Sidgwick's dualism of practical reason

Abstract

Sidgwick is torn between (a) an internalist reading of the dualism of practical reason, according to which utilitarianism and egoism are competing moral theories, and (b) an externalist reading, according to which utilitarianism is the correct moral theory and egoism is the correct theory of individual rationality. Important aspects of Sidgwick’s moral psychology and epistemology, however, suggest that (b) is his considered view.