Book excerpt: This book examines Freud's changing views of human instincts, exploring the moral and social implications. Part One investigates Freud's concept of instinct and discusses the phases of his ongoing attempt to classify the instincts. In Part Two the author argues that Freud's instinct theory leads to a moral philosophy, and he relates this philosophy to Freud's views on group psychology. The notion of instinct is central to psychoanalytic theory, but never before has it been treated so comprehensively, with such close attention to the text. Nor has anyone previously examined in detail the moral and social implications of Freud's instinct theory. In examining these implications, Abel bridges the fields of psychology and philosophy.