Chapter 10 reconstructs Durkheim's conception of sociology as a science of morality, which includes three tasks: orienting our conduct via an account of a morally healthy society; illuminating the connection between social functioning and morality (explaining why moral and social health are the same; and explaining why the moral ideals animating a given society do so and how they vary with changing social conditions. Durkheim's science of morality is similar to Marx's historical materialist account of morality, although the former leaves the moral authority of the rules it explains largely intact. While Durkheim's accounts of specific pathologies imply a critique of certain social rules, they do not discredit the fundamental norms at work in the societies he studies. The chapter concludes that Durkheim does not adequately explain how historically specific moral systems can claim a moral authority irreducible to the narrowly functional value they have for social reproduction.