It is well-known that Sartre's thought developed from an incomplete, abstract, and individualistic concept of human reality, human freedom, and their relation to the world, to a more concrete and richer understanding of the human being, its freedom, the power of circumstances, and the social-political nature of human existence. It is less widely recognised that there is a parallel progression in Sartre's moral thinking, from an abstract, idealistic ethics of authenticity to a more concrete, realistic and materialistic morality. Anderson's book, contains a thorough study of the two most important ethical works of Sartre to have become available since 1980, the Notebooks for an Ethics , written in the late 1940s but published in 1983, and the unpublished manuscript of a lecture on ethics delivered in 1964, containing his most complete discussion of his second morality . In drawing upon these and other sources, Anderson's book is a study of Sartre's first and second ethics. Anderson evaluates Sartre's arguments for his ethical positions, and concludes that his second ethics constitutes a significant advance over his first. Anderson is author of The Foundation and Structure of Sartrean Ethics (1979).