The four contributors to this volume examine the eugenics movements in Germany, France, Brazil, and the Soviet Union, and describe how geneticists and physicians participated in the development of policies concerning the improvement of hereditary qualities in humans. They examine the scientific components of those programs and discuss the involvement of social, religious, and political forces that significantly altered the original scientific goals. The book opens up new and comparative perspectives on the history of eugenics and the social uses of science in general.