This book features new approaches to social contract theory. Whereas traditional social contract theories and their adaptations in the twentieth century were developed for fairly homogeneous societies, societies in the twenty-first century often are characterized by conflicting first-order directives that stem from deep moral, political, religious, and cultural diversity. To address such diversity and the complexities of contemporary societies, new approaches (including formal approaches) to social contract theory have emerged that re-envision the social contract for a fragmented and sometimes polarized, yet interdependent social world. New social contract theory explores how, in a world of continuous disagreement on questions of justice, in particular the ideals of liberty and equality, society can not only progress, but also flourish and become more robust and open in its social fabric. This book brings together, for the first time, defenders and discussants of new social contract theory. It includes contributions by eminent and emerging scholars in this field. The book clarifies the distinct features of new social contract theory and provides a valuable starting point for discussion of this novel movement in social contract theory.