is true of every event, it is true of events such as my doing something or choosing to do something. So my choosing or doing something is fixed by some antecedent state N an d the laws. Since determinism is universal these in turn are fixed, and so backwards to events for which I am clearly not responsible (events before my birth, for example). So, no events can be voluntary or free, where that means that they come about purely because of my willing them I could have done otherwise. If determinism is true, then there will be antecedent states and laws already determining such events: How then can I truly be said to be their author, or be responsible for them?
Reactions to this problem are commonly classified as: (1) Hard determinism. This accepts the conflict and denies that you have real freedom or responsibility (2) Soft determinism or compatibility, whereby reactions in this family assert that everything you should be from a notion of freedom is quite compatible with determinism. In particular, if your actions are caused, it can often be true of you that you could have done otherwise if you had chosen, and this may be enough to render you liable to be held unacceptable (the fact that previous events will have caused you to choose as you did, and is deemed irrelevant on this option). (3) Libertarianism, as this is the view that while compatibilism is only an evasion, there is a more substantiative, real notions of freedom that can yet be preserved in the face of determinism (or, of indeterminism). In Kant, while the empirical or phenomenal self is determined and not free, whereas the noumenal or rational self is capable of being rational, free action. However, the noumenal self exists outside the categorical priorities of space and time, as this freedom seems to be of a doubtful value as other libertarian avenues do include of suggesting that the problem is badly framed, for instance, because the definition of determinism breaks down, or postulates by its suggesting that there are two independent but consistent ways of looking at an agent, the scientific and the humanistic, wherefore it is only through confusing them that the problem seems urgent. Nevertheless, these avenues have gained general popularity, as an error to confuse determinism and fatalism.
The dilemma for which determinism is for itself often supposes of an action that seems as the end of a causal chain, or, perhaps, by some hieratical set of suppositional actions that would stretch back in time to events for which an agent has no conceivable responsibility, then the agent is not responsible for the action.
Once, again, the dilemma adds that if an action is not the end of such a chain, then either two or one of its causes occurs at random, in that no antecedent events brought it about, and in that case nobody is responsible for its ever to occur. So, whether or not determinism is true, responsibility is shown to be illusory.
Still, there is to say, to have a will is to be able to desire an outcome and to purpose to bring it about. Strength of will, or firmness of purpose, is supposed to be good and weakness of will or akrasia badly.
A mental act of willing or trying whose presence is sometimes supposed to make the difference between intentional and voluntary action, as well of mere behaviour. The theory that there are such acts is problematic, and the idea that they make the required difference is a case of explaining a phenomenon by citing another that raises exactly the same problem, since the intentional or voluntary nature of the set of volition now needs explanation. For determinism to act in accordance with the law of autonomy or freedom, is that in ascendance with universal moral law and regardless of selfish advantage.
A categorical notion in the work as contrasted in Kantian ethics show of a hypothetical imperative that embeds of a commentary which is in place only given some antecedent desire or project. If you want to look wise, stay quiet. The injunction to stay quiet only applies to those with the antecedent desire or inclination: If one has no desire to look wise the injunction or advice lapses. A categorical imperative cannot be so avoided, it is a requirement that binds anybody, regardless of their inclination,. It could be repressed as, for example, Tell the truth (regardless of whether you want to or not). The distinction is not always mistakably presumed or absence of the conditional or hypothetical form: If you crave drink, don't become a bartender may be regarded as an absolute injunction applying to anyone, although only activated in the case of those with the stated desire.
In Grundlegung zur Metaphsik der Sitten (1785), Kant discussed some of the given forms of categorical imperatives, such that of (1) The formula of universal law: act only on that maxim through which you can at the same time will that it should become universal law, (2) the formula of the law of nature: Act as if the maxim of your action were to become through your will a universal law of nature, (3) the formula of the end-in-itself, Act in such a way that you always treat humanity of whether in your own person or in the person of any other, never simply as an end, but always at the same time as an end, (4) the formula of autonomy, or consideration; the will of every rational being a will which makes universal law, and (5) the formula of the Kingdom of Ends, which provides a model for systematic union of different rational beings under common laws.
A central object in the study of Kant’s ethics is to understand the expressions of the inescapable, binding requirements of their categorical importance, and to understand whether they are equivalent at some deep level. Kant’s own application of the notions are always convincing: One cause of confusion is relating Kant’s ethical values to theories such as ;expressionism in that it is easy but imperatively must that it cannot be the expression of a sentiment, yet, it must derive from something unconditional or necessary such as the voice of reason. The standard mood of sentences used to issue request and commands are their imperative needs to issue as basic the need to communicate information, and as such to animals signalling systems may as often be interpreted either way, and understanding the relationship between commands and other action-guiding uses of language, such as ethical discourse. The ethical theory of prescriptivism in fact equates the two functions. A further question is whether there is an imperative logic. Hump that bale seems to follows from Tote that barge and hump that bale, follows from Its windy and its raining:.But it is harder to say how to include other forms, does Shut the door or shut the window follows from Shut the window, for example? The usual way to develop an imperative logic is to work in terms of the possibility of satisfying the other one command without satisfying the other, thereby turning it into a variation of ordinary deductive logic.
Despite the fact that the morality of people and their ethics amount to the same thing, there is a usage that I restart morality to systems such as that of Kant, based on notions given as duty, obligation, and principles of conduct, reserving ethics for the more Aristotelian approach to practical reasoning as based on the valuing notions that are characterized by their particular virtue, and generally avoiding the separation of moral considerations from other practical considerations. The scholarly issues are complicated and complex, with some writers seeing Kant as more Aristotelian,. And Aristotle as more involved with a separate sphere of responsibility and duty, than the simple contrast suggests.
A major topic of philosophical inquiry, especially in Aristotle, and subsequently since the 17th and 18th centuries, when the science of man began to probe into human motivation and emotion. For such as these, the French moralist, or Hutcheson, Hume, Smith and Kant, a prime task as to delineate the variety of human reactions and motivations. Such an inquiry would locate our propensity for moral thinking among other faculties, such as perception and reason, and other tendencies as empathy, sympathy or self-interest. The task continues especially in the light of a post-Darwinian understanding of ourselves.
In some moral systems, notably that of Immanuel Kant, real moral worth comes only with interactivity, justly because it is right. However, if you do what is purposely becoming, equitable, but from some other equitable motive, such as the fear or prudence, no moral merit accrues to you. Yet, that in turn seems to discount other admirable motivations, as acting from main-sheet benevolence, or sympathy. The question is how to balance these opposing ideas and how to understand acting from a sense of obligation without duty or rightness , through which their beginning to seem a kind of fetish. It thus stands opposed to ethics and relying on highly general and abstractive principles, particularly. Those associated with the Kantian categorical imperatives. The view may go as far back as to say that taken in its own, no consideration point, for that which of any particular way of life, that, least of mention, the contributing steps so taken as forwarded by reason or be to an understanding estimate that can only proceed by identifying salient features of a situation that weigh on ones side or another.
As random moral dilemmas set out with intense concern, inasmuch as philosophical matters that exert a profound but influential defence of common sense. Situations in which each possible course of action breeches some otherwise binding moral principle, are, nonetheless, serious dilemmas making the stuff of many tragedies. The conflict can be described in different was. One suggestion is that whichever action the subject undertakes, that he or she does something wrong. Another is that his is not so, for the dilemma means that in the circumstances for what she or he did was right as any alternate. It is important to the phenomenology of these cases that action leaves a residue of guilt and remorse, even though it had proved it was not the subjects fault that she or he were considering the dilemma, that the rationality of emotions can be contested. Any normality with more than one fundamental principle seems capable of generating dilemmas, however, dilemmas exist, such as where a mother must decide which of two children to sacrifice, least of mention, no principles are pitted against each other, only if we accept that dilemmas from principles are real and important, this fact can then be used to approach in themselves, such as of utilitarianism, to espouse various kinds may, perhaps, be entered upon the possibility of relating to independent feelings, liken to recognize only one sovereign principle. Alternatively, of regretting the existence of dilemmas and the unordered jumble of furthering principles, in that of creating several of them, a theorist may use their occurrences to encounter upon that which it is to argue for the desirability of locating and promoting a single sovereign principle.
Nevertheless, some theories into ethics see the subject in terms of a number of laws (as in the Ten Commandments). The status of these laws may be that they are the edicts of a divine lawmaker, or that they are truth of reason, given to its situational ethics, virtue ethics, regarding them as at best rules-of-thumb, and, frequently disguising the great complexity of practical representations that for reason has placed the Kantian notions of their moral law.
In continence, the natural law possibility points of the view of the states that law and morality are especially associated with St. Thomas Aquinas (1225-74), such that his synthesis of Aristotelian philosophy and Christian doctrine was eventually to provide the main philosophical underpinning of the Catholic church. Nevertheless, to a greater extent of any attempt to cement the moral and legal order and together within the nature of the cosmos or the nature of human beings, in which sense it found in some Protestant writings, under which had arguably derived functions. From a Platonic view of ethics and its agedly implicit advance of Stoicism. Its law stands above and apart from the activities of human lawmakers: It constitutes an objective set of principles that can be seen as in and for themselves by means of natural usages or by reason itself, additionally, (in religious verses of them), that express of Gods will for creation. Non-religious versions of the theory substitute objective conditions for humans flourishing as the source of constraints, upon permissible actions and social arrangements within the natural law tradition. Different views have been held about the relationship between the rule of the law and Gods will. Grothius, for instance, sides with the view that the content of natural law is independent of any will, including that of God.
While the German natural theorist and historian Samuel von Pufendorf (1632-94) takes the opposite view. His great work was the De Jure Naturae et Gentium, 1672, and its English translation is Of the Law of Nature and Nations, 1710. Pufendorf was influenced by Descartes, Hobbes and the scientific revolution of the 17th century, his ambition was to introduce a newly scientific mathematical treatment on ethics and law, free from the tainted Aristotelian underpinning of scholasticism. Like that of his contemporary - Locke. His conception of natural laws include rational and religious principles, making it only a partial forerunner of more resolutely empiricist and political treatment in the Enlightenment.
Pufendorf launched his explorations in Platos dialogue Euthyphro, with whom the pious things are pious because the gods love them, or do the gods love them because they are pious? The dilemma poses the question of whether value can be conceived as the upshot o the choice of any mind, even a divine one. On the first option the choice of the gods creates goodness and value. Even if this is intelligible it seems to make it impossible to praise the gods, for it is then vacuously true that they choose the good. On the second option we have to understand a source of value lying behind or beyond the will even of the gods, and by which they can be evaluated. The elegant solution of Aquinas is and is therefore distinct form is willing, but not distinct from him.
The dilemma arises whatever the source of authority is supposed to be. Do we care about the good because it is good, or do we just call good those things that we care about? It also generalizes to affect our understanding of the authority of other things: Mathematics, or necessary truth, for example, are truth necessary because we deem them to be so, or do we deem them to be so because they are necessary?
The natural law tradition may either assume a stranger form, in which it is claimed that various facts entails of primary and secondary qualities, any of which is claimed that various facts entail values, reason by itself is capable of discerning moral requirements. As in the ethics of Kant, these requirements are supposed binding on all human beings, regardless of their desires.
The supposed natural or innate abilities of the mind to know the first principle of ethics and moral reasoning, wherein, those expressions are assigned and related to those that distinctions are which make in terms contribution to the function of the whole, as completed definitions of them, their phraseological impression is termed synderesis (or, syntetesis) although traced to Aristotle, the phrase came to the modern era through St. Jerome, whose scintilla conscientiae (gleam of conscience) awaits a popular concept in early scholasticism. Nonetheless, it is mainly associated in Aquinas as an infallible natural, simple and immediate grasp of first moral principles. Conscience, by contrast, is ,more concerned with particular instances of right and wrong, and can be in error, under which the assertion that is taken as fundamental, at least for the purposes of the branch of enquiry in hand.
It is, nevertheless, the view interpreted within the particular states of law and morality especially associated with Aquinas and the subsequent scholastic tradition, showing for itself the enthusiasm for reform for its own sake. Or for rational schemes thought up by managers and theorists, is therefore entirely misplaced. Major o exponent s of this theme include the British absolute idealist Herbert Francis Bradley (1846-1924) and Austrian economist and philosopher Friedrich Hayek. The notably the idealism of Bradley, there is the same doctrine that change is contradictory and consequently unreal: The Absolute is changeless. A way of sympathizing a little with his idea is to reflect that any scientific explanation of change will proceed by finding an unchanging law operating, or an unchanging quantity conserved in the change, so that explanation of change always proceeds by finding that which is unchanged. The metaphysical problem of change is to shake off the idea that each moment is created afresh, and to obtain a conception of events or processes as having a genuinely historical reality, Really extended and unfolding in time, as opposed to being composites of discrete temporal atoms. A step toward this end may be to see time itself not as an infinite container within which discrete events are located, bu as a kind of logical construction from the flux of events. This relational view of time was advocated by Leibniz and a subject of the debate between him and Newtons' Absolutist pupil, Clarke.
Generally, nature is an indefinitely mutable term, changing as our scientific conception of the world changes, and often best seen as signifying a contrast with something considered not part of nature. The term applies both to individual species (it is the nature of gold to be dense or of dogs to be friendly), and also to the natural world as a whole. The sense in which it applies to species quickly links up with ethical and aesthetic ideals: A thing ought to realize its nature, what is natural is what it is good for a thing to become, it is natural for humans to be healthy or two-legged, and departure from this is a misfortune or deformity,. The associations of what is natural with what it is good to become is visible in Plato, and is the central idea of Aristotles philosophy of nature. Unfortunately, the pinnacle of nature in this sense is the mature adult male citizen, with the rest of what we would call the natural world, including women, slaves, children and other species, not quite making it.
Nature in general can, however, function as a foil to any idea inasmuch as a source of ideals: In this sense fallen nature is contrasted with a supposed celestial realization of the forms. The theory of forms is probably the most characteristic, and most contested of the doctrines of Plato. In the background, i.e., the Pythagorean conception of form as the initial orientation to physical nature, bu also the sceptical doctrine associated with the Greek philosopher Cratylus, and is sometimes thought to have been a teacher of Plato before Socrates. He is famous for capping the doctrine of Ephesus of Heraclitus, whereby the guiding idea of his philosophy was that of the logos, is capable of being heard or heardedly by people, it unifies opposites, and it is somehow associated with fire, which is preeminent among the four elements that Heraclitus distinguishes: Fire, air (breath, the stuff of which souls composed), earth, and water. Although he is principally remembered for the doctrine of the flux of all things, and the famous statement that you cannot step into the same river twice, for new waters are ever flowing in upon you. The more extreme implication of the doctrine of flux, e.g., the impossibility of categorizing things truly, do not seem consistent with his general epistemology and views of meaning, and were to his follower Cratylus, although the proper conclusion of his views was that the flux cannot be captured in words. According to Aristotle, he eventually held that since regarding that which everywhere in every respect is changing nothing is just to stay silent and shake ones finger. Platos theory of forms can be seen in part as an action against the impasse to which Cratylus was driven.
The Galilean world view might have been expected to drain nature of its ethical content, however, the term seldom loses its normative force, and the belief in universal natural laws provided its own set of ideals. In the 18th century for example, a painter or writer could be praised as natural, where the qualities expected would include normal (universal) topics treated with simplicity, economy , regularity and harmony. Later on, nature becomes an equally potent emblem of irregularity, wildness, and fertile diversity, but also associated with progress of human history, its incurring definition that has been taken to fit many things as well as transformation, including ordinary human self-consciousness. Nature, being in contrast within integrated phenomenons may include (1) that which is deformed or grotesque or fails to achieve its proper form or function or just the statistically uncommon or unfamiliar, (2) the supernatural, or the world of gods and invisible agencies, (3) the world of rationality and unintelligence, conceived of as distinct from the biological and physical order, or the product of human intervention, and (5) related to that, the world of convention and artifice.
Different conceptions of nature continue to have ethical overtones, for example, the conception of nature red in tooth and claw often provides a justification for aggressive personal and political relations, or the idea that it is women’s nature to be one thing or another is taken to be a justification for differential social expectations. The term functions as a fig-leaf for a particular set of stereotypes, and is a proper target of much feminist writings. Feminist epistemology has asked whether different ways of knowing for instance with different criteria of justification, and different emphases on logic and imagination, characterize male and female attempts to understand the world. Such concerns include awareness of the masculine self-image, itself a social variable and potentially distorting characteristics of what thought and action should be. Again, there is a spectrum of concerns from the highly theoretical principles to the relatively practical. In this latter area particular attention is given to the institutional biases that stand in the way of equal opportunities in science and other academic pursuits, or the ideologies that stand in the way of women seeing themselves as leading contributors to various disciplines. However, to more radical feminists such concerns merely exhibit women wanting for themselves the same power and rights over others that men have claimed, and failing to confront the real problem, which is how to live without such symmetrical powers and rights.
In biological determinism, not only influences but constraints and makes inevitable our development as persons with a variety of traits. At its silliest the view postulates such entities as a gene predisposing people to poverty, and it is the particular enemy of thinkers stressing the parental, social, and political determinants of the way we are.
The philosophy of social science is more heavily intertwined with actual social science than in the case of other subjects such as physics or mathematics, since its question is centrally whether there can be such a thing as sociology. The idea of a science of man, devoted to uncovering scientific laws determining the basic dynamic s of human interactions was a cherished ideal of the Enlightenment and reached its heyday with the positivism of writers such as the French philosopher and social theorist Auguste Comte (1798-1957), and the historical materialism of Marx and his followers. Sceptics point out that what happens in society is determined by peoples own ideas of what should happen, and like fashions those ideas change in unpredictable ways as self-consciousness is susceptible to change by any number of external events: Unlike the solar system of celestial mechanics a society is not at all a closed system evolving in accordance with a purely internal dynamic, but constantly responsive to perturbations from the outside.
Internalist hold that in order to know, one has to know that one knows. The reasons by which a belief is justified must be accessible in principle to the subject holding that belief. Externalists deny this requirement, proposing that this makes knowing too difficult to achieve in most normal contexts. The internalist-externalist is sometimes viewed as a debate between those who think that knowledge can be naturalized (externalists) and those who don't (internalists). Naturalists hold that the evaluative concepts - for example, that justification can be explained in terms of something like reliability. They deny a special normative realm of language that is theoretically different from the kinds of concepts used in factual scientific discourse. Naturalists deny this and hold to the essential difference between the normative and the factual, and the former can never be derived from or constituted by the latter. So, internalists tend to think of reason and rationality as non-explicable in natural, descriptive terms, whereas externalists think such an explanation is possible.
Such a vista is usually seen as a major problem for coherenists, since it lads to radical relativism. This is due to the lack of any principled way of distinguishing systems because coherence is an internal feature of belief systems. And, even so, coherence typically true for the existence of just one system, assembling all our beliefs into a unified body. Such a view has led to the justified science movement in logical positivism, and sometimes transcendental arguments have been used to achieve this uniqueness, arguing from the general nature of belief to the uniqueness of the system of beliefs. Other Coherentists at put to use in observation as a way of picking out the unique system. It is an arguable point to what extent this latter group are still Coherentists, or have moved to a position that is a compounded merger of elements of Foundationalism and coherentism.
In one maintains that there is just one system of beliefs, then one is clearly non-relativistic about epistemic justification. Yet, if one allows a myriad of possible systems, then one falls into extreme relativism. However, there may be a more moderate position where a limited number of alternative systems of knowledge were possible. On a directed version, there would be globally alternatives. There would be several complete and separate systems. On a slightly weak version they would be distinctly local, and is brought upon a coherentist model that ends up with multiple systems and no overall constrains on the proliferation of systems. Moderate relativism would come out as holding to regional substrates, within an international system. In that, relativism about justification is a possibility in both Foundationalist and coherentist theories. However, they're accounts of internalism and externalism are properties belonging of the epistemological tradition from which has been internalist, with externalism emerging as a genuine option in the twentieth century.
Internalist accounts of justification seem more amendable to relativism than externalist accounts. This, nonetheless, that the most appropriate response, for example, given that Johns belief that he is Napoleon, it is quite rational for him to seek to marshal his armies and buy presents for Josephine. Yet the belief that he is Napoleon requires evaluation. This evaluation, as such beliefs, of ones need for a criteria of rationality. This is a stronger sense of rationality than the instrumental one relating to actions, keyed to the idea that there is quality control involved in holding beliefs. It is at this level that relativism about rationality arises acutely. Are there universal criteria that must be used by anyone wishing to evaluate their beliefs, or do they vary with cultural diversities, in what culture and/or historical epoch? The burden to hold that there is a minimal set of criteria.
On a substantive view, certain beliefs are rational, and others are not, due to the content of the belief. This is evident in the common practice of describing rejected belief-systems as irrational - answers this in the negative. On a substantive view, certain beliefs are rational, and others are not, due to the content of the belief. This is evident in the common practice of describing of the belief-systems as irrational, for example, the world-view of the Middle Ages is oftentimes caricatured in this way.
Such, as the Scottish philosopher, historian and essayist David Hume (1711-76),limits the scope of rationality severely, allowing it to characterize mathematical and logical reasoning, but of belief-formation, nor to play an important role in practical reasoning or ethical or aesthetic deliberation. Humes' notorious statement in the Treatise that reason is the slave of the passions, and can aspire to no other office than to serve and obey them is a deliberate reversal of the Platonic picture of reason (the charioteer) dominating the rather unruly passions (the horses). To accept something as rational is to accept it as making sense, as appropriate, or required, or in accordance with some acknowledged goal, such as aiming at truth or aiming at the good. Although it is frequently thought that it is the ability to reason that sets human bings apart from other animals, there is less consensus over the nature of this ability, whether it requires language. Some philosophers have found the exercise of reason to be a large part of the highest good for human beings. Others, find it to be the one way in which persons act freely, contrasting acting rationality with acting because of uncontrolled passions.
The sociological approach to human behaviour is based on the premise that all social behaviour has a biological basis, and seeks to understand that basis in terms of genetic encoding for features that are then selected for through evolutionary history. The philosophical problem is essentially one of methodology: Of finding criteria for identifying features that can usefully be explained in this way, and for finding criteria for assessing various genetic stories that might provide useful explanations.
There is, of course, a final move that the rationalist can make. He can fall back into dogmatism, saying of some selected inference or conclusion or procedure, this just is what it is to be rational, or, this just is valid inference. It is at this point that the rationalist can fight reason, but he is helpless against faith. Just as faith protects the Hole Trinity, or the Azannde oracle, or the ancestral spirits that can protect reason.
Among these features that are proposed for this kind o f explanation are such things as male dominance, male promiscuity versus female fidelity, propensities to sympathy and other emotions, and the limited altruism characteristic of human beings. The strategy has proved unnecessarily controversial, with proponents accused of ignoring the influence of environmental and social factors in moulding peoples characteristics, e.g., at the limit of silliness, by postulating a gene for poverty, however, there is no need for the approach to commit such errors, since the feature explained sociobiological may be indexed to environment: For instance, it ma y be a propensity to develop some feature in some other environments (for even a propensity to develop propensities . . .) The main problem is to separate genuine explanation from speculative, just so stories which may or may not identify as really selective mechanisms.
Subsequently, in the 19th century attempts were made to base ethical reasoning on the presumed facts about evolution. The movement is particularly associated with the English philosopher of evolution Herbert Spencer (1820-1903),. His first major work was the book Social Statics (1851), which advocated an extreme political libertarianism. The Principles of Psychology was published in 1855, and his very influential Education advocating natural development of intelligence, the creation of pleasurable interest, and the importance of science in the curriculum, appeared in 1861. His First Principles (1862) was followed over the succeeding years by volumes on the Principles of biology and psychology, sociology and ethics. Although he attracted a large public following and attained the stature of a sage, his speculative work has not lasted well, and in his own time there was dissident voices. T.H. Huxley said that Spencers definition of a tragedy was a deduction killed by a fact. Writer and social prophet Thomas Carlyle (1795-1881) called him a perfect vacuum, and the American psychologist and philosopher William James (1842-1910) wondered why half of England wanted to bury him in Westminister Abbey, and talked of the hurdy-gurdy monotony of him, his whole system would, as it were, be knocked together out of cracked hemlock.
The premise is that later elements in an evolutionary path are better than earlier ones, the application of this principle then requires seeing western society, laissez-faire capitalism, or some other object of approval, as more evolved than more primitive social forms. Neither the principle nor the applications command much respect. The version of evolutionary ethics called social Darwinism emphasizes the struggle for natural selection, and drawn the conclusion that we should glorify such struggles, usually by enhancing competitive and aggressive relations between people in society or between societies themselves. More recently the relation between evolution and ethics has been re-thought in the light of biological discoveries concerning altruism and kin-selection.
In that, the study of the say in which a variety of higher mental function may be an adaption applicable of a psychology of evolution, a formed response to selective pressures on human populations through evolutionary time. Candidates for such theorizing include material and paternal motivations, capabilities for love and friendship, the development of language as a signalling system, cooperative and aggressive tendencies, our emotional repertoires, our moral reaction, including the disposition to direct and punish those who cheat on an agreement or who turn towards free-riders - those of which who take away the things of others, our cognitive structure and many others. Evolutionary psychology goes hand-in-hand with neurophysiological evidence about the underlying circuitry in the brain which subserves the psychological mechanisms it claims to identify.
For all that, an essential part of the British absolute idealist Herbert Bradley (1846-1924) was largely on the ground s that the self-sufficiency individualized through community and oneself is to contribute to social and other ideals. However, truth as formulated in language is always partial, and dependent upon categories that they are inadequate to the harmonious whole. Nevertheless, these self-contradictory elements somehow contribute to the harmonious whole, or Absolute, lying beyond categorization. Although absolute idealism maintains few adherents today, Bradleys general dissent from empiricism, his holism, and the brilliance and style of his writing continue to make him the most interesting of the late 19th century writers influenced by the German philosopher Friedrich Hegel (1770-1831).
Understandably, something less than the fragmented division that belonging of Bradleys case has a preference, voiced much earlier by the German philosopher, mathematician and polymath was Gottfried Leibniz (1646-1716), for categorical monadic properties over relations. He was particularly troubled by the relation between that which is known and the more that knows it. In philosophy, the Romantics took from the German philosopher and founder of critical philosophy Immanuel Kant (1724-1804) both the emphasis on free-will and the doctrine that reality is ultimately spiritual, with nature itself a mirror of the human soul. To fix upon one among alternatives as the one to be taken, Friedrich Schelling (1775-1854) foregathers nature of becoming a creative spirit whose aspiration is ever further and more to a completed self-realization, although a movement of more generalized natural imperatives. Romanticism drew on the same intellectual and emotional resources as German idealism was increasingly culminating in the philosophy of Hegel (1770-1831) and of absolute idealism.
Being such in comparison with nature may include (1) that which is deformed or grotesque, or fails to achieve its proper form or function, or just the statistically uncommon or unfamiliar, (2) the supernatural, or the world of gods and invisible agencies, (3) the world of rationality and intelligence, conceived of as distinct from the biological and physical order, (4) that which is manufactured and artefactual, or the product of human invention, and (5) related to it, the world of convention and artifice.
Different conceptions of nature continue to have ethical overtones, for example, the conception of nature red in tooth and claw often provide a justification for aggressive personal and political relations. The term functions as a fig-leaf for a particular set of stereotypes, and is a proper target of much feminist writing.
This brings to question, that most of all ethics are contributively distributed as an understanding for which a dynamic function in and among the problems that are affiliated with human desire and needs the achievements of happiness, or the distribution of goods. The central problem specific to thinking about the environment is the independent value to place on such-things as preservation of species, or protection of the wilderness. Such protection can be supported as a mans to ordinary human ends, for instance, when animals are regarded as future sources of medicines or other benefits. Nonetheless, many would want to claim a non-utilitarian, absolute value for the existence of wild things and wild places. It is in their value that thing consist. They put in our proper place, and failure to appreciate this value is not only an aesthetic failure but one of due humility and reverence, a moral disability. The problem is one of expressing this value, and mobilizing it against utilitarian agents for developing natural areas and exterminating species, more or less at will.
Many concerns and disputed clusters around the idea associated with the term substance. The substance of a thing may be considered in: (1) Its essence, or that which makes it what it is. This will ensure that the substance of a thing is that which remains through change in properties. Again, in Aristotle, this essence becomes more than just the matter, but a unity of matter and form. (2) That which can exist by itself, or does not need a subject for existence, in the way that properties need objects, hence (3) that which bears properties, as a substance is then the subject of predication, that about which things are said as opposed to the things said about it. Substance in the last two senses stands opposed to modifications such as quantity, quality, relations, etc. it is hard to keep this set of ideas distinct from the doubtful notion of a substratum, something distinct from any of its properties, and hence, as an incapable characterization. The notion of substances tend to disappear in empiricist thought in fewer of the sensible questions of things with the notion of that in which they infer of giving way to an empirical notion of their regular occurrence. However, this is in turn is problematic, since it only makes sense to talk of the occurrence of an instance of qualities, not of quantities themselves. So the problem of what it is for a value quality to be the instance that remains.
Metaphysics inspired by modern science tends to reject the concept of substance in favour of concepts such as that of a field or a process, each of which may seem to provide a better example of a fundamental physical category.
It must be spoken of a concept that is deeply embedded in 18th century aesthetics, but deriving from the 1st century rhetorical treatise. On the Sublime, by Longinus. The sublime is great, fearful, noble, calculated to arouse sentiments of pride and majesty, as well as awe and sometimes terror. According to Alexander Gerards writing in 1759, When a large object is presented, the mind expands itself to the extent of that objects, and is filled with one grand sensation, which totally possessing it, composes it into a solemn sedateness and strikes it with deep silent wonder, and administration: It finds such a difficulty in spreading itself to the dimensions of its object, as enliven and invigorates which this occasions, it sometimes images itself present in every part of the sense which it contemplates, and from the sense of this immensity, feels a noble pride, and entertains a lofty conception of its own capacity.
In Kant’s aesthetic theory the sublime raises the soul above the height of vulgar complacency. We experience the vast spectacles of nature as absolutely great and of irresistible might and power. This perception is fearful, but by conquering this fear, and by regarding as small those things of which we are wont to be solicitous we quicken our sense of moral freedom. So we turn the experience of frailty and impotence into one of our true, inward moral freedom as the mind triumphs over nature, and it is this triumph of reason that is truly sublime. Kant thus paradoxically places our sense of the sublime in an awareness of ourselves as transcending nature, than in an awareness of ourselves as a frail and insignificant part of it.
Nevertheless, the doctrine that all relations are internal was a cardinal thesis of absolute idealism, and a central point of attack by the British philosophers George Edward Moore (1873-1958) and Bertrand Russell (1872-1970). It is a kind of essentialism, stating that if two things stand in some relationship, then they could not be what they are, did they not do so, if, for instance, I am wearing a hat mow, then when we imagine a possible situation that we would be got to describe as my not wearing the hat now, we would strictly not be imaging as one and the hat, but only some different individual.
The countering partitions a doctrine that bears some resemblance to the metaphysically based view of the German philosopher and mathematician Gottfried Leibniz (1646-1716) that if a person had any other attributes that the ones he has, he would not have been the same person. Leibniz thought that when asked that would have happened if Peter had not denied Christ. That being that if I am asking what had happened if Peter had not been Peter, denying Christ is contained in the complete notion of Peter. But he allowed that by the name Peter might be understood as what is involved in those attributes [of Peter] from which the denial does not follows. In order that we are held accountable to allow of external relations, in that these being relations which individuals could have or not depending upon contingent circumstances. The relations of ideas is used by the Scottish philosopher David Hume (1711-76) in the First Enquiry of Theoretical Knowledge. All the objects of human reason or enquiring naturally, be divided into two kinds: To unite all those, relations of ideas and matter of fact (Enquiry Concerning Human Understanding) the terms reflect the belief that any thing that can be known dependently must be internal to the mind, and hence transparent to us.
In Hume, objects of knowledge are divided into matter of fact (roughly empirical things known by means of impressions) and the relation of ideas. The contrast, also called Humes Fork, is a version of the speculative deductivity distinction, but reflects the 17th and early 18th centauries behind that the deductivity is established by chains of infinite certainty as comparable to ideas. It is extremely important that in the period between Descartes and J.S. Mill that a demonstration is not, but only a chain of intuitive comparable ideas, whereby a principle or maxim can be established by reason alone. It is in this sense that the English philosopher John Locke (1632-704) who believed that theological and moral principles are capable of demonstration, and Hume denies that they are, and also denies that scientific enquiries proceed in demonstrating its results.
A mathematical proof is formally inferred as to an argument that is used to show the truth of a mathematical assertion. In modern mathematics, a proof begins with one or more statements called premises and demonstrates, using the rules of logic, that if the premises are true then a particular conclusion must also be true.
The accepted methods and strategies used to construct a convincing mathematical argument have evolved since ancient times and continue to change. Consider the Pythagorean theorem, named after the 5th century Bc Greek mathematician and philosopher Pythagoras, which states that in a right-angled triangle, the square of the hypotenuse is equal to the sum of the squares of the other two sides. Many early civilizations considered this theorem true because it agreed with their observations in practical situations. But the early Greeks, among others, realized that observation and commonly held opinion do not guarantee mathematical truth. For example, before the 5th century Bc it was widely believed that all lengths could be expressed as the ratio of two whole numbers. But an unknown Greek mathematician proved that this was not true by showing that the length of the diagonal of a square with an area of 1 is the irrational number Ã.
The Greek mathematician Euclid laid down some of the conventions central to modern mathematical proofs. His book The Elements, written about 300 Bc, contains many proofs in the fields of geometry and algebra. This book illustrates the Greek practice of writing mathematical proofs by first clearly identifying the initial assumptions and then reasoning from them in a logical way in order to obtain a desired conclusion. As part of such an argument, Euclid used results that had already been shown to be true, called theorems, or statements that were explicitly acknowledged to be self-evident, called axioms; this practice continues today.
In the 20th century, proofs have been written that are so complex that no one person understands every argument used in them. In 1976, a computer was used to complete the proof of the four-colour theorem. This theorem states that four colours are sufficient to colour any map in such a way that regions with a common boundary ligne have different colours. The use of a computer in this proof inspired considerable debate in the mathematical community. At issue was whether a theorem can be considered proven if human beings have not actually checked every detail of the proof.
The study of the relations of deductibility among sentences in a logical calculus which benefits the proof theory. Deductibility is defined purely syntactically, that is, without reference to the intended interpretation of the calculus. The subject was founded by the mathematician David Hilbert (1862-1943) in the hope that strictly finitary methods would provide a way of proving the consistency of classical mathematics, but the ambition was torpedoed by Gödels second incompleteness theorem.
What is more, the use of a model to test for consistencies in an axiomatized system which is older than modern logic. Descartes algebraic interpretation of Euclidean geometry provides a way of showing that if the theory of real numbers is consistent, so is the geometry. Similar representation had been used by mathematicians in the 19th century, for example to show that if Euclidean geometry is consistent, so are various non-Euclidean geometries. Model theory is the general study of this kind of procedure: The proof theory studies relations of deductibility between formulae of a system, but once the notion of an interpretation is in place we can ask whether a formal system meets certain conditions. In particular, can it lead us from sentences that are true under some interpretation? And if a sentence is true under all interpretations, is it also a theorem of the system?
There are the questions of the soundness and completeness of a formal system. For the propositional calculus this turns into the question of whether the proof theory delivers as theorems all and only tautologies. There are many axiomatizations of the propositional calculus that are consistent and complete. The mathematical logician Kurt Gödel (1906-78) proved in 1929 that the first-order predicate under every interpretation is a theorem of the calculus. In that mathematical method for solving those physical problems that can be stated in the form that a certain value definite integral will have a stationary value for small changes of the functions in the integration sector. and of the limit of integration.
The Euclidean geometry is the greatest example of the pure axiomatic method, and as such had incalculable philosophical influence as a paradigm of rational certainty. It had no competition until the 19th century when it was realized that the fifth axiom of his system (parallel lines never meet) could be denied without inconsistency, leading to Riemannian spherical geometry. The significance of Riemannian geometry lies in its use and extension of both Euclidean geometry and the geometry of surfaces, leading to a number of generalized differential geometries. Its most important effect was that it made a geometrical application possible for some major abstractions of tensor analysis, leading to the pattern and concepts for general relativity later used by Albert Einstein in developing his theory of relativity. Riemannian geometry is also necessary for treating electricity and magnetism in the framework of general relativity. The fifth chapter of Euclid's Elements, is attributed to the mathematician Eudoxus, and contains a precise development of the real number, work which remained unappreciated until rediscovered in the 19th century.
The Axiom, in logic and mathematics, is a basic principle that is assumed to be true without proof. The use of axioms in mathematics stems from the ancient Greeks, most probably during the 5th century Bc, and represents the beginnings of pure mathematics as it is known today. Examples of axioms are the following: No sentence can be true and false at the same time (the principle of contradiction); If equals are added to equals, the sums are equal. The whole is greater than any of its parts. Logic and pure mathematics begin with such unproved assumptions from which other propositions (theorems) are derived. This procedure is necessary to avoid circularity, or an infinite regression in reasoning. The axioms of any system must be consistent with one another, that is, they should not lead to contradictions. They should be independent in the sense that they cannot be derived from one another. They should also be few in number. Axioms have sometimes been interpreted as self-evident truth. The present tendency is to avoid this claim and simply to assert that an axiom is assumed to be true without proof in the system of which it is a part.
The terms axiom and postulate are often used synonymously. Sometimes the word axiom is used to refer to basic principles that are assumed by every deductive system, and the term postulate is used to refer to first principles peculiar to a particular system, such as Euclidean geometry. Infrequently, the word axiom is used to refer to first principles in logic, and the term postulate is used to refer to first principles in mathematics.
The applications of game theory are wide-ranging and account for steadily growing interest in the subject. Von Neumann and Morgenstern indicated the immediate utility of their work on mathematical game theory in which may link it with economic behaviour. Models can be developed, in fact, for markets of various commodities with differing numbers of buyers and sellers, fluctuating values of supply and demand, and seasonal and cyclical variations, as well as significant structural differences in the economies concerned. Here game theory is especially relevant to the analysis of conflicts of interest in maximizing profits and promoting the widest distribution of goods and services. Equitable division of property and of inheritance is another area of legal and economic concern that can be studied with the techniques of game theory.
In the social sciences, n-person game that has interesting uses in studying, for example, the distribution of power in legislative procedures. This problem can be interpreted as a three-person game at the congressional level involving vetoes of the president and votes of representatives and senators, analyzed in terms of successful or failed coalitions to pass a given bill. Problems of majority rule and individual decision making are also amenable to such study.
Sociologists have developed an entire branch of game that devoted to the study of issues involving group decision making. Epidemiologists also make use of game that, especially with respect to immunization procedures and methods of testing a vaccine or other medication. Military strategists turn to game that to study conflicts of interest resolved through battles where the outcome or payoff of a given war game is either victory or defeat. Usually, such games are not examples of zero-sum games, for what one player loses in terms of lives and injuries is not won by the victor. Some uses of game that in analyses of political and military events have been criticized as a dehumanizing and potentially dangerous oversimplification of necessarily complicating factors. Analysis of economic situations is also usually more complicated than zero-sum games because of the production of goods and services within the play of a given game.
All is the same in the classical that of the syllogism, a term in a categorical proposition is distributed if the proposition entails any proposition obtained from it by substituting a term denoted by the original. For example, in all dogs bark the term dogs is distributed, since it entails all terriers bark, which is obtained from it by a substitution. In Not all dogs bark, the same term is not distributed, since it may be true while not all terriers bark is false.
When a representation of one system by another is usually more familiar, in and for itself, that those extended in representation that their workings are supposed analogous to that of the first. This one might model the behaviour of a sound wave upon that of waves in water, or the behaviour of a gas upon that to a volume containing moving billiard balls. While nobody doubts that models have a useful heuristic role in science, there has been intense debate over whether a good model, or whether an organized structure of laws from which it can be deduced and suffices for scientific explanation. As such, the debate of topic was inaugurated by the French physicist Pierre Marie Maurice Duhem (1861-1916), in The Aim and Structure of Physical Thar (1954) by which Duhems conception of science is that it is simply a device for calculating as science provides deductive system that is systematic, economical, and predictive, but not that represents the deep underlying nature of reality. Steadfast and holding of its contributive thesis that in isolation, and since other auxiliary hypotheses will always be needed to draw empirical consequences from it. The Duhem thesis implies that refutation is a more complex matter than might appear. It is sometimes framed as the view that a single hypothesis may be retained in the face of any adverse empirical evidence, if we prepared to make modifications elsewhere in our system, although strictly speaking this is a stronger thesis, since it may be psychologically impossible to make consistent revisions in a belief system to accommodate, say, the hypothesis that there is a hippopotamus in the room when visibly there is not.
Primary and secondary qualities are the division associated with the 17th-century rise of modern science, with its recognition that the fundamental explanatory properties of things that are not the qualities that perception most immediately concerns. The latter are the secondary qualities, or immediate sensory qualities, including colour, taste, smell, felt warmth or texture, and sound. The primary properties are less tied to their deliverance of one particular sense, and include the size, shape, and motion of objects. In Robert Boyle (1627-92) and John Locke (1632-1704) the primary qualities are scientifically tractable, objective qualities essential to anything material, are of a minimal listing of size, shape, and mobility, i.e., the state of being at rest or moving. Locke sometimes adds number, solidity, texture (where this is thought of as the structure of a substance, or way in which it is made out of atoms). The secondary qualities are the powers to excite particular sensory modifications in observers. Once, again, that Locke himself thought in terms of identifying these powers with the texture of objects that, according to corpuscularian science of the time, were the basis of an objects causal capacities. The ideas of secondary qualities are sharply different from these powers, and afford us no accurate impression of them. For Renè Descartes (1596-1650), this is the basis for rejecting any attempt to think of knowledge of external objects as provided by the senses. But in Locke our ideas of primary qualities do afford us an accurate notion of what shape, size,. And mobility are. In English-speaking philosophy the first major discontent with the division was voiced by the Irish idealist George Berkeley (1685-1753), who probably took for a basis of his attack from Pierre Bayle (1647-1706), who in turn cites the French critic Simon Foucher (1644-96). Modern thought continues to wrestle with the difficulties of thinking of colour, taste, smell, warmth, and sound as real or objective properties to things independent of us.
