This book shows how Darwinian biology supports an Aristotelian view of ethics as rooted in human nature. Defending a conception of "Darwinian natural right" based on the claim that the good is the desirable, the author argues that there are at least twenty natural desires that are universal to all human societies because they are based in human biology. The satisfaction of these natural desires constitutes a universal standard for judging social practice as either fulfilling or frustrating human nature, although prudence is required in judging what is best for particular circumstances....