Nonnaturalizm

Nonnaturalizm (nonnaturalism) is a term in philosophy used to describe a view that certain properties—especially moral or evaluative properties—are not natural properties and cannot be reduced to or explained by natural science or naturalistic accounts. In metaethics, nonnaturalism is often contrasted with ethical naturalism, which holds that moral properties are grounded in natural properties and can be characterized by empirical science.

Historically, the most influential proponent is G. E. Moore, who in Principia Ethica (1903) argued that "good" is a simple, non natural property that cannot be defined in terms of natural properties and should be known through intuition. This line of reasoning is known as the open-question argument: any naturalization of "good" leaves open the question of whether that natural property is indeed good. Other forms of nonnaturalism without Moore's intuitionism hold that moral truths are nonnatural but knowable via rational insight or a priori justification; some are realist about moral facts.

Variants include ethical nonnaturalism (the normative claim that ethical properties exist and are nonnatural), and nonnaturalist forms of moral realism that insist moral facts exist independently of beliefs. Critics of nonnaturalism point to the alleged explanatory gap, the naturalistic fallacy, and challenges to the possibility of a priori moral knowledge. Proponents respond by distinguishing descriptive natural properties from evaluative properties and by arguing that moral propositions express objective, non-natural truths.

In contemporary debates, nonnaturalism continues to be discussed alongside naturalistic, quasi-naturalist, and expressivist theories, variously addressing how moral language and truth can be understood without reducing morality to natural science.