In normative ethics, a small number of moral theories, such as Kantianism or consequentialism, take centre stage. Conventional wisdom has it that these individual theories posit very different ways of looking at the world. In this book Marius Baumann develops the idea that just as scientific theories can be underdetermined by data, so can moral theories be underdetermined by our considered judgments about particular cases. Baumann goes on to ask whether moral theories from different traditions might arrive at the same verdicts while remaining explanatorily incompatible. He applies this idea to recent projects in normative ethics, such as Derek Parfit's On What Matters and so-called consequentializing and deontologizing, and outlines its important implications for our understanding of the relationship between the main moral traditions as well as the moral realism debate. This title is also available as Open Access on Cambridge Core.