Norms are a pervasive yet mysterious feature of social life. In Explaining Norms, four philosophers and social scientists team up to grapple with some of the many mysteries, offering a comprehensive account of norms: what they are; how and why they emerge, persist and change; and how they work. Norms, they argue, should be understood in non-reductive terms as clusters of normative attitudes that serve the function of making us accountable to one another—with the different kinds of norms (legal, moral, and social norms) differing in virtue of being constituted by different kinds of normative attitudes that serve to make us accountable in different ways. Explanations of and by norms should be seen as thoroughly pluralist in character. Explanations of norms should appeal to the ways that norms help us to pursue projects and goals, individually and collectively, as well as to enable us to constitute social meanings. Explanations by norms should recognise the multiplicity of ways in which norms may bear upon the actions we perform, the attitudes we form and the modes of deliberation in which we engage: following, merely conforming with, and even breaching norms. While advancing novel and distinctive positions on all of these topics, Explaining Norms will also serve as a sourcebook with a rich array of arguments and illustrations for others to reassemble in ways of their own choosing.