This challenging and provocative book argues against much contemporary orthodoxy in philosophy and the social sciences by showing why objectivity in the domain of ethics is really no different from the objectivity of scientific knowledge. In the course of the book Jean Hampton examines moral realism, the general nature of reason and norms, internalism and externalism, instrumental reasoning, and the expected utility model of practical reasoning. The book should prove to be a seminal work in the theory of rationality that will be read by a broad swathe of philosophers and social scientists.