The somber fact is that we are the cruellest and most ruthless species that has ever walked the earth,"" asserts psychotherapist Anthony Storr, who sets about in his book to prove that aggression is a drive as innate, natural and powerful as sex. Dr. Storr, aware of the destructiveness of hostility, pursues it in the life of the mentally ill and in society, and concludes with suggestions toward its diminution in face of the hydrogen bomb extinction threat. But he is also convinced of the positive function of aggression in the experience of the child, enabling the move toward separation from parents and independence, and the adult, enabling intellectual and creative achievement. His study explores as well the relation of the sexes, the modes of containment (territory, ritual), ways of reducing hostility. It is balanced, penetrating and persuasive, and dedicated to Konrad Lorenz, whose views it pursues in a psychoanalytic orientation. Dr. Storr is also the author of Sexual Deviation and The Integrity of the Personality (1961).