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In [[philosophy]], the term '''anti-realism''' is used to describe any
position involving either the denial of an [[Objectivity (philosophy)|objective]] [[reality]] of [[entities]] of a certain type or the denial that verification-transcendent statements about a type of entity are either true or false. This latter construal is sometimes expressed by saying "there is no fact of the matter as to whether or not P." Thus, we may speak of anti-realism with respect to [[The problem of other minds|other minds]], the [[past]], the [[future]], [[Universal (metaphysics)|universals]], [[mathematics|mathematical entities]] (such as [[natural numbers]]), [[morality|moral categories]], the [[material world]], or even [[thought]]. The two construals are clearly distinct and often confused. For example, an "anti-realist" who denies that other minds exist (i. e., a [[solipsism|solipsist]]) is quite different from an "anti-realist" who claims that there is no fact of the matter as to whether or not there are unobservable other minds (i. e., a logical behaviorist).{{Fact|date=January 2008}}
== Anti-realism in Philosophy ==
=== Michael Dummett ===
The term was popularised by [[Michael Dummett]], who introduced it in
his paper ''Realism'' to re-examine several classical philosophical
disputes involving such doctrines as [[nominalism]],
[[conceptual realism]], [[idealism]] and [[phenomenalism]]. The novelty of
Dummett's approach consisted in seeing these disputes as analogous to
the dispute between [[intuitionism (philosophy of mathematics)|intuitionism]] and [[Platonism]] in the [[philosophy of mathematics]].
According to intuitionists (anti-realists with respect to mathematical objects), the [[truth]] of a mathematical statement consists in our ability to prove it. According to platonists ([[philosophical realism|realists]]), the truth of a statement consists in its correspondence to [[Objectivity (philosophy)|objective]] reality. Thus, intuitionists are ready to accept a statement of the form "P or Q" as true only if we can prove P or if we can prove Q:
this is called the [[disjunction property]]. In particular, we cannot in general claim that "P or not P" is true (the [[law of the excluded middle]]), since in some cases we may not be able either to prove nor disprove the statement P. Similarly, intuitionists object to the failure of the [[existence property]] for classical logic, where one can prove <math>\exists x.\phi(x)</math>, without being able to produce any term <math>t</math> of which <math>\phi</math> holds.
Dummett argues that the intuitionistic notion of truth lies at the
bottom of various classical forms of '''anti-realism'''. He uses this
notion to re-interpret [[phenomenalism]], claiming that it need not
take the form of a [[reductionism]] (often considered untenable).
===Precursors===
Doubts about the possibility of definite truth have been expressed since ancient times, for instance in the [[philosophical skepticism|skepticism]] of [[Pyrrho]]. Anti-realism about [[materialism|matter]] or [[physicalism|physical]] entities also has a long history. It can be found in the [[idealism]] of
[[George Berkeley|Berkeley]], [[Hegel]], and so on.
===Anti-Realist arguments===
Idealists are skeptics about the physical world, maintaining either: 1) that nothing exists outside the mind, or 2) that we would have no access to a mind-independent reality even if it may exist. Realists, in contrast, hold that perceptions or [[sense data]] are caused by mind-independent objects. But
this introduces the possibility of another kind of skepticism: since our understanding of [[causality]] is that the same effect can be produced by multiple causes, there is a [[indeterminacy|lack of determinacy]] about what one is really perceiving. A concrete example of a situation where an individual's sensory input might be caused by something other than what he thinks is causing it is the [[brain in a vat]] scenario.
On a more abstract level, [[model theory|model theoretic]] arguments hold that a given set of [[symbol]]s in a [[theory]] can be mapped onto any number of sets of real-world objects — each set being a "model" of the theory — providing the interrelationships between the objects are the same. (Compare with [[symbol grounding]]).
== Anti-realism in Science ==
In [[philosophy of science]], anti-realism applies chiefly to claims about the non-reality of "unobservable" [[entity|entities]] such as [[electron]]s or [[DNA]], which are not detectable with human senses. For a brief discussion comparing such anti-realism to its opposite, realism, see (Okasha 2002, ch. 4). Ian Hacking (1999, p. 84) also uses the same definition. One prominent anti-realist position in the philosophy of science is [[instrumentalism]], which takes a purely agnostic view towards the existence of unobservable entities: unobservable entity X serves simply as an instrument to aid in the success of theory Y. We need not determine the existence or non-existence of X. Some scientific anti-realists argue further, however, and deny that unobservables exist even as non-truth conditioned instruments.
== Anti-realism in Art ==
In discussions of [[art]] (including [[Visual arts and design|visual art]], writing, [[music]], and [[lyrics]]), ''anti-realism'' and ''anti-realist'' may be used in one of the philosophical senses described above, or may simply be used in contrast to [[realism (arts)|realism]], in whatever sense the latter is meant. Thus [[surrealism]] in visual art is an "anti-realist" tendency, and the [[psychedelic]] bands common in the United States in the 1960s were "anti-realist," etc. These terms may not be as precise when applied to art as when applied to philosophical matters. ''Anti-reality'' is occasionally used in this sense, although it may be used in other senses.
==See also==
* [[Constructivist epistemology]]
* [[Deflationary theory of truth]]
* [[Fact]]
* [[Idealism]]
* [[Intuitionistic logic]]
* [[Irrealism (philosophy)]]
* [[Philosophical realism]]
* [[Quasi-realism]]
* [[Reality]]
* [[Neil Tennant (philosopher)]]
* [[Crispin Wright]]
* [[Fine Art Prices]]
* [[Theory of everything|ToE]]
==External links==
* [http://plato.stanford.edu/entries/realism-sem-challenge/ Stanford Encyclopedia of Philosophy]
== References ==
* Michael Dummett (1963). ''Realism,'' reprinted in: Truth and Other Enigmas, Harvard University Press: 1978, pp. 145-165.
* Michael Dummett (1967). ''Platonism,'' reprinted in: Truth and Other Enigmas, Harvard University Press: 1978, pp. 202-214.
* Ian Hacking (1999). ''The Social Construction of What?''. Harvard University Press: 2001.
* Samir Okasha (2002). ''Philosophy of Science: A Very Short Introduction''. Oxford University Press.
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[[Category:Epistemology]]
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