Ancient ethical theories, based on the notions of virtue and happiness, have struck many as an attractive alternative to modern theories. But we cannot find out whether this is true until we understand ancient ethics - and to do this we need to examine the basic structure of ancient ethical theory, not just the details of one or two theories. In this book, Julia Annas brings together the results of a wide-ranging study of ancient ethical philosophy and presents it in a way that is easily accessible to anyone with an interest in ancient or modern ethics. She examines the fundamental notions of happiness and virtue, the role of nature in ethical justification, and the relation between concern for self and concern for others. Her careful examination of the ancient debates and arguments shows that many widespread assumptions about ancient ethics are mistaken. Ancient ethical theories are not egoistic, and do not depend for their acceptance on metaphysical theories of a teleological kind. Most centrally, they are recognizably theories of morality, and the ancient disputes about the place of virtue in happiness can be seen as akin to modern disputes about the demands of morality. Accessible to nonspecialists and the only comprehensive treatment of ancient ethical theory, The Morality of Happiness will appeal to classicists, ancient philosophers, philosophers in moral and political philosophy, and all those interested in the history of ideas.