Dr. Malcolm Potts, a scientist and obstetrician, has been a frontline witness to conflict around the world. He has worked with governments, aid organizations, and women who have been raped and brutalized in the course of war. In combining personal experience with scientific findings in genetics and anthropology, he explains war’s pivotal position in the human experience and how men in particular evolved under conditions that favored gang behavior, rape and organized aggression. Dr. Potts now charts a course for making warfare less frequent and less brutal. This is the power of ideas.