Probably to most students of Moral Philosophy there comes a time when they feel a vague sense of dissatisfaction with the whole subject. And the sense of dissatisfaction tends to grow rather than to diminish. It is not so much that the positions, and still more the arguments, of particular thinkers seem unconvincing, though this is true. It is rather that the aim of the subject becomes increasingly obscure. "What," it is asked, "are we really going to learn by Moral (...) Philosophy?" "What are books on Moral Philosophy really trying to show, and when their aim is clear, why are they so unconvincing and artificial?" And again: "Why is it so difficult to substitute anything better?" Personally, I have been led by growing dissatisfaction of this kind to wonder whether the reason may not be that the subject, at any rate as usually understood, consists in the attempt to answer an improper question. And in this article, I shall venture to contend that the existence of the whole subject, as usually understood, rests on a mistake, and on a mistake parallel to that on which rests, as I think, the subject usually called the Theory of Knowledge. (shrink)