Based on some 30 years of research on people who claim to remember past lives, this work encompasses the full spectrum of theory and case study on the subject to date. Early in his investigations, Stevenson became aware that some who remember past lives had birthmarks or birth defects that corresponded to wounds, usually fatal, on the person whose life was remembered. The work suggests surprising answers to such questions as the following: Why does someone born with a birth defect have the one he or she has, instead of another one? Why do some children show phobias in early infancy when they have had no traumatic experiences and no model for the phobia in their family? Why are some monozygotic (one-egg) twins markedly different from each other? Why do many boys who later become homosexual show effeminate behavior in infancy before their parents can have influenced them to do so? Writing as a scientist and a Western medical professional, Stevenson realizes that the idea that wounds on a deceased person can influence the embryo of a later-born baby is subversive to many assumptions of modern biology. Knowing that each individual case has some flaw or weakness, he decided to publish the entire corpus of cases of this sort. Photographs of birthmarks and illustrations of weapons form part of the evidence in this daring and explorative research. This work will be of particular interest to physicians, psychiatrists, biologists, and anthropologists. In addition, those concerned with paranormal phenomena and the mind-brain problem will find this work challenging. It is by far the most definitive work on the subject by the “Galileo of the twentieth century” professor Ian Stevenson.