Continuing as such, is the doctrine advocated by the American philosopher David Lewis (1941-2002), in that different possible worlds are to be thought of as existing exactly as this one does. Thinking in terms of possibilities is thinking of real worlds where things are different. The view has been charged with making it impossible to see why it is good to save the child from drowning, since there is still a possible world in which she (or her counterpart) drowned, and from the standpoint of the universe it should make no difference which world is actual. Critics also charge that the notion fails to fit either with current theory, if lf how we know about possible worlds, or with a current theory of why we are interested in them, but Lewis denied that any other way of interpreting modal statements is tenable.
The proposal set forth that characterizes the modality of a proposition as the notion for which it is true or false. The most important division is between propositions true of necessity, and those true as things are: Necessary as opposed to contingent propositions. Other qualifiers sometimes called modal include the tense indicators, it will be the case that p, or it was the case that p, and there are affinities between the deontic indicators, it ought to be the case that p, or it is permissible that p, and the of necessity and possibility.
The aim of a logic is to make explicit the rules by which inferences may be drawn, than to study the actual reasoning processes that people use, which may or may not conform to those rules. In the case of deductive logic, if we ask why we need to obey the rules, the most general form of answer is that if we do not we contradict ourselves (or, strictly speaking, we stand ready to contradict ourselves. Someone failing to draw a conclusion that follows from a set of premises need not be contradicting him or herself, but only failing to notice something. However, he or she is not defended against adding the contradictory conclusion to his or her set of beliefs.) There is no equally simple answer in the case of inductive logic, which is in general a less robust subject, but the aim will be to find reasoning such hat anyone failing to conform to it will have improbable beliefs. Traditional logic dominated the subject until the 19th century, and has become increasingly recognized in the 20th century, in that finer work that were done within that tradition, but syllogistic reasoning is now generally regarded as a limited special case of the form of reasoning that can be reprehend within the promotion and predated values, these form the heart of modern logic, as their central notions or qualifiers, variables, and functions were the creation of the German mathematician Gottlob Frége, who is recognized as the father of modern logic, although his treatment of a logical system as an abstract mathematical structure, or algebraic, has been heralded by the English mathematician and logician George Boole (1815-64), his pamphlet The Mathematical Analysis of Logic (1847) pioneered the algebra of classes. The work was made of in An Investigation of the Laws of Thought (1854). Boole also published several works in our mathematics, and on the that of probability. His name is remembered in the title of Boolean algebra, and the algebraic operations he investigated are denoted by Boolean operations.
The imparting information has been conduced or carried out of the prescribed procedures, as impeding of something that takes place in the chancing encounter out to be to enter oneness mind may from time to time occasion of various doctrines concerning the necessary properties; east of mention, by adding to a prepositional or predicated calculus two operator, □and ◊(sometimes written N and M),meaning necessarily and possible, respectfully. These like p ➞ ◊p and □p ➞ p will be wanted. Controversial these include □p ➞ □□p and ◊p ➞ □◊p. The classical modal theory for modal logic, due to the American logician and philosopher (1940-) and the Swedish logician Sig Kanger, involves valuing prepositions not true or false simpiciter, but as true or false at possible worlds with necessity then corresponding to truth in all worlds, and possibility to truth in some world. Various different systems of modal logic result from adjusting the accessibility relation between worlds.
In Saul Kripke, gives the classical modern treatment of the topic of reference, both clarifying the distinction between names and definite description, and opening te door to many subsequent attempts to understand the notion of reference in terms of a causal link between the use of a term and an original episode of attaching a name to the subject.
One of the three branches into which semiotic is usually divided, the study of semantical meaning of words, and the relation of signs to the degree to which the designs are applicable. In that, in formal studies, a semantics is provided for a formal language when an interpretation of model is specified. However, a natural language comes ready interpreted, and the semantic problem is not that of specification but of understanding the relationship between terms of various categories (names, descriptions, predicate, adverbs . . . ) and their meaning. An influential proposal by attempting to provide a truth definition for the language, which will involve giving a full structure of different kinds have on the truth conditions of sentences containing them.
Holding that the basic case of reference is the relation between a name and the persons or object which it names. The philosophical problems include trying to elucidate that relation, to understand whether other semantic relations, such s that between a predicate and the property it expresses, or that between a description an what it describes, or that between myself and the word I, are examples of the same relation or of very different ones. A great deal of modern work on this was stimulated by the American logician Saul Kripkes, Naming and Necessity (1970). It would also be desirable to know whether we can refer to such things as objects and how to conduct the debate about each and issue. A popular approach, following Gottlob Frége, is to argue that the fundamental unit of analysis should be the whole sentence. The reference of a term becomes a derivative notion it is whatever it is that defines the terms contribution to the trued condition of the whole sentence. There need be nothing further to say about it, given that we have a way of understanding the attribution of meaning or truth-condition to sentences. Other approach, searching for a more substantive possibly that causality or psychological or social constituents are pronounced between words and things.
However, following Ramsey and the Italian mathematician G. Peano (1858-1932), it has been customary to distinguish logical paradoxes that depend upon a notion of reference or truth (semantic notions) such as those of the Liar family, Berry, Richard, etc. form the purely logical paradoxes in which no such notions are involved, such as Russells paradox, or those of Canto and Burali-Forti. Paradoxes of the first type seem to depend upon an element of self-reference, in which a sentence is about itself, or in which a phrase refers to something about itself, or in which a phrase refers to something defined by a set of phrases of which it is itself one. It is to feel that this element is responsible for the contradictions, although self-reference itself is often benign (for instance, the sentence All English sentences should have a verb, includes itself happily in the domain of sentences it is talking about), so the difficulty lies in forming a condition that existence only pathological self-reference. Paradoxes of the second kind then need a different treatment. Whilst the distinction is convenient, it allows for set theory to proceed by circumventing the latter paradoxes by technical mans, even when there is no solution to the semantic paradoxes, it may be a way of ignoring the similarities between the two families. There is still the possibility that while there is no agreed solution to the semantic paradoxes, our understand of Russells paradox may be imperfect as well.
Truth and falsity are two classical truth-values that a statement, proposition or sentence can take, as it is supposed in classical (two-valued) logic, that each statement has one of these values, and non has both. A statement is then false if and only if it is not true. The basis of this scheme is that to each statement there corresponds a determinate truth condition, or way the world must be for it to be true: If this condition obtains the statement is true, and otherwise false. Statements may indeed be felicitous or infelicitous in other dimensions (polite, misleading, apposite, witty, etc.) but truth is the central normative notion governing assertion. Considerations o vagueness may introduce greys into this black-and-white scheme. For the issue to be true, any suppressed premise or background framework of thought necessary make an agreement valid, or a position tenable, a proposition whose truth is necessary for either the truth or the falsity of another statement. Thus if p presupposes q, q must be true for p to be either true or false. In the theory of knowledge, the English philosopher and historian George Collingwood (1889-1943), announces hat any proposition capable of truth or falsity stand on bed of absolute presuppositions which are not properly capable of truth or falsity, since a system of thought will contain no way of approaching such a question (a similar idea later voiced by Wittgenstein in his work On Certainty). The introduction of presupposition therefore mans that either another of a truth value is fond, intermediate between truth and falsity, or the classical logic is preserved, but it is impossible to tell whether a particular sentence empresses a preposition that is a candidate for truth and falsity, without knowing more than the formation rules of the language. Each suggestion carries across through which there is some consensus that at least who were definite descriptions are involved, examples equally given by regarding the overall sentence as false as the existence claim fails, and explaining the data that the English philosopher Frederick Strawson (1919-) relied upon as the effects of implicature.
Views about the meaning of terms will often depend on classifying the implicature of sayings involving the terms as implicatures or as genuine logical implications of what is said. Implicatures may be divided into two kinds: Conversational implicatures of the two kinds and the more subtle category of conventional implicatures. A term may as a matter of convention carry an implicature, thus one of the relations between he is poor and honest and he is poor but honest is that they have the same content (are true in just the same conditional) but the second has implicatures (that the combination is surprising or significant) that the first lacks.
It is, nonetheless, that we find in classical logic a proposition that may be true or false,. In that, if the former, it is said to take the truth-value true, and if the latter the truth-value false. The idea behind the terminological phrases is the analogues between assigning a propositional variable one or other of these values, as is done in providing an interpretation for a formula of the propositional calculus, and assigning an object as the value of any other variable. Logics with intermediate value are called many-valued logics.
Nevertheless, an existing definition of the predicate . . . is true for a language that satisfies convention T, the material adequately condition laid down by Alfred Tarski, born Alfred Teitelbaum (1901-83), whereby his methods of recursive definition, enabling us to say for each sentence what it is that its truth consists in, but giving no verbal definition of truth itself. The recursive definition or the truth predicate of a language is always provided in a metalanguage, Tarski is thus committed to a hierarchy of languages, each with its associated, but different truth-predicate. Whist this enables the approach to avoid the contradictions of paradoxical contemplations, it conflicts with the idea that a language should be able to say everything that there is to say, and other approaches have become increasingly important.
So, that the truth condition of a statement is the condition for which the world must meet if the statement is to be true. To know this condition is equivalent to knowing the meaning of the statement. Although this sounds as if it gives a solid anchorage for meaning, some of the securities disappear when it turns out that the truth condition can only be defined by repeating the very same statement: The truth condition of now is white is that snow is white, the truth condition of Britain would have capitulated had Hitler invaded, is that Britain would have capitulated had Hitler invaded. It is disputed whether this element of running-on-the-spot disqualifies truth conditions from playing the central role in a substantives theory of meaning. Truth-conditional theories of meaning are sometimes opposed by the view that to know the meaning of a statement is to be able to use it in a network of inferences.
Taken to be the view, inferential semantics take on the role of sentence in inference give a more important key to their meaning than this external relations to things in the world. The meaning of a sentence becomes its place in a network of inferences that it legitimates. Also known as functional role semantics, procedural semantics, or conception to the coherence theory of truth, and suffers from the same suspicion that it divorces meaning from any clarity association with things in the world.
Moreover, a theory of semantic truth be that of the view if language is provided with a truth definition, there is a sufficient characterization of its concept of truth, as there is no further philosophical chapter to write about truth: There is no further philosophical chapter to write about truth itself or truth as shared across different languages. The view is similar to the disquotational theory.
The redundancy theory, or also known as the deflationary view of truth fathered by Gottlob Frége and the Cambridge mathematician and philosopher Frank Ramsey (1903-30), who showed how the distinction between the semantic paradoxes, such as that of the Liar, and Russells paradox, made unnecessary the ramified type theory of Principia Mathematica, and the resulting axiom of reducibility. By taking all the sentences affirmed in a scientific theory that use some terms e.g., quark, and to a considerable degree of replacing the term by a variable instead of saying that quarks have such-and-such properties, the Ramsey sentence says that there is something that has those properties. If the process is repeated for all of a group of the theoretical terms, the sentence gives topic-neutral structure of the theory, but removes any implication that we know what the terms so treated denote. It leaves open the possibility of identifying the theoretical item with whatever. It is that, the best fits the description provided. However, it was pointed out by the Cambridge mathematician Newman, that if the process is carried out for all except the logical of excavated fossils of a theory, then by the Löwenheim-Skolem theorem, the result will be interpretable, and the content of the theory may reasonably be felt to have been lost.
All the while, both Frége and Ramsey are agreeing that the essential claim is that the predicate . . . is true does not have a sense, i.e., expresses no substantive or profound or explanatory concept that ought to be the topic of philosophical enquiry. The approach admits of different versions, but centres on the points (1) that it is true that p says no more nor less than p (hence, redundancy): (2) that in less direct contexts, such as everything he said was true, or all logical consequences of true propositions are true, the predicate functions as a device enabling us to generalize than as an adjective or predicate describing the things he said, or the kinds of propositions that follow from true preposition. For example, the second may translate as: (∀p, q)(p & p ➞ q ➞ q) where there is no use of a notion of truth.
There are technical problems in interpreting all uses of the notion of truth in such ways, nevertheless, they are not generally felt to be insurmountable. The approach needs to explain away apparently substantive uses of the notion, such as science aims at the truth, or truth is a norm governing discourse. Postmodern writing frequently advocates that we must abandon such norms. Along with a discredited objective conception of truth. Perhaps, we can have the norms even when objectivity is problematic, since they can be framed without mention of truth: Science wants it to be so that whatever science holds that 'p', then 'p'. Discourse is to be regulated by the principle that it is wrong to assert 'p', when 'not-p'.
Something that tends of something in addition of content, or coming by way to justify such a position can very well be more that in addition to several reasons, as to bring in or joining of something might that there be more so as to a larger combination for us to consider the simplest formulation , is that the claim that expression of the form S is true mean the same as expression of the form S. Some philosophers dislike the ideas of sameness of meaning, and if this I disallowed, then the claim is that the two forms are equivalent in any sense of equivalence that matters. This is, it makes no difference whether people say Dogs bark is true, or whether they say, dogs bark. In the former representation of what they say of the sentence Dogs bark is mentioned, but in the later it appears to be used, of the claim that the two are equivalent and needs careful formulation and defence. On the face of it someone might know that Dogs bark is true without knowing what it means (for instance, if he kids in a list of acknowledged truth, although he does not understand English), and it is different from knowing that dogs bark. Disquotational theories are usually presented as versions of the redundancy theory of truth.
The relationship between a set of premises and a conclusion when the conclusion follows from the premise,. Many philosophers identify this with it being logically impossible that the premises should all be true, yet the conclusion false. Others are sufficiently impressed by the paradoxes of strict implication to look for a stranger relation, which would distinguish between valid and invalid arguments within the sphere of necessary propositions. The search for a strange notion is the field of relevance logic.
From a systematic theoretical point of view, we may imagine the process of evolution of an empirical science to be a continuous process of induction. Theories are evolved and are expressed in short encompassing as statements of as large number of individual observations in the form of empirical laws, from which the general laws can be ascertained by comparison. Regarded in this way, the development of a science bears some resemblance to the compilation of a classified catalogue. It is , a it were, a purely empirical enterprise.
But this point of view by no means embraces the whole of the actual process, for it slurs over the important part played by intuition and deductive thought in the development of an exact science. As soon as a science has emerged from its initial stages, theoretical advances are no longer achieved merely by a process of arrangement. Guided by empirical data, the investigators rather develops a system of thought which, in general, it is built up logically from a small number of fundamental assumptions, the so-called axioms. We call such a system of thought a theory. The theory finds the justification for its existence in the fact that it correlates a large number of single observations, and is just here that the truth of the theory lies.
Corresponding to the same complex of empirical data, there may be several theories, which differ from one another to a considerable extent. But as regards the deductions from the theories which are capable of being tested, the agreement between the theories may be so complete, that it becomes difficult to find any deductions in which the theories differ from each other. As an example, a case of general interest is available in the province of biology, in the Darwinian theory of the development of species by selection in the struggle for existence, and in the theory of development which is based on the hypophysis of the hereditary transmission of acquired characters. The Origin of Species was principally successful in marshalling the evidence for evolution, than providing a convincing mechanisms for genetic change. And Darwin himself remained open to the search for additional mechanisms, while also remaining convinced that natural selection was at the hart of it. It was only with the later discovery of the gene as the unit of inheritance that the synthesis known as neo-Darwinism became the orthodox theory of evolution in the life sciences.
In the 19th century the attempt to base ethical reasoning o the presumed facts about evolution, the movement is particularly associated with the English philosopher of evolution Herbert Spencer (1820-1903). The premise is that later elements in an evolutionary path are better than earlier ones: The application of this principle then requires seeing western society, laissez-faire capitalism, or some other object of approval, as more evolved than more primitive social forms. Neither the principle nor the applications command much respect. The version of evolutionary ethics called social Darwinism emphasized the struggle for natural selection, and draws the conclusion that we should glorify and assist such struggle, usually by enhancing competition and aggressive relations between people in society or between evolution and ethics has been re-thought in the light of biological discoveries concerning altruism and kin-selection.
Once again, the psychology proving attempts are founded to evolutionary principles, in which a variety of higher mental functions may be adaptations, forced in response to selection pressures on the human populations through evolutionary time. Candidates for such theorizing include material and paternal motivations, capacities for love and friendship, the development of language as a signalling system cooperative and aggressive , our emotional repertoire, our moral and reactions, including the disposition to detect and punish those who cheat on agreements or who free-ride on =the work of others, our cognitive structures, and many others. Evolutionary psychology goes hand-in-hand with neurophysiological evidence about the underlying circuitry in the brain which subserves the psychological mechanisms it claims to identify. The approach was foreshadowed by Darwin himself, and William James, as well as the sociology of E.O. Wilson. The term of use are applied, more or less aggressively, especially to explanations offered in sociobiology and evolutionary psychology.
Another assumption that is frequently used to legitimate the real existence of forces associated with the invisible hand in neoclassical economics derives from Darwin view of natural selection as a war-like competing between atomized organisms in the struggle for survival. In natural selection as we now understand it, cooperation appears to exist in complementary relation to competition. It is complementary relationships between such results that are emergent self-regulating properties that are greater than the sum of parts and that serve to perpetuate the existence of the whole.
According to E.O Wilson, the human mind evolved to believe in the gods and people need a sacred narrative to have a sense of higher purpose. Yet it id also clear that the gods in his view are merely human constructs and, therefore, there is no basis for dialogue between the world-view of science and religion. Science for its part, said Wilson, will test relentlessly every assumption about the human condition and in time uncover the bedrock of the moral an religious sentiments. The eventual result of the competition between the other, will be the secularization of the human epic and of religion itself.
Man has come to the threshold of a state of consciousness, regarding his nature and his relationship to te Cosmos, in terms that reflect reality. By using the processes of nature as metaphor, to describe the forces by which it operates upon and within Man, we come as close to describing reality as we can within the limits of our comprehension. Men will be very uneven in their capacity for such understanding, which, naturally, differs for different ages and cultures, and develops and changes over the course of time. For these reasons it will always be necessary to use metaphor and myth to provide comprehensible guides to living. In thus way. Mans imagination and intellect play vital roles on his survival and evolution.
Since so much of life both inside and outside the study is concerned with finding explanations of things, it would be desirable to have a concept of what counts as a good explanation from bad. Under the influence of logical positivist approaches to the structure of science, it was felt that the criterion ought to be found in a definite logical relationship between the explanans (that which does the explaining) and the explanandum (that which is to be explained). The approach culminated in the covering law model of explanation, or the view that an event is explained when it is subsumed under a law of nature, that is, its occurrence is deducible from the law plus a set of initial conditions. A law would itself be explained by being deduced from a higher-order or covering law, in the way that Johannes Kepler(or, Keppler, 1571-1630), was by way of planetary motion that the laws were deducible from Newtons laws of motion. The covering law model may be adapted to include explanation by showing that something is probable, given a statistical law. Questions for the covering law model include querying for the covering law are necessary to explanation (we explain whether everyday events without overtly citing laws): Querying whether they are sufficient (it ma y not explain an event just to say that it is an example of the kind of thing that always happens). And querying whether a purely logical relationship is adapted to capturing the requirements we make of explanations. These may include, for instance, that we have a feel for what is happening, or that the explanation proceeds in terms of things that are familiar to us or unsurprising, or that we can give a model of what is going on, and none of these notions is captured in a purely logical approach. Recent work, therefore, has tended to stress the contextual and pragmatic elements in requirements for explanation, so that what counts as good explanation given one set of concerns may not do so given another.
The argument to the best explanation is the view that once we can select the best of any in something in explanations of an event, then we are justified in accepting it, or even believing it. The principle needs qualification, since something it is unwise to ignore the antecedent improbability of a hypothesis which would explain the data better than others, e.g., the best explanation of a coin falling heads 530 times in 1,000 tosses might be that it is biassed to give a probability of heads of 0.53 but it might be more sensible to suppose that it is fair, or to suspend judgement.
In a philosophy of language is considered as the general attempt to understand the components of a working language, the relationship with the understanding speaker has to its elements, and the relationship they bear to the world. The subject therefore embraces the traditional division of semiotic into syntax, semantics, an d pragmatics. The philosophy of language thus mingles with the philosophy of mind, since it needs an account of what it is in our understanding that enables us to use language. It so mingles with the metaphysics of truth and the relationship between sign and object. Much as much is that the philosophy in the 20th century, has been informed by the belief that philosophy of language is the fundamental basis of all philosophical problems, in that language is the distinctive exercise of mind, and the distinctive way in which we give shape to metaphysical beliefs. Particular topics will include the problems of logical form,. And the basis of the division between syntax and semantics, as well as problems of understanding the number and nature of specifically semantic relationships such as meaning, reference, predication, and quantification. Pragmatics include that of speech acts, while problems of rule following and the indeterminacy of translation infect philosophies of both pragmatics and semantics.
On this conception, to understand a sentence is to know its truth-conditions, and, yet, in a distinctive way the conception has remained central that those who offer opposing theories characteristically define their position by reference to it. The Conception of meanings truth-conditions need not and should not be advanced for being in itself as complete account of meaning. For instance, one who understands a language must have some idea of the range of speech acts contextually performed by the various types of sentence in the language, and must have some idea of the insufficiencies of various kinds of speech act. The claim of the theorist of truth-conditions should rather be targeted on the notion of content: If indicative sentence differ in what they strictly and literally say, then this difference is fully accounted for by the difference in the truth-conditions.
The meaning of a complex expression is a function of the meaning of its constituent. This is just as a sentence of what it is for an expression to be semantically complex. It is one of the initial attractions of the conception of meaning truth-conditions tat it permits a smooth and satisfying account of the way in which the meaning of s complex expression is a function of the meaning of its constituents. On the truth-conditional conception, to give the meaning of an expression is to state the contribution it makes to the truth-conditions of sentences in which it occurs. For singular terms - proper names, indexical, and certain pronouns - this is done by stating the reference of the terms in question. For predicates, it is done either by stating the conditions under which the predicate is true of arbitrary objects, or by stating that conditions under which arbitrary atomic sentences containing it are true. The meaning of a sentence-forming operator is given by stating its contribution to the truth-conditions of as complex sentence, as a function of the semantic values of the sentences on which it operates.
The theorist of truth conditions should insist that not every true statement about the reference of an expression is fit to be an axiom in a meaning-giving theory of truth for a language, such is the axiom: London refers to the city in which there was a huge fire in 1666, is a true statement about the reference of London. It is a consequent of a theory which substitutes this axiom for no different a term than of our simple truth theory that London is beautiful is true if and only if the city in which there was a huge fire in 1666 is beautiful. Since a subject can understand the name London without knowing that last-mentioned truth condition, this replacement axiom is not fit to be an axiom in a meaning-specifying truth theory. It is, of course, incumbent on a theorized meaning of truth conditions, to state in a way which does not presuppose any previous, non-truth conditional conception of meaning
Among the many challenges facing the theorist of truth conditions, two are particularly salient and fundamental. First, the theorist has to answer the charge of triviality or vacuity, second, the theorist must offer an account of what it is for a persons language to be truly describable by as semantic theory containing a given semantic axiom.
Since the content of a claim that the sentence Paris is beautiful is true amounts to no more than the claim that Paris is beautiful, we can trivially describers understanding a sentence, if we wish, as knowing its truth-conditions, but this gives us no substantive account of understanding whatsoever. Something other than grasp of truth conditions must provide the substantive account. The charge rests upon what has been called the redundancy theory of truth, the theory which, somewhat more discriminatingly. Horwich calls the minimal theory of truth. Its conceptual representation that the concept of truth is exhausted by the fact that it conforms to the equivalence principle, the principle that for any proposition p, it is true that p if and only if p. Many different philosophical theories of truth will, with suitable qualifications, except that equivalence principle. The distinguishing feature of the minimal theory is its claim that the equivalence principle exhausts the notion of truth. It is now widely accepted, both by opponents and supporters of truth conditional theories of meaning, that it is inconsistent to accept both minimal theory of truth and a truth conditional account of meaning. If the claim that the sentence Paris is beautiful is true is exhausted by its equivalence to the claim that Paris is beautiful, it is circular to try of its truth conditions. The minimal theory of truth has been endorsed by the Cambridge mathematician and philosopher Plumpton Ramsey (1903-30), and the English philosopher Jules Ayer, the later Wittgenstein, Quine, Strawson. Horwich and - confusing and inconsistently if this article is correct - Frége himself. But is the minimal theory correct?
The minimal theory treats instances of the equivalence principle as definitional of truth for a given sentence, but in fact, it seems that each instance of the equivalence principle can itself be explained. The truth from which such an instance as: London is beautiful is true if and only if London is beautiful. This would be a pseudo-explanation if the fact that London refers to London consists in part in the fact that London is beautiful has the truth-condition it does. But it is very implausible, it is, after all, possible to understand the name London without understanding the predicate is beautiful.
Sometimes, however, the counterfactual conditional is known as 'subjunctive conditionals', insofar as a counterfactual conditional is a conditional of the form if 'p' were to happen 'q' would, or if 'p' were to have happened 'q' would have happened, where the supposition of 'p' is contrary to the known fact that 'not-p'. Such assertions are nevertheless, useful if you broke the bone, the X-ray would have looked different, or if the reactor were to fail, this mechanism wold click in are important truth, even when we know that the bone is not broken or are certain that the reactor will not fail. It is arguably distinctive of laws of nature that yield counterfactuals (if the metal were to be heated, it would expand), whereas accidentally true generalizations may not. It is clear that counterfactuals cannot be represented by the material implication of the propositional calculus, since that conditionals comes out true whenever p is false, so there would be no division between true and false counterfactuals.
Although the subjunctive form indicates a counterfactual, in many contexts it does not seem to matter whether we use a subjunctive form, or a simple conditional form: If you run out of water, you will be in trouble seems equivalent to if you were to run out of water, you would be in trouble, in other contexts there is a big difference: If Oswald did not kill Kennedy, someone else did is clearly true, whereas if Oswald had not killed Kennedy, someone would have is most probably false.
The best-known modern treatment of counterfactuals is that of David Lewis, which evaluates them as true or false according to whether q is true in the most similar possible worlds to ours in which p is true. The similarity-ranking this approach needs has proved controversial, particularly since it may need to presuppose some notion of the same laws of nature, whereas art of the interest in counterfactuals is that they promise to illuminate that notion. There is a growing awareness tat the classification of conditionals is an extremely tricky business, and categorizing them as counterfactuals or not be of limited use.
The pronouncing of any conditional; preposition of the form if 'p' then 'q'. The condition hypothesizes, 'p'. Its called the antecedent of the conditional, and 'q' the consequent. Various kinds of conditional have been distinguished. The weaken in that of material implication, merely telling us that with 'not-p'. or 'q'. stronger conditionals include elements of modality, corresponding to the thought that if 'p' is true then 'q' must be true. Ordinary language is very flexible in its use of the conditional form, and there is controversy whether, yielding different kinds of conditionals with different meanings, or pragmatically, in which case there should be one basic meaning which case there should be one basic meaning, with surface differences arising from other implicatures.
We now turn to a philosophy of meaning and truth, under which it is especially associated with the American philosopher of science and of language (1839-1914), and the American psychologist philosopher William James (1842-1910), wherefore the study in Pragmatism is given to various formulations by both writers, but the core is the belief that the meaning of a doctrine is the same as the practical effects of adapting it. Peirce interpreted of theocratical sentence is only that of a corresponding practical maxim (telling us what to do in some circumstance). In James the position issues in a theory of truth, notoriously allowing that belief, including for example, belief in God, are the widest sense of the works satisfactorially in the widest sense of the word. On James' view almost any belief might be respectable, and even rue, provided it works (but working is no simple matter for James). The apparently subjectivist consequences of this were wildly assailed by Russell (1872-1970), Moore (1873-1958), and others in the early years of the 20 century. This led to a division within pragmatism between those such as the American educator John Dewey (1859-1952), whose humanistic conception of practice remains inspired by science, and the more idealistic route that especially by the English writer F.C.S. Schiller (1864-1937), embracing the doctrine that our cognitive efforts and human needs actually transform the reality that we seek to describe. James often writes as if he sympathizes with this development. For instance, in The Meaning of Truth (1909), he considers the hypothesis that other people have no minds (dramatized in the sexist idea of an automatic sweetheart or female zombie) and remarks hat the hypothesis would not work because it would not satisfy our egoistic craving for the recognition and admiration of others. The implication that this is what makes it true that the other persons have minds in the disturbing part.
Modern pragmatists such as the American philosopher and critic Richard Rorty (1931-) and some writings of the philosopher Hilary Putnam (1925-) who have usually tried to dispense with an account of truth and concentrate, as perhaps James should have done, upon the nature of belief and its relations with human attitude, emotion, and need. The driving motivation of pragmatism is the idea that belief in the truth on te one hand must have a close connexion with success in action on the other. One way of cementing the connexion is found in the idea that natural selection must have adapted us to be cognitive creatures because belief have effects, as they work. Pragmatism can be found in Kants doctrine of the primary of practical over pure reason, and continued to play an influential role in the theory of meaning and of truth.
In case of fact, the philosophy of mind is the modern successor to behaviourism, as do the functionalism that its early advocates were Putnam (1926-) and Sellars (1912-89), and its guiding principle is that we can define mental states by a triplet of relations they have on other mental states, what effects they have on behaviour. The definition need not take the form of a simple analysis, but if it were it could write down the totality of axioms, or postdate, or platitudes that govern our theories about what things of other mental states, and our theories about what things are apt to cause (for example), a belief state, what effects it would have on a variety of other mental states, and what affects it is likely to have on behaviour, then we would have done all that is needed to make the state a proper theoretical notion. It could be implicitly defied by this, for which of Functionalism is often compared with descriptions of a computer, since according to mental descriptions correspond to a description of a machine in terms of software, that remains silent about the underlaying hardware or realization of the program the machine is running. The principal advantage of functionalism include its fit with the way we know of mental states both of ourselves and others, which is via their effects on behaviour and other mental states. As with behaviourism, critics charge that structurally complex items that do not bear mental states might nevertheless, imitate the functions that are cited. According to this criticism functionalism is too generous and would count too many things as having minds. It is also queried whether functionalism is too paradoxical, able to see mental similarities only when there is causal similarity, when our actual practices of interpretations enable us to ascribe thoughts and desires to different from our own, it may then seem as though beliefs and desires can be variably realized causal architecture, just as much as they can be in different neurophysiological states.
The philosophical movement of Pragmatism had a major impact on American culture from the late 19th century to the present. Pragmatism calls for ideas and theories to be tested in practice, by assessing whether acting upon the idea or theory produces desirable or undesirable results. According to pragmatists, all claims about truth, knowledge, morality, and politics must be tested in this way. Pragmatism has been critical of traditional Western philosophy, especially the notion that there are absolute truth and absolute values. Although pragmatism was popular for a time in France, England, and Italy, most observers believe that it encapsulates an American faith in knowing how and the practicality is an equally American distrust of abstract theories and ideologies.
In mentioning the American psychologist and philosopher we find William James, who helped to popularize the philosophy of pragmatism with his book Pragmatism: A New Name for Old Ways of Thinking (1907). Influenced by a theory of meaning and verification developed for scientific hypotheses by American philosopher C. S. Peirce, James held that truth is what works, or has good experimental results. In a related theory, James argued the existence of God is partly verifiable because many people derive benefits from believing.
The Association for International Conciliation first published William James' pacifist statement, The Moral Equivalent of War, in 1910. James, a highly respected philosopher and psychologist, was one of the founders of pragmatism - a philosophical movement holding that ideas and theories must be tested in practice to assess their worth. James hoped to find a way to convince men with a long-standing history of pride and glory in war to evolve beyond the need for bloodshed and to develop other avenues for conflict resolution. Spelling and grammar represent standards of the time.
Pragmatists regard all theories and institutions as tentative hypotheses and solutions. For this reason they believed that efforts to improve society, through such means as education or politics, must be geared toward problem solving and must be ongoing. Through their emphasis on connecting theory to practice, pragmatist thinkers attempted to transform all areas of philosophy, from metaphysics to ethics and political philosophy.
Pragmatism sought a middle ground between traditional ideas about the nature of reality and radical theories of nihilism and irrationalism, which had become popular in Europe in the late 19th century. Traditional metaphysics assumed that the world has a fixed, intelligible structure and that human beings can know absolute or objective truth about the world and about what constitutes moral behaviour. Nihilism and irrationalism, on the other hand, denied those very assumptions and their certitude. Pragmatists today still try to steer a middle course between contemporary offshoots of these two extremes.
The ideas of the pragmatists were considered revolutionary when they first appeared. To some critics, pragmatisms refusal to affirm any absolutes carried negative implications for society. For example, pragmatists do not believe that a single absolute idea of goodness or justice exists, but rather that these concepts are changeable and depend on the context in which they are being discussed. The absence of these absolutes, critics feared, could result in a decline in moral standards. The pragmatists denial of absolutes, moreover, challenged the foundations of religion, government, and schools of thought. As a result, pragmatism influenced developments in psychology, sociology, education, semiotics (the study of signs and symbols), and scientific method, as well as philosophy, cultural criticism, and social reform movements. Various political groups have also drawn on the assumptions of pragmatism, from the progressive movements of the early 20th century to later experiments in social reform.
Pragmatism is best understood in its historical and cultural context. It arose during the late 19th century, a period of rapid scientific advancement typified by the theories of British biologist Charles Darwin, whose theories suggested too many thinkers that humanity and society are in a perpetuated state of progress. During this same period a decline in traditional religious beliefs and values accompanied the industrialization and material progress of the time. In consequence it became necessary to rethink fundamental ideas about values, religion, science, community, and individuality.
The three most important pragmatists are American philosophers Charles Sanders Peirce, William James, and John Dewey. Peirce was primarily interested in scientific method and mathematics; his objective was to infuse scientific thinking into philosophy and society, and he believed that human comprehension of reality was becoming ever greater and that human communities were becoming increasingly progressive. Peirce developed pragmatism as a theory of meaning - in particular, the meaning of concepts used in science. The meaning of the concept 'brittle', for example, is given by the observed consequences or properties that objects called brittle exhibit. For Peirce, the only rational way to increase knowledge was to form mental habits that would test ideas through observation, experimentation, or what he called inquiry. Many philosophers known as logical positivists, a group of philosophers who have been influenced by Peirce, believed that our evolving species was fated to get ever closer to Truth. Logical positivists emphasize the importance of scientific verification, rejecting the assertion of positivism that personal experience is the basis of true knowledge.
James moved pragmatism in directions that Peirce strongly disliked. He generalized Peirces doctrines to encompass all concepts, beliefs, and actions; he also applied pragmatist ideas to truth as well as to meaning. James was primarily interested in showing how systems of morality, religion, and faith could be defended in a scientific civilization. He argued that sentiment, as well as logic, is crucial to rationality and that the great issues of life - morality and religious belief, for example - are leaps of faith. As such, they depend upon what he called the will to believe and not merely on scientific evidence, which can never tell us what to do or what is worthwhile. Critics charged James with relativism (the belief that values depend on specific situations) and with crass expediency for proposing that if an idea or action works the way one intends, it must be right. But James can more accurately be described as a pluralist - someone who believes the world to be far too complex for any-one philosophy to explain everything.
Deweys' philosophy can be described as a version of philosophical naturalism, which regards human experience, intelligence, and communities as ever-evolving mechanisms. Using their experience and intelligence, Dewey believed, human beings can solve problems, including social problems, through inquiry. For Dewey, naturalism led to the idea of a democratic society that allows all members to acquire social intelligence and progress both as individuals and as communities. Dewey held that traditional ideas about knowledge, truth, and values, in which absolutes are assumed, are incompatible with a broadly Darwinian world-view in which individuals and society are progressing. In consequence, he felt that these traditional ideas must be discarded or revised. Indeed, for pragmatists, everything people know and do depend on a historical context and is thus tentative rather than absolute.
Many followers and critics of Dewey believe he advocated elitism and social engineering in his philosophical stance. Others think of him as a kind of romantic humanist. Both tendencies are evident in Deweys writings, although he aspired to synthesize the two realms.
The pragmatists tradition was revitalized in the 1980s by American philosopher Richard Rorty, who has faced similar charges of elitism for his belief in the relativism of values and his emphasis on the role of the individual in attaining knowledge. Interest has renewed in the classic pragmatists - Pierce, James, and Dewey - have an alternative to Rortys interpretation of the tradition.
The Philosophy of Mind, is the branch of philosophy that considers mental phenomena such as sensation, perception, thought, belief, desire, intention, memory, emotion, imagination, and purposeful action. These phenomena, which can be broadly grouped as thoughts and experiences, are features of human beings; many of them are also found in other animals. Philosophers are interested in the nature of each of these phenomena as well as their relationships to one another and to physical phenomena, such as motion.
The most famous exponent of dualism was the French philosopher René Descartes, who maintained that body and mind are radically different entities and that they are the only fundamental substances in the universe. Dualism, however, does not show how these basic entities are connected.
In the work of the German philosopher Gottfried Wilhelm Leibniz, the universe is held to consist of an infinite number of distinct substances, or monads. This view is pluralistic in the sense that it proposes the existence of many separate entities, and it is monistic in its assertion that each monad reflects within itself the entire universe.
Other philosophers have held that knowledge of reality is not derived from a priori principles, but is obtained only from experience. This type of metaphysics is called empiricism. Still another school of philosophy has maintained that, although an ultimate reality does exist, it is altogether inaccessible to human knowledge, which is necessarily subjective because it is confined to states of mind. Knowledge is therefore not a representation of external reality, but merely a reflection of human perceptions. This view is known as skepticism or agnosticism in respect to the soul and the reality of God.
The 18th-century German philosopher Immanuel Kant published his influential work The Critique of Pure Reason in 1781. Three years later, he expanded on his study of the modes of thinking with an essay entitled What is Enlightenment? In this 1784 essay, Kant challenged readers to dare to know, arguing that it was not only a civic but also a moral duty to exercise the fundamental freedoms of thought and expression.
Several major viewpoints were combined in the work of Kant, who developed a distinctive critical philosophy called transcendentalism. His philosophy is agnostic in that it denies the possibility of a strict knowledge of ultimate reality; it is empirical in that it affirms that all knowledge arises from experience and is true of objects of actual and possible experience; and it is rationalistic in that it maintains the a priori character of the structural principles of this empirical knowledge.
These principles are held to be necessary and universal in their application to experience, for in Kants view the mind furnishes the archetypal forms and categories (space, time, causality, substance, and relation) to its sensations, and these categories are logically anterior to experience, although manifested only in experience. Their logical anteriority to experience makes these categories or structural principles transcendental; they transcend all experience, both actual and possible. Although these principles determine all experience, they do not in any way affect the nature of things in themselves. The knowledge of which these principles are the necessary conditions must not be considered, therefore, as constituting a revelation of things as they are in themselves. This knowledge concerns things only insofar as they appear to human perception or as they can be apprehended by the senses. The argument by which Kant sought to fix the limits of human knowledge within the framework of experience and to demonstrate the inability of the human mind to penetrate beyond experience strictly by knowledge to the realm of ultimate reality constitutes the critical feature of his philosophy, giving the key word to the titles of his three leading treatises, Critique of Pure Reason, Critique of Practical Reason, and Critique of Judgment. In the system propounded in these works, Kant sought also to reconcile science and religion in a world of two levels, comprising noumena, objects conceived by reason although not perceived by the senses, and phenomena, things as they appear to the senses and are accessible to material study. He maintained that, because God, freedom, and human immortality are noumenal realities, these concepts are understood through moral faith rather than through scientific knowledge. With the continuous development of science, the expansion of metaphysics to include scientific knowledge and methods became one of the major objectives of metaphysicians.
Some of Kants most distinguished followers, notably Johann Gottlieb Fichte, Friedrich Schelling, Georg Wilhelm Friedrich Hegel, and Friedrich Schleiermacher, negated Kants criticism in their elaborations of his transcendental metaphysics by denying the Kantian conception of the thing-in-itself. They thus developed an absolute idealism in opposition to Kants critical transcendentalism.
Since the formation of the hypothesis of absolute idealism, the development of metaphysics has resulted in as many types of metaphysical theory as existed in pre-Kantian philosophy, despite Kants contention that he had fixed definitely the limits of philosophical speculation. Notable among these later metaphysical theories are radical empiricism, or pragmatism, a native American form of metaphysics expounded by Charles Sanders Peirce, developed by William James, and adapted as instrumentalism by John Dewey; voluntarism, the foremost exponents of which are the German philosopher Arthur Schopenhauer and the American philosopher Josiah Royce; phenomenalism, as it is exemplified in the writings of the French philosopher Auguste Comte and the British philosopher Herbert Spencer; emergent evolution, or creative evolution, originated by the French philosopher Henri Bergson; and the philosophy of the organism, elaborated by the British mathematician and philosopher Alfred North Whitehead. The salient doctrines of pragmatism are that the chief function of thought is to guide action, that the meaning of concepts is to be sought in their practical applications, and that truth should be tested by the practical effects of belief; according to instrumentalism, ideas are instruments of action, and their truth is determined by their role in human experience. In the theory of voluntarism the will are postulated as the supreme manifestation of reality. The exponents of phenomenalism, who are sometimes called positivists, contend that everything can be analyzed in terms of actual or possible occurrences, or phenomena, and that anything that cannot be analyzed in this manner cannot be understood. In emergent or creative evolution, the evolutionary process is characterized as spontaneous and unpredictable rather than mechanistically determined. The philosophy of the organism combines an evolutionary stress on constant process with a metaphysical theory of God, the external objects, and creativity.
