This book offers a contractarian reading of the European integration process that corroborates, complements and, on occasion, contests European integration theory. It argues that the social contract theories of Thomas Hobbes and John Rawls provide us with insufficiently exploited clues to the formation and justification of European supranational institutions and redistributive instruments. An advanced understanding of the normative foundations of European integration seems to be all the more important in times of multiple crises, differentiated integration and even disintegration – all accompanied and accelerated by the growth of Euroscepticism and anti-European parties.