In this essay, I shall discuss Sidgwick's argument for the claim that pleasure is the good. Along the way I shall point to various problematic points in his argument. And in the end I shall try to show what kinds of amendments might solve the difficulties that I see. The basic problem that arises in Sidgwick's view concerns the motivation for introducing desire as the material element in his theory of the good. Sidgwick never tells us why he entertains a desire-based conception of goodness. This difficulty is related to the question of why Sidgwick thinks that we must concern ourselves with the sorts of objects that are desired, or so I shall show. Finally, one wonders why Sidgwick thinks that he has even come close to solving the problem of the ultimate good when he has conceded that he cannot reduce, to his opponents' satisfaction, the value of some instances of “ideal goods” (such as knowledge, virtue, or aesthetic appreciation) to some function of pleasure. The difficulties that Sidgwick's account encounters are, I think, problems for any view of the good that is desire-based and that imposes formal requirements of rationality on conceptions of goodness. Thus, though I shall focus my attention on Sidgwick's theory, I believe that the problems raised in this essay are significant for many desire-based theories of value.