ABSTRACT
The distinctive feature of Rationalist moral philosophy is its dependence on moral intuition—insights, it is believed, into the more or less self-evident truths of Moral Reason. The philosopher who does this important task depends on moral intuition at every stage of his inquiry. An instructive exception is Henry Sidgwick, whose Methods of Ethics, the most widely read work of Victorian moral theory, and went through seven editions before its author died in 1900. What Sidgwick called the "perceptional", phase of intuitionism includes the efforts of two main groups. Platonists like Clarke and Stewart held that moral intuitions are exercises of Pure Reason. Sidgwick knew that the friends of intuition thought they could get around this obstacle by distinguishing real intuitions from what only seemed to the unreflective to be intuitions. Few of the philosophers who came in Sidgwick's wake thought it could. The most celebrated was G. E. Moore. Moore was an intuitionist and a utilitarian like Sidgwick.
