There are three paths to constitutionalism in the modern world. Under the first, revolutionary outsiders use the constitution to commit their new regime to the principles proclaimed during their previous struggle. India, South Africa, Italy and France have followed this path. Under the second, establishment insiders use the constitution to make strategic concessions to disrupt revolutionary movements before they can gain power. Britain provides paradigmatic examples. Under the third, ordinary citizens remain passive while political and social elites construct a new constitution. Spain, Japan and Germany provide variations on this theme. Different paths generate different legitimation problems, but the EU confronts a special difficulty. Since its members emerge out of three divergent pathways, they disagree about the nature of the union’s constitutional problem, not merely its solution. Thus the EU confronts a cultural, not merely an economic, crisis.