All social groups have ideals for behavior, and in trying to understand why, Patricia Churchland brings together an understanding of the influences of nature and nurture. She looks to evolution to show how our brains are configured to form bonds, to cooperate, and to care. In this "thoughtful, accessible, and enlightening book" (Kirkus Reviews), Churchland then turns to such philosophers as Socrates and Aquinas to explore why morality is central to all societies, how it is transmitted through the generations, and why different cultures live by different morals.