Inanalytic philosophy,anti-realism is the position that the truth of astatement rests on its demonstrability through internal logic mechanisms, such as thecontext principle orintuitionistic logic, in direct opposition to therealist notion that the truth of a statement rests on its correspondence to an external, independent reality.[1] In anti-realism, this external reality ishypothetical and is not assumed.[2][3]
There are many varieties of anti-realism, such as metaphysical, mathematical, semantic, scientific, moral and epistemic. The term was first articulated by BritishphilosopherMichael Dummett in anargument against a form ofrealism Dummett saw as 'colorless reductionism'.[4]
Anti-realism in its most general sense can be understood as being in contrast to ageneric realism, which holds that distinctive objects of a subject-matter exist and have properties independent of one's beliefs and conceptual schemes.[5] The ways in which anti-realism rejects these types of claims can vary dramatically. Because this encompasses statements containingabstract ideal objects (i.e. mathematical objects), anti-realism may apply to a wide range of philosophical topics, frommaterial objects to the theoreticalentities ofscience,mathematical statements,mental states, events and processes, thepast and thefuture.[6]
One kind ofmetaphysical anti-realism maintains askepticism about the physical world, arguing either: 1) that nothing exists outside the mind, or 2) that we would have no access to a mind-independent reality, even if it exists.[7] The latter case often takes the form of a denial of the idea that we can have 'unconceptualised' experiences (seeMyth of the Given). Conversely, most realists (specifically,indirect realists) hold that perceptions orsense data are caused by mind-independent objects. But this introduces the possibility of another kind of skepticism: since our understanding ofcausality is that the same effect can be produced by multiple causes, there is alack of determinacy about what one is really perceiving, as in thebrain in a vat scenario. The main alternative to this sort of metaphysical anti-realism ismetaphysical realism.
On a more abstract level,model-theoretic anti-realist arguments hold that a given set ofsymbols in atheory can be mapped onto any number of sets of real-world objects—each set being a "model" of the theory—provided the relationship between the objects is the same (compare withsymbol grounding.)
Inancient Greek philosophy,nominalist (anti-realist) doctrines aboutuniversals were proposed by theStoics, especiallyChrysippus.[8][9] Inearly modern philosophy,conceptualist anti-realist doctrines about universals were proposed by thinkers likeRené Descartes,John Locke,Baruch Spinoza,Gottfried Wilhelm Leibniz,George Berkeley, andDavid Hume.[10][11] Inlate modern philosophy, anti-realist doctrines about knowledge were proposed by theGerman idealistGeorg Wilhelm Friedrich Hegel. Hegel was a proponent of what is now calledinferentialism: he believed that the ground for the axioms and the foundation for the validity of the inferences are the right consequences and that the axioms do not explain the consequence.[12] Kant and Hegel held conceptualist views about universals.[13][14] Incontemporary philosophy, anti-realism was revived in the form ofempirio-criticism,logical positivism,semantic anti-realism and scientificinstrumentalism (see below).
In thephilosophy of mathematics, realism is the claim that mathematical entities such as 'number' have an observer-independent existence.Empiricism, which associates numbers with concrete physical objects, andPlatonism, in which numbers are abstract, non-physical entities, are the preeminent forms of mathematical realism.
The "epistemic argument" against Platonism has been made byPaul Benacerraf andHartry Field. Platonism posits that mathematical objects areabstract entities. By general agreement, abstract entities cannot interactcausally with physical entities ("the truth-values of our mathematical assertions depend on facts involving platonic entities that reside in a realm outside of space-time"[15]). Whilst our knowledge of physical objects is based on our ability toperceive them, and therefore to causally interact with them, there is no parallel account of how mathematicians come to have knowledge of abstract objects.[16][17][18]
Field developed his views intofictionalism. Benacerraf also developed the philosophy ofmathematical structuralism, according to which there are no mathematical objects. Nonetheless, some versions of structuralism are compatible with some versions of realism.
Anti-realist arguments hinge on the idea that a satisfactory,naturalistic account of thought processes can be given for mathematical reasoning. One line of defense is to maintain that this is false, so that mathematical reasoning uses some specialintuition that involves contact with thePlatonic realm, as in the argument given bySir Roger Penrose.[19]
Another line of defense is to maintain that abstract objects are relevant to mathematical reasoning in a way that is non causal, and not analogous to perception. This argument is developed byJerrold Katz in his 2000 bookRealistic Rationalism. In this book, he put forward a position calledrealistic rationalism, which combines metaphysical realism andrationalism.
A more radical defense is to deny the separation of physical world and the platonic world, i.e. themathematical universe hypothesis (a variety ofmathematicism). In that case, a mathematician's knowledge of mathematics is one mathematical object making contact with another.
The term "anti-realism" was introduced byMichael Dummett in his 1963 paper "Realism" in order to re-examine a number of classical philosophical disputes, involving such doctrines asnominalism,Platonic realism,idealism andphenomenalism. The novelty of Dummett's approach consisted in portraying these disputes as analogous to the dispute betweenintuitionism andPlatonism in thephilosophy of mathematics.