In the 20th century the validity of metaphysical thinking has been disputed by the logical positivists and by the so-called dialectical materialism of the Marxists. The basic principle maintained by the logical positivists is the verifiability theory of meaning. According to this theory a sentence has factual meaning only if it meets the test of observation. Logical positivists argue that metaphysical expressions such as Nothing exists except material particles and Everything is part of one all-encompassing spirit cannot be tested empirically. Therefore, according to the verifiability theory of meaning, these expressions have no factual cognitive meaning, although they can have an emotive meaning relevant to human hopes and feelings.
The dialectical materialists assert that the mind is conditioned by and reflects material reality. Therefore, speculations that conceive of constructs of the mind as having any other than material reality are themselves unreal and can result only in delusion. To these assertions metaphysicians reply by denying the adequacy of the verifiability theory of meaning and of material perception as the standard of reality. Both logical positivism and dialectical materialism, they argue, conceal metaphysical assumptions, for example, that everything is observable or at least connected with something observable and that the mind has no distinctive life of its own. In the philosophical movement known as existentialism, thinkers have contended that the questions of the nature of being and of the individuals relationship to it are extremely important and meaningful in terms of human life. The investigation of these questions is therefore considered valid whether its results can be verified objectively.
Since the 1950s the problems of systematic analytical metaphysics have been studied in Britain by Stuart Newton Hampshire and Peter Frederick Strawson, the former concerned, in the manner of Spinoza, with the relationship between thought and action, and the latter, in the manner of Kant, with describing the major categories of experience as they are embedded in language. Metaphysics have been pursued much in the spirit of positivism by Wilfred Stalker Sellars and Willard Van Orman Quine. Sellars has sought to express metaphysical questions in linguistic terms, and Quine has attempted to determine whether the structure of language commits the philosopher to asserting the existence of any entities whatever and, if so, what kind. In these new formulations the issues of metaphysics and ontology remain vital.
n the 17th century, French philosopher René Descartes proposed that only two substances ultimately exist; mind and body. Yet, if the two are entirely distinct, as Descartes believed, how can one substance interact with the other? How, for example, is the intention of a human mind able to cause movement in the persons limbs? The issue of the interaction between mind and body is known in philosophy as the mind-body problem.
Many fields other than philosophy share an interest in the nature of mind. In religion, the nature of mind is connected with various conceptions of the soul and the possibility of life after death. In many abstract theories of mind there is considerable overlap between philosophy and the science of psychology. Once part of philosophy, psychology split off and formed a separate branch of knowledge in the 19th century. While psychology used scientific experiments to study mental states and events, philosophy uses reasoned arguments and thought experiments in seeking to understand the concepts that underlie mental phenomena. Also influenced by philosophy of mind is the field of artificial intelligence, which endeavour to develop computers that can mimic what the human mind can do. Cognitive science attempts to integrate the understanding of mind provided by philosophy, psychology, AI, and other disciplines. Finally, all of these fields benefit from the detailed understanding of the brain that has emerged through neuroscience in the late 20th century.
Philosophers use the characteristics of inward accessibility, subjectivity, intentionality, goal-directedness, creativity and freedom, and consciousness to distinguish mental phenomena from physical phenomena.
Perhaps the most important characteristic of mental phenomena is that they are inwardly accessible, or available to us through introspection. We each know our own minds - our sensations, thoughts, memories, desires, and fantasies - in a direct sense, by internal reflection. We also know our mental states and mental events in a way that no one else can. In other words, we have privileged access to our own mental states.
Certain mental phenomena, those we generally call experiences, have a subjective nature - that is, they have certain characteristics we become aware of when we reflect, for instance, there is something as definitely to feel pain, or have an itch, or see something red. These characteristics are subjective in that they are accessible to the subject of the experience, the person who has the experience, but not to others.
Other mental phenomena, which we broadly refer to as thoughts, have a characteristic philosophers call intentionality. Intentional thoughts are about other thoughts or objects, which are represented as having certain properties or for being related to one another in a certain way. The belief that London is west of Toronto, for example, is about London and Toronto and represents the former as west of the latter. Although we have privileged access to our intentional states, many of them do not seem to have a subjective nature, at least not in the way that experiences do.
The contrast between the subjective and the objective is made in both the epistemic and the ontological divisions of knowledge. In the objective field of study, it is oftentimes identified with the distension between the intrapersonal and the interpersonal, or with that between matters whose resolving power depends on the psychology of the person in question, and who in this way is dependent, or, sometimes, with the distinction between the biassed and the impartial. Therefore, an objective question might be one answerable by a method usable by any competent investigator, while a subjective question would be answerable only from the questioners point of view. In the ontological domain, the subjective-objective contrast is often between what is what is not mind-dependent: Secondary qualities, e.g., colours, have been variability with observation conditions. The truth of a proposition, for instance: Apart from certain propositions about oneself, would be objective if it is interdependent of the perspective, especially for beliefs of those judging it. Truth would be subjective if it lacks such independence, because it is a construct from justified beliefs, e.g., those well-confirmed by observation.
One notion of objectivity can be basic and the other as an end point of reasoning and observation, if only to infer of it as a conclusion. If the epistemic notion is essentially an underlying of something as related to or dealing with such that are to fundamental primitives, then the criteria for objectivity in the ontological sense derive from considerations of justification: An objective question is one answerable by a procedure that yields (adequate) justification is a matter of amenability to such a means or procedures used to attaining an end. , its method, if, on the other hand, the ontological notion is basic, the criteria for an interpersonal method and its objective use are a matter of its mind-independence and tendency to lead to objective truth, perhaps, its applying to external objects and yielding predictive success. Since, the use of these criteria requires employing the methods which, on the epistemic conception, define objectivists most notably scientific methods - but no similar dependence obtains in the other direction, the epistemic notion os often taken as basic.
A different theory of truth, or the epistemic theory, is motivated by the desire to avoid negative features of the correspondence theory, which celebrates the existence of God, whereby, its premises are that all natural things are dependent for their existence on something else, whereas the totality of dependent beings must then itself depend upon a non-dependent, or necessarily existent, being, which is God. So, the God that ends the question must exist necessarily, it must not be an entity of which the same kinds of questions can be raised. The problem with such is the argument that it unfortunately affords no reason for attributing concern and care to the deity, nor for connecting the necessarily existent being it derives with human values and aspirations.
This presents in truth as that which is licenced by our best theory of reality, truth is distributively contributed as a function of our thinking about the world and all surrounding surfaces. An obvious problem with this is the fact of revision; theories are constantly refined and corrected. To deal with this objection it is at the end of enquiry. We never in fact reach it, but it serves as a direct motivational disguised enticement, as an asymptotic end of enquiry. Nonetheless, the epistemic theory of truth is not antipathetic to ontological relativity, since it has no commitment to the ultimate furniture of the world and it also is open to the possibilities of some kinds of epistemological relativism.
Lest be said, however, that of epistemology, the subjective-objective contrast arises above all for the concept of justification and its relatives. Externalism, particularly reliabilism, and since, for reliabilism, truth-conduciveness (non-subjectivity conceived) is central for justified belief. Internalism may or may not construe justification subjectivistically, depending on whether the proposed epistemic standards are interpersonally grounded. There are also various kinds of subjectivity: Justification may, e.g., be grounded in ones considered standards of simply in what one believes to be sound. Yet, justified beliefs accorded with precise or explicitly considered standards whether or not deem it a purposive necessity to think them justifiably made so.
Any conception of objectivity may treat one domain as fundamental and the others derivatively. Thus, objectivity for methods (including sensory observation) might be thought basic. Let us look upon an objective method be that one is (1) interpersonally usable and tends to yield justification regarding the questions to which it applies (an epistemic conception), or (2) trends to yield truth when properly applied (an ontological conception) or (3) both. Then an objective person is one who appropriately uses objective methods by an objective method, as one appraisable by an objective method, an objective discipline is whose methods are objective, and so on. Typically, those who conceive objectivity epistemically tend to take methods as fundamental, and those who conceive it ontologically tend to take statements as basic.
A number of mental phenomena appear to be connected to one another as elements in an intelligent, goal-directed system. The system works as follows: First, our sense organs are stimulated by events in our environment; next, by virtue of these stimulations, we perceive things about the external world; finally, we use this information, as well as information we have remembered or inferred, to guide our actions in ways that further our goals. Goal-directedness seems to accompany only mental phenomena.
Another important characteristic of mind, especially of human minds, is the capacity for choice and imagination. Rather than automatically converting past influences into future actions, individual minds are capable of exhibiting creativity and freedom. For instance, we can imagine things we have not experienced and can act in ways that no one expects or could predict.
Mental phenomena are conscious, and consciousness may be the closest term we have for describing what is special about mental phenomena. Minds are sometimes referred to as consciousness, yet it is difficult to describe exactly what consciousness is. Although consciousness is closely related to inward accessibility and subjectivity, these very characteristics seem to hinder us in reaching an objective scientific understanding of it.
Although philosophers have written about mental phenomena since ancient times, the philosophy of mind did not garner much attention until the work of French philosopher René Descartes in the 17th century. Descartes work represented a turning point in thinking about mind by making a strong distinction between bodies and minds, or the physical and the mental. This duality between mind and body, known as Cartesian dualism, has posed significant problems for philosophy ever since.
Descartes believed there are two basic kinds of things in the world, a belief known as substance dualism. For Descartes, the principles of existence for these two groups of things - bodies and minds - are completely different from one another: Bodies exist by being extended in space, while minds exist by being conscious. According to Descartes, nothing can be done to give a body thought and consciousness. No matter how we shape a body or combine it with other bodies, we cannot turn the body into a mind, a thing that is conscious, because being conscious is not a way of being extended.
For Descartes, a person consists of a human body and a human mind causally interacting with one another. For example, the intentions of a human being, that may have conceivably, caused that persons limbs to move. In this way, the mind can affect the body. In addition, the sense organs of a human being as forced, in effect of a refractive ray of light, pressure, or sound, external sources which in turn affect the brain, affecting mental states. Thus the body may affect the mind. Exactly how mind can affect body, and vice versa, is a central issue in the philosophy of mind, and is known as the mind-body problem. According to Descartes, this interaction of mind and body is peculiarly intimate. Unlike the interaction between a pilot and his ship, the connexion between mind and body more closely resembles two substances that have been thoroughly mixed together.
In response to the mind-body problem arising from Descartes theory of substance dualism, a number of philosophers have advocated various forms of substance monism, the doctrine that there is ultimately just one kind of thing in reality. In the 18th century, Irish philosopher George Berkeley claimed there were no material objects in the world, only minds and their ideas. Berkeley thought that talk about physical objects was simply a way of organizing the flow of experience. Near the turn of the 20th century, American psychologist and philosopher William James proposed another form of substance monism. James claimed that experience is the basic stuff from which both bodies and minds are constructed.
Most philosophers of mind today are substance monists of a third type: They are materialists who believe that everything in the world is basically material, or a physical object. Among materialists, there is still considerable disagreement about the status of mental properties, which are conceived as properties of bodies or brains. Materialists who those properties undersized by duality, yet believe that mental properties are an additional kind of property or attribute, not reducible to physical properties. Property diarists have the problem of explaining how such properties can fit into the world envisaged by modern physical science, according to which there are physical explanations for all things.
Materialists who are property monists believe that there is ultimately only one type of property, although they disagree on whether or not mental properties exist in material form. Some property monists, known as reductive materialists, hold that mental properties exist simply as a subset of relatively complex and non-basic physical properties of the brain. Reductive materialists have the problem of explaining how the physical states of the brain can be inwardly accessible and have a subjective character, as mental states do. Other property monists, known as eliminative materialists, consider the whole category of mental properties to be a mistake. According to them, mental properties should be treated as discredited postulates of an out-mounded theory. Eliminative materialism is difficult for most people to accept, since we seem to have direct knowledge of our own mental phenomena by introspection and because we use the general principles we understand about mental phenomena to predict and explain the behaviour of others.
Philosophy of mind concerns itself with a number of specialized problems. In addition to the mind-body problem, important issues include those of personal identity, immortality, and artificial intelligence.
During much of Western history, the mind has been identified with the soul as presented in Christian theology. According to Christianity, the soul is the source of a persons identity and is usually regarded as immaterial; thus it is capable of enduring after the death of the body. Descartes conception of the mind as a separate, nonmaterial substance fits well with this understanding of the soul. In Descartes view, we are aware of our bodies only as the cause of sensations and other mental phenomena. Consequently our personal essence is composed more fundamentally of mind and the preservation of the mind after death would constitute our continued existence.
The mind conceived by materialist forms of substance monism does not fit as neatly with this traditional concept of the soul. With materialism, once a physical body is destroyed, nothing enduring remains. Some philosophers think that a concept of personal identity can be constructed that permits the possibility of life after death without appealing to separate immaterial substances. Following in the tradition of 17th-century British philosopher John Locke, these philosophers propose that a person consists of a stream of mental events linked by memory. It is these links of memory, rather than a single underlying substance, that provides the unity of a single consciousness through time. Immortality is conceivable if we think of these memory links as connecting a later consciousness in heaven with an earlier one on earth.
The field of artificial intelligence also raises interesting questions for the philosophy of mind. People have designed machines that mimic or model many aspects of human intelligence, and there are robots currently in use whose behaviour is described in terms of goals, beliefs, and perceptions. Such machines are capable of behaviour that, were it exhibited by a human being, would surely be taken to be free and creative. As an example, in 1996 an IBM computer named Deep Blue won a chess game against Russian world champion Garry Kasparov under international match regulations. Moreover, it is possible to design robots that have some sort of privileged access to their internal states. Philosophers disagree over whether such robots truly think or simply appear to think and whether such robots should be considered to be conscious
Dualism, in philosophy, the theory that the universe is explicable only as a whole composed of two distinct and mutually irreducible elements. In Platonic philosophy the ultimate dualism is between being and nonbeing - that is, between ideas and matter. In the 17th century, dualism took the form of belief in two fundamental substances: mind and matter. French philosopher René Descartes, whose interpretation of the universe exemplifies this belief, was the first to emphasize the irreconcilable difference between thinking substance (mind) and extended substance (matter). The difficulty created by this view was to explain how mind and matter interact, as they apparently do in human experience. This perplexity caused some Cartesians to deny entirely any interaction between the two. They asserted that mind and matter are inherently incapable of affecting each other, and that any reciprocal action between the two is caused by God, who, on the occasion of a change in one, produces a corresponding change in the other. Other followers of Descartes abandoned dualism in favour of monism.
In the 20th century, reaction against the monistic aspects of the philosophy of idealism has to some degree revived dualism. One of the most interesting defences of dualism is that of Anglo-American psychologist William McDougall, who divided the universe into spirit and matter and maintained that good evidence, both psychological and biological, indicates the spiritual basis of physiological processes. French philosopher Henri Bergson in his great philosophic work Matter and Memory likewise took a dualistic position, defining matter as what we perceive with our senses and possessing in itself the qualities that we perceive in it, such as colour and resistance. Mind, on the other hand, reveals itself as memory, the faculty of storing up the past and utilizing it for modifying our present actions, which otherwise would be merely mechanical. In his later writings, however, Bergson abandoned dualism and came to regard matter as an arrested manifestation of the same vital impulse that composes life and mind.
Dualism, in philosophy, the theory that the universe is explicable only as a whole composed of two distinct and mutually irreducible elements. In Platonic philosophy the ultimate dualism is between being and nonbeing - that is, between ideas and matter. In the 17th century, dualism took the form of belief in two fundamental substances: mind and matter. French philosopher René Descartes, whose interpretation of the universe exemplifies this belief, was the first to emphasize the irreconcilable difference between thinking substance (mind) and extended substance (matter). The difficulty created by this view was to explain how mind and matter interact, as they apparently do in human experience. This perplexity caused some Cartesians to deny entirely any interaction between the two. They asserted that mind and matter are inherently incapable of affecting each other, and that any reciprocal action between the two is caused by God, who, on the occasion of a change in one, produces a corresponding change in the other. Other followers of Descartes abandoned dualism in favour of monism.
In the 20th century, reaction against the monistic aspects of the philosophy of idealism has to some degree revived dualism. One of the most interesting defences of dualism is that of Anglo-American psychologist William McDougall, who divided the universe into spirit and matter and maintained that good evidence, both psychological and biological, indicates the spiritual basis of physiological processes. French philosopher Henri Bergson in his great philosophic work Matter and Memory likewise took a dualistic position, defining matter as what we perceive with our senses and possessing in itself the qualities that we perceive in it, such as colour and resistance. Mind, on the other hand, reveals itself as memory, the faculty of storing up the past and utilizing it for modifying our present actions, which otherwise would be merely mechanical. In his later writings, however, Bergson abandoned dualism and came to regard matter as an arrested manifestation of the same vital impulse that composes life and mind.
For many people understanding the place of mind in nature is the greatest philosophical problem. Mind is often though to be the last domain that stubbornly resists scientific understanding and philosophers defer over whether they find that cause for celebration or scandal. The mind-body problem in the modern era was given its definitive shape by Descartes, although the dualism that he espoused is in some form whatever there is a religious or philosophical tradition there is a religious or philosophical tradition whereby the soul may have an existence apart from the body. While most modern philosophers of mind would reject the imaginings that lead us to think that this makes sense, there is no consensus over the best way to integrate our understanding of people as bearers of physical properties lives on the other.
Occasionalist find from it term as employed to designate the philosophical system devised by the followers of the 17th-century French philosopher René Descartes, who, in attempting to explain the interrelationship between mind and body, concluded that God is the only cause. The occasionalists began with the assumption that certain actions or modifications of the body are preceded, accompanied, or followed by changes in the mind. This assumed relationship presents no difficulty to the popular conception of mind and body, according to which each entity is supposed to act directly on the other; these philosophers, however, asserting that cause and effect must be similar, could not conceive the possibility of any direct mutual interaction between substances as dissimilar as mind and body.
According to the occasionalists, the action of the mind is not, and cannot be, the cause of the corresponding action of the body. Whenever any action of the mind takes place, God directly produces in connexion with that action, and by reason of it, a corresponding action of the body; the converse process is likewise true. This theory did not solve the problem, for if the mind cannot act on the body (matter), then God, conceived as mind, cannot act on matter. Conversely, if God is conceived as other than mind, then he cannot act on mind. A proposed solution to this problem was furnished by exponents of radical empiricism such as the American philosopher and psychologist William James. This theory disposed of the dualism of the occasionalists by denying the fundamental difference between mind and matter.
Generally, along with consciousness, that experience of an external world or similar scream or other possessions, takes upon itself the visual experience or deprive of some normal visual experience, that this, however, does not perceive the world accurately. In its frontal experiment. As researchers reared kittens in total darkness, except that for five hours a day the kittens were placed in an environment with only vertical lines. When the animals were later exposed to horizontal lines and forms, they had trouble perceiving these forms.
While, in the theory of probability the Cambridge mathematician and philosopher Frank Ramsey (1903-30), was the first to show how a personalized theory could be developed, based on precise behavioural notions of preference and expectation. In the philosophy of language, Ramsey was one of the first thinkers to accept a redundancy theory of truth, which he combined with radical views of the function of many kinds of propositions. Neither generalizations nor causal propositions, nor those treating probability or ethics, described facts, but each has a different specific function in our intellectual economy.
Ramsey advocates that of a sentence generated by taking all the sentence affirmed in a scientific theory that use some term, e.g., quark. Replacing the term by a variable, and existentially quantifying into the result. Instead of saying quarks have such-and-such properties, Ramsey postdated that the sentence as saying that there is something that has those properties. If the process is repeated, the sentence gives the topic-neutral structure of the theory, but removes any implications that we know what the term so treated denote. It leaves open the possibility of identifying the theoretical item with whatever, and it is that best fits the description provided. Nonetheless, it was pointed out by the Cambridge mathematician Newman that if the process is carried out for all except the logical bones of the theory, then by the Löwenheim-Skolem theorem, the result will be interpretable in any domain of sufficient cardinality, and the content of the theory may reasonably be felt to have been lost.
Nevertheless, probability is a non-negative, additive set function whose maximum value is unity. What is harder to understand is the application of the formal notion to the actual world. One point of application is statistical, when kinds of event or trials (such as the tossing of a coin) can be described, and the frequency of occurrence of particular outcomes (such as the coin falling heads) is measurable, then we can begin to think of the probability of that kind of outcome in that kind of trial. One account of probability is therefore the frequency theory, associated with Venn and Richard von Mises (1883-1953), that identifies the probability of an event with such a frequency of occurrence. A second point of application is the description of an hypothesis as probable when the evidence bears a favoured relation is conceived of as purely logical in nature, as in the works of Keynes and Carnap, probability statement are not empirical measures of frequency, but represent something like partial entailments or measures of possibilities left open by the evidence and by the hypothesis.
Formal confirmation theories and range theories of probability are developments of this idea. The third point of application is in the use probability judgements have in regulating the confidence with which we hold various expectations. The approach sometimes called subjectivism or personalism, but more commonly known as Bayesianism, associated with de Finetti and Ramsey, whom of both, see probability judgements as expressions of a subjects degree of confidence in an event or kind of event, and attempts to describe constraints on the way we should have degrees of confidence in different judgements that explain those judgements having the mathematical form of judgements of probability. For Bayesianism, probability or chance is probability or chance is not an objective or real factor in the world, but rather a reflection of our own states of mind. However, these states of mind need to be governed by empirical frequencies, so this is not an invitation to licentious thinking.
This concept of sampling and accompanying application of the laws of probability find extensive use in polls, public opinion polls. Polls to determine what radio or television program is being watched and listened to, polls to determine house-wives reaction to a new product, political polls, and the like. In most cases the sampling is carefully planned and often a margin of error is stated. Polls cannot, however, altogether eliminate the fact that certain people dislike being questioned and may deliberately conceal or give false information. In spite of this and other objections, the method of sampling often makes results available in situations where the cost of complete enumeration would be prohibitive both from the standpoint of time and of money.
Thus we can see that probability and statistics are used in insurance, physics, genetics, biology, business, as well as in games of chance, and we are inclined to agree with P.S. LaPlace who said: We see . . . that the theory of probabilities is at bottom only common sense reduced to calculation, it makes us appreciate with exactitude what reasonable minds feel by a sort of instinct, often being able to account for it . . . it is remarkable that [this] science, which originated in the consideration of games of chance, should have become the most important object of human knowledge.
It seems, that the most taken of are the paradoxes in the foundations of set theory as discovered by Russell in 1901. Some classes have themselves as members: The class of all abstract objects, for example, is an abstract object, whereby, others do not: The class of donkeys is not itself a donkey. Now consider the class of all classes that are not members of themselves, is this class a member of itself, that, if it is, then it is not, and if it is not, then it is.
The paradox is structurally similar to easier examples, such as the paradox of the barber. Such one like a village having a barber in it, who shaves all and only the people who do not have in themselves. Who shaves the barber? If he shaves himself, then he does not, but if he does not shave himself, then he does not. The paradox is actually just a proof that there is no such barber or in other words, that the condition is inconsistent. All the same, it is no too easy to say why there is no such class as the one Russell defines. It seems that there must be some restriction on the kind of definition that are allowed to define classes and the difficulty that of finding a well-motivated principle behind any such restriction.
The French mathematician and philosopher Henri Jules Poincaré (1854-1912) believed that paradoxes like those of Russell and the barber were due to such as the impredicative definitions, and therefore proposed banning them. But, it turns out that classical mathematics required such definitions at too many points for the ban to be easily absolved. Having, in turn, as forwarded by Poincaré and Russell, was that in order to solve the logical and semantic paradoxes it would have to ban any collection (set) containing members that can only be defined by means of the collection taken as a whole. It is, effectively by all occurring principles into which have an adopting vicious regress, as to mark the definition for which involves no such failure. There is frequently room for dispute about whether regresses are benign or vicious, since the issue will hinge on whether it is necessary to reapply the procedure. The cosmological argument is an attempt to find a stopping point for what is otherwise seen for being an infinite regress, and, to ban of the predicative definitions.
The investigation of questions that arise from reflection upon sciences and scientific inquiry, are such as called of a philosophy of science. Such questions include, what distinctions in the methods of science? s there a clear demarcation between scenes and other disciplines, and how do we place such enquires as history, economics or sociology? And scientific theories probable or more in the nature of provisional conjecture? Can the be verified or falsified? What distinguished good from bad explanations? Might there be one unified since, embracing all special sciences? For much of the 20th century their questions were pursued in a highly abstract and logical framework it being supposed that as general logic of scientific discovery that a general logic of scientific discovery a justification might be found. However, many now take interests in a more historical, contextual and sometimes sociological approach, in which the methods and successes of a science at a particular time are regarded less in terms of universal logical principles and procedure, and more in terms of their availability to methods and paradigms as well as the social context.
In addition, to general questions of methodology, there are specific problems within particular sciences, giving subjects as biology, mathematics and physics.
The intuitive certainty that sparks aflame the dialectic awarenesses for its immediate concerns are either of the truth or by some other in an object of apprehensions, such as a concept. Awareness as such, has to its amounting quality value the place where philosophical understanding of the source of our knowledge are, however, in covering the sensible apprehension of things and pure intuition it is that which structural sensation into the experience of things accent of its direction that orchestrates the celestial overture into measures in space and time.
The notion that determines how something is seen or evaluated of the status of law and morality especially associated with St. Thomas Aquinas and the subsequent scholastic tradition. More widely, any attempt to cement the moral and legal order together with the nature of the cosmos or how the nature of human beings, for which sense it is also found in some Protestant writers, and arguably derivative from a Platonic view of ethics, and is implicit in ancient Stoicism. Law stands above and apart from the activities of human lawmaker, it constitutes an objective set of principles that can be seen true by natural light or reason, and (in religion versions of the theory) that express Gods will for creation. Non-religious versions of the theory substitute objective conditions for human flourishing as the source of constraints upon permissible actions and social arrangements. Within the natural law tradition, different views have been held about the relationship between the rule of law about God s will, for instance the Dutch philosopher Hugo Grothius (1583-1645), similarly takes upon the view that the content of natural law is independent of any will, including that of God, while the German theorist and historian Samuel von Pufendorf (1632-94) takes the opposite view, thereby facing the problem of one horn of the Euthyphro dilemma, that simply states, that its dilemma arises from whatever the source of authority is supposed to be, for in which do we care about the general good because it is good, or do we just call good things that we care about. Wherefore, by facing the problem that may be to assume of a strong form, in which it is claimed that various facts entail values, or a weaker form, from which it confines itself to holding that reason by itself is capable of discerning moral requirements that are supposedly of binding to all human bings regardless of their desires
Although the morality of people send the ethical amount from which the same thing, is that there is a usage that restricts morality to systems such as that of the German philosopher and founder of ethical philosophy Immanuel Kant (1724-1804), based on notions such as duty, obligation, and principles of conduct, reserving ethics for more than the Aristotelian approach to practical reasoning based on the notion of a virtue, and generally avoiding the separation of moral considerations from other practical considerations. The scholarly issues are complex, with some writers seeing Kant as more Aristotelian and Aristotle as, ore involved in a separate sphere of responsibility and duty, than the simple contrast suggests. Some theorists see the subject in terms of a number of laws (as in the Ten Commandments). The status of these laws may be test, and they are the edicts of a divine lawmaker, or that they are truth of reason, knowable deductively. Other approaches to ethics (e.g., eudaimonism, situational ethics, virtue ethics) eschew general principles as much as possible, frequently disguising the great complexity of practical reasoning. For Kantian notion of the moral law is a binding requirement of the categorical imperative, and to understand whether they are equivalent at some deep level. Kants own applications of the notion are not always convincing, as for one cause of confusion in relating Kants ethics to theories such additional expressivism, is that it is easy, but mistaken, to suppose that the categorical nature of the imperative means that it cannot be the expression of sentiment, but must derive from something unconditional or necessary such as the voice of reason.
For which ever reason, the mortal being makes of its presence to the future of weighing of that which one must do, or that which can be required of one. The term carries implications of that which is owed (due) to other people, or perhaps in oneself. Universal duties would be owed to persons (or sentient beings) as such, whereas special duty in virtue of specific relations, such for being the child of someone, or having made someone a promise. Duty or obligation is the primary concept of deontological approaches to ethics, but is constructed in other systems out of other notions. In the system of Kant, a perfect duty is one that must be performed whatever the circumstances: Imperfect duties may have to give way to the more stringent ones. In another way, perfect duties are those that are correlative with the right to others, imperfect duties are not. Problems with the concept include the ways in which due needs to be specified (a frequent criticism of Kant is that his notion of duty is too abstract). The concept may also suggest of a regimented view of ethical life in which we are all forced conscripts in a kind of moral army, and may encourage an individualistic and antagonistic view of social relations.
The most generally accepted account of externalism and/or internalism, that this distinction is that a theory of justification is internalist if only if it requiem that all of the factors needed for a belief to be epistemologically justified for a given person be cognitively accessible to that person, internal to his cognitive perception, and externalist, if it allows that at least some of the justifying factors need not be thus accessible, so that they can be external to the believers cognitive perceptive, beyond any such given relations. However, epistemologists often use the distinction between internalist and externalist theories of epistemic justification without offering any very explicit explication.
The externalist/internalist distinction has been mainly applied to theories of epistemic justification: It has also been applied in a closely related way to accounts of knowledge and in a rather different way to accounts of belief and thought contents.
The internalist requirement of cognitive accessibility can be interpreted in at least two ways: A strong version of internalism would require that the believer actually be aware of the justifying factor in order to be justified: While a weaker version would require only that he be capable of becoming aware of them by focussing his attentions appropriately, but without the need for any change of position, new information, etc. Though the phrase cognitively accessible suggests the weak interpretation, the main intuitive motivation for internalism, viz. the idea that epistemic justification requires that the believer actually have in his cognitive possession a reason for thinking that the belief is true, and would require the strong interpretation.
Perhaps, the clearest example of an internalist position would be a Foundationalist view according to which foundational beliefs pertain to immediately experienced states of mind and other beliefs are justified by standing in cognitively accessible logical or inferential relations to such foundational beliefs. Such a view could count as either a strong or a weak version of internalism, depending on whether actual awareness of the justifying elements or only the capacity to become aware of them is required. Similarly, a current view could also be internalist, if both the beliefs or other states with which a justification belief is required to cohere and the coherence relations themselves are reflectively accessible.
It should be carefully noticed that when internalism is construed in this way, it is neither necessary nor sufficient by itself for internalism that the justifying factors literally be internal mental states of the person in question. Not necessary, necessary, because on at least some views, e.g., a direct realist view of perception, something other than a mental state of the believer can be cognitively accessible: Not sufficient, because there are views according to which at least some mental states need not be actual (strong version) or even possible (weak version) objects of cognitive awareness. Also, on this way of drawing the distinction, a hybrid view, according to which some of the factors required for justification must be cognitively accessible while others need not and in general will not be, would count as an externalist view. Obviously too, a view that was externalist in relation to a strong version of internalism (by not requiring that the believer actually be aware of all justifying factors) could still be internalist in relation to a weak version (by requiring that he at least be capable of becoming aware of them.)
The most prominent recent externalist views have been versions of Reliabilism, whose requirements for justification is roughly that the belief be produced in a way or via a process that makes of objectively likely that the belief is true. What makes such a view externalist is the absence of any requirement that the person for whom the belief is justified have any sort of cognitive access to the relations of reliability in question. Lacking such access, such a person will in general have no reason for thinking that the belief is true or likely to be true , but will, on such an account, nonetheless be epistemically justified in according it. Thus such a view arguably marks a major break from the modern epistemological tradition, stemming from Descartes, which identifies epistemic justification with having a reason, perhaps even a conclusive reason for thinking that the belief is true. An epistemologist working within this tradition is likely to feel that the externalist, than offering a competing account of the same concept of epistemic justification with which the traditional epistemologist is concerned, has simply changed the subject.
The main objection to externalism rests on the intuitive certainty that the basic requirement for epistemic justification is that the acceptance of the belief in question be rational or responsible in relation to the cognitive goal of truth, which seems to require in turn that the believer actually be dialectally aware of a reason for thinking that the belief is true (or, at the very least, that such a reason be available to him). Since the satisfaction of an externalist condition is neither necessary nor sufficient for the existence of such a cognitively accessible reason, it is argued, externalism is mistaken as an account of epistemic justification. This general point has been elaborated by appeal to two sorts of putative intuitive counter-examples to externalism. The first of these challenges the necessity of belief which seem intuitively to be justified, but for which the externalist conditions are not satisfied. The standard examples in this sort are cases where beliefs are produced in some very nonstandard way, e.g., by a Cartesian demon, but nonetheless, in such a way that the subjective experience of the believer is indistinguishable from that of someone whose beliefs are produced more normally. The intuitive claim is that the believer in such a case is nonetheless epistemically justified, as much so as one whose belief is produced in a more normal way, and hence that externalist account of justification must be mistaken.
Perhaps the most striking reply to this sort of counter-example, on behalf of a cognitive process is to be assessed in normal possible worlds, i.e., in possible worlds that are actually the way our world is common-seismically believed to be, than in the world which contains the belief being judged. Since the cognitive processes employed in the Cartesian demon cases are, for which we may assume, reliable when assessed in this way, the reliabilism can agree that such beliefs are justified. The obvious, to a considerable degree of bringing out the issue of whether it is or not an adequate rationale for this construal of Reliabilism, so that the reply is not merely a notional presupposition guised as having representation.
The correlative way of elaborating on the general objection to justificatory externalism challenges the sufficiency of the various externalist conditions by citing cases where those conditions are satisfied, but where the believers in question seem intuitively not to be justified. In this context, the most widely discussed examples have to do with possible occult cognitive capacities, like clairvoyance. Considering the point in application once, again, to Reliabilism, the claim is that to think that he has such a cognitive power, and, perhaps, even good reasons to the contrary, is not rational or responsible and therefore not epistemically justified in accepting the belief that result from his clairvoyance, despite the fact that the reliabilism condition is satisfied.
One sort of response to this latter sorts of objection is to bite the bullet and insist that such believers are in fact justified, dismissing the seeming intuitions to the contrary as latent internalist prejudice. A more widely adopted response attempts to impose additional conditions, usually of a roughly internalist sort, which will rule out the offending example, while stopping far of a full internalism. But, while there is little doubt that such modified versions of externalism can handle particular cases, as well enough to avoid clear intuitive implausibility, the usually problematic cases that they cannot handle, and also whether there is and clear motivation for the additional requirements other than the general internalist view of justification that externalist are committed to reject.
A view in this same general vein, one that might be described as a hybrid of internalism and externalism holds that epistemic justification requires that there is a justificatory factor that is cognitively accessible to the believer in question (though it need not be actually grasped), thus ruling out, e.g., a pure Reliabilism. At the same time, however, though it must be objectively true that beliefs for which such a factor is available are likely to be true, in addition, the fact need not be in any way grasped or cognitively accessible to the believer. In effect, of the premises needed to argue that a particular belief is likely to be true, one must be accessible in a way that would satisfy at least weak internalism, the internalist will respond that this hybrid view is of no help at all in meeting the objection and has no belief nor is it held in the rational, responsible way that justification intuitively seems to require, for the believer in question, lacking one crucial premise, still has no reason at all for thinking that his belief is likely to be true.
An alternative to giving an externalist account of epistemic justification, one which may be more defensible while still accommodating many of the same motivating concerns, is to give an externalist account of knowledge directly, without relying on an intermediate account of justification. Such a view will obviously have to reject the justified true belief account of knowledge, holding instead that knowledge is true belief which satisfies the chosen externalist condition, e.g., a result of a reliable process (and perhaps, further conditions as well). This makes it possible for such a view to retain internalist account of epistemic justification, though the centrality of that concept to epistemology would obviously be seriously diminished.
Such an externalist account of knowledge can accommodate the commonsense conviction that animals, young children, and unsophisticated adults posses knowledge, though not the weaker conviction (if such a conviction does exist) that such individuals are epistemically justified in their beliefs. It is also at least less vulnerable to internalist counter-examples of the sort discussed, since the intuitions involved there pertain more clearly to justification than to knowledge. What is uncertain is what ultimate philosophical significance the resulting conception of knowledge is supposed to have. In particular, does it have any serious bearing on traditional epistemological problems and on the deepest and most troubling versions of scepticism, which seems in fact to be primarily concerned with justification, that of knowledge?`
A rather different use of the terms internalism and externalism has to do with the issue of how the content of beliefs and thoughts is determined: According to an internalist view of content, the content of such intention states depends only on the non-relational, internal properties of the individuals mind or grain, and not at all on his physical and social environment: While according to an externalist view, content is significantly affected by such external factors and suggests a view that appears of both internal and external elements is standardly classified as an external view.
As with justification and knowledge, the traditional view of content has been strongly internalist in character. The main argument for externalism derives from the philosophy y of language, more specifically from the various phenomena pertaining to natural kind terms, indexical, etc. that motivate the views that have come to be known as direct reference theories. Such phenomena seem at least to show that the belief or thought content that can be properly attributed to a person is dependent on facts about his environment - e.g., whether he is on Earth or Twin Earth, what is fact pointing at, the classificatory criteria employed by expects in his social group, etc. - not just on what is going on internally in his mind or brain.
An objection to externalist account of content is that they seem unable to do justice to our ability to know the content of our beliefs or thought from the inside, simply by reflection. If content is depending on external factors pertaining to the environment, then knowledge of content should depend on knowledge of these factors - which will not in general be available to the person whose belief or thought is in question.
The adoption of an externalist account of mental content would seem to support an externalist account of justification, by way that if part or all of the content of a belief inaccessible to the believer, then both the justifying status of other beliefs in relation to that content and the status of that content as justifying further beliefs will be similarly inaccessible, thus contravening the internalist requirement for justification. An internalist must insist that there are no justification relations of these sorts, that our internally associable content can be either justified or justly for anything else: But such a response appears lame unless it is coupled with an attempt to show that the externalist account of content is mistaken.
In addition, to what to the Foundationalist, but the view in epistemology that knowledge must be regarded as a structure raised upon secure, certain foundations. These are found in some combination of experience and reason, with different schools (empirical, rationalism) emphasizing the role of one over that of the other. Foundationalism was associated with the ancient Stoics, and in the modern era with Descartes, who discovered his foundations in the clear and distinct ideas of reason. Its main opponent is Coherentism or the view that a body of propositions my be known without as foundation is certain, but by their interlocking strength. Rather as a crossword puzzle may be known to have been solved correctly even if each answer, taken individually, admits of uncertainty.
Truth, alone with coherence is the study of concept, in such a study in philosophy is that it treats both the meaning of the word true and the criteria by which we judge the truth or falsity in spoken and written statements. Philosophers have attempted to answer the question What is truth? for thousands of years. The four main theories they have proposed to answer this question are the correspondence, pragmatic, coherence, and deflationary theories of truth.
There are various ways of distinguishing types of Foundationalist epistemology by the use of the variations that have been enumerating. Planntinga has put forward an influence conception of classical Foundationalism, specified in terms of limitations on the foundations. He construes this as a disjunction of ancient and medieval Foundationalism;, which takes foundations to comprise that with self-evident and evident to the senses, and modern Foundationalism that replace evident Foundationalism that replaces evident to the senses with the replaces of evident to the senses with incorrigibly, which in practice was taken to apply only to beliefs bout ones present state of consciousness? Plantinga himself developed this notion in the context of arguing that items outside this territory, in particular certain beliefs about God, could also be immediately justified. A popular recent distinction is between what is variously strong or extremely Foundationalism and moderate, modest or minimal and moderately modest or minimal Foundationalism with the distinction depending on whether epistemic immunities are reassured of foundations. While depending on whether it require of a foundation only that it be required of as foundation, that only it be immediately justified, or whether it be immediately justified. In that it make just the comforted preferability, only to suggest that the plausibility of the string requiring stems from both a level confusion between beliefs on different levels.
Emerging sceptic tendencies come forth in the 14th-century writings of Nicholas of Autrecourt. His criticisms of any certainty beyond the immediate deliverance of the senses and basic logic, and in particular of any knowledge of either intellectual or material substances, anticipate the later scepticism of Balye and Hume. The; latter distinguishes between Pyrrhonistic and excessive scepticism, which he regarded as unlivable, and the more mitigated scepticism that accepts every day or commonsense beliefs (not as the delivery of reason, but as due more to custom and habit), but is duly wary of the power of reason to give us much more. Mitigated scepticism is thus closer to the attitude fostered by ancient scepticism from Pyrrho through to Sexus Empiricus. Although the phrase Cartesian scepticism is sometimes used, Descartes himself was not a sceptic, but in the method of doubt, uses a sceptical scenario in order to begin the process of finding a secure mark of knowledge. Descartes himself trusts a category of clear and distinct ideas, not far removed from the phantasia kataleptiké of the Stoics.
Scepticism should not be confused with relativism, which is a doctrine about the nature of truth, and may be motivated by trying to avoid scepticism. Nor is it identical with eliminativism, which counsels abandoning an area of thought together, not because we cannot know the truth, but because there are no truth capable of being framed in the terms we use.
Descartes theory of knowledge starts with the quest for certainty, for an indubitable starting-point or foundation on the basis alone of which progress is possible. This is eventually found in the celebrated Cogito ergo sum: I think therefore I am. By locating the point of certainty in my own awareness of my own self, Descartes gives a first-person twist to the theory of knowledge that dominated them following centuries in spite of various counter-attacks on behalf of social and public starting-points. The metaphysics associated with this priority is the famous Cartesian dualism, or separation of mind and matter into two different but interacting substances, Descartes rigorously and rightly sees that it takes divine dispensation to certify any relationship between the two realms thus divided, and to prove the reliability of the senses invokes a clear and distinct perception of highly dubious proofs of the existence of a benevolent deity. This has not met general acceptance: as Hume drily puts it, to have recourse to the veracity of the supreme Being, in order to prove the veracity of our senses, is surely making a very unexpected circuit.
