 The question of the relation between moral theory and bioethics is made difficult by a number of factors, not the least of which is the absence of any one account of what constitutes philosophical theory. There are, of course, the standard moral theories of introduction to moral philosophy—consequentialism, deontology, and virtue ethics. And we also speak of mid-level theories, such as moral principlism and casuistry, though the extent to which such approaches are strictly speaking theoretical is somewhat unsettled. What do we mean by moral theory? What characterizes an approach to moral philosophy and bioethics as theoretical? Add to such questions the fact that bioethics itself is not a monolithic discipline, and our topic is complicated right from the start.