Participants: Krister Bykvist, Toby Ord and William MacAskill. Very often we are uncertain about what we ought, morally, to do. We do not know how to weigh the interests of animals against humans, how strong our duties are to improve the lives of distant strangers, or how to think about the ethics of bringing new people into existence. But we still need to act. At this seminar, three philosophers present a book on what to do in such cases.