The Harmony of the Soul creates a naturalistic grounding for ethics and a moral grounding for psychotherapy. It is an original and startling synthesis of the ideas of mental health and moral virtue based on neglected affinities between classical Greek ethics, contemporary virtue ethics, sociobiology, and the basic presuppositions of psychotherapy. A central thesis of the book is that we can assume "the worst" about what science tells us about the human animal without having to sacrifice any of the things that are of most importance to ethics: virtue and the good life, harmony of the soul, freedom, conscience, and moral knowledge.