Abstract
Moral philosophy has traditionally been concerned with the question: ‘what ought I to do?’ But once we acknowledge that more often than not morally relevant outcomes (and actions) are collectively generated (or performed), we need to ask the complementary question: ‘what ought we to do?’ Some of our moral obligations are collective in nature – they are held jointly by two or more agents in that neither agent has that obligation on its own. This chapter contains a summary of my theory of collective obligations and introduces some of the core arguments.