Richard Semon was a German evolutionary biologist who wrote, during the first decade of the 20th century, two analyses of the workings of human memory which were ahead of their time. Although these have been virtually unknown to modern researchers, Semon's work has been rediscovered during the past two decades and has begun to have an influence on the field. This book not only examines Semon's contribution to memory research, but also tells the story of an extraordinary life set against the background of a turbulent period in European history and major developments in science and evolutionary theory. The resulting book is a blend of biographical, historical and psychological material. Through the remarkable story of an almost forgotten German biologist, this book addresses not only key questions in memory research but also wide-ranging and substantive issues in the history and psychology of science.