The question "What is pleasure?" has been a thorn in the side of philosophy since the time of Socrates. David L. Perry attempts to arrive at a satisfactory answer in the form of a definition of pleasure. In the end, he offers two definitions, turning on two radically different notions of pleasure--that of enjoyment and that of being pleased about. Perry is best when dealing with the cognitive aspects of pleasure and with pleasure as a reason for acting. He discusses the extent to which belief is involved in pleasure, the notion of a "false pleasure," the relation between taking pleasure in something and thinking it a good thing, one's knowledge of one's own pleasure, and the ways in which pleasure can be given as a reason for acting. In the end, it appears there can be no single definition of pleasure, and this problematic concept remains to be satisfactorily elucidated by philosophers.