In his own time Descartes conception of the entirely separate substance of the mind was recognized to give rise to insoluble problems of the nature of the causal connexion between the two. It also gives rise to the problem, insoluble in its own terms, of other minds. Descartes notorious denial that non-human animals are conscious is a stark illustration of the problem. In his conception of matter Descartes also gives preference to rational cogitation over anything derived from the senses. Since we can conceive of the matter of a ball of wax surviving changes to its sensible qualities, matter is not an empirical concept, but eventually an entirely geometrical one, with extension and motion as its only physical nature. Descartes thought, as reflected in Leibniz, that the qualities of sense experience have no resemblance to qualities of things, so that knowledge of the external world is essentially knowledge of structure rather than of filling. On this basis Descartes erects a remarkable physics. Since matter is in effect the same as extension there can be no empty space or void, since there is no empty space motion is not a question of occupying previously empty space, but is to be thought of in terms of vortices (like the motion of a liquid).
Although the structure of Descartes epistemology, theory of mind, and theory of matter have ben rejected many times, their relentless exposure of the hardest issues, their exemplary clarity, and even their initial plausibility, all contrive to make him the central point of reference for modern philosophy.
The self conceived as Descartes presents it in the first two Meditations: aware only of its own thoughts, and capable of disembodied existence, neither situated in a space nor surrounded by others. This is the pure self of I-ness that we are tempted to imagine as a simple unique thing that make up our essential identity. Descartes view that he could keep hold of this nugget while doubting everything else is criticized by Lichtenberg and Kant, and most subsequent philosophers of mind.
Descartes holds that we do not have any knowledge of any empirical proposition about anything beyond the contents of our own minds. The reason, roughly put, is that there is a legitimate doubt about all such propositions because there is no way to deny justifiably that our senses are being stimulated by some cause (an evil spirit, for example) which is radically different from the objects that we normally think affect our senses.
He also points out, that the senses (sight, hearing, touch, etc., are often unreliable, and it is prudent never to trust entirely those who have deceived us even once, he cited such instances as the straight stick that looks ben t in water, and the square tower that looks round from a distance. This argument of illusion, has not, on the whole, impressed commentators, and some of Descartes contemporaries pointing out that since such errors become known as a result of further sensory information, it cannot be right to cast wholesale doubt on the evidence of the senses. But Descartes regarded the argument from illusion as only the first stage in a softening up process which would lead the mind away from the senses. He admits that there are some cases of sense-base belief about which doubt would be insane, e.g., the belief that I am sitting here by the fire, wearing a winter dressing gown.
Descartes was to realize that there was nothing in this view of nature that could explain or provide a foundation for the mental, or from direct experience as distinctly human. In a mechanistic universe, he said, there is no privileged place or function for mind, and the separation between mind and matter is absolute. Descartes was also convinced, that the immaterial essences that gave form and structure to this universe were coded in geometrical and mathematical ideas, and this insight led him to invent algebraic geometry.
A scientific understanding of these ideas could be derived, said Descartes, with the aid of precise deduction, and also claimed that the contours of physical reality could be laid out in three-dimensional coordinates. Following the publication of Newtons Principia Mathematica in 1687, reductionism and mathematical modelling became the most powerful tools of modern science. And the dream that the entire physical world could be known and mastered through the extension and refinement of mathematical theory became the central feature and guiding principle of scientific knowledge.
Having to its recourse of knowledge, its central questions include the origin of knowledge, the place of experience in generating knowledge, and the place of reason in doing so, the relationship between knowledge and certainty, and between knowledge and the impossibility of error, the possibility of universal scepticism, and the changing forms of knowledge that arise from new conceptualizations of the world. All of these issues link with other central concerns of philosophy, such as the nature of truth and the natures of experience and meaning.
Foundationalism was associated with the ancient Stoics, and in the modern era with Descartes (1596-1650). Who discovered his foundations in the clear and distinct ideas of reason? Its main opponent is Coherentism, or the view that a body of propositions mas be known without a foundation in certainty, but by their interlocking strength, than as a crossword puzzle may be known to have been solved correctly even if each answer, taken individually, admits of uncertainty. Difficulties at this point led the logical passivists to abandon the notion of an epistemological foundation altogether, and to flirt with the coherence theory of truth. It is widely accepted that trying to make the connexion between thought and experience through basic sentences depends on an untenable myth of the given.
There is no functionally solid basis within the contemporary fields of thought for believing in the stark Cartesian division between mind and world that some have moderately described as ‘the disease of the Western mind’. Dialectic orchestration will serve as the background for understanding a new relationship between parts and wholes in physics, with a similar view of that relationship that has emerged in the co-called ‘new biology’ and in recent studies of the evolution of a scientific understanding to a more conceptualized representation of ideas, and includes its allied ‘content’.
Nonetheless, it seems a strong possibility that Plotonic and Whitehead connect upon the issue of the creation of the sensible world may by looking at actual entities as aspects of nature’s contemplation. The contemplation of nature is obviously an immensely intricate affair, involving a myriad of possibilities, therefore one can look at actual entities as, in some sense, the basic elements of a vast and expansive process.
We could derive a scientific understanding of these ideas with the aid of precise deduction, as Descartes continued his claim that we could lay the contours of physical reality out in three-dimensional co-ordinates. Following the publication of Isaac Newton’s ‘Principia Mathematica’ in 1687, reductionism and mathematical modeling became the most powerful tools of modern science. The dream that we could know and master the entire physical world through the extension and refinement of mathematical theory became the central feature and principals of scientific knowledge.
The radical separation between mind and nature formalized by Descartes served over time to allow scientists to concentrate on developing mathematical descriptions of matter as pure mechanism without any concern about its spiritual dimensions or ontological foundations. Meanwhile, attempts to rationalize, reconcile or eliminate Descartes’s merging division between mind and matter became the most central feature of Western intellectual life.
Philosophers like John Locke, Thomas Hobbes, and David Hume tried to articulate some basis for linking the mathematical describable motions of matter with linguistic representations of external reality in the subjective space of mind. Descartes’ compatriot Jean-Jacques Rousseau reified nature as the ground of human consciousness in a state of innocence and proclaimed that ‘Liberty, Equality, Fraternities’ are the guiding principles of this consciousness. Rousseau also fabricated the idea of the ‘general will’ of the people to achieve these goals and declared that those who do not conform to this will were social deviants.
The Enlightenment idea of ‘deism’, which imaged the universe as a clockwork and God as the clockmaker, provided grounds for believing in a divine agency, from which the time of moment the formidable creations also imply, in of which, the exhaustion of all the creative forces of the universe at origins ends, and that the physical substrates of mind were subject to the same natural laws as matter. In that the only means of mediating the gap between mind and matter was pure reason, causally by the traditional Judeo-Christian theism, which had previously been based on both reason and revelation, responded to the challenge of deism by debasing tradionality as a test of faith and embracing the idea that we can know the truths of spiritual reality only through divine revelation. This engendered a conflict between reason and revelation that persists to this day. And laid the foundation for the fierce completion between the mega-narratives of science and religion as frame tales for mediating the relation between mind and matter and the manner in which they should ultimately define the special character of each.
The nineteenth-century Romantics in Germany, England and the United States revived Rousseau’s attempt to posit a ground for human consciousness by reifying nature in a different form. Goethe and Friedrich Schelling proposed a natural philosophy premised on ontological Monism (the idea that adhering manifestations that govern toward evolutionary principles have grounded inside an inseparable spiritual Oneness) and argued God, man, and nature for the reconciliation of mind and matter with an appeal to sentiment, mystical awareness, and quasi-scientific attempts, as he afforded the efforts of mind and matter, nature became a mindful agency that ‘loves illusion’, as it shrouds man in mist, presses him or her heart and punishes those who fail to see the light. Schelling, in his version of cosmic unity, argued that scientific facts were at best partial truths and that the mindful creative spirit that unities mind and matter is progressively moving toward self-realization and ‘undivided wholeness’.
The British version of Romanticism, articulated by figures like William Wordsworth and Samuel Taylor Coleridge, placed more emphasis on the primary of the imagination and the importance of rebellion and heroic vision as the grounds for freedom. As Wordsworth put it, communion with the ‘incommunicable powers’ of the ‘immortal sea’ empowers the mind to release itself from all the material constraints of the laws of nature. The founders of American transcendentalism, Ralph Waldo Emerson and Henry David Theoreau, articulated a version of Romanticism that commensurate with the ideals of American democracy.
The American envisioned a unified spiritual reality that manifested itself as a personal ethos that sanctioned radical individualism and bred aversion to the emergent materialism of the Jacksonian era. They were also more inclined than their European counterpart, as the examples of Thoreau and Whitman attest, to embrace scientific descriptions of nature. However, the Americans also dissolved the distinction between mind and natter with an appeal to ontological monism and alleged that mind could free itself from all the constraint of assuming that by some sorted limitation of matter, in which such states have of them, some mystical awareness.
Since scientists, during the nineteenth century were engrossed with uncovering the workings of external reality and seemingly knew of themselves that these virtually overflowing burdens of nothing, in that were about the physical substrates of human consciousness, the business of examining the distributive contribution in dynamic functionality and structural foundation of mind became the province of social scientists and humanists. Adolphe Quételet proposed a ‘social physics’ that could serve as the basis for a new discipline called sociology, and his contemporary Auguste Comte concluded that a true scientific understanding of the social reality was quite inevitable. Mind, in the view of these figures, was a separate and distinct mechanism subject to the lawful workings of a mechanical social reality.
More formal European philosophers, such as Immanuel Kant, sought to reconcile representations of external reality in mind with the motions of matter-based on the dictates of pure reason. This impulse was also apparent in the utilitarian ethics of Jerry Bentham and John Stuart Mill, in the historical materialism of Karl Marx and Friedrich Engels, and in the pragmatism of Charles Smith, William James and John Dewey. These thinkers were painfully aware, however, of the inability of reason to posit a self-consistent basis for bridging the gap between mind and matter, and each remains obliged to conclude that the realm of the mental exists only in the subjective reality of the individual
A particular yet peculiar presence is awaiting to the future and has framed its proposed new understanding of relationships between mind and world, within the larger context of the history of mathematical physics, the origin and extensions of the classical view of the fundamentals of scientific knowledge, and the various ways that physicists have attempted to prevent previous challenges to the efficacy of classical epistemology.
There is no basis in contemporary physics or biology for believing in the stark Cartesian division between mind and world that some have moderately described as ‘the disease of the Western mind’. The dialectic orchestrations will serve as background for understanding a new relationship between parts and wholes in physics, with a similar view of that relationship that has emerged in the co-called ‘new biology’ and in recent studies of the evolution of a scientific understanding to a more conceptualized representation of ideas, and includes its allied ‘content’.
Nonetheless, it seems a strong possibility that Plotonic and Whitehead connect upon the issue of the creation of the sensible world may by looking at actual entities as aspects of nature’s contemplation. The contemplation of nature is obviously an immensely intricate affair, involving a myriad of possibilities, therefore one can look at actual entities as, in some sense, the basic elements of a vast and expansive process.
We could derive a scientific understanding of these ideas with the aid of precise deduction, as Descartes continued his claim that we could lay the contours of physical reality out in three-dimensional co-ordinates. Following the publication of Isaac Newton’s “Principia Mathematica” in 1687, reductionism and mathematical modeling became the most powerful tools of modern science. The dream that we could know and master the entire physical world through the extension and refinement of mathematical theory became the central feature and principals of scientific knowledge.
The radical separation between mind and nature formalized by Descartes served over time to allow scientists to concentrate on developing mathematical descriptions of matter as pure mechanism without any concern about its spiritual dimensions or ontological foundations. Meanwhile, attempts to rationalize, reconcile or eliminate Descartes’s merging division between mind and matter became the most central feature of Western intellectual life.
Philosophers like John Locke, Thomas Hobbes, and David Hume tried to articulate some basis for linking the mathematical describable motions of matter with linguistic representations of external reality in the subjective space of mind. Descartes’ compatriot Jean-Jacques Rousseau reified nature as the ground of human consciousness in a state of innocence and proclaimed that “Liberty, Equality, Fraternities” are the guiding principles of this consciousness. Rousseau also fabricated the idea of the ‘general will’ of the people to achieve these goals and declared that those who do not conform to this will were social deviants.
The Enlightenment idea of ‘deism’, which imaged the universe as a clockwork and God as the clockmaker, provided grounds for believing in a divine agency, from which the time of moment the formidable creations also imply, in of which, the exhaustion of all the creative forces of the universe at origins ends, and that the physical substrates of mind were subject to the same natural laws as matter. In that the only means of mediating the gap between mind and matter was pure reason, causally by the traditional Judeo-Christian theism, which had previously been based on both reason and revelation, responded to the challenge of deism by debasing tradionality as a test of faith and embracing the idea that we can know the truths of spiritual reality only through divine revelation. This engendered a conflict between reason and revelation that persists to this day. And laid the foundation for the fierce completion between the mega-narratives of science and religion as frame tales for mediating the relation between mind and matter and the manner in which they should ultimately define the special character of each.
The nineteenth-century Romantics in Germany, England and the United States revived Rousseau’s attempt to posit a ground for human consciousness by reifying nature in a different form. Goethe and Friedrich Schelling proposed a natural philosophy premised on ontological Monism (the idea that adhering manifestations that govern toward evolutionary principles have grounded inside an inseparable spiritual Oneness) and argued God, man, and nature for the reconciliation of mind and matter with an appeal to sentiment, mystical awareness, and quasi-scientific attempts, as he afforded the efforts of mind and matter, nature became a mindful agency that ‘loves illusion’, as it shrouds man in mist, presses him or her heart and punishes those who fail to see the light. Schelling, in his version of cosmic unity, argued that scientific facts were at best partial truths and that the mindful creative spirit that unities mind and matter is progressively moving toward self-realization and ‘undivided wholeness’.
The British version of Romanticism, articulated by figures like William Wordsworth and Samuel Taylor Coleridge, placed more emphasis on the primary of the imagination and the importance of rebellion and heroic vision as the grounds for freedom. As Wordsworth put it, communion with the “incommunicable powers” of the “immortal sea” empowers the mind to release itself from all the material constraints of the laws of nature. The founders of American transcendentalism, Ralph Waldo Emerson and Henry David Theoreau, articulated a version of Romanticism that commensurate with the ideals of American democracy.
The American envisioned a unified spiritual reality that manifested itself as a personal ethos that sanctioned radical individualism and bred aversion to the emergent materialism of the Jacksonian era. They were also more inclined than their European counterpart, as the examples of Thoreau and Whitman attest, to embrace scientific descriptions of nature. However, the Americans also dissolved the distinction between mind and natter with an appeal to ontological monism and alleged that mind could free itself from all the constraint of assuming that by some sorted limitation of matter, in which such states have of them, some mystical awareness.
Since scientists, during the nineteenth century were engrossed with uncovering the workings of external reality and seemingly knew of themselves that these virtually overflowing burdens of nothing, in that were about the physical substrates of human consciousness, the business of examining the distributive contribution in dynamic functionality and structural foundation of mind became the province of social scientists and humanists. Adolphe Quételet proposed a ‘social physics’ that could serve as the basis for a new discipline called sociology, and his contemporary Auguste Comte concluded that a true scientific understanding of the social reality was quite inevitable. Mind, in the view of these figures, was a separate and distinct mechanism subject to the lawful workings of a mechanical social reality.
More formal European philosophers, such as Immanuel Kant, sought to reconcile representations of external reality in mind with the motions of matter-based on the dictates of pure reason. This impulse was also apparent in the utilitarian ethics of Jerry Bentham and John Stuart Mill, in the historical materialism of Karl Marx and Friedrich Engels, and in the pragmatism of Charles Smith, William James and John Dewey. These thinkers were painfully aware, however, of the inability of reason to posit a self-consistent basis for bridging the gap between mind and matter, and each remains obliged to conclude that the realm of the mental exists only in the subjective reality of the individual.
It might be supposed that the pictorial/discursive distinction is best made in terms of the phenomenal and nonphenomenal distinction, but it is not obvious that this is the case. For one thing, there may be nonphenomenal properties of representations that vary continuously. Moreover, there are ways of understanding pictorial representation that presuppose neither phenomenality nor analogicity. According to Kosslyn (1980, 1982, 1983), a mental representation is "quasi-pictorial" when every part of the representation corresponds to a part of the object represented, and relative distances between parts of the object represented are preserved among the parts of the representation. But distances between parts of a representation can be defined functionally rather than spatially-for example, in terms of the number of discrete computational steps required to combine stored information about them. (Rey 1981.)
Tye (1991) proposes a view of images on which they are hybrid representations, consisting both of pictorial and discursive elements. On Tye's account, images are "(labelled) interpreted symbol-filled arrays." The symbols represent discursively, while their arrangement in arrays has representational significance (the location of each "cell" in the array represents a specific viewer-centred 2-D location on the surface of the imagined object)
The contents of mental representations are typically taken to be abstract objects (properties, relations, propositions, sets, etc.). A pressing question, especially for the naturalist, is how mental representations come to have their contents. Here the issue is not how to naturalize content (abstract objects can't be naturalized), but, rather, how to provide a naturalistic account of the content-determining relations between mental representations and the abstract objects they express. There are two basic types of contemporary naturalistic theories of content-determination, causal-informational and functional.
Causal-informational theories (Dretske 1981, 1988, 1995) hold that the content of a mental representation is grounded in the information it carries about what does (Devitt 1996) or would (Fodor 1987, 1990) cause it to occur. There is, however, widespread agreement that causal-informational relations are not sufficient to determine the content of mental representations. Such relations are common, but representation is not. Tree trunks, smoke, thermostats and ringing telephones carry information about what they are causally related to, but they do not represent (in the relevant sense) what they carry information about. Further, a representation can be caused by something it does not represent, and can represent something that has not caused it.
The main attempts to specify what makes a causal-informational state a mental representation are Asymmetric Dependency Theories (e.g., Fodor 1987, 1990, 1994) and Teleological Theories (Fodor 1990, Millikan 1984, Papineau 1987, Dretske 1988, 1995). The Asymmetric Dependency Theory distinguishes merely informational relations from representational relations on the basis of their higher-order relations to each other: informational relations depend upon representational relations, but not vice-versa. For example, if tokens of a mental state type are reliably caused by horses, cows-on-dark-nights, zebras-in-the-mist and Great Danes, then they carry information about horses, etc. If, however, such tokens are caused by cows-on-dark-nights, etc. because they were caused by horses, but not vice versa, then they represent horses.
According to Teleological Theories, representational relations are those a representation-producing mechanism has the selected (by evolution or learning) function of establishing. For example, zebra-caused horse-representations do not mean zebra, because the mechanism by which such tokens are produced has the selected function of indicating horses, not zebras. The horse-representation-producing mechanism that responds to zebras is malfunctioning.
Functional theories (Block 1986, Harman 1973), hold that the content of a mental representation is grounded in its (causal computational, inferential) relations to other mental representations. They differ on whether relata should include all other mental representations or only some of them, and on whether to include external states of affairs. The view that the content of a mental representation is determined by its inferential/computational relations with all other representations is holism; the view it is determined by relations to only some other mental states is localism (or molecularism). (The view that the content of a mental state depends on none of its relations to other mental states is atomism.) Functional theories that recognize no content-determining external relata have been called solipsistic (Harman 1987). Some theorists posit distinct roles for internal and external connections, the former determining semantic properties analogous to sense, the latter determining semantic properties analogous to reference (McGinn 1982, Sterelny 1989)
(Reductive) representationalists (Dretske, Lycan, Tye) usually take one or another of these theories to provide an explanation of the (Non-conceptual) content of experiential states. They thus tend to be Externalists about phenomenological as well as conceptual content. Phenomenalists and non-deductive representationalists (Block, Chalmers, Loar, Peacocke, Siewert), on the other hand, take it that the representational content of such states is (at least in part) determined by their intrinsic phenomenal properties. Further, those who advocate a phenomenology-based approach to conceptual content (Horgan and Tiensen, Loar, Pitt, Searle, Siewert) also seem to be committed to internalist individuation of the content (if not the reference) of such states.
Generally, those who, like informational theorists, think relations to one's (natural or social) environment are (at least partially) determinative of the content of mental representations are Externalists (e.g., Burge 1979, 1986, McGinn 1977, Putnam 1975), whereas those who, like some proponents of functional theories, think representational content is determined by an individual's intrinsic properties alone, are internalists (or individualists; cf. Putnam 1975, Fodor 1981)
This issue is widely taken to be of central importance, since psychological explanation, whether commonsense or scientific, is supposed to be both causal and content-based. (Beliefs and desires cause the behaviours they do because they have the contents they do. For example, the desire that one have a beer and the beliefs that there is beer in the refrigerator and that the refrigerator is in the kitchen may explain one's getting up and going to the kitchen.) If, however, a mental representation's having a particular content is due to factors extrinsic to it, it is unclear how its having that content could determine its causal powers, which, arguably, must be intrinsic. Some who accept the standard arguments for externalism have argued that internal factors determine a component of the content of a mental representation. They say that mental representations have both "narrow" content (determined by intrinsic factors) and "wide" or "broad" content (determined by narrow content plus extrinsic factors). This distinction may be applied to the sub-personal representations of cognitive science as well as to those of commonsense psychology.
Looking back a century, one can see a striking degree of homogeneity among the philosophers of the early twentieth century about the topics central to their concerns. More inertly taken to place, is the apparent obscurity and abstruseness of the concerns, which seem at first glance to be removed from the great debates of previous centuries, between ‘realism’ and ‘idealist’, say, of ‘rationalists’ and ‘empiricist’.
Thus, no matter what the current debate or discussion, the central issue is often without conceptual and contentual representations, that if one is without concept, is without idea, such that in one foul swoop would ingest the mere truth that lies to the underlying paradoxes of why is there something instead of nothing? Whatever it is that makes, what would otherwise be mere utterances and inscriptions into instruments of communication and understanding. This philosophical problem is to demystify this overblowing emptiness, and to relate to what we know of ourselves and the world.
Contributions to this study include the theory of ‘speech arts’, and the investigation of communicable communications, especially the relationship between words and ideas, and words and the world. It is, nonetheless, that which and utterance or sentence expresses, the proposition or claim made about the world. By extension, the content of a predicate that any expression that is capable of connecting with one or more singular terms to make a sentence, the expressed condition that the entities referred to may satisfy, in which case the resulting sentence will be true. Consequently we may think of a predicate as a function from things to sentences or even to truth-values, or other sub-sentential components that contribute to sentences that contain it. The nature of content is the central concern of the philosophy of language.
What some person expresses of a sentence often depends on the environment in which he or she is placed. For example, the disease that may be referred to by a term like ‘arthritis’ or the kind of tree referred as a criterial definition of an ‘oak’, of which, horticulturally I know next to nothing. This raises the possibility of imaging two persons in comparatively different environments, but in which everything appears the same to each of them. The wide content of their thoughts and saying will be different if the situation surrounding them is appropriately different, ‘situation’ may here include the actual objects they perceive, or the chemical or physical kinds of objects in the world they inhabit, or the history of their words, or the decisions of authorities on what counts as an example of some terms thy use. The narrow content is that part of their thought that remains identical, through the identity of the way things appear, no matter these differences of surroundings. Partisans of wide . . . ‘as, something called broadly, content may doubt whether any content is in this sense narrow, partisans of narrow content believe that it is the fundamental notion, with wide content being of narrow content plus context.
All and all, assuming their rationality has characterized people is common, and the most evident display of our rationality is capable to think. This is the rehearsal in the mind of what to say, or what to do. Not all thinking is verbal, since chess players, composers, and painters all think, and there is no deductive reason that their deliberations should take any more verbal a form than their actions. It is permanently tempting to conceive of this activity as for the presence in the mind of elements of some language, or other medium that represents aspects of the world and its surrounding surface structures. Nevertheless, they have attacked the model, notably by Ludwig Wittgenstein (1889-1951), whose influential application of these ideas was in the philosophy of mind. Wittgenstein explores the role that report of introspection, or sensations, or intentions, or beliefs actually play our social lives, to undermine the Cartesian picture that functionally describes the goings-on in an inner theatre of which the subject is the lone spectator. Passages that have subsequentially become known as the ‘rule following’ considerations and the ‘private language argument’ are among the fundamental topics of modern philosophy of language and mind, although their precise interpretation is endlessly controversial.
Effectively, the hypotheses especially associated with Jerry Fodor (1935-), whom is known for the ‘resolute realism’, about the nature of mental functioning, that occurs in a language different from one’s ordinary native language, but underlying and explaining our competence with it. The idea is a development of the notion of an innate universal grammar (Chomsky), in as such, that we agree that since a computer programs are linguistically complex sets of instructions were the relative executions by which explains of surface behaviour or the adequacy of the computerized programming installations, if it were definably amendable and, advisably corrective, in that most are disconcerting of many that are ultimately a reason for ‘us’ of thinking intuitively and without the indulgence of retrospective preferences, but an ethical majority in defending of its moral line that is already confronting ‘us’. That these programs may or may not improve to conditions that are lastly to enhance of the right a type of existence posted exactly to position of something for its nature in so that make it believed, and imposes on seizing the defensive quality value amounts in humanities lesser extensions that embrace one’s riff of necessity to humanities’ suspension to express in the determined qualities.
As of an ordinary language-learning and competence, the hypothesis has not found universal favour, as only ordinary representational powers that by invoking the image of the learning person’s capabilities are apparently whom the abilities for translating are contending of an innate language whose own powers are mysteriously a biological given. Perhaps, the view that everyday attributions of intentionality, beliefs, and meaning to other persons act by means of a tactic use of a theory that enables one to construct these interpretations as s of their doings. We have commonly held the view along with ‘functionalism’, according to which psychological states are theoretical entities, identified by the network of their causes and effects. The theory-theory has different implications, depending upon which feature of theories is being stressed. We may think of theories as capable of formalization, as yielding predictions and, as achieved by a process of theorizing, as answering to empirical evidence that is in principle describable without them, as liable to be overturned by newer and better theories, and so on.
The main problem with seeing our understanding of others as the outcome of a piece of theorizing is the nonexistence of a medium in which we can couch this theory, as the child learns simultaneously the minds of others and the meaning of terms in its native language, is not gained by the tactic use of a ‘theory’, enabling ‘us’ to imply what thoughts or intentions explain their actions, but by realizing the situation ‘in their shoes’ or from their point of view, and by that understanding what they experienced and theory, and therefore expressed. We achieve understanding others when we can ourselves deliberate as they did, and hear their words as if they are our own. The suggestion is a modern development usually associated in the ‘Verstehen’ traditions of Dilthey (1833-1911), Weber (1864-1920) and Collingwood (1889-1943).
We may call any process of drawing a conclusion from a set of premises a process of reasoning. If the conclusion concerns what to do, the process is called practical reasoning, otherwise pure or theoretical reasoning. Evidently, such processes may be good or bad, if they are good, the premises support or even entail the conclusion drawn, and if they are bad, the premises offer no support to the conclusion. Formal logic studies the cases in which conclusions are validly drawn from premises, but little human reasoning is overly of the forms logicians identify. Partly, we are concerned to draw conclusions that ‘go beyond’ our premises, in the way that conclusions of logically valid arguments do not for the process of using evidence to reach a wider conclusion. However, such anticipatory pessimism about the prospects of conformation theory, denying that we can assess the results of abduction as to probability.
Some inciting historians feel that there were four contributions to the theory of probability that overshadowed all the rest. The first was the work of Jacob Bernoulli, and the second De Moivre’s, Doctrine of Chances, the third dealt with Bayes’ Inverse Probability, and the fourth was the outstanding work by LaPlace. In fact, it was LaPlace himself who gave the classic ‘definition’ of probability-if an event can result in ‘n’ equally likely outcomes, then the probability of such an event ‘E’ is the ratio of the number of outcomes favourable to ‘E’ to the total number of outcomes.
A process of reasoning in which a conclusion is drawn from a set of premises usually confined to cases in which the conclusions are supposed in following from the premises, i.e., the inference is logically valid, in that of deductibility in a logically defined syntactic premise but without there being to any reference to the intended interpretation of its theory. Moreover, as we reason we use the indefinite lore or commonsense set of presuppositions about what it is likely or not a task of an automated reasoning project, which is to mimic this causal use of knowledge of the way of the world in computer programs.
Some ‘theories’ usually emerge as a component position, such as those presented by truth-values determined by truth values of a component thesis, in so doing, the imaginative formation of the metal act is or should be perpetuated of the form or actual existence in the mind for being real nor as it presents itself to the senses as for being non-real, supposed truths that are not organized, making the theory difficult to survey or study as a whole. The axiomatic method is an idea for organizing a theory, one in which tries to select from among the supposed truths a small number from which they can see all others to be deductively inferable. This makes the theory moderately tractable since, in a sense, we have contained all truths in those few. In a theory so organized, we have called the few truths from which we have deductively inferred all others ‘axioms’. David Hilbert (1862-1943) had argued that, just as algebraic and differential equations, which we were used to study mathematical and physical processes, could they be made mathematical objects, so axiomatic theories, like algebraic and differential equations, which are means to representing physical processes and mathematical structures could be of investigation.
According to theory, the philosophy of science, is a generalization or set referring to unobservable entities, e.g., atoms, genes, quarks, unconscious wishes. The ideal gas law, for example, refers only to such observables as pressure, temperature, and volume, the ‘molecular-kinetic theory’ refers to molecules and their properties, . . . although an older usage suggests the lack of adequate evidence in support of it (merely a theory), current philosophical usage does in fact follow in the tradition (as in Leibniz, 1704), as many philosophers had the conviction that all truths, or all truths about a particular domain, followed from as few than for being the greater of governing principles, These self-aggrandizing principles, taken to be either metaphysically prior or epistemologically prior or both. In the first sense, they we took to be entities of such a nature that what exists s ‘caused’ by them. When we took the principles as epistemologically prior, that is, as ‘axioms’, we took them to be either epistemologically privileged, e.g., self-evident, not needing to be demonstrated, or again, included ‘or’, to such that all truths so indeed follow from them, by deductive inferences. Gödel (1984) showed in the spirit of Hilbert, treating axiomatic theories as themselves mathematical objects that mathematics, and even a small part of mathematics, elementary number theory, could not be axiomatized, that more precisely, any class of axioms that is such that we could effectively decide, of any proposition, whether or not it was in that class, would be too small to capture in of the truths.
The notion of truth occurs with remarkable frequency in our reflections on language, thought and action. We are inclined to suppose, for example, that truth is the proper aim of scientific inquiry, that true beliefs help to achieve our goals, that to understand a sentence is to know which circumstances would make it true, that reliable preservation of truth as one argues of valid reasoning, that moral pronouncements should not be regarded as objectively true, and so on. To assess the plausibility of such theses, and to refine them and to explain why they hold (if they do), we require some view of what truth be a theory that would account for its properties and its relations to other matters. Thus, there can be little prospect of understanding our most important faculties in the sentence of a good theory of truth.
The most influential idea in the theory of meaning in the past hundred years is the thesis that the meaning of an indicative sentence is given by its truth-conditions. On this conception, to understand a sentence is to know of its truth-condition. The conception was first clearly formulated by Frége, was developed in a distinctive way by the early Wittgenstein, and is a leading idea of Davidson. The conception has remained so central that those who offer opposing theories characteristically define their position by reference to it.
The conception of meaning as truth-conditions needs not and should not be advanced for being a complete account of meaning. For instance, one who understands a language must have some idea of the range of speech acts conventionally acted by the various types of sentences in the language, and must have some idea of the significance of various kinds of speech acts. The claim of the theorist of truth-conditions should be targeted on the notion of content: If two indicative sentences differ in what they strictly and literally say, then this difference is fully accounted for by the difference in their truth-conditions.
The meaning of a complex expression depends on the meaning of its constituent. This is simply a conscionable statement of what it is for an expression to be semantically complex. It is one initial attraction of the conception of meaning as truth-conditions that it permits a smooth and satisfying account of the way in which the meaning of a complex expression is function of meaning of its constituents. On the truth-conditional conception, to give the meaning of an expression is to state the contribution it makes to the truth-conditions of a sentence in which it occurs. For singular terms-proper names, indexicals, and certain pronouns-this is done by stating the reference of the term in question. For predicates, it is done either by stating the conditions under which the predicate is true of arbitrary objects, or by stating the conditions under which arbitrary atomic sentences containing it is true. The meaning of a sentence-forming operator is given by stating its contribution to the truth-conditions of a complete sentence, as a function of the semantic values of the sentences on which it operates.
Among the many challenges facing the theorist of truth conditions, two are particularly salient and fundamental. First, the theorist has to answer the charge of triviality or vacuity. Second, the theorist must offer an account of what it is for a person’s language to be truly described by a semantic theory containing a given semantic axiom.
We can take the charge of triviality first, since the content of a claim that the sentence ‘Paris is beautiful’ is true and amounts to no more than the claim that Paris is beautiful, we can trivially describe understanding a sentence, if we wish, as knowing its truth-conditions, but this gives us no substantive account of understanding whatsoever. Something other than the grasp of truth conditions must provide the substantive account. The charge rests upon what has been called the redundancy theory of truth, the theory that, is somewhat more discriminatively, Horwich calls the minimal theory of true. The minimal theory states that the concept of truth is exhausted by the fact that it conforms to the equivalence principle, the principle that for any proposition ‘p’. It is true that ‘p’ if and only if ‘p’. Many different philosophical theories of truth will, with suitable qualifications, accept that equivalence principle. The distinguishing feature of the minimal theory is its claim that the equivalence principle exhausts the notion of truth. It is now widely accepted, both by opponents and supporters of truth conditional theories of meaning, that it is inconsistent to accept both the minimal theory of truth and a truth conditional account of meaning. In the claim that the sentence, ‘Paris is beautiful’ is true that Paris is beautiful, it is circular to try to explain the sentence’s meaning under its truth conditions. The minimal theory of truth has been endorsed by Ramsey, Ayer, the later Wittgenstein, Quine, Srawson, Horwich, and -confusingly and inconsistently if this is correct- Frége himself. But is the minimal theory correct?
The minimal theory treats instances of the equivalence principle as definitional truth for a given sentence. But in fact it seems that each instance of the equivalence principle can itself be explained. The truth from which such a condition would occur as:
‘London is beautiful’ is true if and only if London is beautiful.
This would be a pseudo-explanation if the fact that ‘London’ refers to London consists in part in the fact that ‘London is beautiful’ has the truth-condition it does. But that is very implausible: It is, after all, possible to align itself with the name, ‘London’ without understanding the predicate ‘is beautiful’.
The defender of the minimalist theory is likely to say that if a sentence ‘S’ of a foreign language is best translated by our sentencer ‘p’, then the foreign sentence ‘S’ is true if and only if ‘p’. Now the best translation of a sentence must preserve the concepts expressed in the sentence. Constraints involving a general notion of truth are pervasive in a plausible philosophical theory of concepts. It is, for example, a condition of adequacy on an individuating account of any concept that there exits what is called a ‘Determination Theory’ for the account-that is, a specification of how the account contributes to fixing the semantic value of that concept. The notion of a concept’s semantic value is the notion of something that makes a certain contribution to the truth conditions of thoughts in which the concept occurs. But this is to presuppose, than to elucidate, a general notion of truth.
It is also plausible that there are general constraints on the form in Determination Theories, constraints that involve truth which is not derivable from the minimalist’s conception. Supposed that concepts are individuated by their possession condition. One such plausible general constraint is then the requirement that when a thinker forms beliefs involving a concept according to its possession condition, a semantic value belief are assigned to the concept so that the belief is true. Some general principles involving truth can indeed, as Horwich has emphasized, be derived from the equivalence schema using minimal logical apparatus. Consider, for instance, the principle that ‘Paris is beautiful and London is beautiful’ is true if and only if ‘Paris is beautiful’ is true and ‘London is beautiful’ is true. This follows logically from the three instances of the equivalence principle: ‘Paris is beautiful and London is beautiful’ is true if and only if Paris is beautiful and London is beautiful: ‘Paris is beautiful’ is true if and only if Paris is beautiful: And ‘London is beautiful’ is true if and only if London is beautiful. But no logical manipulations of the equivalence schema will allow the derivation of that general constraint governing possession conditions, truth and the assignment of semantic values. That constraint can, of course, be regarded as a further elaboration of the idea that truth is one of the aims of judgement.
What is it for a person’s language to be correctly describable by a semantic theory containing a particular axiom? This question may be addressed at two depths of generality. At the shallower level, the question may take for granted the person’s possession of the concept of conjunction, and be concerned with what has to be true for the axiom to describe his language correctly. At a deeper level, an answer should not duck the issue of what it is to possess the concept. The answers to both questions are of great interest. When a person mans conjunction by ‘and’, he could not formulate the axiom. Even if he can formulate it, his ability to formulate it is not the casual basis of his capacity to hear sentences containing the word ‘and’ as meaning something involving conjunction by sentences he utters containing the word ‘and’. Is it then right to regard a truth theory as part of an unconscious psychological computation, and to regard understanding a sentence involving a particular way of deriving a theorem from a truth theory at some level of unconscious processing? One problem with this is that it is quite implausible that everyone who speaks the same language has to use the same algorithms for computing the meaning of a sentence. In the past thirteen years, a conception has evolved according to which an axiom is true of a person’s language only if there is a common component in the explanation of his understanding of each sentence containing the word ‘and’, a common component that explains why each such sentence is understood as meaning something involving conjunction (Davies, 1987). What conception can also be elaborated in computational terms? It is to suggest for an axiom to be true of a person’s language is for the unconscious mechanisms that produce understanding to draw n the information that a sentence of the form ‘A’ and ‘B’ are true if and only if ‘A’ is true and ‘B’ is true (Peacocke, 1986). Many different algorithms may equally draw on this information. The psychological reality of a semantic theory thus involves, in Marr’s (1982) classification, something intermediate between his level one, the function computed, and his level two, the algorithm by which it is computed. Thus, its conception of the psychological reality of a semantic theory can be applied to syntactic and phonological theories. Theories in semantics, syntax and phonology are not themselves required to specifically particular algorithms that the language user employs. The identification of the particular computational methods employed is a task for psychology. But semantic, syntactic and phonological theorists are answerable to psychological data, and are potentially refutable by them-for these linguistic theories do make commitments to the information drawn upon by mechanisms in the language user.
This answer to the question of what it is for an axiom to be true of a person’s language clearly takes for granted the person’s possession of the concept expressed by the word translated by the axiom. In this example, the information drawn upon is those sentences of the form ‘A’ and ‘B’ are true if and only if ‘A’ is true and ‘B’ is true. This informational content employs, as I, to am adequate, the concept of conjunction used in stating the meaning of sentences containing ‘and’. So the computational answer we have returned needs further elaboration if we are to address the deeper question, which does not want to take for granted possession of the concepts expressed in the language. It is at this point is the theory of linguistic understanding to draw upon a theory of concepts. This is only part of what is involved in the required dovetailing. Given what we have already said about the uniform explanation of the understanding of the various occurrences of a given weird, we should also add that there is a uniform (unconscious, computational) explanation of the language user’s willingness to make the corresponding transition involving the sentence ‘A’ and ‘B’.
Our thinking, and our perceptions of the world about us, is limited by the nature of the language that our culture employs, instead of language possessing, as had previously been widely assumed, much less significant, purely instrumental, function in our living. Human beings do not live in the objective world alone, nor alone in the world social activity as ordinarily understood, but are very much at the mercy of the particular language that has become the medium of expression for their society. It is quite an illusion to imagine that language is merely an incidental means of solving specific problems of communication or reflection. The consideration is that the ‘real world’ is, largely, unconsciously built up on the language habits of the group, we see and hear and otherwise we experience very largely as we do because the language habits of our community predispose certain choices of interpretation.
Such a thing, however, has been notoriously elusive. The ancient idea that truth is some sort of ‘correspondence with reality’ has still never been articulated satisfactorily, and the nature of the alleged ‘correspondence’ and the alleged ‘reality’ remain objectionably obscure. Yet the familiar alternative suggestions that true beliefs are those that are ‘mutually coherent’, or ‘pragmatically useful’, or ‘verifiable in suitable conditions’ has each been confronted with persuasive counterexamples. A twentieth-century departure from these traditional analyses is the view that truth is not a property at all that the syntactic form of the predicate, ‘is true’, distorts its really semantic character, which is not to describe propositions but to endorse them. However, this radical approach is also faced with difficulties and suggests, quasi counter intuitively, that truth cannot have the vital theoretical role in semantics, epistemology and elsewhere that we are naturally inclined to give it. Thus, truth threatens to remain one of the most enigmatic of notions: An explicit account of it can seem essential yet beyond our reach. However, recent work provides some grounds for optimism.
We have based a theory in philosophy of science, is a generalization or set as concerning observable entities, i.e., atoms, quarks, unconscious wish, and so on. The ideal gas law, for example, refers only to such observables as pressure, temperature, and volume, the molecular-kinetic theory refers top molecules and their properties, although an older usage suggests the lack of adequate evidence in support of it (merely a theory), progressive toward its sage; the usage does not carry that connotation. Einstein’s special; Theory of relativity, for example, is considered extremely well founded.
These are two main views on the nature of theories. According to the ‘received view’ theories are partially interpreted axiomatic systems, according to the semantic view, a theory is a collection of models (Suppe, 1974). Under which, some theories usually emerge as exemplifying or occurring in fact, from which are we to find on practical matters and concern of experiencing the real world, nonetheless, that it of supposed truths that are not neatly organized, making the theory difficult to survey or study as a whole. The axiomatic method is an ideal for organizing a theory (Hilbert, 1970), one tries to select from among the supposed truths a small number from which all the others can be seen to be deductively inferable. This makes the theory more tractable since, in a sense, they contain all truth’s in those few. In a theory so organized, they call the few truths from which they deductively infer all others ‘axioms’. David Hilbert (1862-1943) had argued that, just as algebraic and differential equations, which were used to study mathematical and physical processes, could they be made mathematical objects, so we could make axiomatic theories, like algebraic and differential equations, which are means of representing physical processes and mathematical structures, objects of mathematical investigation.
