Normative ethics is concerned with the questions of how we should live, how we should act, and what sort of persons we should strive to become. One of its central aims is therefore to articulate and justify proposals about the moral standards that measure our conduct. According to one influential way of conceiving it, the execution of this task involves distinguishing the factors that have intrinsic moral significance, explaining why they have the significance they do and describing how they interact (Kagan 1998). The goal of this book has been to make a contribution to contemporary normative ethics by defending the claim that an agent’s intentions in acting are among these morally significant factors. In particular, I have defended the principle of double effect: