Philosophers have been arguing about the meaning of well-being since the time of the Ancients. Participants in the contemporary debate about it include governments who promote it to encourage a work ethic, corporations who reconfigure it as a marketing strategy, "mindfulness" gurus who seek to realise it by retreating from the world, and Aristotelians who imagine it in the context of the good life or eudemonia. This book argues that none of these approaches enable us to understand fully the nature of well-being or what we have to do in order to realise a sustainable form of it.