Many philosophers had the conviction that all truths, or all truths about a particular domain, followed from a few principles. These principles were taken to be either metaphysically prior or epistemologically prior or both. In the first sense, we took them to be entities of such a nature that what exists is ‘caused’ by them. When we took the principles as epistemologically prior, that is, as ‘axioms’, we took them to be either epistemologically privileged, i.e., self-evident, not needing to be demonstrated, or again, inclusive ‘or’, to be such that all truths do indeed follow from them, by means of deductive inferences. Gödel (1984) showed in the spirit of Hilbert, treating axiomatic theories as themselves mathematical objects that mathematics, and even a small part. Of mathematics, elementary number theory, could not be axiomatized, that, more precisely, any class of axioms that is such that we could effectively decide, of any proposition, whether or not it was in that class, would be too small to capture all of the truths.
The notion of truth occurs with remarkable frequency in our reflections on language, thought, and action. We are inclined to suppose, for example, that truth is the proper aim of scientific inquiry, that true beliefs help ‘us’ to achieve our goals, that to understand a sentence is to know which circumstances would make it true, that reliable preservation of truth as one argues from premises to a conclusion is the mark of valid reasoning, that we should not regard moral pronouncements as objectively true, and so on. To assess the plausible of such theses, and to refine them and to explain why they hold (if they do), we require some view of what truth be a theory that would account for its properties and its relations to other matters. Thus, there can be little prospect of understanding our most important faculties lacking a good theory of truth.
The nature of the alleged ‘correspondence’ and the alleged ‘reality remains objectivably obscures’. Yet, the familiar alternative suggests, ~ that true beliefs are those that are ‘mutually coherent’, or ‘pragmatically useful’, or ‘they establish by induction of each to a confronted verifiability in some suitable conditions with persuasive counterexamples. A twentieth-century departure from these traditional analyses is the view that truth is not a property at all ~. That the syntactic form of the predicate, ‘is true’, distorts its really semantic character, which is not to describe propositions but to endorse them. Nevertheless, they have also faced this radical approach with difficulties and suggest, a counter intuitively, that truth cannot have the vital theoretical role in semantics, epistemology and elsewhere that we are naturally inclined to give it. Thus, truth threatens to remain one of the most enigmatic of notions, and an explicit account of it can seem essential yet, beyond our reach. However, recent work provides some grounds for optimism.
The belief that snow is white owes its truth to a certain feature of the external world, namely, to the fact that snow is white. Similarly, the belief that dogs bark is true because of the fact that dogs bark. This trivial observation leads to what is perhaps the most natural and popular account of truth, the ‘correspondence theory’, according to which a belief (statement, a sentence, propositions, etc.) as true just in case there exists a fact corresponding to it (Wittgenstein, 1922). This thesis is unexceptionably for finding out whether one should account of truth are that it is clearly compared with the correspondence theory, and that it succeeds in connecting truth with verification. However, if it is to provide a rigorous, substantial and complete theory of truth ~. If it is to be more than merely a picturesque way of asserting all equivalences to the form:
The belief that ‘p’ is ‘true p’.
Then we must supplement it with accounts of what facts are, and what it is for a belief to correspond to a fact, and these are the problems on which the correspondence theory of truth has foundered. For one thing, it is far form clear that reducing ‘the belief achieves any significant gain in understanding that ‘snow is white is true’ to ‘the facts that ‘snow is white’ exists’: For these expressions seem equally resistant to analysis and too close in meaning for one to provide an illuminating account of the other. In addition, the general relationship that holds in particular between the belief that snow is white and the simple fact is, that snow is white, between the belief that dogs bark and the fact that dogs bark, and so on, is very hard to identify. The best attempt to date is Wittgenstein’s (1922) so-called ‘picture theory’, under which an elementary proposition is a configuration of terms, with whatever stare of affairs it reported, as an atomic fact is a configuration of simple objects, an atomic fact corresponds to an elementary proposition (and makes it true) when their configurations are identical and when the terms in the proposition for it to the similarly-placed objects in the fact, and the truth value of each complex proposition the truth values of the elementary ones have entailed. However, even if this account is correct as far as it goes, it would need to be completed with plausible theories of ‘logical configuration’, ‘elementary proposition’, ‘reference’ and ‘entailment’, none of which is easy to come by way of the central characteristic of truth. One that any adequate theory must explain is that when a proposition satisfies its ‘conditions of proof or verification’, then it is regarded as true. To the extent that the property of corresponding with reality is mysterious, we are going to find it impossible to see what we take to verify a proposition should indicate the possession of that property. Therefore, a tempting alternative to the correspondence theory an alternative that eschews obscure, metaphysical concept which explains quite straightforwardly why Verifiability implies, truth is simply to identify truth with verifiability (Peirce, 1932). This idea can take on variously formed. One version involves the further assumption that verification is ‘holistic’, i.e., that of a belief is justified (i.e., turn over evidence of the truth) when it is part of an entire system of beliefs that are consistent and ‘harmonious’ (Bradley, 1914 and Hempel, 1935). We have known this as the ‘coherence theory of truth’. Another version involves the assumption associated with each proposition, some specific procedure for finding out whether one should on sensing and responding to the definitive qualities or stare of being actual or true, such that a person, an entity, or an event, that is actually might be gainfully to employ the totality of things existent of possessing actuality or essence. On this account, to say that a proposition is true is to sa that the appropriate procedure would verify (Dummett, 1979, and Putnam, 1981). From mathematics this amounts to the identification of truth with probability.
The attractions of the verificationist account of truth are that it is refreshingly clear compared with the correspondence theory, and that it succeeds in connecting truth with verification. The trouble is that the bond it postulates between these notions is implausibly strong. We do indeed take verification to indicate truth, but also we recognize the possibility that a proposition may be false in spite of there being impeccable reasons to believe it, and that a proposition may be true although we are not able to discover that it is. Verifiability and ruth are no doubt highly correlated, but surely not the same thing.
A well-known account of truth is known as ‘pragmatism’ (James, 1909 and Papineau, 1987). As we have just seen, the verificationist selects a prominent property of truth and considers it the essence of truth. Similarly, the pragmatist focuses on another important characteristic namely, that true belief is a good basis for action and takes this to be the very nature of truth. We have said that true assumptions were, by definition, those that provoke actions with desirable results. Again, we have an account with a single attractive explanatory feature, but again, it postulates between truth and its alleged analysand then, utility is implausibly close. Granted, true belief tends to foster success, but it happens regularly that actions based on true beliefs lead to disaster, while false assumptions, by pure chance, produce wonderful results.
One of the few uncontroversial facts about truth is that the proposition that snow is white if and only if snow is white, the proposition that lying is wrong is true if and only if lying is wrong, and so on. Traditional theories acknowledge this fact but regard it as insufficient and, as we have seen, inflate it with some further principle of the form, ‘x is true’ if and only if ‘x’ has property ‘p’ (such as corresponding to reality, Verifiability, or being suitable as a basis for action), which is supposed to specify what truth is. Some radical alternatives to the traditional theories result from denying the need for any such further specification (Ramsey, 1927, Strawson, 1950 and Quine, 1990). For example, ne might suppose that the basic theory of truth contains nothing more that equivalences of the form, ‘The proposition that ‘p’ is true if and only if ‘p’ (Horwich, 1990).
This sort of proposal is best presented with an account of the ‘raison de étre’ of our notion of truth, namely that it enables ‘us ’ to express attitudes toward these propositions we can designate but not explicitly formulate. Suppose, for example, they tell you that Einstein’s last words expressed a claim about physics, an area in which you think he was very reliable. Suppose that, unknown to you, his claim was the proposition whose quantum mechanics are wrong. What conclusion can you draw? Exactly which proposition becomes the appropriate object of your belief? Surely not that quantum mechanics are wrong, because you are not aware that is what he said. What we have needed is something equivalent to the infante conjunction:
If what Einstein said was that E = mc2, then E = mc2,
and if that he said as that Quantum mechanics were
wrong, then Quantum mechanics are wrong
. . . . And so on?
That is, a proposition, ‘K’ with the following properties, that from ‘K’ and any further premises of the form. ‘Einstein’s claim was the proposition that p’ you can infer p’. Whatever it is. Now suppose, as the deflationist says, that our understanding of the truth predicate consists in the stimulative decision to accept any instance of the schema. ‘The proposition that ‘p; is true if and only if ‘p’, then we have solved your problem. For ‘K’ is the proposition, ‘Einstein’s claim is true ’, it will have precisely the inferential power that we have needed. From it and ‘Einstein’s claim is the proposition that quantum mechanics are wrong’, you can use Leibniz’s law to infer ‘The proposition that quantum mechanic is wrong is true, which given the relevant axiom of the deflationary theory, allows you to derive ‘Quantum mechanics is wrong’. Thus, one point in favour of the deflationary theory is that it squares with a plausible story about the function of our notion of truth, in that its axioms explain that function without the need for further analysis of ‘what truth ‘is’.
Not all variants of deflationism have this virtue, according to the redundancy performative theory of truth, implicate a pair of sentences, ‘The proposition that ‘p’ is true’ and plain ‘p’s’, has the same meaning and expresses the same statement as one and another, so it is a syntactic illusion to think that p is true’ attributes any sort of property to a proposition (Ramsey, 1927 and Strawson, 1950). Nonetheless, it becomes hard to explain why we are entitled to infer ‘The proposition that quantum mechanics are wrong is true’ form ‘Einstein’s claim is the proposition that quantum mechanics are wrong. ‘Einstein’s claim is true’. For if truth is not property, then we can no longer account for the inference by invoking the law that if ‘x’, appears identical with ‘Y’ then any property of ‘x’ is a property of ‘Y’, and vice versa. Thus the redundancy/performative theory, by identifying rather than merely correlating the contents of ‘The proposition that ‘p’ is true’ and ‘p’, precludes the prospect of a good explanation of one on truth’s most significant and useful characteristics. So restricting our claim to the ineffectually weak, accedes of a favourable Equivalence schematic: The proposition that ‘p’ is true is and is only ‘p’.
Support for deflationism depends upon the possibility of showing that its axiom instances of the equivalence schema non-supplements by any further analysis, will suffice to explain all the central facts about truth, for example, that the verification of a proposition indicates its truth, and that true beliefs have a practical value. The first of these facts follows trivially from the deflationary axioms, for given a deductive assimilation to knowledge of the equivalence of ‘p’ and ‘The proposition that ‘p is true’, any reason to believe that ‘p’ becomes an equally good reason to believe that the preposition that ‘p’ is true. We can also explain the second fact as to the deflationary axioms, but not quite so easily. Consider, to begin with, beliefs of the form:
(B) If I perform the act ‘A’, then my desires will be fulfilled.
Notice that the psychological role of such a belief is, roughly, to cause the performance of ‘A’. In other words, gave that I do have belief (B), then typically.
I will perform the act ‘A’
Notice also that when the belief is true then, given the deflationary axioms, the performance of ‘A’ will in fact lead to the fulfilment of one’s desires, i.e.,
If (B) is true, then if I perform ‘A’, my desires will be fulfilled
Therefore:
If (B) is true, then my desires will be fulfilled
So valuing the truth of beliefs of that form is quite reasonable. Nevertheless, inference derives such beliefs from other beliefs and can be expected to be true if those other beliefs are true. So valuing the truth of any belief that might be used in such an inference is reasonable.
To the extent that they can give such deflationary accounts of all the acts involving truth, then the collection will meet the explanatory demands on a theory of truth of all statements like, ‘The proposition that snow is white is true if and only if snow is white, and we will undermine the sense that we need some deep analysis of truth.
Nonetheless, there are several strongly felt objections to deflationism. One reason for dissatisfaction is that the theory has many axioms, and therefore cannot be completely written down. It can be described as the theory whose axioms are the propositions of the fore ‘p if and only if it is true that p’, but not explicitly formulated. This alleged defect has led some philosophers to develop theories that show, first, how the truth of any proposition derives from the referential properties of its constituents, and second, how the referential properties of primitive constituents are determined (Tarski, 1943 and Davidson, 1969). However, assuming that all propositions including belief attributions remain controversial, law of nature and counterfactual conditionals depends for their truth values on what their constituents refer to. Moreover, there is no immediate prospect of a decent, finite theory of reference, so that it is far form clear that the infinite, that we can avoid list-like character of deflationism.
Another source of dissatisfaction with this theory is that certain instances of the equivalence schema are clearly false. Consider.
(a) THE PROPOSITION EXPRESSED BY THE SENTENCE
IN CAPITAL LETTERS IN NOT TRUE.
Substituting this into the schema one gets a version of the ‘liar’ paradox: Specifically: (b) The proposition that the proposition expressed by the
sentence in capital letters is not true is true if and only if the proposition expressed by the sentence in capital letters are not true,
From which a contradiction is easily derivable. (Given (b), the supposition that (a) is true implies that (a) is not true, and the supposition that it is not true that it is.) Consequently, not every instance of the equivalence schema can be included in the theory of truth, but it is no simple matter to specify the ones to be excluded. In "Naming and Necessity" (1980), Kripler gave the classical modern treatment of the topic reference, both clarifying the distinction between names and definite descriptions, and opening the door to many subsequent attempts to understand the notion of reference in terms and an original episode of attaching a name to a subject. Of course, deflationism is far from alone in having to confront this problem.
A third objection to the version of the deflationary theory presented here concerns its reliance on ‘propositions’ as the basic vehicles of truth. It is widely felt that the notion of the proposition is defective and that we should not employ it in semantics. If this point of view is accepted then the natural deflationary reaction is to attempt a reformation that would appeal only to sentences, for example:
‘p’ is true if and only if p.
Nevertheless, this so-called ‘disquotational theory of truth’ (Quine, 1990) has trouble over indexicals, demonstratives and other terms whose referents vary with the context of use. It is not true, for example, that every instance of ‘I am hungry’ is true and only if ‘I am hungry’. There is no simple way of modifying the disquotational schema to accommodate this problem. A possible way of these difficulties is to resist the critique of propositions. Such entities may exhibit an unwelcome degree of indeterminancy, and might defy reduction to familiar items, however, they do offer a plausible account of belief, as relations to propositions, and, in ordinary language at least, we indeed take them to be the primary bearers of truth. To believe a proposition is too old for it to be true. The philosophical problem includes discovering whether belief differs from other varieties of assent, such as ‘acceptance’, discovering to what extent degrees of belief are possible, understanding the ways in which belief is controlled by rational and irrational factors, and discovering its links with other properties, such as the possession of conceptual or linguistic skills. This last set of problems includes the question of whether they have properly said that pre-linguistic infants or animals have beliefs.
Additionally, it is commonly supposed that problems about the nature of truth are intimately bound up with questions as to the accessibility and autonomy of facts in various domains: Questions about whether we can know the facts, and whether they can exist independently of our capacity to discover them (Dummett, 1978, and Putnam, 1981). One might reason, for example, that if ‘t is true’ means’ nothing more than ‘t will be verified’, then certain forms of scepticism, specifically, those that doubt the correctness of our methods of verification, that will be precluded, and that the facts will have been revealed as dependent on human practices. Alternatively, we might say that if truth were an inexplicable, primitive, non-epistemic property, then the fact that ‘t’ is true would be completely independent of ‘us’. Moreover, we could, there, have no reason to assume that the propositions we believe actually have tis property, so scepticism would be unavoidable. In a similar vein, we might think that as special, and perhaps undesirable features of the deflationary approach, is that we have deprived truth of such metaphysical or epistemological implications.
At this point, we now turn to a philosophy of and truth, for which it is especially associated with the American philosopher of science and of language (1839-1914), and the American psychologist philosopher William James (1842-1910), wherefore the study in Pragmatism is given to various formulations by both writers, but the core is the belief that the meaning of a doctrine is the same as the practical effects of adapting it. Peirce interpreted of theocratical sentence ids only that of a corresponding practical maxim (telling us what to do in some circumstance). In James the position issues in a theory of truth, notoriously allowing that belief, including for example, belief in God, is the widest sense of the works satisfactorily in the widest sense of the word. On James”s view almost any belief might be respectable, and even rue, provided it works (but working is no simple matter for James). The apparently subjectivist consequences of tis were wildly assailed by Russell (1872-1970), Moore (1873-1958), and others in the early years of the 20 century. This led to a division within pragmatism between those such as the American educator John Dewey (1859-1952), whose humanistic conception of practice remains inspired by science, and the more idealistic route that especially by the English writer F.C.S. Schiller (1864-1937), embracing the doctrine that our cognitive efforts and human needs actually transform the reality that we seek to describe. James often writes as if he sympathizes with this development. For instance, in The Meaning of Truth (1909), he considers the hypothesis that other people have no minds (dramatized in the sexist idea of an “automatic sweetheart” or female zombie) and remarks hat the hypothesis would not work because it would not satisfy our egoistic craving for the recognition and admiration of others. The implication that this is what makes it true that the other persons have minds in the disturbing part.
Modern pragmatists such as the American philosopher and critic Richard Rorty (1931-) and some writings of the philosopher Hilary Putnam (1925-) who has usually tried to dispense with an account of truth and concentrate, as perhaps James should have done, upon the nature of belief and its relations with human attitude, emotion, and need. The driving motivation of pragmatism is the idea that belief in the truth on te one hand must have a close connection with success in action on the other. One way of cementing the connection is found in the idea that natural selection must have adapted us to be cognitive creatures because beliefs have effects, as they work. Pragmatism can be found in Kant”s doctrine of the primary of practical over pure reason, and continued to play an influential role in the theory of meaning and of truth.
In case of fact, the philosophy of mind is the modern successor to behaviourism, as do the functionalism that its early advocates were Putnam (1926-) and Sellars (1912-89), and its guiding principle is that we can define mental states by a triplet of relations they have on other mental stares, what effects they have on behaviour. The definition need not take the form of a simple analysis, but if w could write down the totality of axioms, or postdate, or platitudes that govern our theories about what things of other mental states, and our theories about what things are apt to cause (for example), a belief state, what effects it would have on a variety of other mental states, and what affects it is likely to have on behaviour, then we would have done all that is needed to make the state a proper theoretical notion. It could be implicitly defied by these theses. Functionalism is often compared with descriptions of a computer, since according to mental descriptions correspond to a description of a machine in terms of software, that remains silent about the underlaying hardware or “realization” of the program the machine is running. The principal advantage of functionalism includes its fit with the way we know of mental states both of ourselves and others, which is via their effects on behaviour and other mental states. As with behaviourism, critics charge that structurally complex items that do not bear mental states might nevertheless, imitate the functions that are cited. According to this criticism functionalism is too generous and would count too many things as having minds. It is also queried whether functionalism is too paradoxical, able to see mental similarities only when there is causal similarity, when our actual practices of interpretations enable us to ascribe thoughts and desires to differently from our own, it may then seem as though beliefs and desires can be “variably realized” causal architecture, just as much as they can be in different neurophysiological states.
The philosophical movement of Pragmatism had a major impact on American culture from the late 19th century to the present. Pragmatism calls for ideas and theories to be tested in practice, by assessing whether acting upon the idea or theory produces desirable or undesirable results. According to pragmatists, all claims about truth, knowledge, morality, and politics must be tested in this way. Pragmatism has been critical of traditional Western philosophy, especially the notions that there are absolute truths and absolute values. Although pragmatism was popular for a time in France, England, and Italy, most observers believe that it encapsulates an American faith in know-how and practicality and an equally American distrust of abstract theories and ideologies.
In mentioning the American psychologist and philosopher we find William James, who helped to popularize the philosophy of pragmatism with his book Pragmatism: A New Name for Old Ways of Thinking (1907). Influenced by a theory of meaning and verification developed for scientific hypotheses by American philosopher C. S. Peirce, James held that truths are what works, or has good experimental results. In a related theory, James argued the existence of God is partly verifiable because many people derive benefits from believing.
The Association for International Conciliation first published a William James”s pacifist statement, “The Moral Equivalent of War,” in 1910. James, a highly respected philosopher and psychologist, was one of the founders of pragmatism-a philosophical movement holding that ideas and theories must be tested in practice to assess their worth. James hoped to find a way to convince men with a long-standing history of pride and glory in war to evolve beyond the need for bloodshed and to develop other avenues for conflict resolution. Spelling and grammars represent standards of the time.
Pragmatists regard all theories and institutions as tentative hypotheses and solutions. For this reason they believed that efforts to improve society, through such means as education or politics, must be geared toward problem solving and must be ongoing. Through their emphasis on connecting theory to practice, pragmatist thinkers attempted to transform all areas of philosophy, from metaphysics to ethics and political philosophy.
Pragmatism sought a middle ground between traditional ideas about the nature of reality and radical theories of nihilism and irrationalism, which had become popular in Europe in the late 19th century. Traditional metaphysics assumed that the world has a fixed, intelligible structure and that human beings can know absolute or objective truths about the world and about what constitutes moral behavior. Nihilism and irrationalism, on the other hand, denied those very assumptions and their certitude. Pragmatists today still try to steer a middle course between contemporary offshoots of these two extremes.
The ideas of the pragmatists were considered revolutionary when they first appeared. To some critics, pragmatism”s refusal to affirm any absolutes carried negative implications for society. For example, pragmatists do not believe that a single absolute idea of goodness or justice exists, but rather than these concepts are changeable and depend on the context in which they are being discussed. The absence of these absolutes, critics feared, could result in a decline in moral standards. The pragmatists” denial of absolutes, moreover, challenged the foundations of religion, government, and schools of thought. As a result, pragmatism influenced developments in psychology, sociology, education, semiotics (the study of signs and symbols), and scientific method, as well as philosophy, cultural criticism, and social reform movements. Various political groups have also drawn on the assumptions of pragmatism, from the progressive movements of the early 20th century to later experiments in social reform.
Pragmatism is best understood in its historical and cultural context. It arose during the late 19th century, a period of rapid scientific advancement typified by the theories of British biologist Charles Darwin, whose theories suggested too many thinkers that humanity and society are in a perpetual state of progress. During this same period a decline in traditional religious beliefs and values accompanied the industrialization and material progress of the time. In consequence it became necessary to rethink fundamental ideas about values, religion, science, community, and individuality.
The three most important pragmatists are American philosophers” Charles Sanders Peirce, William James, and John Dewey. Peirce was primarily interested in scientific method and mathematics; his objective was to infuse scientific thinking into philosophy and society, and he believed that human comprehension of reality was becoming ever greater and that human communities were becoming increasingly progressive. Peirce developed pragmatism as a theory of meaning-in particular, the meaning of concepts used in science. The meaning of the concept “brittle”, for example, is given by the observed consequences or properties that objects called “brittle” exhibit. For Peirce, the only rational way to increase knowledge was to form mental habits that would test ideas through observation, experimentation, or what he called inquiry. Many philosophers known as logical positivist, a group of philosophers who have been influenced by Peirce, believed that our evolving species was fated to get ever closer to Truth. Logical positivist emphasize the importance of scientific verification, rejecting the assertion of positivism that personal experience is the basis of true knowledge.
James moved pragmatism in directions that Peirce strongly disliked. He generalized Peirce”s doctrines to encompass all concepts, beliefs, and actions; he also applied pragmatist ideas to truth as well as to meaning. James was primarily interested in showing how systems of morality, religion, and faith could be defended in a scientific civilization. He argued that sentiment, as well as logic, is crucial to rationality and that the great issues of life-morality and religious belief, for example-are leaps of faith. As such, they depend upon what he called “the will to believe” and not merely on scientific evidence, which can never tell us what to do or what is worthwhile. Critics charged James with relativism (the belief that values depend on specific situations) and with crass expediency for proposing that if an idea or action works the way one intends, it must be right. But James can more accurately be described as a pluralist-someone who believes the world to be far too complex for any one philosophy to explain everything.
Dewey”s philosophy can be described as a version of philosophical naturalism, which regards human experience, intelligence, and communities as ever-evolving mechanisms. Using their experience and intelligence, Dewey believed, human beings can solve problems, including social problems, through inquiry. For Dewey, naturalism led to the idea of a democratic society that allows all members to acquire social intelligence and progress both as individuals and as communities. Dewey held that traditional ideas about knowledge, truth, and values, in which absolutes are assumed, are incompatible with a broadly Darwinian world-view in which individuals and society is progressing. In consequence, he felt that these traditional ideas must be discarded or revised. Indeed, for pragmatists, everything people know and do depend on a historical context and are thus tentative rather than absolute.
Many followers and critics of Dewey believe he advocated elitism and social engineering in his philosophical stance. Others think of him as a kind of romantic humanist. Both tendencies are evident in Dewey”s writings, although he aspired to synthesize the two realms.
The pragmatists” tradition was revitalized in the 1980s by American philosopher Richard Rorty, who has faced similar charges of elitism for his belief in the relativism of values and his emphasis on the role of the individual in attaining knowledge. Interest has renewed in the classic pragmatists-Pierce, James, and Dewey-have an alternative to Rorty”s interpretation of the tradition.
The Philosophy of Mind, is the branch of philosophy that considers mental phenomena such as sensation, perception, thought, belief, desire, intention, memory, emotion, imagination, and purposeful action. These phenomena, which can be broadly grouped as thoughts and experiences, are features of human beings; many of them are also found in other animals. Philosophers are interested in the nature of each of these phenomena as well as their relationships to one another and to physical phenomena, such as motion.
The most famous exponent of dualism was the French philosopher René Descartes, who maintained that body and mind are radically different entities and that they are the only fundamental substances in the universe. Dualism, however, does not show how these basic entities are connected.
In the work of the German philosopher Gottfried Wilhelm Leibniz, the universe is held to consist of an infinite number of distinct substances, or monad. This view is pluralistic in the sense that it proposes the existence of many separate entities, and it is monistic in its assertion that each monad reflects within itself the entire universe.
Other philosophers have held that knowledge of reality is not derived from a priori principles, but is obtained only from experience. This type of metaphysic is called empiricism. Still another school of philosophy has maintained that, although an ultimate reality does exist, it is altogether inaccessible to human knowledge, which is necessarily subjective because it is confined to states of mind. Knowledge is therefore not a representation of external reality, but merely a reflection of human perceptions. This view is known as skepticism or agnosticism in respect to the soul and the reality of God.
The 18th-century German philosopher Immanuel Kant published his influential work The Critique of Pure Reason in 1781. Three years later, he expanded on his study of the modes of thinking with an essay entitled “What is Enlightenment?” In this 1784 essay, Kant challenged readers to “dare to know,” arguing that it was not only a civic but also a moral duty to exercise the fundamental freedoms of thought and expression.
Several major viewpoints were combined in the work of Kant, who developed a distinctive critical philosophy called transcendentalism. His philosophy is agnostic in that it denies the possibility of a strict knowledge of ultimate reality; it is empirical in that it affirms that all knowledge arises from experience and is true of objects of actual and possible experience; and it is rationalistic in that it maintains the a priori character of the structural principles of this empirical knowledge.
These principles are held to be necessary and universal in their application to experience, for in Kant”s view the mind furnishes the archetypal forms and categories (space, time, causality, substance, and relation) to its sensations, and these categories are logically anterior to experience, although manifested only in experience. Their logical anteriority to experience makes these categories or structural principle”s transcendental; they transcend all experience, both actual and possible. Although these principles determine all experience, they do not in any way affect the nature of things in themselves. The knowledge of which these principles are the necessary conditions must not be considered, therefore, as constituting a revelation of things as they are in themselves. This knowledge concerns things only insofar as they appear to human perception or as they can be apprehended by the senses. The argument by which Kant sought to fix the limits of human knowledge within the framework of experience and to demonstrate the inability of the human mind to penetrate beyond experience strictly by knowledge to the realm of ultimate reality constitutes the critical feature of his philosophy, giving the key word to the titles of his three leading treatises, Critique of Pure Reason, Critique of Practical Reason, and Critique of Judgment. In the system propounded in these works, Kant sought also to reconcile science and religion in a world of two levels, comprising noumena, objects conceived by reason although not perceived by the senses, and phenomena, things as they appear to the senses and are accessible to material study. He maintained that, because God, freedom, and human immortality are noumenal realities, these concepts are understood through moral faith rather than through scientific knowledge. With the continuous development of science, the expansion of metaphysics to include scientific knowledge and methods became one of the major objectives of metaphysicians.
Some of Kant”s most distinguished followers, notably Johann Gottlieb Fichte, Friedrich Schelling, Georg Wilhelm Friedrich Hegel, and Friedrich Schleiermacher, negated Kant”s criticism in their elaborations of his transcendental metaphysics by denying the Kantian conception of the thing-in-itself. They thus developed an absolute idealism in opposition to Kant”s critical transcendentalism.
Since the formation of the hypothesis of absolute idealism, the development of metaphysics has resulted in as many types of metaphysical theory as existed in pre-Kantian philosophy, despite Kant”s contention that he had fixed definitely the limits of philosophical speculation. Notable among these later metaphysical theories is radical empiricism, or pragmatism, a native American form of metaphysics expounded by Charles Sanders Peirce, developed by William James, and adapted as instrumentalism by John Dewey; voluntarism, the foremost exponents of which are the German philosopher Arthur Schopenhauer and the American philosopher Josiah Royce; phenomenalism, as it is exemplified in the writings of the French philosopher Auguste Comte and the British philosopher Herbert Spencer; emergent evolution, or creative evolution, originated by the French philosopher Henri Bergson; and the philosophy of the organism, elaborated by the British mathematician and philosopher Alfred North Whitehead. The salient doctrines of pragmatism are that the chief function of thought is to guide action, that the meaning of concepts is to be sought in their practical applications, and that truth should be tested by the practical effects of belief; according to instrumentalism, ideas are instruments of action, and their truth is determined by their role in human experience. In the theory of voluntarism the will is postulated as the supreme manifestation of reality. The exponents of phenomenalism, who are sometimes called positivist, contend that everything can be analyzed in terms of actual or possible occurrences, or phenomena, and that anything that cannot be analyzed in this manner cannot be understood. In emergent or creative evolution, the evolutionary process is characterized as spontaneous and unpredictable rather than mechanistically determined. The philosophy of the organism combines an evolutionary stress on constant process with a metaphysical theory of God, the eternal objects, and creativity.
In the 20th century the validity of metaphysical thinking has been disputed by the logical positivist and by the so-called dialectical materialism of the Marxists. The basic principle maintained by the logical positivist is the verifiability theory of meaning. According to this theory a sentence has factual meaning only if it meets the test of observation. Logical positivist argue that metaphysical expressions such as “Nothing exists except material particles” and “Everything is part of one all-encompassing spirit” cannot be tested empirically. Therefore, according to the verifiability theory of meaning, these expressions have no factual cognitive meaning, although they can have an emotive meaning relevant to human hopes and feelings.
The dialectical materialists assert that the mind is conditioned by and reflects material reality. Therefore, speculations that conceive of constructs of the mind as having any other than material reality are themselves unreal and can result only in delusion. To these assertions metaphysicians reply by denying the adequacy of the verifiability theory of meaning and of material perception as the standard of reality. Both logical positivism and dialectical materialism, they argue, conceal metaphysical assumptions, for example, that everything is observable or at least connected with something observable and that the mind has no distinctive life of its own. In the philosophical movement known as existentialism, thinkers have contended that the questions of the nature of being and of the individual”s relationships to it are extremely important and meaningful in terms of human life. The investigation of these questions is therefore considered valid whether its results can be verified objectively.
Since the 1950s the problems of systematic analytical metaphysics have been studied in Britain by Stuart Newton Hampshire and Peter Frederick Strawson, the former concerned, in the manner of Spinoza, with the relationship between thought and action, and the latter, in the manner of Kant, with describing the major categories of experience as they are embedded in language. In the U.S. metaphysics has been pursued much in the spirit of positivism by Wilfred Stalker Sellars and Willard Van Orman Quine. Sellars have sought to express metaphysical questions in linguistic terms, and Quine has attempted to determine whether the structure of language commits the philosopher to asserting the existence of any entities whatever and, if so, what kind. In these new formulations the issues of metaphysics and ontology remain vital.
In the 17th century, French philosopher René Descartes proposed that only two substances ultimately exist; mind and body. Yet, if the two are entirely distinct, as Descartes believed, how can one substance interact with the other? How, for example, is the intention of a human mind able to cause movement in the person”s limbs? The issue of the interaction between mind and body is known in philosophy as the mind-body problem.
Many fields other than philosophy shares an interest in the nature of mind. In religion, the nature of mind is connected with various conceptions of the soul and the possibility of life after death. In many abstract theories of mind there is considerable overlap between philosophy and the science of psychology. Once part of philosophy, psychology split off and formed a separate branch of knowledge in the 19th century. While psychology used scientific experiments to study mental states and events, philosophy uses reasoned arguments and thought experiments in seeking to understand the concepts that underlie mental phenomena. Also influenced by philosophy of mind is the field of artificial intelligence (AI), which endeavors to develop computers that can mimic what the human mind can do. Cognitive science attempts to integrate the understanding of mind provided by philosophy, psychology, AI, and other disciplines. Finally, all of these fields benefit from the detailed understanding of the brain that has emerged through neuroscience in the late 20th century.
Philosophers use the characteristics of inward accessibility, subjectivity, intentionality, goal-directedness, creativity and freedom, and consciousness to distinguish mental phenomena from physical phenomena.
Perhaps the most important characteristic of mental phenomena is that they are inwardly accessible, or available to us through introspection. We each know our own minds-our sensations, thoughts, memories, desires, and fantasies-in a direct sense, by internal reflection. We also know our mental states and mental events in a way that no one else can. In other words, we have privileged access to our own mental states.
Certain mental phenomena, those we generally call experiences, have a subjective nature-that is, they have certain characteristics we become aware of when we reflect. For instance, there is “something it is like” to feel pain, or have an itch, or see something red. These characteristics are subjective in that they are accessible to the subject of the experience, the person who has the experience, but not to others.
Other mental phenomena, which we broadly refer to as thoughts, have a characteristic philosophers call intentionality. Intentional thoughts are about other thoughts or objects, which are represented as having certain properties or for being related to one another in a certain way. The belief that California is west of Nevada, for example, is about California and Nevada and represents the former for being west of the latter. Although we have privileged access to our intentional states, many of them do not seem to have a subjective nature, at least not in the way that experiences do.
A number of mental phenomena appear to be connected to one another as elements in an intelligent, goal-directed system. The system works as follows: First, our sense organs are stimulated by events in our environment; next, by virtue of these stimulations, we perceive things about the external world; finally, we use this information, as well as information we have remembered or inferred, to guide our actions in ways that further our goals. Goal-directedness seems to accompany only mental phenomena.
Another important characteristic of mind, especially of human minds, is the capacity for choice and imagination. Rather than automatically converting past influences into future actions, individual minds are capable of exhibiting creativity and freedom. For instance, we can imagine things we have not experienced and can act in ways that no one expects or could predict.
Mental phenomena are conscious, and consciousness may be the closest term we have for describing what is special about mental phenomena. Minds are sometimes referred to as consciousness, yet it is difficult to describe exactly what consciousness is. Although consciousness is closely related to inward accessibility and subjectivity, these very characteristics seem to hinder us in reaching an objective scientific understanding of it.
Although philosophers have written about mental phenomena since ancient times, the philosophy of mind did not garner much attention until the work of French philosopher René Descartes in the 17th century. Descartes”s work represented a turning point in thinking about mind by making a strong distinction between bodies and minds, or the physical and the mental. This duality between mind and body, known as Cartesian dualism, has posed significant problems for philosophy ever since.
Descartes believed there are two basic kinds of things in the world, a belief known as substance dualism. For Descartes, the principles of existence for these two groups of things-bodies and minds-are completely different from one another: Bodies exist by being extended in space, while minds exist by being conscious. According to Descartes, nothing can be done to give a body thought and consciousness. No matter how we shape a body or combine it with other bodies, we cannot turn the body into a mind, a thing that is conscious, because being conscious is not a way of being extended.
For Descartes, a person consists of a human body and a human mind causally interacting with one another. For example, the intentions of a human being may cause that person's limbs to move. In this way, the mind can affect the body. In addition, the sense organs of a human being maybe affected by light, pressure, or sound, external sources, which in turn affect the brain, affecting mental states. Thus, the body may affect the mind. Exactly how mind can affect body, and vice versa, is a central issue in the philosophy of mind, and is known as the mind-body problem. According to Descartes, this interaction of mind and body is peculiarly intimate. Unlike the interaction between a pilot and his ship, the connection between mind and body more closely resembles two substances that have been thoroughly mixed together.
In response to the mind-body problem arising from Descartes”s theory of substance dualism, a number of philosophers have advocated various forms of substance monism, the doctrine that there is ultimately just one kind of thing in reality. In the 18th century, Irish philosopher George Berkeley claimed there were no material objects in the world, only minds and their ideas. Berkeley thought that talk about physical objects was simply a way of organizing the flow of experience. Near the turn of the 20th century, American psychologist and philosopher William James proposed another form of substance monism. James claimed that experience is the basic stuff from which both bodies and minds are constructed.
Most philosophers of mind today are substance monists of a third type: They are materialists who believe that everything in the world is basically material, or a physical object. Among materialists, there is still considerable disagreement about the status of mental properties, which are conceived as properties of bodies or brains. Materialists who are property diarists believe that mental properties are an additional kind of property or attribute, not reducible to physical properties. Property dualists have the problem of explaining how such properties can fit into the world envisaged by modern physical science, according to which there are physical explanations for all things.
Materialists who are property monists believe that there is ultimately only one type of property, although they disagree on whether or not mental properties exist in material form. Some property monists, known as reductive materialists, hold that mental properties exist simply as a subset of relatively complex and nonbasic physical properties of the brain. Reductive materialists have the problem of explaining how the physical states of the brain can be inwardly accessible and have a subjective character, as mental states do. Other property monists, known as eliminative materialists, consider the whole category of mental properties to be a mistake. According to them, mental properties should be treated as discredited postulates of an outmoded theory. Eliminative materialism is difficult for most people to accept, since we seem to have direct knowledge of our own mental phenomena by introspection and because we use the general principles we understand about mental phenomena to predict and explain the behavior of others.
Philosophy of mind concerns itself with a number of specialized problems. In addition to the mind-body problem, important issues include those of personal identity, immortality, and artificial intelligence.
During much of Western history, the mind has been identified with the soul as presented in Christian Theology. According to Christianity, the soul is the source of a person”s identity and is usually regarded as immaterial; thus, it is capable of enduring after the death of the body. Descartes”s conception of the mind as a separate, nonmaterial substance fits well with this understanding of the soul. In Descartes”s view, we are aware of our bodies only as the cause of sensations and other mental phenomena. Consequently our personal essence is composed more fundamentally of mind and the preservation of the mind after death would constitute our continued existence.
The mind conceived by materialist forms of substance monism does not fit as neatly with this traditional concept of the soul. With materialism, once a physical body is destroyed, nothing enduring remains. Some philosophers think that a concept of personal identity can be constructed that permits the possibility of life after death without appealing to separate immaterial substances. Following in the tradition of 17th-century British philosopher John Locke, these philosophers propose that a person consists of a stream of mental events linked by memory. It is these links of memory, rather than a single underlying substance, that provides the unity of a single consciousness through time. Immortality is conceivable if we think of these memory links as connecting a later consciousness in heaven with an earlier one on earth.
The field of artificial intelligence also raises interesting questions for the philosophy of mind. People have designed machines that mimic or model many aspects of human intelligence, and there are robots currently in use whose behavior is described in terms of goals, beliefs, and perceptions. Such machines are capable of behavior that, were it exhibited by a human being, would surely be taken to be free and creative. As an example, in 1996 an IBM computer named Deep Blue won a chess game against Russian world champion Garry Kasparov under international match regulations. Moreover, it is possible to design robots that have some sort of privileged access to their internal states. Philosophers disagree over whether such robots truly think or simply appear to think and whether such robots should be considered to be conscious
Dualism, in philosophy, the theory that the universe is explicable only as a whole composed of two distinct and mutually irreducible elements. In Platonic philosophy the ultimate dualism is between “being” and “nonbeing”-that is, between ideas and matter. In the 17th century, dualism took the form of belief in two fundamental substances: mind and matter. French philosopher René Descartes, whose interpretation of the universe exemplifies this belief, was the first to emphasize the irreconcilable difference between thinking substance (mind) and extended substance (matter). The difficulty created by this view was to explain how mind and matter interact, as they apparently do in human experience. This perplexity caused some Cartesians to deny entirely any interaction between the two. They asserted that mind and matter are inherently incapable of affecting each other, and that any reciprocal action between the two is caused by God, who, on the occasion of a change in one, produces a corresponding change in the other. Other followers of Descartes abandoned dualism in favor of monism.
In the 20th century, reaction against the monistic aspects of the philosophy of idealism has to some degree revived dualism. One of the most interesting defenses of dualism is that of Anglo-American psychologist William McDougall, who divided the universe into spirit and matter and maintained that good evidence, both psychological and biological, indicates the spiritual basis of physiological processes. French philosopher Henri Bergson in his great philosophic work Matter and Memory likewise took a dualistic position, defining matter as what we perceive with our senses and possessing in itself the qualities that we perceive in it, such as color and resistance. Mind, on the other hand, reveals itself as memory, the faculty of storing up the past and utilizing it for modifying our present actions, which otherwise would be merely mechanical. In his later writings, however, Bergson abandoned dualism and came to regard matter as an arrested manifestation of the same vital impulse that composes life and mind.
