antirealist

Antirealism is a family of philosophical positions that questions or rejects the central realist claim that there are mind-independent facts about the world that science and other disciplines aim to describe. The term is most commonly used in the philosophy of science, but it also appears in ethics, mathematics, and aesthetics. Anti-realist views typically resist the idea that theories must offer true or approximately true descriptions of unobservable entities, or that explaining phenomena requires positing a complete, objective reality behind appearances.

In the philosophy of science, anti-realism contrasts with scientific realism. Constructive empiricism, associated with Bas van Fraassen, holds that science aims at empirical adequacy and that belief in the existence of unobservable entities is not obligatory. Instrumentalism treats theories as tools for predicting observations rather than as descriptions of reality. Other forms emphasize semantic or epistemic aspects, arguing that truth or justification in science is relative to a framework or to available concepts.

Beyond science, anti-realism arises in ethics, mathematics, and metaphysics. Moral anti-realism denies objective moral facts or claims that moral judgments express attitudes rather than truths. Semantic anti-realism questions whether truth possesses a straightforward, mind-independent status. Some anti-realist positions in mathematics treat mathematical entities as fictional or useful fictions, or deny their independent existence.

Debate and assessment: anti-realists point to underdetermination, theory-ladenness, and the predictive success of theories without committing to unobservables. Realists argue that explanation, success, and convergence across theories support the existence of a mind-independent reality. The debate persists across scientific, ethical, and mathematical domains.

Notable figures associated with anti-realism include Bas van Fraassen, Paul Feyerabend, and Richard Rorty, as well as other positions ranging from instrumentalism to semantic anti-realism and moral anti-realism.