Error theory

Error theory is the meta-ethical position, most closely associated with J.L. Mackie, that all moral judgments are systematically false. The theory does not deny that people make moral judgments, or that these judgments are meaningful, or that they play important roles in social coordination. It denies that any moral judgment is \textit{true} — because the property it ascribes (objective moral wrongness,rightness, or obligation) does not exist.

Mackie's argument proceeds from two claims. First, moral discourse is committed to the existence of objectively prescriptive properties — properties that provide reasons for action independent of any agent's desires or interests. Second, no such properties exist in the world. The first claim is conceptual: to call an act 'wrong' is to claim more than that it fails to satisfy some desire or convention; it is to claim that the act has a property that would give any rational agent a reason to avoid it. The second claim is ontological: the universe contains no such properties. If both claims hold, all moral judgments are false.

Error theory is not moral nihilism in the popular sense. It does not entail that we should stop making moral judgments, or that cruelty is permissible. It entails only that the metaphysical underpinning of our moral discourse is mistaken. What follows from this — whether we should reform moral language, abolish it, or continue using it despite its falsehood — is the subject of ongoing debate among error theorists and their critics.

Error theory is often dismissed as a philosophical curiosity — a position too radical to be taken seriously in practical ethics. But the rise of artificial intelligence forces a confrontation with error-theoretic concerns. If moral properties are not objective features of the world, then the alignment problem — the problem of aligning AI systems with human values — is not a problem of discovering and implementing objective values. It is a problem of coordinating artificial agents around conventions that we know to be conventional. The stakes of error theory are higher than its critics admit.