Dualism, in philosophy, the theory that the universe is explicable only as a whole composed of two distinct and mutually irreducible elements. In Platonic philosophy the ultimate dualism is between “being” and “nonbeing-that is, between ideas and matter. In the 17th century, dualism took the form of belief in two fundamental substances: mind and matter. French philosopher René Descartes, whose interpretation of the universe exemplifies this belief, was the first to emphasize the irreconcilable difference between thinking substance (mind) and extended substance (matter). The difficulty created by this view was to explain how mind and matter interact, as they apparently do in human experience. This perplexity caused some Cartesians to deny entirely any interaction between the two. They asserted that mind and matter are inherently incapable of affecting each other, and that any reciprocal action between the two is caused by God, who, on the occasion of a change in one, produces a corresponding change in the other. Other followers of Descartes abandoned dualism in favor of monism.
In the 20th century, reaction against the monistic aspects of the philosophy of idealism has to some degree revived dualism. One of the most interesting defenses of dualism is that of Anglo-American psychologist William McDougall, who divided the universe into spirit and matter and maintained that good evidence, both psychological and biological, indicates the spiritual basis of physiological processes. French philosopher Henri Bergson in his great philosophic work Matter and Memory likewise took a dualistic position, defining matter as what we perceive with our senses and possessing in itself the qualities that we perceive in it, such as color and resistance. Mind, on the other hand, reveals itself as memory, the faculty of storing up the past and utilizing it for modifying our present actions, which otherwise would be merely mechanical. In his later writings, however, Bergson abandoned dualism and came to regard matter as an arrested manifestation of the same vital impulse that composes life and mind.
For many people understanding the place of mind in nature is the greatest philosophical problem. Mind is often though to be the last domain that stubbornly resists scientific understanding and philosophers defer over whether they find that cause for celebration or scandal. The mind-body problem in the modern era was given its definitive shape by Descartes, although the dualism that he espoused is in some form whatever there is a religious or philosophical tradition there is a religious or philosophical tradition whereby the soul may have an existence apart from the body. While most modern philosophers of mind would reject the imaginings that lead us to think that this makes sense, there is no consensus over the best way to integrate our understanding of people as bearers of physical properties lives on the other
Occasionalism finds from it terms as employed to designate the philosophical system devised by the followers of the 17th-century French philosopher René Descartes, who, in attempting to explain the interrelationship between mind and body, concluded that God is the only cause. The occasionalists began with the assumption that certain actions or modifications of the body are preceded, accompanied, or followed by changes in the mind. This assumed relationship presents no difficulty to the popular conception of mind and body, according to which each entity is supposed to act directly on the other; these philosophers, however, asserting that cause and effect must be similar, could not conceive the possibility of any direct mutual interaction between substances as dissimilar as mind and body.
According to the occasionalists, the action of the mind is not, and cannot be, the cause of the corresponding action of the body. Whenever any action of the mind takes place, God directly produces in connection with that action, and by reason of it, a corresponding action of the body; the converse process is likewise true. This theory did not solve the problem, for if the mind cannot act on the body (matter), then God, conceived as mind, cannot act on matter. Conversely, if God is conceived as other than mind, then he cannot act on mind. A proposed solution to this problem was furnished by exponents of radical empiricism such as the American philosopher and psychologist William James. This theory disposed of the dualism of the occasionalists by denying the fundamental difference between mind and matter.
Generally, along with consciousness, that experience of an external world or similar scream or other possessions, takes upon itself the visual experience or deprive of some normal visual experience, that this, however, does not perceive the world accurately. In its frontal experiment. As researchers reared kittens in total darkness, except that for five hours a day the kittens were placed in an environment with only vertical lines. When the animals were later exposed to horizontal lines and forms, they had trouble perceiving these forms.
Philosophers have long debated the role of experience in human perception. In the late 17th century, Irish philosopher William Molyneux wrote to his friend, English philosopher John Locke, and asked him to consider the following scenario: Suppose that you could restore sight to a person who was blind. Using only vision, would that person be able to tell the difference between a cube and a sphere, which she or he had previously experienced only through touch? Locke, who emphasized the role of experience in perception, thought the answer was no. Modern science actually allows us to address this philosophical question, because a very small number of people who were blind have had their vision restored with the aid of medical technology.
Two researchers, British psychologist Richard Gregory and British-born neurologists” Oliver Sacks, have written about their experiences with men who were blind for a long time due to cataracts and then had their vision restored late in life. When their vision was restored, they were often confused by visual input and were unable to see the world accurately. For instance, they could detect motion and perceive colors, but they had great difficulty with complex stimuli, such as faces. Much of their poor perceptual ability was probably due to the fact that the synapses in the visual areas of their brains had received little or no stimulation throughout their lives. Thus, without visual experience, the visual system does not develop properly.
Visual experience is useful because it creates memories of past stimuli that can later serve as a context for perceiving new stimuli. Thus, you can think of experience as a form of context that you carry around with you. A visual illusion occurs when your perceptual experience of a stimulus is substantially different from the actual stimulus you are viewing. In the previous example, you saw the green circles as different sizes, even though they were actually the same size. To experience another illusion, look at the illustration entitled “Zöllner Illusion.” What shape do you see? You may see a trapezoid that is wider at the top, but the actual shape is a square. Such illusions are natural artifacts of the way our visual systems work. As a result, illusions provide important insights into the functioning of the visual system. In addition, visual illusions are fun to experience.
Consider the pair of illusions in the accompanying illustration, “Illusions of Length.” These illusions are called geometrical illusions, because they use simple geometrical relationships to produce the illusory effects. The first illusion, the Müller-Lyer illusion, is one of the most famous illusions in psychology. Which of the two horizontal lines is longer? Although your visual system tells you that the lines are not equal, a ruler would tell you that they are equal. The second illusion is called the Ponzo illusion. Once again, the two lines do not appear to be equal in length, but they are.
Prevailing states of consciousness, are not as simple, or agreed-upon by any steadfast and held definition of itself, in so, that, consciousness exists. Attempted definitions tend to be tautological (for example, consciousness defined s awareness) or merely descriptive (for example, consciousness described as sensations, thoughts, or feelings). Despite this problem of definition, the subject of consciousness has had a remarkable history. At one time the primary subject matter of psychology, consciousness as an area of study suffered an almost total demise, later reemerging to become a topic of current interest.
René Descartes applied rigorous scientific methods of deduction to his exploration of philosophical questions. Descartes is probably best known for his pioneering work in philosophical skepticism. Author Tom Sorell examines the concepts behind Descartes”s work Meditationes de Prima Philosophia (1641; Meditations on First Philosophy), focusing on its unconventional use of logic and the reactions it aroused. Most of the philosophical discussions of consciousness arose from the mind-body issues posed by the French philosopher and mathematician René Descartes in the 17th century. Descartes asked: Is the mind, or consciousness, independent of matter? Is consciousness extended (physical) or unextended (nonphysical)? Is consciousness determinative, or is it determined? English philosophers such as John Locke equated consciousness with physical sensations and the information they provide, whereas European philosophers such as Gottfried Wilhelm Leibniz and Immanuel Kant gave a more central and active role to consciousness.
The philosopher who most directly influenced subsequent exploration of the subject of consciousness was the 19th-century German educator Johann Friedrich Herbart, who wrote that ideas had quality and intensity and that they may inhibit or facilitate one another. Thus, ideas may pass from “states of reality” (consciousness) to “states of tendency” (unconsciousness), with the dividing line between the two states being described as the threshold of consciousness. This formulation of Herbart clearly presages the development, by the German psychologist and physiologist Gustav Theodor Fechner, of the psychophysical measurement of sensation thresholds, and the later development by Sigmund Freud of the concept of the unconscious.
The experimental analysis of consciousness dates from 1879, when the German psychologist Wilhelm Max Wundt started his research laboratory. For Wundt, the task of psychology was the study of the structure of consciousness, which extended well beyond sensations and included feelings, images, memory, attention, duration, and movement. Because early interest focused on the content and dynamics of consciousness, it is not surprising that the central methodology of such studies was introspection; that is, subjects reported on the mental contents of their own consciousness. This introspective approach was developed most fully by the American psychologist Edward Bradford Titchener at Cornell University. Setting his task as that of describing the structure of the mind, Titchener attempted to detail, from introspective self-reports, the dimensions of the elements of consciousness. For example, taste was “dimensionalized” into four basic categories: sweet, sour, salt, and bitter. This approach was known as structuralism.
By the 1920s, however, a remarkable revolution had occurred in psychology that was to essentially remove considerations of consciousness from psychological research for some 50 years: Behaviorism captured the field of psychology. The main initiator of this movement was the American psychologist John Broadus Watson. In a 1913 article, Watson stated, “I believe that we can write a psychology and never use the term”s consciousness, mental states, mind . . . imagery and the like.” Psychologists then turned almost exclusively to behavior, as described in terms of stimulus and response, and consciousness was totally bypassed as a subject. A survey of eight leading introductory psychology texts published between 1930 and the 1950s found no mention of the topic of consciousness in five texts, and in two it was treated as a historical curiosity.
Beginning in the late 1950s, however, interest in the subject of consciousness returned, specifically in those subjects and techniques relating to altered states of consciousness: sleep and dreams, meditation, biofeedback, hypnosis, and drug-induced states. Much of the surge in sleep and dream research was directly fueled by a discovery relevant to the nature of consciousness. A physiological indicator of the dream state was found: At roughly 90-minute intervals, the eyes of sleepers were observed to move rapidly, and at the same time the sleepers” brain waves would show a pattern resembling the waking state. When people were awakened during these periods of rapid eye movement, they almost always reported dreams, whereas if awakened at other times they did not. This and other research clearly indicated that sleep, once considered a passive state, were instead an active state of consciousness.
During the 1960s, an increased search for “higher levels” of consciousness through meditation resulted in a growing interest in the practices of Zen Buddhism and Yoga from Eastern cultures. A full flowering of this movement in the United States was seen in the development of training programs, such as Transcendental Meditation, that were self-directed procedures of physical relaxation and focused attention. Biofeedback techniques also were developed to bring body systems involving factors such as blood pressure or temperature under voluntary control by providing feedback from the body, so that subjects could learn to control their responses. For example, researchers found that persons could control their brain-wave patterns to some extent, particularly the so-called alpha rhythms generally associated with a relaxed, meditative state. This finding was especially relevant to those interested in consciousness and meditation, and a number of “alpha training” programs emerged.
Another subject that led to increased interest in altered states of consciousness was hypnosis, which involves a transfer of conscious control from the subject to another person. Hypnotism has had a long and intricate history in medicine and folklore and has been intensively studied by psychologists. Much has become known about the hypnotic state, relative to individual suggestibility and personality traits; the subject has now largely been demythologized, and the limitations of the hypnotic state are fairly well known. Despite the increasing use of hypnosis, however, much remains to be learned about this unusual state of focused attention.
Finally, many people in the 1960s experimented with the psychoactive drugs known as hallucinogens, which produce disorders of consciousness. The most prominent of these drugs are lysergic acid diethylamide, or LSD; mescaline, and psilocybin; the latter two have long been associated with religious ceremonies in various cultures. LSD, because of its radical thought-modifying properties, was initially explored for its so-called mind-expanding potential and for its psychotomimetic effects (imitating psychoses). Little positive use, however, has been found for these drugs, and their use is highly restricted.
As the concept of a direct, simple linkage between environment and behavior became unsatisfactory in recent decades, the interest in altered states of consciousness may be taken as a visible sign of renewed interest in the topic of consciousness. That persons are active and intervening participants in their behavior has become increasingly clear. Environments, rewards, and punishments are not simply defined by their physical character. Memories are organized, not simply stored. An entirely new area called cognitive psychologies have emerged that centers on these concerns. In the study of children, increased attention is being paid to how they understand, or perceive, the world at different ages. In the field of animal behavior, researchers increasingly emphasize the inherent characteristics resulting from the way a species has been shaped to respond adaptively to the environment. Humanistic psychologists, with a concern for self-actualization and growth, have emerged after a long period of silence. Throughout the development of clinical and industrial psychology, the conscious states of persons in terms of their current feelings and thoughts were of obvious importance. The role of consciousness, however, was often deemphasized in favor of unconscious needs and motivations. Trends can be seen, however, toward a new emphasis on the nature of states of consciousness.
Perception (psychology), spreads of a process by which organisms interpret and organize sensation to produce a meaningful experience of the world. Sensation usually refers to the immediate, relatively unprocessed result of stimulation of sensory receptors in the eyes, ears, nose, tongue, or skin. Perception, on the other hand, better describes one”s ultimate experience of the world and typically involves further processing of sensory input. In practice, sensation and perception are virtually impossible to separate, because they are part of one continuous process.
Our sense organs translate physical energy from the environment into electrical impulses processed by the brain. For example, light, in the form of electromagnetic radiation, causes receptor cells in our eyes to activate and send signals to the brain. But we do not understand these signals as pure energy. The process of perception allows us to interpret them as objects, events, people, and situations.
Without the ability to organize and interpret sensations, life would seem like a meaningless jumble of colors, shapes, and sounds. A person without any perceptual ability would not be able to recognize faces, understand language, or avoid threats. Such a person would not survive for long. In fact, many species of animals have evolved exquisite sensory and perceptual systems that aid their survival.
Organizing raw sensory stimuli into meaningful experiences involves cognition, a set of mental activities that includes thinking, knowing, and remembering. Knowledge and experience are extremely important for perception, because they help us make sense of the input to our sensory systems. To understand these ideas, try to read the following passage:
You could probably read the text, but not as easily as when you read letters in their usual orientation. Knowledge and experience allowed you to understand the text. You could read the words because of your knowledge of letter shapes, and maybe you even have some prior experience in reading text upside down. Without knowledge of letter shapes, you would perceive the text as meaningless shapes, just as people who do not know Chinese or Japanese see the characters of those languages as meaningless shapes. Reading, then, is a form of visual perception.
Note that as above, whereby you did not stop to read every single letter carefully. Instead, you probably perceived whole words and phrases. You may have also used context to help you figure out what some of the words must be. For example, recognizing the upside may have helped you predict down, because the two words often occur together. For these reasons, you probably overlooked problems with the individual letters-some of them, such as the n in down, are mirror images of normal letters. You would have noticed these errors immediately if the letters were right side up, because you have much more experience seeing letters in that orientation.
How people perceive a well-organized pattern or whole, instead of many separate parts, is a topic of interest in Gestalt psychology. According to Gestalt psychologists, the whole is different from the sum of its parts. Gestalt is a German word meaning configuration or pattern.
The three founders of Gestalt psychology were German researcher’s Max Wertheimer, Kurt Koffka, and Wolfgang Köhler. These men identified a number of principles by which people organize isolated parts of a visual stimulus into groups or whole objects. There are five main laws of grouping: proximity, similarity, continuity, closure, and common fate. A sixth law, that of simplicity, encompasses all of these laws.
Although most often applied to visual perception, the Gestalt laws also apply to perception in other senses. When we listen to music, for example, we do not hear a series of disconnected or random tones. We interpret the music as a whole, relating the sounds to each other based on how similar they are in pitch, how close together they are in time, and other factors. We can perceive melodies, patterns, and form in music. When a song is transposed to another key, we still recognize it, even though all of the notes have changed.
The law of proximity states that the closer objects are to one another, the more likely we are to mentally group them together. In the illustration below, we perceive as groups the boxes that are closest to one another. Note that we do not see the second and third boxes from the left as a pair, because they are spaced farther apart.
The law of similarity leads us to link together parts of the visual field that are similar in color, lightness, texture, shape, or any other quality. That is why, in the following illustration, we perceive rows of objects instead of columns or other arrangements.
The law of continuity leads us to see a line as continuing in a particular direction, rather than making an abrupt turn. In the drawing on the left below, we see a straight line with a curved line running through it. Notice that we do not see the drawing as consisting of the two pieces in the drawing on the right.
According to the law of closure, we prefer complete forms to incomplete forms. Thus, in the drawing below, we mentally close the gaps and perceive a picture of a duck. This tendency allows us to perceive whole objects from incomplete and imperfect forms.
The law of common fate leads us to group together objects that move in the same direction. In the following illustration, imagine that three of the balls are moving in one direction, and two of the balls are moving in the opposite direction. If you saw these in actual motion, you would mentally group the balls that moved in the same direction. Because of this principle, we often see flocks of birds or schools of fish as one unit.
Central to the approach of Gestalt psychologists is the law of prägnanz, or simplicity. This general notions, which encompasses all other Gestalt laws, states that people intuitively prefer the simplest, most stable of possible organizations. For example, look at the illustration below. You could perceive this in a variety of ways: as three overlapping disks; as one whole disk and two partial disks with slices cut out of their right sides; or even as a top view of three-dimensional, cylindrical objects. The law of simplicity states that you will see the illustration as three overlapping disks, because that is the simplest interpretation.
Not only does perception involve organization and grouping, it also involves distinguishing an object from its surroundings. Notice that once you perceive an object, the area around that object becomes the background. For example, when you look at your computer monitor, the wall behind it becomes the background. The object, or figure, is closer to you, and the background, or ground, is farther away.
Gestalt psychologists have devised ambiguous figure-ground relationships-that is, drawings in which the figure and ground can be reversed-to illustrate their point that the whole is different from the sum of its parts. Consider the accompanying illustration entitled “Figure and Ground.” You may see a white vase as the figure, in which case you will see it displayed on a dark ground. However, you may also see two dark faces that point toward one another. Notice that when you do so, the white area of the figure becomes the ground. Even though your perception may alternate between these two possible interpretations, the parts of the illustration are constant. Thus, the illustration supports the Gestalt position that the whole is not determined solely by its parts. The Dutch artist M. C. Escher was intrigued by ambiguous figure-ground relationships.
Although such illustrations may fool our visual systems, people are rarely confused about what they see. In the real world, vases do not change into faces as we look at them. Instead, our perceptions are remarkably stable. Considering that we all experience rapidly changing visual input, the stability of our perceptions is more amazing than the occasional tricks that fool our perceptual systems. How we perceive, a stable world is due, in part, to a number of factors that maintain perceptual constancy.
As we view an object, the image it projects on the retinas of our eyes changes with our viewing distance and angle, the level of ambient light, the orientation of the object, and other factors. Perceptual constancy allows us to perceive an object as roughly the same in spite of changes in the retinal image. Psychologists have identified a number of perceptual consistencies, including lightness constancy, color constancy, shape constancy, and size constancy.
Lightness constancy means that our perception of an object”s lightness or darkness remains constant despite changes in illumination. To understand lightness constancy, try the following demonstration. First, take a plain white sheet of paper into a brightly lit room and note that the paper appears to be white. Then, turn out a few of the lights in the room. Note that the paper continues to appear white. Next, if it will not make the room pitch black, turn out some more lights. Note that the paper appears to be white regardless of the actual amount of light energy that enters the eye.
Lightness constancy illustrates an important perceptual principle: Perception is relative. Lightness constancy may occur because the white piece of paper reflects more light than any of the other objects in the room-regardless of the different lighting conditions. That is, you may have determined the lightness or darkness of the paper relative to the other objects in the room. Another explanation, proposed by 19th-century German physiologist Hermann von Helmholtz, is that we unconsciously take the lighting of the room into consideration when judging the lightness of objects.
Color constancy is closely related to lightness constancy. Color constancy means that we perceive the color of an object as the same despite changes in lighting conditions. You have experienced color constancy if you have ever worn a pair of sunglasses with colored lenses. In spite of the fact that the colored lenses change the color of light reaching your retina, you still perceive white objects as white and red objects as red. The explanations for color constancy parallel those for lightness constancy. One proposed explanation is that because the lenses tint everything with the same color, we unconsciously “subtract” that color from the scene, leaving the original colors.
Another perceptual constancy is shape constancy, which means that you perceive objects as retaining the same shape despite changes in their orientation. To understand shape constancy, hold a book in front of your face so that you are looking directly at the cover. The rectangular nature of the book should be very clear. Now, rotate the book away from you so that the bottom edge of the cover is much closer to you than the top edge. The image of the book on your retina will now be quite different. In fact, the image will now be trapezoidal, with the bottom edge of the book larger on your retina than the top edge. (Try to see the trapezoid by closing one eye and imagining the cover as a two-dimensional shape.) In spite of this trapezoidal retinal image, you will continue to see the book as rectangular. In large measure, shape constancy occurs because your visual system takes depth into consideration.
Depth perception also plays a major role in size constancy, the tendency to perceive objects as staying the same size despite changes in our distance from them. When an object is near to us, its image on the retina is large. When that same object is far away, its image on the retina is small. In spite of the changes in the size of the retinal image, we perceive the object as the same size. For example, when you see a person at a great distance from you, you do not perceive that person as very small. Instead, you think that the person is of normal size and far away. Similarly, when we view a skyscraper from far away, its image on our retina is very small-yet we perceive the building as very large.
Psychologists have proposed several explanations for the phenomenon of size constancy. First, people learn the general size of objects through experience and use this knowledge to help judge size. For example, we know that insects are smaller than people and that people are smaller than elephants. In addition, people take distance into consideration when judging the size of an object. Thus, if two objects have the same retinal image size, the object that seems farther away will be judged as larger. Even infants seem to possess size constancy.
Another explanation for size constancy involves the relative sizes of objects. According to this explanation, we see objects as the same size at different distances because they stay the same size relative to surrounding objects. For example, as we drive toward a stop sign, the retinal image sizes of the stop sign relative to a nearby tree remain constant-both images grow larger at the same rate.
Depth perception is the ability to see the world in three dimensions and to perceive distance. Although this ability may seem simple, depth perception is remarkable when you consider that the images projected on each retina are two-dimensional. From these flat images, we construct a vivid three-dimensional world. To perceive depth, we depend on two main sources of information: binocular disparity, a depth cue that requires both eyes; and monocular cues, which allow us to perceive depth with just one eye.
An autostereogram is a remarkable kind of two-dimensional image that appears three-dimensional (3-D) when viewed in the right way. To see the 3-D image, first make sure you are viewing the expanded version of this picture. Then try to focus your eyes on a point in space behind the picture, keeping your gaze steady. An image of a person playing a piano will appear.
Because our eyes are spaced about 7 cm. (about 3 in.) apart, the left and right retinas receive slightly different images. This difference in the left and right images is called binocular disparity. The brain integrates these two images into a single three-dimensional image, allowing us to perceive depth and distance.
For a demonstration of binocular disparity, fully extend your right arm in front of you and hold up your index finger. Now, alternate closing your right eye and then your left eye while focusing on your index finger. Notice that your finger appears to jump or shift slightly-a consequence of the two slightly different images received by each of your retinas. Next, keeping your focus on your right index finger, hold your left index finger up much closer to your eyes. You should notice that the nearer finger creates a double image, which is an indication to your perceptual system that it is at a different depth than the farther finger. When you alternately close your left and right eyes, notice that the nearer finger appears to jump much more than the more distant finger, reflecting a greater amount of binocular disparity.
You have probably experienced a number of demonstrations that use binocular disparity to provide a sense of depth. A stereoscope is a viewing device that presents each eye with a slightly different photograph of the same scene, which generates the illusion of depth. The photographs are taken from slightly different perspectives, one approximating the view from the left eye and the other representing the view from the right eye. The View-Master, a children”s toy, is a modern type of stereoscope.
Filmmakers have made use of binocular disparity to create 3-D (three-dimensional) movies. In 3-D movies, two slightly different images are projected onto the same screen. Viewers wear special glasses that use colored filters (as for most 3-D movies) or polarizing filters (as for 3-D IMAX movies). The filters separate the image so that each eye receives the image intended for it. The brain combines the two images into a single three-dimensional image. Viewers who watch the film without the glasses see a double image.
Another phenomenon that makes use of binocular disparity is the autostereogram. The autostereogram is a two-dimensional image that can appear three-dimensional without the use of special glasses or a stereoscope. Several different types of autostereograms exist. The most popular, based on the single-image random point at which to point of a stereogram, seemingly becomes three-dimensional when the viewer relaxes or delouses the eyes, as if focusing on a point in space behind the image. The two-dimensional image usually consists of random dots or lines, which, when viewed properly, coalesce into a previously unseen three-dimensional image. This type of autostereogram was first popularized in the Magic Eye series of books in the early 1990s, although its invention traces back too 1979. Most autostereograms are produced using computer software. The mechanism by which autostereograms work is complex, but they employ the same principle as the stereoscope and 3-D movies. That is, each eye receives a slightly different image, which the brain fuses into a single three-dimensional image.
Although binocular disparity is a very useful depth cue, it is only effective over a fairly short range-less than three m (10 ft.). As our distance from objects increases, the binocular disparity decreases-that is, the images received by each retina become more and more similar. Therefore, for distant objects, your perceptual system cannot rely on binocular disparity as a depth cue. However, you can still determine that some objects are nearer and some farther away because of monocular cues about depth.
To portray a realistic three-dimensional world on a two-dimensional canvas, artists must make use of a variety of depth cues. It was not until the 1400s, during the Italian Renaissance, that artists began to understand linear perspective fully and to portray depth convincingly. Shown here are several paintings that produce a sense of depth.
Close one eye and look around you. Notice the richness of depth that you experience. How does this sharp sense of three-dimensionality emerge from input to a single two-dimensional retina? The answer lies in monocular cues, or cues to depth that are effective when viewed with only one eye.
The problem of encoding depth on the two-dimensional retina is quite similar to the problem faced by an artist who wishes to realistically portray depth on a two-dimensional canvas. Some artists are amazingly adept at doing so, using a variety of monocular cues to give their works a sense of depth.
Although there are many kinds of monocular cues, the most important are interposition, atmospheric perspective, texture gradient, linear perspective, size cues, height cues, and motion parallax.
People commonly rely on interposition, or the overlap between objects, to judge distances. When one object partially obscures our view of another object, we judge the covered object as farther away from us.
Probably the most important monocular cue is interposition, or overlap. When one object overlaps or partly blocks our view of another object, we judge the covered object for being farther away from us. This depth cue is all around us-look around you and notice how many objects are partly obscured by other objects. To understand how much we rely on interposition, try this demonstration. Hold two pens, one in each hand, a short distance in front of your eyes. Hold the pens several centimeters apart so they do not overlap, but move one pen just slightly farther away from you than the other. Now close one eye. Without binocular vision, notice how difficult it is to judge which pen is more distant. Now, keeping one eye closed, move your hands closer and closer together until one pen moves in front of the other. Notice how interposition makes depth perception much easier.
When we look out over vast distances, faraway points look hazy or blurry. This effect is known as atmospheric perspective, and it helps us to judge distances. In this picture, the ridges that are farther away appear hazier and less detailed than the closer ridges.
The air contains microscopic particles of dust and moisture that make distant objects look hazy or blurry. This effect is called atmospheric perspective or aerial perspective, and we use it to judge distance. In the anthem, “Oh Canada” it draws reference to the effect of atmospheric perspectives, which make’s distant mountains appear bluish or purple. When you are standing on a mountain, you see brown earth, gray rocks, and green trees and grass-but little that is purple. When you are looking at a mountain from a distance, however, atmospheric particles bend the light so that the rays that reach your eyes lie in the blue or purple part of the color spectrum. This same effect makes the sky appear blue.
An influential American psychologist, James J. Gibson, was among the first people to recognize the importance of texture gradient in perceiving depth. A texture gradient arises whenever we view a surface from a slant, rather than directly from above. Most surfaces-such as the ground, a road, or a field of flowers-have a texture. The texture becomes denser and less detailed as the surface recedes into the background, and this information helps us to judge depth. For example, look at the floor or ground around you. Notice that the apparent texture of the floor changes over distance. The texture of the floor near you appears more detailed than the texture of the floor farther away. When objects are placed at different locations along a texture gradient, judging their distance from you becomes fairly easy.
Linear perspective means that parallel lines, such as the white lines of this road, appear to converge with greater distance and reach a vanishing point at the horizon. We use our knowledge of linear perspective to help us judge distances.
Artists have learned to make great use of linear perspective in representing a three-dimensional world on a two-dimensional canvas. Linear perspective refers to the fact that parallel lines, such as railroad tracks, appear to converge with distance, eventually reaching a vanishing point at the horizon. The more the lines converge, the farther away they appear.
When estimating an object”s distance from us, we take into account the size of its image relative to other objects. This depth cue is known as relative size. In this photograph, because we assume that the airplanes are the same size, we judge the airplanes that take up less of the image for being farther away from the camera.
Another visual cue to apparent depth is closely related to size constancy. According to size constancy, even though the size of the retinal image may change as an object moves closer to us or farther from us, we perceive that object as staying about the same size. We are able to do so because we take distance into consideration. Thus, if we assume that two objects are the same size, we perceive the object that casts a smaller retinal image as farther away than the object that casts a larger retinal image. This depth cue is known as relative size, because we consider the size of an object”s retinal image relative to other objects when estimating its distance.
Another depth cue involves the familiar size of objects. Through experience, we become familiar with the standard size of certain objects, such as houses, cars, airplanes, people, animals, books, and chairs. Knowing the size of these objects helps us judge our distance from them and from objects around them.
When judging an object”s distance, we consider its height in our visual field relative to other objects. The closer an object is to the horizon in our visual field, the farther away we perceive it to be. For example, the wildebeest that are higher in this photograph appear farther away than those that are lower.
We perceive points nearer to the horizon as more distant than points that are farther away from the horizon. This means that below the horizon, objects higher in the visual field appear farther away than those that are lower. Above the horizon, objects lower in the visual field appear farther away than those that are higher. For example, in the accompanying picture entitled “Relative Height,” the animals higher in the photo appear farther away than the animals lower in the photo. But above the horizon, the clouds lower in the photo appear farther away than the clouds higher in the photo. This depth cue is called relative elevation or relative height, because when judging an object”s distance, we consider its height in our visual field relative to other objects.
The monocular cues discussed so far-interposition, atmospheric perspective, texture gradient, linear perspective, size cues, and height cues-are sometimes called pictorial cues, because artists can use them to convey three-dimensional information. Another monocular cue cannot be represented on a canvas. Motion parallax occurs when objects at different distances from you appear to move at different rates when you are in motion. The next time you are driving along in a car, pay attention to the rate of movement of nearby and distant objects. The fence near the road appears to whiz past you, while the more distant hills or mountains appear to stay in virtually the same position as you move. The rate of an object”s movement provides a cue to its distance.
Although motion plays an important role in depth perception, the perception of motion is an important phenomenon in its own right. It allows a baseball outfielder to calculate the speed and trajectory of a ball with extraordinary accuracy. Automobile drivers rely on motion perception to judge the speeds of other cars and avoid collisions. A cheetah must be able to detect and respond to the motion of antelopes, its chief prey, in order to survive.
Initially, you might think that you perceive motion when an object”s image moves from one part of your retina to another part of your retina. In fact, which is what occurs if you are staring straight ahead and a person walks in front of you. Motion perception, however, is not that simple-if it were, the world would appear to move every time we moved our eyes. Keep in mind that you are almost always in motion. As you walk along a path, or simply move your head or your eyes, images from many stationary objects move around on your retina. How does your brain know which movement on the retina is due to your own motion and which is due to motion in the world? Understanding that distinction is the problem that faces psychologists who want to explain motion perception.
One explanation of motion perception involves a form of unconscious inference. That is, when we walk around or move our head in a particular way, we unconsciously expect that images of stationary objects will move on our retina. We discount such movement on the retina as due to our own bodily motion and perceive the objects as stationary.
In contrast, when we are moving and the image of an object does not move on our retina, we perceive that object as moving. Consider what happens as a person moves in front of you and you track that person”s motion with your eyes. You move your head and your eyes to follow the person”s movement, with the result that the image of the person does not move on your retina. The fact that the person”s image stays in roughly the same part of the retina leads you to perceive the person as moving.
Psychologist James J. Gibson thought that this explanation of motion perception was too complicated. He reasoned that perception does not depend on internal thought processes. He thought, instead, that the objects in our environment contain all the information necessary for perception. Think of the aerial acrobatics of a fly. Clearly, the fly is a master of motion and depth perception, yet few people would say the fly makes unconscious inferences. Gibson identified a number of cues for motion detection, including the covering and uncovering of background. Research has shown that motion detection is, in fact, much easier against a background. Thus, as a person moves in front of you, that person first covers and then uncovers portions of the background.
People may perceive motion when none actually exists. For example, motion pictures are really a series of slightly different still pictures flashed on a screen at a rate of 24 pictures, or frames, per second. From this rapid succession of still images, our brain perceives fluid motion-a phenomenon known as stroboscopic movement. For more information about illusions of emotion.
Experience in interacting with the world is vital to perception. For instance, kittens raised without visual experience or deprived of normal visual experience do not perceive the world accurately. In one experiment, researchers reared kittens in total darkness, except that for five hours a day the kittens were placed in an environment with only vertical lines. When the animals were later exposed to horizontal lines and forms, they had trouble perceiving these forms.
Philosophers have long debated the role of experience in human perception. In the late 17th century, Irish philosopher William Molyneux wrote to his friend, English philosopher John Locke, and asked him to consider the following scenario: Suppose that you could restore sight to a person who was blind. Using only vision, would that person be able to tell the difference between a cube and a sphere, which she or he had previously experienced only through touch? Locke, who emphasized the role of experience in perception, thought the answer was no. Modern science actually allows us to address this philosophical question, because a very small number of people who were blind have had their vision restored with the aid of medical technology.
Two researchers, British psychologist Richard Gregory and British-born neurologist Oliver Sacks, have written about their experiences with men who were blind for a long time due to cataracts and then had their vision restored late in life. When their vision was restored, they were often confused by visual input and were unable to see the world accurately. For instance, they could detect motion and perceive colors, but they had great difficulty with complex stimuli, such as faces. Much of their poor perceptual ability was probably due to the fact that the synapses in the visual areas of their brains had received little or no stimulation throughout their lives. Thus, without visual experience, the visual system does not develop properly.
Visual experience is useful because it creates memories of past stimuli that can later serve as a context for perceiving new stimuli. Thus, you can think of experience as a form of context that you carry around with you.
Ordinarily, when you read, you use the context of your prior experience with words to process the words you are reading. Context may also occur outside of you, as in the surrounding elements in a visual scene. When you are reading and you encounter an unusual word, you may be able to determine the meaning of the word by its context. Your perception depends on the context.
Although context is useful most of the time, on some rare occasions context can lead you to misperceive a stimulus. Look at Example B in the “Context Effects” illustration. Which of the green circles is larger? You may have guessed that the green circle on the right is larger. In fact, the two circles are the same size. Your perceptual system was fooled by the context of the surrounding red circles.
Against a background of slanted lines, a perfect square appears trapezoidal-that is, wider at the top than at the bottom. This illusion may occur because the lines create a sense of depth, making the top of the square seem farther away and larger.
A visual illusion occurs when your perceptual experience of a stimulus is substantially different from the actual stimulus you are viewing. In the previous example, you saw the green circles as different sizes, even though they were actually the same size. To experience another illusion, look at the illustration entitled “Zöllner Illusion.” What shape do you see? You may see a trapezoid that is wider at the top, but the actual shape is a square. Such illusions are natural artifacts of the way our visual systems work. As a result, illusions provide important insights into the functioning of the visual system. In addition, visual illusions are fun to experience.
An ascribing notion to awaiting the idea that something debated finds to its intent of meaning the explicit significance of the same psychology that is immeasurably the scientific study of behavior and the mind. This definition contains three elements. The first is that psychology is a scientific enterprise that obtains knowledge through systematic and objective methods of observation and experimentation. Second is that psychologists study behavior, which refers to any action or reaction that can be measured or observed-such as the blink of an eye, an increase in heart rate, or the unruly violence that often erupts in a mob. Third is that psychologists study the mind, which refers to both conscious and unconscious mental states. These states cannot actually be seen, only inferred from observable behavior.
Many people think of psychologists as individuals who dispense advice, analyze personality, and help those who are troubled or mentally ill. But psychology is far more than the treatment of personal problems. Psychologists strive to understand the mysteries of human nature-why people think, feel, and act as they do. Some psychologists also study animal behavior, using their findings to determine laws of behavior that apply to all organisms and to formulate theories about how humans behave and think.
With its broad scope, psychology investigates an enormous range of phenomena: learning and memory, sensation and perception, motivation and emotion, thinking and language, personality and social behavior, intelligence, infancy and child development, mental illness, and much more. Furthermore, psychologists examine these topics from a variety of complementary perspectives. Some conduct detailed biological studies of the brain, others explore how we process information; others analyze the role of evolution, and still others study the influence of culture and society.
Psychologists seek to answer a wide range of important questions about human nature: Are individuals genetically predisposed at birth to develop certain traits or abilities? How accurate are people at remembering faces, places, or conversations from the past? What motivates us to seek out friends and sexual partners? Why do so many people become depressed and behave in ways that seem self-destructive? Do intelligence test scores predict success in school, or later in a career? What causes prejudice, and why is it so widespread? Can the mind be used to heal the body? Discoveries from psychology can help people understand themselves, relate better to others, and solve the problems that confront them.
The term psychology comes from two Greek words: psyche, which means “soul,” and logos, "the study of." These root words were first combined in the 16th century, at a time when the human soul, spirit, or mind was seen as distinct from the body.
Psychology overlaps with other sciences that investigate behavior and mental processes. Certain parts of the field share much with the biological sciences, especially physiology, the biological study of the functions of living organisms and their parts. Like physiologists, many psychologists study the inner workings of the body from a biological perspective. However, psychologists usually focus on the activity of the brain and nervous system.
The social sciences of sociology and anthropology, which study human societies and cultures, also intersect with psychology. For example, both psychology and sociology explore how people behave when they are in groups. However, psychologists try to understand behavior from the vantage point of the individual, whereas sociologists focus on how behavior is shaped by social forces and social institutions. Anthropologists investigate behavior as well, paying particular attention to the similarities and differences between human cultures around the world.
Psychology is closely connected with psychiatry, which is the branch of medicine specializing in mental illnesses. The study of mental illness is one of the largest areas of research in psychology. Psychiatrists and psychologists differ in their training. A person seeking to become a psychiatrist first obtains a medical degree and then engages in further formal medical education in psychiatry. Most psychologists have a doctoral graduate degree in psychology.
The study of psychology draws on two kinds of research: basic and applied. Basic researchers seek to test general theories and build a foundation of knowledge, while applied psychologists study people in real-world settings and use the results to solve practical human problems. There are five major areas of research: biopsychology, clinical psychology, cognitive psychology, developmental psychology, and social psychology. Both basic and applied research is conducted in each of these fields of psychology.
This section describes basic research and other activities of psychologists in the five major fields of psychology. Applied research is discussed in the Practical Applications of Psychology section of this article.
Magnetic resonance imaging (MRI) reveals structural differences between a normal adult brain, left, and the brain of a person with schizophrenia, right. The schizophrenic brain has enlarged ventricles (fluid-filled cavities), shown in light gray. However, not all people with schizophrenia show this abnormality.
How do body and mind interact? Are body and mind fundamentally different parts of a human being, or are they one and the same, interconnected in important ways? Inspired by this classic philosophical debate, many psychologists specialize in biopsychology, the scientific study of the biological underpinnings of behavior and mental processes.
At the heart of this perspective is the notion that human beings, like other animals, have an evolutionary history that predisposes them to behave in ways that are uniquely adaptive for survival and reproduction. Biopsychologists work in a variety of subfields. Researchers in the field of ethology observe fish, reptiles, birds, insects, primates, and other animal species in their natural habitats. Comparative psychologists study animal behavior and make comparisons among different species, including humans. Researchers in evolutionary psychology theorize about the origins of human aggression, altruism, mate selection, and other behaviors. Those in behavioral genetics seek to estimate the extent to which human characteristics such as personality, intelligence, and mental illness are inherited.
Particularly important to biopsychology is a growing body of research in behavioral neuroscience, the study of the links between behavior and the brain and nervous system. Facilitated by computer-assisted imaging techniques that enable researchers to observe the living human brain in action, this area is generating great excitement. In the related area of cognitive neuroscience, researchers record physical activity in different regions of the brain as the subject reads, speaks, solves math problems, or engages in other mental tasks. Their goal is to pinpoint activities in the brain that correspond to different operations of the mind. In addition, many Biopsychologists are involved in psychopharmacology, the study of how drugs affect mental and behavioral functions.
This chart illustrates the percentage of people in the United States who experience a particular mental illness at some point during their lives. The figures are derived from the National Comorbidity Survey, in which researchers interviewed more than 8000 people aged 15 to 54 years. Homeless people and those living in prisons, nursing homes, or other institutions were not included in the survey.
Clinical psychology is dedicated to the study, diagnosis, and treatment of mental illnesses and other emotional or behavioral disorders. More psychologists work in this field than in any other branch of psychology. In hospitals, community clinics, schools, and in private practice, they use interviews and tests to diagnose depression, anxiety disorders, schizophrenia, and other mental illnesses. People with these psychological disorders often suffer terribly. They experience disturbing symptoms that make it difficult for them to work, relate to others, and cope with the demands of everyday life.
Over the years, scientists and mental health professionals have made great strides in the treatment of psychological disorders. For example, advances in psychopharmacology have led to the development of drugs that relieve severe symptoms of mental illness. Clinical psychologists usually cannot prescribe drugs, but they often work in collaboration with a patient”s physician. Drug treatment is often combined with psychotherapy, a form of intervention that relies primarily on verbal communication to treat emotional or behavioral problems. Over the years, psychologists have developed many different forms of psychotherapy. Some forms, such as psychoanalysis, focus on resolving internal, unconscious conflicts stemming from childhood and past experiences. Other forms, such as cognitive and behavioral therapies, focus more on the person”s current level of functioning and try to help the individual change distressing thoughts, feelings, or behaviors.
In addition to studying and treating mental disorders, many clinical psychologists study the normal human personality and the ways in which individuals differ from one another. Still, others administer a variety of psychological tests, including intelligence tests and personality tests. These tests are commonly given to individuals in the workplace or in school to assess their interests, skills, and level of functioning. Clinical psychologists also use tests to help them diagnose people with different types of psychological disorders.
