This book explores historical and current discussions of the relevance of evolutionary theory to ethics. The historical section conveys the intellectual struggle that took place within the framework of Darwinism from its inception up to the work of G. C. Williams, W. D. Hamilton, R. D. Alexander, A. L. Trivers, E. O. Wilson, R. Dawkins, and others. The contemporary section discusses ethics within the framework of evolutionary theory as enriched by the works of biologists such as those mentioned above. The issue of whether ethical practice and ethical theory can be grounded in the theory of evolution has taken a new and significant direction within the context of sociobiology and is proving to be a challenge to previous thinking. This book conveys that challenge.