According to intuitionists (anti-realists with respect to mathematical objects), thetruth of a mathematical statement consists in our ability to prove it. According to Platonic realists, the truth of a statement is proven in its correspondence toobjective reality. Thus, intuitionists are ready to accept a statement of the form "P or Q" as trueonly if we can prove P or if we can prove Q. In particular, we cannot in general claim that "P or not P" is true (thelaw of excluded middle), since in some caseswe may not be able to prove the statement "P" nor prove the statement "not P". Similarly, intuitionists object to theexistence property for classical logic, where one can prove, without being able to produce any term of which holds.
Dummett argues that this notion of truth lies at the bottom of various classical forms of anti-realism, and uses it to re-interpretphenomenalism, claiming that it need not take the form ofreductionism.
Dummett's writings on anti-realism draw heavily on the later writings ofLudwig Wittgenstein, concerning meaning and rule following, and can be seen as an attempt to integrate central ideas from thePhilosophical Investigations into the constructive tradition ofanalytic philosophy deriving fromGottlob Frege.
Inphilosophy of science, anti-realism applies chiefly to claims about the non-reality of "unobservable" entities such aselectrons orgenes, which are not detectable with human senses.[20][21]
One prominent variety ofscientific anti-realism isinstrumentalism, which takes a purely agnostic view towards the existence of unobservable entities, in which the unobservable entity X serves as an instrument to aid in the success of theory Y and does not require proof for the existence or non-existence of X.
Anti-representationalism rejects the idea that thought and language function by mirroring or representing an independent reality. Instead, it adopts a deflationary view of truth and reference, treating them as pragmatic tools within discourse rather than robust semantic relations.[22] Anti-representationalists likeRichard Rorty andHuw Price argue that all ontological commitments are framework-dependent, denying any privileged "external" perspective to judge which claims (including scientific ones) correspond to reality.[22]
In thephilosophy of ethics, moral anti-realism (or moral irrealism) is ameta-ethical doctrine that there are no objectivemoral values or normative facts. It is usually defined in opposition tomoral realism, which holds that there are objective moral values, such that a moral claim may be either true or false. Specifically the moral anti-realist is committed to denying at least one of the following three statements:[23][24]
Different version of moral anti-realism deny different statements: specifically,non-cognitivism denies the first claim, arguing that moral statements have no meaning or truth content,[25]error theory denies the second claim, arguing that all moral statements are false,[26] andethical subjectivism denies the third claim, arguing that the truth of moral statements is mind dependent.[27]
Examples of anti-realist moral theories might be:[28]
There is a debate as to whethermoral relativism is actually an anti-realist position. While many versions deny the metaphysical thesis, some do not, as one could imagine a system of morality which requires you to obey the written laws in your country.[29] Such a system would be a version of moral relativism, as different individuals would be required to follow different laws, but the moral facts are physical facts about the world, not mental facts, so they are metaphysically ordinary. Thus, different versions of moral relativism might be considered anti-realist or realist.[30]
Just as moral anti-realism asserts the nonexistence of normative facts, epistemic anti-realism asserts the nonexistence of facts in the domain ofepistemology.[31] Thus, the two are now sometimes grouped together as "metanormative anti-realism".[31] Prominent defenders of epistemic anti-realism includeHartry Field,Simon Blackburn, Matthew Chrisman, andAllan Gibbard, among others.[31]
No single description is likely to capture all realist views, but a reasonably accurate rule is to understand moral realism as the conjunction of three theses: The semantic thesis: The primary semantic role of moral predicates (such as "right" and "wrong") is to refer to moral properties (such as rightness and wrongness), so that moral statements (such as "honesty is good" and "slavery is unjust") purport to represent moral facts, and express propositions that are true or false (or approximately true, largely false and so on). The alethic thesis: Some moral propositions are in fact true. The metaphysical thesis: Moral propositions are true when actions and other objects of moral assessment have the relevant moral properties (so that the relevant moral facts obtain), where these facts and properties are robust: their metaphysical status, whatever it is, is not relevantly different from that of (certain types of ordinary non-moral facts and properties).
This one is used to designate that family of ethical positions in which it is supposed that moral judgements do not possess truth-value and hence can not be known. An example of a non-cognitivist position is emotivism; that is, the claim that moral judgements are merely expressions of emotion.
The moral error theorist thinks that although our moral judgments aim at the truth, they systematically fail to secure it. The moral error theorist stands to morality as the atheist stands to religion.
A subjectivist ethical theorist is a theory according to which moral judgements about men or their actions are judgements about the way people react to these men and actions - that is, the way they think or feel about them.
In all cases, it may be that what determines the difference in the relevant contexts is something "mind-dependent"—in which case it would be anti-realist relativism—but it need not be; perhaps what determines the relevant difference is an entirely mind-independent affair, making for an objectivist (and potentially realist) relativism.
Moral relativism is sometimes thought of as a version of anti-realism, but (short of stipulating usage) there is no basis for this classification; it is better to say that some versions of relativism may be anti-realist and others may be realist.