The field of counseling psychology is closely related to clinical psychology. Counseling psychologists may treat mental disorders, but they more commonly treat people with less-severe adjustment problems related to marriage, family, school, or career. Many other types of professionals care for and treat people with psychological disorders, including psychiatrists, psychiatric social workers, and psychiatric nurses.
To take the Stroop test, name aloud each color in the two columns at left as quickly as you can. Next, look at the right side of the illustration and quickly name the colors in which the words are printed. Which task took longer to complete? The test, devised in 1935 by American psychologist John Stroop, shows that people cannot help but process word meanings, and that this processing interferes with the color-naming task.
How do people learn from experience? How and where in the brain are visual images, facts, and personal memories stored? What causes forgetting? How do people solve problems or make difficult life decisions? Does language limit the way people think? And to what extent are people influenced by information outside of conscious awareness?
These are the kinds of questions posed within cognitive psychology, the scientific study of how people acquire, process, and utilize information. Cognition refers to the process of knowing and encompasses nearly the entire range of conscious and unconscious mental processes: sensation and perception, conditioning and learning, attention and consciousness, sleep and dreaming, memory and forgetting, reasoning and decision making, imagining, problem solving, and language.
Decades ago, the invention of digital computers gave cognitive psychologists a powerful new way of thinking about the human mind. They began to see human beings as information processors who receive input, process and store information, and produce output. This approach became known as the information-processing model of cognition. As computers have become more sophisticated, cognitive psychologists have extended the metaphor. For example, most researchers now reject the idea that information is processed in linear, sequential steps. Instead they find that the human mind is capable of parallel processing, in which multiple operations are carried out simultaneously.
In this information-processing model of memory, information that enters the brain is briefly recorded in sensory memory. If we focus our attention on it, the information may become part of working memory (also called short-term memory), where it can be manipulated and used. Through encoding techniques such as repetition and rehearsal, information may be transferred to long-term memory. Retrieving long-term memories makes them active again in working memory.
Are people programmed by inborn biological dispositions? Or is an individual”s fate molded by culture, family, peers, and other socializing influences within the environment? These questions about the roles of nature and nurture are central to the study of human development.
An incredibly complex array of influences, including families, acquaintances, mass media, and society as a whole, help determine the moral development of children. Although a rash of violent incidents in American schools in the late 1990s focused attention on deviant youth behavior, the vast majority of children seem to function harmoniously with others. In this August 1999 article from Scientific American, William Damon, director of the Center on Adolescence at Stanford University in California, explores recent findings on how young people develop morality.
Developmental psychology focuses on the changes that come with age. By comparing people of different ages, and by tracking individuals over time, researchers in this area study the ways in which people mature and change over the life span. Within this area, those who specialize in child development or child psychology study physical, intellectual, and social development in fetuses, infants, children, and adolescents. Recognizing that human development is a lifelong process, other developmental psychologists study the changes that occur throughout adulthood. Still others specialize in the study of old age, even the process of dying.
A “shock generator,” top, was used by American psychologist Stanley Milgram in experiments designed to test the obedience of people to authority. An experimenter instructed subjects to administer what they believed were painful electric shocks to Mr. Wallace, bottom, an accomplice of the experimenter who was strapped into a chair and connected to the generator by electrodes on his skin. No actual shocks occurred. The experimenter ordered the subjects to continue as the shocks increased to a level the subjects believed were dangerous or even lethal. In Milgram”s initial study, 65 percent of people obeyed the experimenter and delivered the maximum shock of 450 volts. Milgram discusses his conclusions in this sound clip.
Social psychology is the scientific study of how people think, feel, and behave in social situations. Researchers in this field ask questions such as, How do we form impressions of others? How are people persuaded to change their attitudes or beliefs? What causes people to conform with group situations? What leads someone to help or ignore a person in need? Under what circumstances do people obey or resist orders?
By observing people in real-world social settings, and by carefully devising experiments to test people”s social behavior, social psychologists learn about the ways people influence, perceive, and interact with one another. The study of social influence includes topics such as conformity, obedience to authority, the formation of attitudes, and the principles of persuasion. Researchers interested in social perception study how people come to know and evaluate one another, how people form group stereotypes, and the origins of prejudice. Other topics of particular interest to social psychologists include physical attraction, love and intimacy, aggression, altruism, and group processes. Many social psychologists are also interested in cultural influences on interpersonal behavior.
Whereas basic researchers test theories about mind and behavior, applied psychologists are motivated by a desire to solve practical human problems. Four particularly active areas of application are health, education, business, and law.
Today, many psychologists work in the emerging area of health psychology, the application of psychology to the promotion of physical health and the prevention and treatment of illness. Researchers in this area have shown that human health and well-being depends on both biological and psychological factors.
Many psychologists in this area study psychophysiological disorders (also called psychosomatic disorders), conditions that are brought on or influenced by psychological states, most often stress. These disorders include high blood pressure, headaches, asthma, and ulcers. Researchers have discovered that chronic stress is associated with an increased risk of coronary heart disease. In addition, stress can compromise the body”s immune system and increase susceptibility to illness.
Health psychologists also study how people cope with stress. They have found that people who have family, friends, and other forms of social support are healthier and live longer than those who are more isolated. Other researchers in this field examine the psychological factors that underlie smoking, drinking, drug abuse, risky sexual practices, and other behaviors harmful to health.
Psychologists in all branches of the discipline contribute to our understanding of teaching, learning, and education. Some help develop standardized tests used to measure academic aptitude and achievement. Others study the ages at which children become capable of attaining various cognitive skills, the effects of rewards on their motivation to learn, computerized instruction, bilingual education, learning disabilities, and other relevant topics. Perhaps the best-known application of psychology to the field of education occurred in 1954 when, in the case of Brown v Board of Education, the Supreme Court of the United States outlawed the segregation of public schools by race. In its ruling, the Court cited psychological studies suggesting that segregation had a damaging effect on black students and tended to encourage prejudice.
In addition to the contributions of psychology as a whole, two fields within psychology focus exclusively on education: educational psychology and school psychology. Educational psychologists seek to understand and improve the teaching and learning process within the classroom and other educational settings. Educational psychologists study topics such as intelligence and ability testing, student motivation, discipline and classroom management, curriculum plans, and grading. They also test general theories about how students learn most effectively. School psychologists work in elementary and secondary school systems administering tests, making placement recommendations, and counseling children with academic or emotional problems.
The business world, psychology is applied in the workplace and in the marketplace. Industrial-organizational (I-O) psychology focuses on human behavior in the workplace and other organizations. I-O psychologists conduct research, teach in business schools or universities, and work in private industry. Many I-O psychologists study the factors that influence worker motivation, satisfaction, and productivity. Others study the personal traits and situations that foster great leadership. Still, others focus on the processes of personnel selection, training, and evaluation. Studies have shown, for example, that face-to-face interviews sometimes result in poor hiring decisions and may be biased by the applicant's gender, race, and physical attractiveness. Studies have also shown that certain standardized tests can help to predict on-the-job performance.
Consumer psychology is the study of human decision making and behavior in the marketplace. In this area, researchers analyze the effects of advertising on consumers attitudes and buying habits. Consumer psychologists also study various aspects of marketing, such as the effects of packaging, price, and other factors that lead people to purchase one product rather than another.
Many psychologists today work in the legal system. They consult with attorneys, testify in court as expert witnesses, counsel prisoners, teach in law schools, and research various justice-related issues. Sometimes referred to as forensic psychologists, those who apply psychology to the law study a range of issues, including jury selection, eyewitness testimony, confessions to police, lie-detector tests, the death penalty, criminal profiling, and the insanity defense.
Studies in forensic psychology have helped to illuminate weaknesses in the legal system. For example, based on trial-simulation experiments, researchers have found that jurors are often biased by various facts not in evidence-that is, facts the judge tells them to disregard. In studying eyewitness testimony, researchers have staged mock crimes and asked witnesses to identify the assailant or recall other details. These studies have revealed that under certain condition’s eyewitnesses are highly prone to error.
Psychologists in this area often testify in court as expert witnesses. In cases involving the insanity defense, forensic clinical psychologists are often called to court to give their opinion about whether individual defendants are sane or insane. Used as a legal defense, insanity means that defendants, because of a mental disorder, cannot appreciate the wrongfulness of their conduct or control it. Defendants who are legally insane at the time of the offense may be absolved of criminal responsibility for their conduct and judged not guiltily. Psychologists are often called to testify in court on other controversial matters as well, including the accuracy of eyewitness testimony, the mental competence (fitness) of defendants to stand trial, and the reliability of early childhood memories.
Psychology has applications in many other domains of human life. Environmental psychologists focus on the relationship between people and their physical surroundings. They study how street noise, heat, architectural design, population density, and crowding affect people”s behavior and mental health. In a related field, human factor’s psychologists work on the design of appliances, furniture, tools, and other manufactured items in order to maximize their comfort, safety, and convenience. Sports psychologists advise athletes and study the physiological, perceptual-motor, motivational, developmental, and social aspects of athletic performance. Other psychologists specialize in the study of political behavior, religion, sexuality, or behavior in the military.
Psychologists from all areas of specialization use the scientific method to test their theories about behavior and mental processes. A theory is an organized set of principles that is designed to explain and predict some phenomenon. Good theories also provide specific testable predictions, or hypotheses, about the relation between two or more variables. Formulating a hypothesis to be tested is the first important step in conducting research.
Over the years, psychologists have devised numerous ways to test their hypotheses and theories. Many studies are conducted in a laboratory, usually located at a university. The laboratory setting allows researchers to control what happens to their subjects and make careful and precise observations of behavior. For example, a psychologist who studies memory can bring volunteers into the lab, ask them to memorize a list of words or pictures, and then test their recall of that material seconds, minutes, or days later.
As indicated by the term field research, studies may also be conducted in real-world locations. For example, a psychologist investigating the reliability of eyewitness testimony might stage phony crimes in the street and then ask unsuspecting bystanders to identify the culprit from a set of photographs. Psychologists observe people in a wide variety of other locations outside the laboratory, including classrooms, offices, hospitals, college dormitories, bars, restaurants, and prisons.
In both laboratory and field settings, psychologists conduct their research using a variety of methods. Among the most common methods are archival studies, case studies, surveys, naturalistic observations, correlational studies, experiments, literature reviews, and measures of brain activity.
One way to learn about people is through archival studies, an examination of existing records of human activities. Psychological researchers often examine old newspaper stories, medical records, birth certificates, crime reports, popular books, and artwork. They may also examine statistical trends of the past, such as crime rates, birth rates, marriage and divorce rates, and employment rates. The strength of such measures is that by observing people only secondhand, researchers cannot unwittingly influence the subjects by their presence. However, available records of human activity are not always complete or detailed enough to be useful.
Archival studies are particularly valuable for examining cultural or historical trends. For example, in one study of physical attractiveness, researchers wanted to know if American standards of female beauty have changed over several generations. These researchers looked through two popular women”s magazines between 1901 and 1981 and examined the measurements of the female models. They found that “curvaceousness” (as measured by the bust-to-waist ratio) varied over time, with a boyish, slender look considered desirably in some time periods but not in others.
Sometimes psychologists interview, test, observe, and investigate the backgrounds of specific individuals in detail. Such case studies are conducted when researchers believe that an in-depth look at one individual will reveal something important about people in general.
Case studies often take a great deal of time to complete, and the results may be limited by the fact that the subject is atypical. Yet case studies have played a prominent role in the development of psychology. Austrian physician Sigmund Freud based his theory of psychoanalysis on his experiences with troubled patients. Swiss psychologist Jean Piaget first began to formulate a theory of intellectual development by questioning his own children. Neuroscientists learn about how the human brain works by testing patients who have suffered brain damage. Cognitive psychologists learn about human intelligence by studying child prodigies and other gifted individuals. Social psychologists learn about group decision making by analyzing the policy decisions of government and business groups. When an individual is exceptional in some way, or when a hypothesis can be tested only through intensive, long-term observation, the case study is a valuable method.
An electroencephalogram, or EEG, is a recording of the action potential, or electrical, activity of the cerebral cortex of the brain. An EEG is made by attaching electrodes to the scalp, then collecting, amplifying, and recording the electrical impulses of the brain.
Biopsychologists interested in the links between brain and behavior use a variety of specialized techniques in their research. One approach is to observe and test patients who have suffered damage to a specific region of the brain to determine what mental functions and behaviors were affected by that damage. British-born neurologist Oliver Sacks has written several books in which he describes case studies of brain-damaged patients who exhibited specific deficits in their speech, memory, sleep, and even in their personalities.
This positron emission tomography (PET) scan of the brain shows the activity of brain cells in the resting state and during three types of auditory stimulation. PET uses radioactive substances introduced into the brain to measure such brain functions as cerebral metabolism, blood flow and volume, oxygen use, and the formation of neurotransmitters. This imaging method collects data from many different angles, feeding the information into a computer that produces a series of cross-sectional images.
A second approach is too physically altar the brain and measure the effects of that change on behavior. The alteration can be achieved in different ways. For example, animal researchers often damage or destroy a specific region of a laboratory animal's brain through surgery. Other researchers might spark or inhibit activity in the brain through the use of drugs or electrical stimulation.
This magnetic resonance imaging (MRI) scan of a normal adult head shows the brain, airways, and soft tissues of the face. The large cerebral cortex, appearing in yellow and green, forms the bulk of the brain tissue; the circular cerebellum, center left, in red, and the elongated brainstem, center, in red, are also prominently shown.
Another way to study the relationship between the brain and behavior is to record the activity of the brain with machines while a subject engages in certain behaviors or activities. One such instrument is the electroencephalograph, a device that can detect, amplify, and record the level of electrical activity in the brain by means of metal electrodes taped to the scalp.
Advances in technology in the early 1970s allowed psychologists to see inside the living human brain for the first time without physically cutting into it. Today, psychologists use a variety of sophisticated brain-imaging techniques. The computerized axial tomography (CT or CAT) scan provides a computer-enhanced X-ray image of the brain. The more advanced positron emission tomography (PET) scan tracks the level of activity in specific parts of the brain by measuring the amount of glucose being used there. These measurements are then fed to a computer, which produces a color-coded image of brain activity. Another technique is magnetic resonance imaging (MRI), which produces high-resolution cross-sectional images of the brain. A high-speed version of MRI known as functional MRI produces moving images of the brain as its activity changes in real time. These relatively new brain imaging techniques have generated great excitement, because they allow researchers to identify parts of the brain that are active while people read, speak, listen to music, solve math problems, and engage in other mental activities.
In contrast with the in-depth study of one person, surveys describe a specific population or group of people. Surveys involve asking people a series of questions about their behaviors, thoughts, or opinions. Surveys can be conducted in person, over the phone, or through the mail. Most surveys study a specific group-for example, college students, working mothers, men, or homeowners. Rather than questioning every person in the group, survey researchers choose a representative sample of people and generalize the findings to the larger population.
Surveys may pertain to almost any topic. Often surveys ask people to report their feelings about various social and political issues, the TV shows they watch, or the consumers’ products they purchase. Surveys are also used to learn about people”s sexual practices; to estimate the use of cigarettes, alcohol, and other drugs; and to approximate the proportion of people who experience feelings of life satisfaction, loneliness, and other psychological states that cannot be directly observed.
Surveys must be carefully designed and conducted to ensure their accuracy. The results can be influenced, and biased, by two factors: who the respondents are and how the questions are asked. For a survey to be accurate, the sample being questioned must be representative of the population on key characteristics such as sex, race, age, region, and cultural background. To ensure similarity to the larger population, survey researchers usually try to make sure that they have a random sample, a method of selection in which everyone in the population has an equal chance of being chosen.
When the sample is not random, the results can be misleading. For example, prior to the 1936 United States presidential election, pollsters for the magazine Literary Digest mailed postcards to more than 10 million people who were listed in telephone directories or as registered owners of automobiles. The cards asked for whom they intended to vote. Based on the more than 2 million ballots that were returned, the Literary Digest predicted that Republican candidate Alfred M. Landon would win in a landslide over Democrat Franklin D. Roosevelt. At the time, however, more Republicans than Democrats owned telephones and automobiles, skewing the poll results. In the election, Landon won only two states.
The results of survey research can also be influenced by the way that questions are asked. For example, when asked about “welfare,” a majority of Americans in one survey said that the government spends too much money. But when asked about “assistance to the poor,” significantly fewer people gave this response.
In naturalistic observation, the researcher observes people as they behave in the real world. The researcher simply records what occurs and does not intervene in the situation. Psychologists use naturalistic observation to study the interactions between parents and children, doctors and patients, police and citizens, and managers and workers.
Naturalistic observation is common in anthropology, in which field workers seek to understand the everyday life of a culture. Ethologists, who study the behavior of animals in their natural habitat, also use this method. For example, British ethologist Jane Goodall spent many years in African jungles observing chimpanzees-their social structure, courting rituals, struggles for dominance, eating habits, and other behaviors. Naturalistic observation is also common among developmental psychologists who study social play, parent-child attachments, and other aspects of child development. These researchers observe children at home, in school, on the playground, and in other settings.
Case studies, surveys, and naturalistic observations are used to describe behavior. Correlational studies are further designed to find statistical connections, or correlations, between variables so that some factors can be used to predict others.
A correlation is a statistical measure of the extent to which two variables are associated. A positive correlation exists when two variables increase or decrease together. For example, frustration and aggression are positively correlated, meaning that as frustration rises, so do acts of aggression. More of one means more of the other. A negative correlation exists when increases in one variable are accompanied by decreases in the other, and vice versa. For example, friendships and stress-induced illness are negatively correlated, meaning that the more close friends a person has, the fewer stress-related illnesses the person suffers. More of one means less of the other.
Based on correlational evidence, researchers can use one variable to make predictions about another variable. But researchers must use caution when drawing conclusions from correlations. It is nature-but incorrect-to assume that because one variable predicts another, the first must have caused the second. For example, one might assume that frustration triggers aggression, or that friendships foster health. Regardless of how intuitive or accurate these conclusions may be, correlation does not prove causation. Thus, although it is possible that frustration causes aggression, there are other ways to interpret the correlation. For example, it is possible that aggressive people are more likely to suffer social rejection and become frustrated as a result.
Correlations enable researchers to predict one variable from another. But to determine if one variable actually causes another, psychologists must conduct experiments. In an experiment, the psychologist manipulates one factor in a situation-keeping other aspects of the situation constant-and then observes the effect of the manipulation on behavior. The people whose behavior is being observed are the subjects of the experiment. The factor that an experimenter varies (the proposed cause) is known as the independent variable, and the behavior being measured (the proposed effect) is called the dependent variable. In a test of the hypothesis that frustration triggers aggression, frustration would be the independent variable, and aggression the dependent variable.
There are three requirements for conducting a valid scientific experiment: (1) control over the independent variable, (2) the use of a comparison group, and (3) the random assignment of subjects to conditions. In its most basic form, then, a typical experiment compares a large number of subjects who are randomly assigned to experience one condition with a group of similar subjects who are not. Those who experience the condition compose the experimental group, and those who do not make up the control group. If the two groups differ significantly in their behavior during the experiment, that difference can be attributed to the presence of the condition, or independent variable. For example, to test the hypothesis that frustration triggers aggression, one group of researchers brought subjects into a laboratory, impeded their efforts to complete an important task (other subjects in the experiment were not impeded), and measured their aggressiveness toward another person. These researchers found that subjects who had been frustrated were more aggressive than those who had not been frustrated.
Psychologists use many different methods in their research. Yet no single experiment can fully prove a hypothesis, so the science of psychology builds slowly over time. First, a new discovery must be replicated. Replication refers to the process of conducting a second, nearly identical study to see if the initial findings can be repeated. If so, then researchers try to determine if these findings can be applied, transferred, or generalized to other settings. Generalizability refers to the extent to which a finding obtained less than one set of conditions can also be obtained at another time, in another place, and in other populations.
Because the science of psychology proceeds in small increments, many studies must be conducted before clear patterns emerge. To summarize and interpret an entire body of research, psychologists rely on two methods. One method is a narrative review of the literature, in which a reviewer subjectively evaluates the strengths and weaknesses of the various studies on a topic and argues for certain conclusions. Another method is meta-analysis, a statistical procedure used to combine the results from many different studies. By meta-analyzing a body of research, psychologists can often draw precise conclusions concerning the strength and breadth of support for a hypothesis.
Psychological research involving human subjects raises ethical concerns about the subject”s right to privacy, the possible harm or discomfort caused by experimental procedures, and the use of deception. Over the years, psychologists have established various ethical guidelines. The American Psychological Association recommends that researchers (1) tell prospective subjects what they will experience so they can give informed consent to participate; (2) instruct subjects that they may withdraw from the study at any time; (3) minimize all harm and discomfort; (4) keep the subjects” responses and behavior’s confidential; and (5) debrief subjects who were deceived in some way by fully explaining the research after they have participated. Some psychologists argue that such rules should never be broken. Others say that some degree of flexibility is needed in order to study certain important issues, such as the effects of stress on test performance.
Laboratory experiments that use rats, mice, rabbits, pigeons, monkeys, and other animals are an important part of psychology, just as in medicine. Animal research serves three purposes in psychology: to learn more about certain types of animals, to discover general principles of behavior that pertain to all species, and to study variables that cannot ethically be tested with human beings. But is it ethical to experiment on animals?
Some animal rights activists believe that it is wrong to use animals in experiments, particularly in those that involve surgery, drugs, social isolation, food deprivation, electric shock, and other potentially harmful procedures. These activists see animal experimentation as unnecessary and question whether results from such research can be applied to humans. Many activists also argue that like humans, animals have the capacity to suffer and feel pain. In response to these criticisms, many researchers point out that animal experimentation has helped to improve the quality of human life. They note that animal studies have contributed to the treatment of anxiety, depression, and other mental disorders. Animal studies have also contributed to our understanding of conditions such as Alzheimer's disease, obesity, alcoholism, and the effects of stress on the immune system. Most researchers follow strict ethical guidelines that require them to minimize pain and discomfort to animals and to use the least invasive procedures possible. In addition, federal animal-protection laws in the United States require researchers to provide humane care and housing of animals and to tend to the psychological well-being of primates used in research.
One of the youngest sciences, psychology did not emerge as a formal discipline until the late 19th century. But its roots extend to the ancient past. For centuries, philosophers and religious scholars have wondered about the nature of the mind and the soul. Thus, the history of psychological thought begins in philosophy.
From about 600 to 300 Bc, Greek philosophers inquired about a wide range of psychological topics. They were especially interested in the nature of knowledge and how human beings come to know the world, a field of philosophy known as epistemology. The Greek philosopher Socrates and his followers, Plato and Aristotle, wrote about pleasure and pain, knowledge, beauty, desire, free will, motivation, common sense, rationality, memory, and the subjective nature of perception. They also theorized about whether human traits are innate or the product of experience. In the field of ethics, philosophers of the ancient world probed a variety of psychological questions: Are people inherently good? How can people attain happiness? What motives or drives do people have? Are human beings naturally social?
Second-century physician Galen was one of the most influential figures in ancient medicine, second in importance only to Hippocrates. Using animal dissection and other means, Galen proposed numerous theories about the function of different parts of the human body, most notably the brain, heart, and liver. He also derived an impressive understanding of the differences between veins and arteries. In the selection below, Galen discusses his idea that the optimal state, or “constitution,” of the body should be a perfect balance of various internal and external components.
Early thinkers also considered the causes of mental illness. Many ancient societies thought that mental illness resulted from supernatural causes, such as the anger of gods or possession by evil spirits. Both Socrates and Plato focused on psychological forces as the cause of mental disturbance. For example, Plato thought madness results when a person's irrational, animal-like psyche (mind or soul) overwhelms the intellectual, rational psyche. The Greek physician Hippocrates viewed mental disorders as stemming from natural causes, and he developed the first classification system for mental disorders. Galen, a Greek physician who lived in the 2nd century ad, echoed this belief in a physiological basis for mental disorders. He thought they resulted from an imbalance of the four bodily humors: black bile, yellow bile, blood, and phlegm. For example, Galen thought that melancholia (depression) resulted from a person having too much black bile.
More recently, many other men and women contributed to the birth of modern psychology. In the 1600s French mathematician and philosopher René Descartes theorized that the body and mind are separate entities. He regarded the body as a physical entity and the mind as a spiritual entity, and believed the two interacted only through the pineal gland, a tiny structure at the base of the brain. This position became known as dualism. According to dualism, the behavior of the body is determined by mechanistic laws and can be measured in a scientific manner. But the mind, which transcends the material world, cannot be similarly studied.
English philosopher’s Thomas Hobbes and John Locke disagreed. They argued that all human experiences-including sensations, images, thoughts, and feelings-are physical processes occurring within the brain and nervous system. Therefore, these experiences are valid subjects of study. In this view, which later became known as monism, the mind and body are one and the same. Today, in light of years of research indicating that the physical and mental aspects of the human experience are intertwined, most psychologists reject a rigid dualists position.
Many philosophers of the past also debated the question of whether human knowledge is inborn or the product of experience. Nativists believed that certain elementary truths are innate to the human mind and need not be gained through experience. In contrast, empiricist believed that at birth, a person”s mind is like a tabula rasa, or blank slate, and that all human knowledge ultimately comes from sensory experience. Today, all psychologists agree that both types of factors are important in the acquisition of knowledge.
Modern psychology can also be traced to the study of physiology (a branch of biology that studies living organisms and their parts) and medicine. In the 19th century, physiologists began studying the human brain and nervous system, paying particular attention to the topic of sensation. For example, in the 1850s and 1860s German scientist Hermann von Helmholtz studied sensory receptors in the eye and ear, investigating topics such as the speed of neural impulses, color vision, hearing, and space perception. Another important German scientist, Gustav Fechner, founded psychophysics, the study of the relationship between physical stimuli and our subjective sensations of those stimuli. Building on the work of his compatriot Ernst Weber, Fechner developed a technique for measuring people”s subjective sensations of various physical stimuli. He sought to determine the minimum intensity level of a stimulus that is needed to produce a sensation.
English naturalist Charles Darwin was particularly influential in the development of psychology. In 1859 Darwin published On the Origin of Species, in which he proposed that all living forms were a product of the evolutionary process of natural selection. Darwin had based his theory on plants and nonhuman animals, but he later asserted that people had evolved through similar processes, and that human anatomy and behavior could be analyzed in the same way. Darwin's theory of evolution invited comparisons between humans and other animals, and scientists soon began using animals in psychological research.
French neurologist Jean Martin Charcot shows colleagues a female patient with hysteria at La Salpêtrière, a Paris hospital. Charcot gained renown throughout Europe for his method of treating hysteria and other “nervous disorders” through hypnosis. Charcot”s belief that hysteria had psychological rather than physical origins influenced Austrian neurologist Sigmund Freud, who studied under Charcot.
In medicine, physicians were discovering new links between the brain and language. For example, French surgeon Paul Broca discovered that people who suffer damage to a specific part of the brain’s left hemisphere lose the ability to produce fluent speech. This area of the brain became known as Broca's area. A German neurologist, Carl Wernicke, reported in 1874 that people with damage to a different area of the left hemisphere lose their ability to comprehend speech. This region became known as Wernicke's area.
Other physicians focused on the study of mental disorders. In the late 19th century, French neurologist Jean Charcot discovered that some of the patients he was treating for so-called nervous disorders could be cured through hypnosis, a psychological-not medical-form of intervention. Charcot”s work had a profound impact on Sigmund Freud, an Austrian neurologist whose theories would later revolutionize psychology.
Austrian physician Franz Fredrich Anton Mesmer pioneered the induction of trance-like states to cure medical ailments. Mesmer”s work sparked interest among some of his scientific colleagues but was later dismissed as charlatanism. Today, however, Mesmer is considered a pioneer in hypnosis, which is widely believed to be helpful in managing certain medical conditions.
Psychology was predated and somewhat influenced by various pseudoscientific schools of thought-that is, theories that had no scientific foundation. In the late 18th and early 19th centuries, Viennese physician Franz Joseph Gall developed phrenology, the theory that psychological traits and abilities reside in certain parts of the brain and can be measured by the bumps and indentations in the skull. Although phrenology found popular acceptance among the lay public in western Europe and the United States, most scientists ridiculed Gall's ideas. However, research later confirmed the more general point that certain mental activities can be traced to specific parts of the brain.
Physicians in the 18th and 19th centuries used crude devices to treat mental illness, none of which offered any real relief. The circulating swing, top left, was used to spin depressed patients at high speed. American physician Benjamin Rush devised the tranquilizing chair, top right, to calm people with mania. The crib, bottom, was widely used to restrain violent patients.
Another Viennese physician of the 18th century, Franz Anton Mesmer, believed that illness was caused by an imbalance of magnetic fluids in the body. He believed he could restore the balance by passing his hands across the patient”s body and waving a magnetic wand over the infected area. Mesmer claimed that his patients would fall into a trance and awaken from it feeling better. The medical community, however, soundly rejected the claim. Today, Mesmer”s technique, known as mesmerism, is regarded as an early forerunner of modern hypnosis.
Modern psychology is deeply rooted in the older disciplines of philosophy and physiology. But the official birth of psychology is often traced to 1879, at the University of Leipzig, in Leipzig, Germany. There, physiologist Wilhelm Wundt established the first laboratory dedicated to the scientific study of the mind. Wundt”s laboratory soon attracted leading scientists and students from Europe and the United States. Among these were James McKeen Cattell, one of the first psychologists to study individual differences through the administration of “mental tests,” Emil Kraepelin, a German psychiatrist who postulated a physical cause for mental illnesses and in 1883 published the first classification system for mental disorders; and Hugo Münsterberg, the first to apply psychology to industry and the law. Wundt was extraordinarily productive over the course of his career. He supervised a total of 186 doctoral dissertations, taught thousands of students, founded the first scholarly psychological journal, and published innumerable scientific studies. His goal, which he stated in the preface of a book he wrote, was “to mark out a new domain of science.”
Compared to the philosophers who preceded him, Wundt”s approach to the study of mind was based on systematic and rigorous observation. His primary method of research was introspection. This technique involved training people to concentrate and report on their conscious experiences as they reacted to visual displays and other stimuli. In his laboratory, Wundt systematically studied topics such as attention span, reaction time, vision, emotion, and time perception. By recruiting people to serve as subjects, varying the conditions of their experience, and then rigorously repeating all observations, Wundt laid the foundation for the modern psychology experiment.
In the United States, Harvard University professor William James observed the emergence of psychology with great interest. Although trained in physiology and medicine, James was fascinated by psychology and philosophy. In 1875 he offered his first course in psychology. In 1890 James published a two-volume book entitled Principles of Psychology. It immediately became the leading psychology text in the United States, and it brought James a worldwide reputation as a man of great ideas and inspiration. In 28 chapters, James wrote about the stream of consciousness, the formation of habits, individuality, the link between mind and body, emotions, the self, and other topics that inspired generations of psychologists. Today, historians consider James the founder of American psychology.
James's students also made lasting contributions to the field. In 1883 G. Stanley Hall (who also studied with Wundt) established the first true American psychology laboratory in the United States at Johns Hopkins University, and in 1892 he founded and became the first president of the American Psychological Association. Mary Whiton Calkins created an important technique for studying memory and conducted one of the first studies of dreams. In 1905 she was elected the first female president of the American Psychological Association. Edward Lee Thorndike conducted some of the first experiments on animal learning and wrote a pioneering textbook on educational psychology.
During the first decades of psychology, two main schools of thought dominated the field: structuralism and functionalism. Structuralism was a system of psychology developed by Edward Bradford Titchener, an American psychologist who studied under Wilhelm Wundt. Structuralists believed that the task of psychology is to identify the basic elements of consciousness in much the same way that physicists break down the basic particles of matter. For example, Titchener identified four elements in the sensation of taste: sweet, sour, salty, and bitter. The main method of investigation in structuralism was introspection. The influence of structuralism in psychology faded after Titchener's death in 1927.
In contradiction to the Structuralists movement, William James promoted a school of thought known as functionalism, the belief that the real task of psychology is to investigate the function, or purpose, of consciousness rather than its structure. James was highly influenced by Darwin”s evolutionary theory that all characteristics of a species must serve some adaptive purpose. Functionalism enjoyed widespread appeal in the United States. Its three main leaders were James Rowland Angell, a student of James; John Dewey, who was also one of the foremost American philosophers and educators; and Harvey A. Carr, a psychologist at the University of Chicago.
In their efforts to understand human behavioral processes, the functional psychologists developed the technique of longitudinal research, which consists of interviewing, testing, and observing one person over a long period of time. Such a system permits the psychologist to observe and record the person”s development and how he or she reacts to different circumstances.
In the late 19th century Viennese neurologist Sigmund Freud developed a theory of personality and a system of psychotherapy known as psychoanalysis. According to this theory, people are strongly influenced by unconscious forces, including innate sexual and aggressive drives. In this 1938 British Broadcasting Corporation interview, Freud recounts the early resistance to his ideas and later acceptance of his work. Freud's speech is slurred because he was suffering from cancer of the jaw. He died the following year.
Alongside Wundt and James, a third prominent leader of the new psychology was Sigmund Freud, a Viennese neurologist of the late 19th and early 20th century. Through his clinical practice, Freud developed a very different approach to psychology. After graduating from medical school, Freud treated patients who appeared to suffer from certain ailments but had nothing physically wrong with them. These patients were not consciously faking their symptoms, and often the symptoms would disappear through hypnosis, or even just by talking. On the basis of these observations, Freud formulated a theory of personality and a form of psychotherapy known as psychoanalysis. It became one of the most influential schools of Western thought of the 20th century.
Freud introduced his new theory in The Interpretation of Dreams (1889), the first of 24 books he would write. The theory is summarized in Freud's last book, An Outline of Psychoanalysis, published in 1940, after his death. In contrast to Wundt and James, for whom psychology was the study of conscious experience, Freud believed that people are motivated largely by unconscious forces, including strong sexual and aggressive drives. He likened the human mind to an iceberg: The small tip that floats on the water is the conscious part, and the vast region beneath the surface comprises the unconscious. Freud believed that although unconscious motives can be temporarily suppressed, they must find a suitable outlet in order for a person to maintain a healthy personality.
To probe the unconscious mind, Freud developed the psychotherapy technique of free association. In free association, the patient reclines and talks about thoughts, wishes, memories, and whatever else comes to mind. The analyst tries to interpret these verbalizations to determine their psychological significance. In particular, Freud encouraged patients to free associate about their dreams, which he believed were the “royal road to the unconscious.” According to Freud, dreams are disguised expressions of deep, hidden impulses. Thus, as patients recount the conscious manifest content of dreams, the psychoanalyst tries to unmask the underlying latent content-what the dreams really mean.
From the start of psychoanalysis, Freud attracted followers, many of whom later proposed competing theories. As a group, these neo-Freudians shared the assumption that the unconscious plays an important role in a person”s thoughts and behaviors. Most parted company with Freud, however, over his emphasis on sex as a driving force. For example, Swiss psychiatrist Carl Jung theorized that all humans inherit a collective unconscious that contains universal symbols and memories from their ancestral past. Austrian physician Alfred Adler theorized that people are primarily motivated to overcome inherent feelings of inferiority. He wrote about the effects of birth order in the family and coined the term sibling rivalry. Karen Horney, a German-born American psychiatrist, argued that humans have a basic need for love and security, and become anxious when they feel isolated and alone.
Motivated by a desire to uncover unconscious aspects of the psyche, psychoanalytic researchers devised what are known as projective tests. A projective test asks people to respond to an ambiguous stimulus such as a word, an incomplete sentence, an inkblot, or an ambiguous picture. These tests are based on the assumption that if a stimulus is vague enough to accommodate different interpretations, then people will use it to project their unconscious needs, wishes, fears, and conflicts. The most popular of these tests are the Rorschach Inkblot Test, which consists of ten inkblots, and the Thematic Apperception Test, which consists of drawings of people in ambiguous situations.
Psychoanalysis has been criticized on various grounds and is not as popular as in the past. However, Freud's overall influence on the field has been deep and lasting, particularly his ideas about the unconscious. Today, most psychologists agree that people can be profoundly influenced by unconscious forces, and that people often have a limited awareness of why they think, feel, and behave as they do.
In 1885 German philosopher Hermann Ebbinghaus conducted one of the first studies on memory, using himself as a subject. He memorized lists of nonsense syllables and then tested his memory of the syllables at intervals ranging from 20 minutes to 31 days. As shown in this curve, he found that he remembered less than 40 percent of the items after nine hours, but that the rate of forgetting leveled off over time.
In addition to Wundt, James, and Freud, many other’s scholars helped to define the science of psychology. In 1885 German philosopher Hermann Ebbinghaus conducted a series of classic experiments on memory, using nonsense syllables to establish principles of retention and forgetting. In 1896 American psychologist Lightner Witmer opened the first psychological clinic, which initially treated children with learning disorders. He later founded the first journal and training program in a new helping profession that he named clinical psychology. In 1905 French psychologist Alfred Binet devised the first major intelligence test in order to assess the academic potential of schoolchildren in Paris. The test was later translated and revised by Stanford University psychologist Lewis Terman and is now known as the Stanford-Binet intelligence test. In 1908 American psychologist Margaret Floy Washburn (who later became the second female president of the American Psychological Association) wrote an influential book called The Animal Mind, in which she synthesized animal research to that time.
In 1912 German psychologist Max Wertheimer discovered that when two stationary lights flash in succession, people see the display as a single light moving back and forth. This illusion inspired the Gestalt psychology movement, which was based on the notion that people tend to perceive a well-organized whole or pattern that is different from the sum of isolated sensations. Other leaders of Gestalt psychology included Wertheimer”s close associates Wolfgang Köhler and Kurt Koffka. Later, German American psychologist Kurt Lewin extended Gestalt psychology to studies of motivation, personality, social psychology, and conflict resolution. German American psychologist Fritz Heider then extended this approach to the study of how people perceive themselves and others.
In the late 19th century, American psychologist Edward L. Thorndike conducted some of the first experiments on animal learning. Thorndike formulated the law of effect, which states that behaviors that are followed by pleasant consequences will be more likely to be repeated in the future.
William James had defined psychology as “the science of mental life.” But in the early 1900s, growing numbers of psychologists voiced criticism of the approach used by scholars to explore conscious and unconscious mental processes. These critics doubted the reliability and usefulness of the method of introspection, in which subjects are asked to describe their own mental processes during various tasks. They were also critical of Freud's emphasis on unconscious motives. In search of more-scientific methods, psychologists gradually turned away from research on invisible mental processes and began to study only behavior that could be observed directly. This approach, known as behaviorism, ultimately revolutionized psychology and remained the dominant school of thought for nearly 50 years.
Russian physiologist Ivan Pavlov discovered a major type of learning, classical conditioning, by accident while conducting experiments on digestion in the early 1900s. He devoted the rest of his life to discovering the underlying principles of classical conditioning.
Among the first to lay the foundation for the new behaviorism was American psychologist Edward Lee Thorndike. In 1898 Thorndike conducted a series of experiments on animal learning. In one study, he put cats into a cage, put food just outside the cage, and timed how long it took the cats to learn how to open an escape door that led to the food. Placing the animals in the same cage again and again, Thorndike found that the cats would repeat behaviors that worked and would escape more and more quickly with successive trials. Thorndike thereafter proposed the law of effect, which states that behaviors that are followed by a positive outcome are repeated, while those followed by a negative outcome or none at all are extinguished.
In 1906 Russian physiologist Ivan Pavlov-who had won a Nobel Prize two years earlier for his studies of digestion-stumbled onto one of the most important principles of learning and behavior. Pavlov was investigating the digestive process in dogs by putting food in their mouths and measuring the flow of saliva. He found that after repeated testing, the dogs would salivate in anticipation of the food, even before he put it in their mouth. He soon discovered that if he rang a bell just before the food was presented each time, the dogs would eventually salivate at the mere sound of the bell. Pavlov had discovered a basic form of learning called classical conditioning (also referred to as Pavlovian conditioning) in which an organism comes to associate one stimulus with another. Later research showed that this basic process can account for how people form certain preferences and fears.
American psychologist John B. Watson believed psychologists should study observable behavior instead of speculating about a person”s inner thoughts and feelings. Watson's approach, which he termed behaviorism, dominated psychology for the first half of the 20th century.
Although Thorndike and Pavlov set the stage for behaviorism, it was not until 1913 that a psychologist set forward a clear vision for behaviorist psychology. In that year John Watson, a well-known animal psychologist at Johns Hopkins University, published a landmark paper entitled “Psychology as the Behaviorist Views It.” Watson”s goal was nothing less than a complete redefinition of psychology. “Psychology as the behaviorist views it.” Watson wrote, “is a purely objective experimental branch of natural science. Its theoretical goal is the prediction and control of behavior.” Watson narrowly defined psychology as the scientific study of behavior. He urged his colleagues to abandon both introspection and speculative theories about the unconscious. Instead he stressed the importance of observing and quantifying behavior. In light of Darwin”s theory of evolution, he also advocated the use of animals in psychological research, convinced that the principles of behavior would generalize across all species.
American psychologist B. F. Skinner became famous for his pioneering research on learning and behavior. During his 60-year career, Skinner discovered important principles of operant conditioning, a type of learning that involves reinforcement and punishment. A strict behaviorist, Skinner believed that operant conditioning could explain even the most complex of human behaviors.
Many American psychologists were quick to adopt behaviorism, and animal laboratories were set up all over the country. Aiming to predict and control behavior, the "behaviorists” strategy was to vary a stimulus in the environment and observe an organism's response. They saw no need to speculate about mental processes inside the head. For example, Watson argued that thinking was simply talking to oneself silently. He believed that thinking could be studied by recording the movement of certain muscles in the throat.
American psychologist B. F. Skinner designed an apparatus, now called a Skinner box, that allowed him to formulate important principles of animal learning. An animal placed inside the box is rewarded with a small bit of food each time it makes the desired response, such as pressing a lever or pecking a key. A device outside the box records the animal”s responses.
