Moral Nihilism

Core Idea

Moral nihilism denies that anything has objective moral value or that any moral claim is true. Unlike expressivists or constructivists, nihilists think moral language systematically fails and morality is an illusion. Nihilism follows if we accept error theory (moral claims presuppose objective facts that don't exist) and doubt any constructivist repair. It faces the persistent challenge of explaining why we maintain moral practices if nothing is actually morally wrong.

Explainer

From moral anti-realism, you know that moral anti-realists deny the existence of objective moral facts. But anti-realism comes in several flavors. Expressivists say moral claims are not truth-apt — "murder is wrong" expresses disapproval rather than describing a fact, so it can't be false. Constructivists say moral truths are constructed through rational procedures or social agreements — they're not mind-independent, but they're real enough. Moral nihilism is more uncompromising: it holds that moral language is in the truth-aptness business, making genuine claims about the world, but that business always fails because the world contains no moral facts to make those claims true.

The nihilist's argument starts with error theory (Mackie's version is canonical). Moral claims presuppose the existence of objective, prescriptively binding facts — facts that are both true about the world and capable of generating reasons for action independently of anyone's desires. Nihilism agrees with the error theorist's diagnosis: no such facts exist. The radical conclusion follows: "murder is wrong" and "murder is permissible" are both false, or both lack truth value in the relevant sense. Moral language, like astrology or phlogiston chemistry, is a systematic misdescription of reality.

What distinguishes nihilism from its neighbors is the refusal of any pragmatic repair. An expressivist might say: moral claims don't describe facts, but they serve a different function — expressing attitudes, coordinating behavior, expressing commitment. A constructivist might say: moral truths are constructed from what rational agents would agree to in ideal conditions. The nihilist rejects both moves. Moral claims purport to be objectively and bindingly true; if they fail at that, no functional substitute saves them. Quasi-realism (Blackburn's program) tries to earn back moral language even on an expressivist base, but the nihilist sees this as a sleight of hand.

The deepest challenge to nihilism is practical: if nothing is actually wrong, why do humans universally engage in moral reasoning, experience moral emotions, and organize societies around moral norms? The nihilist has two main responses. First, evolutionary and social explanations: moral practices evolved because they solved coordination problems and promoted group cohesion, not because they tracked moral facts. Second, moral fictionalism: we can continue using moral language as a useful fiction — speaking of rights and obligations as if they existed, while not literally believing in them, just as we speak of the average person without thinking they exist. Fictionalism blurs into constructivism at the edges, and where nihilism ends and pragmatic reconstruction begins is a live dispute in contemporary metaethics.