The most forceful leader of behaviorism was B. F. Skinner, an American psychologist who began studying animal learning in the 1930s. Skinner coined the term reinforcement and invented a new research apparatus called the Skinner box for use in testing animals. Based on his experiments with rats and pigeons, Skinner identified a number of basic principles of learning. He claimed that these principles explained not only the behavior of laboratory animals, but also accounted for how human beings learn new behaviors or change existing behaviors. He concluded that nearly all behavior is shaped by complex patterns of reinforcement in a person”s environment, a process that he called operant conditioning (also referred to as instrumental conditioning). Skinner”s views on the causes of human behavior made him one of the most famous and controversial psychologists of the 20th century.
Operant conditioning, pioneered by American psychologist B. F. Skinner, is the process of shaping behavior by means of reinforcement and punishment. This illustration shows how a mouse can learn to maneuver through a maze. The mouse is rewarded with food when it reaches the first turn in the maze (A). Once the first behavior becomes ingrained, the mouse is not rewarded until it makes the second turn (B). After many times through the maze, the mouse must reach the end of the maze to receive its reward ©.
Skinner and others applied his findings to modify behavior in the workplace, the classroom, the clinic, and other settings. In World War II (1939-1945), for example, he worked for the U.S. government on a top-secret project in which he trained pigeons to guide an armed glider plane toward enemy ships. He also invented the first teaching machine, which allowed students to learn at their own pace by solving a series of problems and receiving immediate feedback. In his popular book Walden Two (1948), Skinner presented his vision of a behaviorist utopia, in which socially adaptive behaviors are maintained by rewards, or positive reinforcements. Throughout his career, Skinner held firm to his belief that psychologists should focus on the prediction and control of behavior.
Faced with a choice between psychoanalysis and behaviorism, many psychologists in the 1950s and 1960s sensed a void in psychology”s conception of human nature. Freud had drawn attention to the darker forces of the unconscious, and Skinner was interested only in the effects of reinforcement on observable behavior. Humanistic psychology was born out of a desire to understand the conscious mind, free will, human dignity, and the capacity for self-reflection and growth. An alternative to psychoanalysis and behaviorism, humanistic psychology became known as “the third force.”
The humanistic movement was led by American psychologists Carl Rogers and Abraham Maslow. According to Rogers, all humans are born with a drive to achieve their full capacity and to behave in ways that are consistent with their true selves. Rogers, a psychotherapist, developed person-centered therapy, a nonjudgmental, nondirective approach that helped clients clarify their sense of whom they are in an effort to facilitate their own healing process. At about the same time, Maslow theorized that all people are motivated to fulfill a hierarchy of needs. At the bottom of the hierarchy are basic physiological needs, such as hunger, thirst, and sleep. Further up the hierarchy are needs for safety and security, needs for belonging and love, and esteem-related needs for status and achievement. Once these needs are met, Maslow believed, people strive for self-actualization, the ultimate state of personal fulfillment. As Maslow put it: A musician must make music, an artist must paint, a poet must write, if he is ultimately to be at peace with himself. "What a man can be, he must be.
Swiss psychologist Jean Piaget based his early theories of intellectual development on his questioning and observation of his own children. From these and later studies, Piaget concluded that all children pass through a predictable series of cognitive stages.
From the 1920s through the 1960s, behaviorism dominated psychology in the United States. Eventually, however, psychologists began to move away from strict behaviorism. Many became increasingly interested in cognition, a term used to describe all the mental processes involved in acquiring, storing, and using knowledge. Such processes include perception, memory, thinking, problem solving, imagining, and language. This shift in emphasis toward cognition had such a profound influence on psychology that it has often been called the cognitive revolution. The psychological study of cognition became known as cognitive psychology.
One reason for psychologists” renewed interest in mental processes was the invention of the computer, which provided an intriguing metaphor for the human mind. The hardware of the computer was likened to the brain, and computer programs provided a step-by-step model of how information from the environment is input, stored, and retrieved to produce a response. Based on the computer metaphor, psychologists began to formulate information-processing models of human thought and behavior.
In the 1950s American linguist Noam Chomsky proposed that the human brain is especially constructed to detect and reproduce language and that the ability to form and understand language is innate to all human beings. According to Chomsky, young children learn and apply grammatical rules and vocabulary as they are exposed to them and do not require initial formal teaching.
The pioneering work of Swiss psychologist Jean Piaget also inspired psychologists to study cognition. During the 1920s, while administering intelligence tests in schools, Piaget became interested in how children think. He designed various tasks and interview questions to reveal how children of different ages reason about time, nature, numbers, causality, morality, and other concepts. Based on his many studies, Piaget theorized that from infancy to adolescence, children advance through a predictable series of cognitive stages.
The cognitive revolution also gained momentum from developments in the study of language. Behaviorist B. F. Skinner had claimed that language is acquired according to the laws of operant conditioning, in much the same way that rats learn to press a bar for food pellets. In 1959, however, American linguist Noam Chomsky charged that Skinner's account of language development was wrong. Chomsky noted that children all over the world start to speak at roughly the same age and proceed through roughly the same stages without being explicitly taught or rewarded for the effort. According to Chomsky, the human capacity for learning language is innate. He theorized that the human brain is “hardwired” for language as a product of evolution. By pointing to the primary importance of biological dispositions in the development of language, Chomsky”s theory dealt a serious blow to the behaviorist assumption that all human behaviors are formed and maintained by reinforcement.
Before psychology became established in science, it was popularly associated with extrasensory perception (ESP) and other paranormal phenomena (phenomena beyond the laws of science). Today, these topics lie outside the traditional scope of scientific psychology and fall within the domain of parapsychology. Psychologists note that thousands of studies have failed to demonstrate the existence of paranormal phenomena.
Grounded in the conviction that mind and behavior must be studied using statistical and scientific methods, psychology has become a highly respected and socially useful discipline. Psychologists now study important and sensitive topics such as the similarities and differences between men and women, racial and ethnic diversity, sexual orientation, marriage and divorce, abortion, adoption, intelligence testing, sleep and sleep disorders, obesity and dieting, and the effects of psychoactive drugs such as methylphenidate (Ritalin) and fluoxetine (Prozac).
In the last few decades, researchers have made significant breakthroughs in understanding the brain, mental processes, and behavior. This section of the article provides examples of contemporary research in psychology: the plasticity of the brain and nervous system, the nature of consciousness, memory distortions, competence and rationality, genetic influences on behavior, infancy, the nature of intelligence, human motivation, prejudice and discrimination, the benefits of psychotherapy, and the psychological influences on the immune system.
Psychologists once believed that the neural circuits of the adult brain and nervous system were fully developed and no longer subject to change. Then in the 1980s and 1990s a series of provocative experiments showed that the adult brain has flexibility, or plasticity-a capacity to change as a result of usage and experience.
These experiments showed that adult rats flooded with visual stimulation formed new neural connections in the brain's visual cortex, where visual signals are interpreted. Likewise, those trained to run an obstacle course formed new connections in the cerebellum, where balance and motor skills are coordinated. Similar results with birds, mice, and monkeys have confirmed the point: Experience can stimulate the growth of new connections and mold the brain”s neural architecture.
Once the brain reaches maturity, the number of neurons does not increase, and any neurons that are damaged are permanently disabled. But the plasticity of the brain can greatly benefit people with damage to the brain and nervous system. Organisms can compensate for loss by strengthening old neural connections and sprouting new ones. That is why people who suffer strokes are often able to recover their lost speech and motor abilities.
In 1860 German physicist Gustav Fechner theorized that if the human brain were divided into right and left halves, each side would have its own stream of consciousness. Modern medicine has actually allowed scientists to investigate this hypothesis. People who suffer from life-threatening epileptic seizures sometimes undergo a radical surgery that severs the corpus callosum, a bridge of nerve tissue that connects the right and left hemispheres of the brain. After the surgery, the two hemispheres can no longer communicate with each other.
Scientists have long considered the nature of consciousness without producing a fully satisfactory definition. In the early 20th century American philosopher and psychologist William James suggested that consciousness is a mental process involving both attention to external stimuli and short-term memory. Later scientific explorations of consciousness mostly expanded upon James”s work. In this article from a 1997 special issue of Scientific American, Nobel laureate Francis Crick, who helped determine the structure of DNA, and fellow biophysicist Christof Koch explain how experiments on vision might deepen our understanding of consciousness.
Beginning in the 1960s American neurologist Roger Sperry and others tested such split-brain patients in carefully designed experiments. The researchers found that the hemispheres of these patients seemed to function independently, almost as if the subjects had two brains. In addition, they discovered that the left hemisphere was capable of speech and language, but not the right hemisphere. For example, when split-brain patients saw the image of an object flashed in their left visual field (thus sending the visual information to the right hemisphere), they were incapable of naming or describing the object. Yet they could easily point to the correct object with their left hand (which is controlled by the right hemisphere). As Sperry”s colleague Michael Gazzaniga stated, “Each half brain seemed to work and function outside of the conscious realm of the other.”
Other psychologists interested in consciousness have examined how people are influenced without their awareness. For example, research has demonstrated that under certain conditions in the laboratory, people can be fleetingly affected by subliminal stimuli, sensory information presented so rapidly or faintly that it falls below the threshold of awareness. (Note, however, that scientists have discredited claims that people can be importantly influenced by subliminal messages in advertising, rock music, or other media.) Other evidence for influence without awareness comes from studies of people with a type of amnesia that prevents them from forming new memories. In experiments, these subjects are unable to recognize words they previously viewed in a list, but they are more likely to use those words later in an unrelated task. In fact, memory without awareness is normal, as when people come up with an idea they think is original, only later to realize that they had inadvertently borrowed it from another source.
Cognitive psychologists have often likened human memory to a computer that encodes, stores, and retrieves information. It is now clear, however, that remembering is an active process and that people construct and alter memories according to their beliefs, wishes, needs, and information received from outside sources.
Without realizing it, people sometimes create memories that are false. In one study, for example, subjects watched a slide show depicting a car accident. They saw either a “STOP” sign or a “YIELD” sign in the slides, but afterward they were asked a question about the accident that implied the presence of the other sign. Influenced by this suggestion, many subjects recalled the wrong traffic sign. In another study, people who heard a list of sleep-related words (bed, yawn) or music-related words (jazz, instrument) were often convinced moments later that they had also heard the words sleep or music-words that fit the category but were not on the list. In a third study, researchers asked college students to recall their high-school grades. Then the researchers checked those memories against the students” actual transcripts. The students recalled most grades correctly, but most of the errors inflated their grades, particularly when the actual grades were low. When scientists distinguish between human beings and other animals, they point to our larger cerebral cortex (the outer part of the brain) and to our superior intellect-as seen in the abilities to acquire and store large amounts of information, solve problems, and communicate through the use of language.
In recent years, however, those studying human cognition have found that people are often less than rational and accurate in their performance. Some researchers have found that people are prone to forgetting, and worse, that memories of past events are often highly distorted. Others have observed that people often violate the rules of logic and probability when reasoning about real events, as when gamblers overestimate the odds of winning in games of chance. One reason for these mistakes is that we commonly rely on cognitive heuristics, mental shortcuts that allow us to make judgments that are quick but often in error. To understand how heuristics can lead to mistaken assumptions, imagine offering people a lottery ticket containing six numbers out of a pool of the numbers 1 through 40. If given a choice between the tickets 6-39-2-10-24-30 or 1-2-3-4-5-6, most people select the first ticket, because it has the appearance of randomness. Yet out of the 3,838,380 possible winning combinations, both sequences are equally likely.
One of the oldest debates in psychology, and in philosophy, concerns whether individual human traits and abilities are predetermined from birth or due to one's upbringing and experiences. This debate is often termed the nature-nurture debate. A strict genetic (nature) position states that people are predisposed to become sociable, smart, cheerful, or depressed according to their genetic blueprint. In contrast, a strict environmental (nurture) position says that people are shaped by parents, peers, cultural institutions, and life experiences.
Research shows that the more genetically related a person is to someone with schizophrenia, the greater the risk that person has of developing the illness. For example, children of one parent with schizophrenia have a 13 percent chance of developing the illness, whereas children of two parents with schizophrenia have a 46 percent chance of developing the disorder.
Researchers can estimate the role of genetic factors in two ways: (1) twin studies and (2) adoption studies. Twin studies compare identical twins with fraternal twins of the same sex. If identical twins (who share all the same genes) are more similar to each other on a given trait than are same-sex fraternal twins (who share only about half of the same genes), then genetic factors are assumed to influence the trait. Other studies compare identical twins who are raised together with identical twins who are separated at birth and raised in different families. If the twins raised together are more similar to each other than the twins raised apart, childhood experiences are presumed to influence the trait. Sometimes researchers conduct adoption studies, in which they compare adopted children to their biological and adoptive parents. If these children display traits that resemble those of their biological relatives more than their adoptive relatives, genetic factors are assumed to play a role in the trait.
In recent years, several twin and adoption studies have shown that genetic factors play a role in the development of intellectual abilities, temperament and personality, vocational interests, and various psychological disorders. Interestingly, however, this same research indicates that at least 50 percent of the variation in these characteristics within the population is attributable to factors in the environment. Today, most researchers agree that psychological characteristics spring from a combination of the forces of nature and nurture.
Helpless to survive on their own, newborn babies nevertheless possess a remarkable range of skills that aid in their survival. Newborns can see, hear, taste, smell, and feel pain; vision is the least developed sense at birth but improves rapidly in the first months. Crying communicates their need for food, comfort, or stimulation. Newborns also have reflexes for sucking, swallowing, grasping, and turning their head in search of their mother”s nipple.
In 1890 William James described the newborn”s experience as “one great blooming, buzzing confusion.” However, with the aid of sophisticated research methods, psychologists have discovered that infants are smarter than was previously known.
A period of dramatic growth, infancy lasts from birth to around 18 months of age. Researchers have found that infants are born with certain abilities designed to aid their survival. For example, newborns show a distinct preference for human faces over other visual stimuli.
To learn about the perceptual world of infants, researchers measure infants” head movements, eye movements, facial expressions, brain waves, heart rate, and respiration. Using these indicators, psychologists have found that shortly after birth, infants show a distinct preference for the human face over other visual stimuli. Also suggesting that newborns are tuned into the face as a social object is the fact that within 72 hours of birth, they can mimic adults who purse the lips or stick out the tongue-a rudimentary form of imitation. Newborns can distinguish between their mother”s voice and that of another woman. And at two weeks old, nursing infants are more attracted to the body odor of their mother and other breast-feeding females than to that of other women. Taken together, these findings show that infants are equipped at birth with certain senses and reflexes designed to aid their survival.
In 1905 French psychologist Alfred Binet and colleague Théodore Simon devised one of the first tests of general intelligence. The test sought to identify French children likely to have difficulty in school so that they could receive special education. An American version of Binet”s test, the Stanford-Binet Intelligence Scale, is still used today.
In 1905 French psychologist Alfred Binet devised the first major intelligence test for the purpose of identifying slow learners in school. In doing so, Binet assumed that intelligence could be measured as a general intellectual capacity and summarized in a numerical score, or intelligence quotient (IQ). Consistently, testing has revealed that although each of us is more skilled in some areas than in others, a general intelligence underlies our more specific abilities.
Intelligence tests often play a decisive role in determining whether a person is admitted to college, graduate school, or professional school. Thousands of people take intelligence tests every year, but many psychologists and education experts question whether these tests are an accurate way of measuring who will succeed or fail in school and later in life. In this 1998 Scientific American article, psychology and education professor Robert J. Sternberg of Yale University in New Haven, Connecticut, presents evidence against conventional intelligence tests and proposes several ways to improve testing.
Today, many psychologists believe that there is more than one type of intelligence. American psychologist Howard Gardner proposed the existence of multiple intelligence, each linked to a separate system within the brain. He theorized that there are seven types of intelligence: linguistic, logical-mathematical, spatial, musical, bodily-kinesthetic, interpersonal, and intrapersonal. American psychologist Robert Sternberg suggested a different model of intelligence, consisting of three components: analytic (“school smarts,” as measured in academic tests), creative (a capacity for insight), and practical (“street smarts,” or the ability to size up and adapt to situations). Psychologists from all branches of the discipline study the topic of motivation, an inner state that moves an organism toward the fulfillment of some goal. Over the years, different theories of motivation have been proposed. Some theories state that people are motivated by the need to satisfy physiological needs, whereas others state that people seek to maintain an optimum level of bodily arousal (not too little and not too much). Still other theories focus on the ways in which people respond to external incentives such as money, grades in school, and recognition. Motivation researchers study a wide range of topics, including hunger and obesity, sexual desire, the effects of reward and punishment, and the needs for power, achievement, social acceptance, love, and self-esteem.
In 1954 American psychologist Abraham Maslow proposed that all people are motivated to fulfill a hierarchical pyramid of needs. At the bottom of Maslow”s pyramid are needs essential to survival, such as the needs for food, water, and sleep. The need for safety follows these physiological needs. According to Maslow, higher-level needs become important to us only after our more basic needs are satisfied. These higher needs include the need for love and belongingness, the need for esteem, and the need for self-actualization (in Maslow”s theory, a state in which people realize their greatest potential).
The view that the role of sentences in inference gives a more important key to their meaning than their “external” relations to things in the world. The meaning of a sentence becomes its place in a network of inferences that it legitimates. Also, known as its functional role semantics, procedural semantic or conceptual role semantics. As these view bear some relation to the coherence theory of truth, and suffers from the same suspicion that divorces meaning from any clear association with things in the world.
Paradoxes rest upon the assumption that analysis is a relation with concept, then are involving entities of other sorts, such as linguistic expressions, and that in true analysis, analysand and analysandum are one and the same concept. However, these assumptions are explicit in the British philosopher George Edward Moore, but some of Moore”s remarks hint at a solution that a statement of an analysis is a statement partially taken about the concept involved and partly about the verbal expression used to express it. Moore is to suggest that he thinks of a solution of this sort is bound to be right, however, facts to suggest one because he cannot reveal of any way in which the analysis can be as part of the expression.
Elsewhere, the possibility clearly does set of apparent incontrovertible premises giving unacceptable or contradictory conclusions. To solve a paradox will involve showing that either these hidden flaws in the premises, or what the reasoning is erroneous, or that the apparently unacceptable conclusion can, in fact, be tolerable. Paradoxes are therefore important in philosophy, for until one is solved it shows that there is something about our reasoning and our concepts that we do not understand. Famous families of paradoxes include the semantic paradoxes and Zeno's paradoxes. At the beginning of the 20th century, Russell's paradox and other set-theoretic paradoxes of set theory, while the Sorites paradox has led to the investigation of the semantics of vagueness, and fuzzy logic. Paradoxes are under their other titles. Much as there is as much as a puzzle arising when someone says “p but I do not believe that p.” What is said is not contradictory, since (for many instances of p) both parts of it could br. true. But the person nevertheless violates one presupposition of normal practice, namely that you assert something only if you believe it: By adding that you do not believe what you just said you undo the natural significance of the original act saying it.
Furthermore, the moral philosopher and epistemologist Bernard Bolzano (1781-1848), whose logical work was based on a strong sense of there being an ontological underpinning of science and epistemology, lying in a theory of the objective entailments masking up the structure of scientific theories. His ability to challenge wisdom and come up with startling new ideas, as a Christian philosopher whether than from any position of mathematical authority, that for considerations of infinity, Bolzano”s significant work was Paradoxin des Unenndlichen, written in retirement and translated into the English as Paradoxes of the Infinite. Here, Bolzano considered directly the points that had concerned Galileo-the conflicting result that seem to emerge when infinity is studied. Certainly most of the paradoxical statements encountered in the mathematical domain . . . are propositions which either immediately contain the idea of the infinite, or at least in some way or other depends upon that idea for their attempted proof.
Continuing, Bolzano looks at two possible approaches to infinity. One is simply the case of setting up a sequence of numbers, such as the whole numbers, and saying that as it cannot conceivably be said to have a last term, it is inherently infinite-not finite. It is easy enough to show that the whole numbers do not have a point at which they stop, giving a name to that last number whatever it might have been to call it “ultimate.” Then what”s wrong with ultimate + 1? Why is that not a whole number?
The second approach to infinity, which Bolzano ascribes in Paradoses of the Infinite to “some philosophers . . . Taking this approach describe his first conception of infinity as the “bad infinity.” Although the German philosopher Friedrich George Hegel (1770-1831) applies the conceptual form of infinity and points that it is, rather, the basis for a substandard infinity that merely reaches toward the absolute, but never reaches it. In Paradoses of the Infinite, he calls this form of potential infinity as a variable quantity knowing no limit to its growth (a definition adopted, even by many mathematicians) . . . always growing int the infinite and never reaching it. As far as Hegel and his colleagues were concerned, using this uprush, there was no need for a real infinity beyond some unreachable absolute. Instead we deal with a variable quality that is as big as we need it to be, or often in calculus as small as we need it to be, without ever reaching the absolute, ultimate, truly infinite.
Bolzano argues, though, that there is something else, an infinity that does not have this “whatever you need it to be” elasticity. In fact a truly infinite quantity (for example, the length of a straight line unbounded in either direction, meaning: The magnitude of the spatial entity containing all the points determined solely by their abstractly conceivable relation to two fixed points) does not by any means need to be variable, and in an adduced example it is in fact not variable. Conversely, it is quite possible for a quantity merely capable of being taken greater than we have already taken it, and of becoming larger than any pre-assigned (finite) quantity, nevertheless to mean at all times merely finitely, which holds in particular of every numerical quantity 1, 2, 3, 4, 5.
In other words, for Bolzano there could be a true infinity that was not a variable “something” that was only bigger than anything you might specify. Such a true infinity was the result of joining two pints together and extending that line in both directions without stopping. And what is more, he could separate off the demands of calculus, using a finite quality without ever bothering with the slippery potential infinity. Here was both a deeper understanding of the nature of infinity and the basis on which are built in his “safe” infinity free calculus.
This use of the inexhaustible follows on directly from most Bolzano”s criticism of the way that ∞we used as a variable something that would be bigger than anything you could specify, but never quite reached the true, absolute infinity. In Paradoxes of the Infinity Bolzano points out that is possible for a quantity merely capable of becoming larger than any other one pre-assigned (finite) quantity, nevertheless to remain at all times merely finite.
Bolzano intended tis as a criticism of the way infinity was treated, but Professor Jacquette sees it instead of a way of masking use of practical applications like calculus without the need for weasel words about infinity.
By replacing ∞with ¤ we do away with one of the most common requirements for infinity, but is there anything left that map out to the real world? Can we confine infinity to that pure mathematical other world, where anything, however unreal, can be constructed, and forget about it elsewhere? Surprisingly, this seems to have been the view, at least at one point in time, even of the German mathematician and founder of set-theory Georg Cantor (1845-1918), himself, whose comments in 1883, that only the finite numbers are real.
Keeping within the lines of reason, both the Cambridge mathematician and philosopher Frank Plumpton Ramsey (1903-30) and the Italian mathematician G. Peano (1858-1932) have been to distinguish logical paradoxes and that depend upon the notion of reference or truth (semantic notions), such are the postulates justifying mathematical induction. It ensures that a numerical series is closed, in the sense that nothing but zero and its successors can be numbers. In that any series satisfying a set of axioms can be conceived as the sequence of natural numbers. Candidates from set theory include the Zermelo numbers, where the empty set is zero, and the successor of each number is its unit set, and the von Neuman numbers, where each number is the set of all smaller numbers. A similar and equally fundamental complementarity exists in the relation between zero and infinity. Although the fullness of infinity is logically antithetical to the emptiness of zero, infinity can be obtained from zero with a simple mathematical operation. The division of many numbers by zero is infinity, while the multiplication of any number by zero is zero.
With the set theory developed by the German mathematician and logician Georg Cantor. From 1878 to 1807, Cantor created a theory of abstract sets of entities that eventually became a mathematical discipline. A set, as he defined it, is a collection of definite and distinguished objects in thought or perception conceived as a whole.
Cantor attempted to prove that the process of counting and the definition of integers could be placed on a solid mathematical foundation. His method was to repeatedly place the elements in one set into “one-to-one” correspondence with those in another. In the case of integers, Cantor showed that each integer (1, 2, 3, . . . n) could be paired with an even integer (2, 4, 6, . . . n), and, therefore, that the set of all integers was equal to the set of all even numbers.
Amazingly, Cantor discovered that some infinite sets were large than others and that infinite sets formed a hierarchy of greater infinities. After this failed attempt to save the classical view of logical foundations and internal consistency of mathematical systems, it soon became obvious that a major crack had appeared in the seemingly sold foundations of number and mathematics. Meanwhile, an impressive number of mathematicians began to see that everything from functional analysis to the theory of real numbers depended on the problematic character of number itself.
While, in the theory of probability Ramsey was the first to show how a personalised theory could be developed, based on precise behavioural notions of preference and expectation. In the philosophy of language, Ramsey was one of the first thinkers to accept a “redundancy theory of truth,” which hr combined with radical views of the function of many kinds of propositions. Neither generalizations nor causal propositions, nor those treating probability or ethics, describe facts, but each has a different specific function in our intellectual economy.
Ramsey advocates that of a sentence generated by taking all the sentences affirmed in a scientific theory that use some term, e.g., “quark.” Replacing the term by a variable, and existentially quantifying into the result. Instead of saying quarks have such-and-such properties, Ramsey postdated that the sentence as saying that there is something that has those properties. If the process is repeated, the sentence gives the “topic-neutral” structure of the theory, but removes any implications that we know what the term so treated denote. I t leaves open the possibility of identifying the theoretical item with whatever it is that best fits the description provided. Nonetheless, it was pointed out by the Cambridge mathematician Newman that if the process is carried out for all except the logical bones of the theory, then by the Löwenheim-Skolem theorem, the result will be interpretable in any domain of sufficient cardinality, and the content of the theory may reasonably be felt to have been lost.
It seems, that the most taken of paradoxes in the foundations of “set theory” as discovered by Russell in 1901. Some classes have themselves as members: The class of all abstract objects, for example, is an abstract object, whereby, others do not: The class of donkeys is not itself a donkey. Now consider the class of all classes that are not members of themselves, is this class a member of itself, that, if it is, then it is not, and if it is not, then it is.
The paradox is structurally similar to easier examples, such as the paradox of the barber. Such one like a village having a barber in it, who shaves all and only the people who do not have in themselves. Who shaves the barber? If he shaves himself, then he does not, but if he does not shave himself, then he does not. The paradox is actually just a proof that there is no such barber or in other words, that the condition is inconsistent. All the same, it is no too easy to say why there is no such class as the one Russell defines. It seems that there must be some restriction on the kind of definition that are allowed to define classes and the difficulty that of finding a well-motivated principle behind any such restriction.
The French mathematician and philosopher Henri Jules Poincaré (1854-1912) believed those paradoses like those of Russell nd the “barber” were due to such as the im predicative definitions, and therefore proposed banning them. But, it tuns out that classical mathematics required such definitions at too many points for the ban to be easily absolved. Having, in turn, as forwarded by Poincaré and Russell, was that in order to solve the logical and semantic paradoxes it would have to ban any collection (set) containing members that can only be defined by means of the collection taken as a whole. It is, effectively by all occurring principles into which have an adopting vicious regress, as to mark the definition for which involves no such failure. There is frequently room for dispute about whether regresses are benign or vicious, since the issue will hinge on whether it is necessary to reapply the procedure. The cosmological argument is an attempt to find a stopping point for what is otherwise seen as an infinite regress, and, to ban of the predicative definitions.
The investigation of questions that arise from reflection upon sciences and scientific inquiry, are such as called of a philosophy of science. Such questions include, what distinctions in the methods of science? Is there a clear demarcation between scenes and other disciplines, and how do we place such enquires as history, economics or sociology? And scientific theories probable or more in the nature of provisional conjecture? Can the be verified or falsified? What distinguished good from bad explanations? Might there be one unified since, embracing all the special science? For much of the 20th century their questions were pursued in a high abstract and logical framework it being supposed that as general logic of scientific discovery that a general logic of scientific discovery a justification might be found. However, many now take interests in a more historical, contextual and sometimes sociological approach, in which the methods and successes of a science at a particular time are regarded less in terms of universal logical principles and procedure, and more in terms of their availability to methods and paradigms as well as the social context.
In addition, to general questions of methodology, there are specific problems within particular sciences, giving subjects as biology, mathematics and physics.
The intuitive certainty that sparks aflame the dialectic awarenesses for its immediate concerns are either of the truths or by some other in an object of apprehensions, such as a concept. Awareness as such, has to its amounting quality value the place where philosophically understanding of the source of our knowledge are, however, in covering the sensible apprehension of things and pure intuition it is that which stricture sensation into the experience of things accent of its direction that orchestrates the celestial overture into measures in space and time.
The notion that determines how something is seen or evaluated of the status of law and morality especially associated with St Thomas Aquinas and the subsequent scholastic tradition. More widely, any attempt to cement the moral and legal order together with the nature of the cosmos or how the nature of human beings, for which sense it is also found in some Protestant writers, and arguably derivative from a Platonic view of ethics, and is implicit in ancient Stoicism. Law stands above and apart from the activities of human lawmaker, it constitutes an objective set of principles that can be seen true by “natural light” or reason, and (in religion versions of the theory) that express God”s will for creation. Non-religious versions of the theory substitute objective conditions for human flourishing as the source of constraints upon permissible actions and social arrangements. Within the natural law tradition, different views have been held about the relationship between the rule of law about God' s will, for instance the Dutch philosopher Hugo Grothius (1583-1645), similarly takes upon the view that the content of natural law is independent of any will, including that of God, while the German theorist and historian Samuel von Pufendorf (1632-94) takes the opposite view, thereby facing the problem of one horn of the Euthyphro dilemma, that simply states, that its dilemma arises from whatever the source of authority is supposed to be, for in which do we care about the general good because it is good, or do we just call good things that we care about. Wherefore, by facing the problem that may be to assume of a strong form, in which it is claimed that various facts entail values, or a weaker form, from which it confines itself to holding that reason by itself is capable of discerning moral requirements that are supped of binding to all human bings regardless of their desires
Although the morality of people send the ethical amount, from which the same thing, is that there is a usage that restricts morality to systems such as that of the German philosopher and founder of ethical philosophy Immanuel Kant (1724-1804), based on notions such as duty, obligation, and principles of conduct, reserving ethics for more than the Aristotelian approach to practical reasoning based on the notion of a virtue, and generally avoiding the separation of “moral” considerations from other practical considerations. The scholarly issues are complex, with some writers seeing Kant as more Aristotelian and Aristotle as, ore involved in a separate sphere of responsibility and duty, than the simple contrast suggests. Some theorists see the subject in terms of a number of laws (as in the Ten Commandments). The status of these laws may be test they are the edicts of a divine lawmaker, or that they are truths of reason, knowable deductively. Other approaches to ethics (e.g., eudaimonism, situation ethics, virtue ethics) eschew general principles as much as possible, frequently disguising the great complexity of practical reasoning. For Kantian notion of the moral law is a binding requirement of the categorical imperative, and to understand whether they are equivalent at some deep level. Kant's own applications of the notion are not always convincing, as for one cause of confusion in relating Kant's ethics to theories such additional expressivism is that it is easy, but mistaken, to suppose that the categorical nature of the imperative means that it cannot be the expression of sentiment, but must derive from something “unconditional” or “necessary” such as the voice of reason.
For whichever reason, the mortal being makes of its presence to the future of weighing of that which one must do, or that which can be required of one. The term carries implications of that which is owed (due) to other people, or perhaps in onself. Universal duties would be owed to persons (or sentient beings) as such, whereas special duty in virtue of specific relations, such for being the child of someone, or having made someone a promise. Duty or obligation is the primary concept of “deontological” approaches to ethics, but is constructed in other systems out of other notions. In the system of Kant, a perfect duty is one that must be performed whatever the circumstances: Imperfect duties may have to give way to the more stringent ones. In another way, perfect duties are those that are correlative with the right to others, imperfect duties are not. Problems with the concept include the ways in which due needs to be specified (a frequent criticism of Kant is that his notion of duty is too abstract). The concept may also suggest of a regimented view of ethical life in which we are all forced conscripts in a kind of moral army, and may encourage an individualistic and antagonistic view of social relations.
The most generally accepted account of externalism and/or internalism, that this distinction is that a theory of justification is internalist if only if it requiem that all of the factors needed for a belief to be epistemologically justified for a given person be cognitively accessible to that person, internal to his cognitive perceptive, and externalist, if it allows that at least some of the justifying factors need not be thus accessible, so that thy can be external to the believer”s cognitively perceptive, beyond any such given relations. However, epistemologists often use the distinction between internalist and externalist theories of epistemic justification without offering any very explicit explication.
The externalist/internalist distinction has been mainly applied to theories of epistemic justification: It has also been applied in a closely related way to accounts of knowledge and in a rather different way to accounts of belief and thought contents.
The internalist requirement of cognitive accessibility can be interpreted in at least two ways: A strong version of internalism would require that the believer actually be aware of the justifying factor in order to be justified: While a weaker version would require only that he be capable of becoming aware of them by focussing his attentions appropriately, but without the need for any change of position, new information, etc. Though the phrase “cognitively accessible” suggests the weak interpretation, the main intuitive motivation for internalism, viz. the idea that epistemic justification requires that the believer actually have in his cognitive possession a reason for thinking that the belief is true, and would require the strong interpretation.
Perhaps, the clearest example of an internalist position would be a Foundationalist view according to which foundational beliefs pertain to immediately experienced states of mind and other beliefs are justified by standing in cognitively accessible logical or inferential relations to such foundational beliefs. Such a view could count as either a strong or a weak version of internalism, depending on whether actual awareness of the justifying elements or only the capacity to become aware of them is required. Similarly, a coherent view could also be internalist, if both the beliefs or other states with which a justification belief is required to cohere and the coherence relations themselves are reflectively accessible.
It should be carefully noticed that when internalism is construed in this way, it is neither necessary nor sufficient by itself for internalism that the justifying factors literally be internal mental states of the person in question. Not necessary, necessary, because on at least some views, e.g., a direct realist view of perception, something other than a mental state of the believer can be cognitively accessible: Not sufficient, because there are views according to which at least some mental states need not be actual (strong version) or even possible (weak version) objects of cognitive awareness. Also, on this way of drawing the distinction, a hybrid view, according to which some of the factors required for justification must be cognitively accessible while others need not and in general will not be, would count as an externalist view. Obviously too, a view that was externalist in relation to a strong version of internalism (by not requiring that the believer actually be aware of all justifying factors) could still be internalist in relation to a weak version (by requiring that he at least be capable of becoming aware of them).
The most prominent recent externalist views have been versions of reliabilism, whose requirements for justification is roughly that the belief be produced in a way or via a process that makes of objectively likely that the belief is true. What makes such a view externalist is the absence of any requirement that the person for whom the belief is justified have any sort of cognitive access to the relations of reliability in question. Lacking such access, such a person will in general have no reason for thinking that the belief is true or likely to be true, but will, on such an account, nonetheless be epistemically justified in according it. Thus such a view arguably marks a major break from the modern epistemological tradition, stemming from Descartes, which identifies epistemic justification with having a reason, perhaps even a conclusive reason for thinking that the belief is true. An epistemologist working within this tradition is likely to feel that the externalist, than offering a competing account of the same concept of epistemic justification with which the traditional epistemologist is concerned, has simply changed the subject.
The main objection to externalism rests on the intuitive certainty that the basic requirement for epistemic justification is that the acceptance of the belief in question be rational or responsible in relation to the cognitive goal of truth, which seems to require in turn that the believer actually be dialectally aware of a reason for thinking that the belief is true (or, at the very least, that such a reason be available to him). Since the satisfaction of an externalist condition is neither necessary nor sufficient for the existence of such a cognitively accessible reason, it is argued, externalism is mistaken as an account of epistemic justification. This general point has been elaborated by appeal to two sorts of putative intuitive counter-examples to externalism. The first of these challenges the necessity of belief which seem intuitively to be justified, but for which the externalist conditions are not satisfied. The standard examples in this sort are cases where beliefs are produced in some very nonstandard way, e.g., by a Cartesian demon, but nonetheless, in such a way that the subjective experience of the believer is indistinguishable from that of someone whose beliefs are produced more normally. The intuitive claim is that the believer in such a case is nonetheless epistemically justified, as much so as one whose belief is produced in a more normal way, and hence that externalist account of justification must be mistaken.
Perhaps the most striking reply to this sort of counter-example, on behalf of a cognitive process is to be assessed in “normal” possible worlds, i.e., in possible worlds that are actually the way our world is common-seismically believed to be, than in the world which contains the belief being judged. Since the cognitive processes employed in the Cartesian demon cases are, for which we may assume, reliable when assessed in this way, the reliabilist can agree that such beliefs are justified. The obvious, to a considerable degree of bringing out the issue of whether it is or not an adequate rationale for this construal of reliabilism, so that the reply is not merely a notional presupposition guised as having representation.
The correlative way of elaborating on the general objection to justificatory externalism challenges the sufficiency of the various externalist conditions by citing cases where those conditions are satisfied, but where the believers in question seem intuitively not to be justified. In this context, the most widely discussed examples have to do with possible occult cognitive capacities, like clairvoyance. Considering the point in application once, again, to reliabilism, the claim is that to think that he has such a cognitive power, and, perhaps, even good reasons to the contrary, is not rational or responsible and therefore not epistemically justified in accepting the belief that result from his clairvoyance, despite the fact that the reliablist condition is satisfied.
One sort of response to this latter sorts of objection is to “bite the bullet” and insist that such believers are in fact justified, dismissing the seeming intuitions to the contrary as latent internalist prejudice. A more widely adopted response attempts to impose additional conditions, usually of a roughly internalist sort, which will rule out the offending example, while stopping far of a full internalism. But, while there is little doubt that such modified versions of externalism can handle particular cases, as well enough to avoid clear intuitive implausibility, the usually problematic cases that they cannot handle, and also whether there is and clear motivation for the additional requirements other than the general internalist view of justification that externalist are committed to reject.
An alternative to giving an externalist account of epistemic justification, one which may be more defensible while still accommodating many of the same motivating concerns, is to give an externalist account of knowledge directly, without relying on an intermediate account of justification. Such a view will obviously have to reject the justified true belief account of knowledge, holding instead that knowledge is true belief which satisfies the chosen externalist condition, e.g., a result of a reliable process (and perhaps, further conditions as well). This makes it possible for such a view to retain internalist account of epistemic justification, though the centrality of that concept to epistemology would obviously be seriously diminished.
Such an externalist account of knowledge can accommodate the commonsense conviction that animals, young children, and unsophisticated adult's posse's knowledge, though not the weaker conviction (if such a conviction does exist) that such individuals are epistemically justified in their beliefs. It is also at least less vulnerable to internalist counter-examples of the sort discussed, since the intuitions involved there pertain more clearly to justification than to knowledge. What is uncertain is what ultimate philosophical significance the resulting conception of knowledge is supposed to have. In particular, does it have any serious bearing on traditional epistemological problems and on the deepest and most troubling versions of scepticism, which seems in fact to be primarily concerned with justification, the an knowledge?`
A rather different use of the terms “internalism” and “externalism” has to do with the issue of how the content of beliefs and thoughts is determined: According to an internalist view of content, the content of such intention states depends only on the non-relational, internal properties of the individual's mind or grain, and not at all on his physical and social environment: While according to an externalist view, content is significantly affected by such external factors and suggests a view that appears of both internal and external elements is standardly classified as an external view.
As with justification and knowledge, the traditional view of content has been strongly internalist in character. The main argument for externalism derives from the philosophy y of language, more specifically from the various phenomena pertaining to natural kind terms, indexicals, etc. that motivate the views that have come to be known as “direct reference” theories. Such phenomena seem at least to show that the belief or thought content that can be properly attributed to a person is dependant on facts about his environment -, e.g., whether he is on Earth or Twin Earth, what is fact pointing at, the classificatory criteria employed by expects in his social group, etc.-not just on what is going on internally in his mind or brain.
An objection to externalist account of content is that they seem unable to do justice to our ability to know the content of our beliefs or thought “from the inside,” simply by reflection. If content is depending on external factors pertaining to the environment, then knowledge of content should depend on knowledge of these factors-which will not in general be available to the person whose belief or thought is in question.
The adoption of an externalist account of mental content would seem to support an externalist account of justification, by way that if part or all of the content of a belief inaccessible to the believer, then both the justifying status of other beliefs in relation to that content and the status of that content ss justifying further beliefs will be similarly inaccessible, thus contravening the internalist requirement for justification. An internalist must insist that there are no justification relations of these sorts, that our internally associable content can either be justified or justly anything else: But such a response appears lame unless it is coupled with an attempt to show that the externalist account of content is mistaken.
The process of moving from a provisional formulation of acceptance of some position to acceptance of others, is that the goal of logic and classical epistemology is to codify kinds of inference, and to provide principles for separating good from bad inherences.
The rule of reference begins by implicating of question through which it is asked “What the tortoise said to Achilles” in the journal “Mind” in 1895. Lewis Carroll raised the Zeno like problem of how a proof ever gets started.” Suppose I have as premise (1) p and (2) p ➞q. Can I infer q? Only, it seems, if I am sure of (3) (p & p p ➞q) ➞q. Can I then infer q? Only, it seems if I am sure that (4) (p & p ➞q & (p & p ➞q) ➞q) ➞q. For each new axiom (N) I need a further axiom (N. + 1) telling me that the set so far implies q, and the regress never stops, usual solution is to trat a system as containing not only axioms but also rules of reference allow only axioms, but also rules of inference, allowing movement from the axiom. The rule modus ponens slows us to pass from the first two premises to q. Carroll”s puzzle shows that it is essential to distinguish two theoretical categories, although there may be choice bout which theses to put in which category.
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