The "Brexit" has been seen as a major blow that changes the future of Europe, at the time when nationalist and separatist movements seem most ascendant, and the EU seems to be the toxic subject for plebiscites, the European Union is expanding its role as a global actor. These referendums, and threats to withdraw, are spurring Member States to return to the roots of the European Project. From its historical foundation, that project prizes freedom from war on the continent, and prosperity through free movement of trade and social capital.

Theodor Fontane, the master of German realist fiction, published his first novel, Before the Storm, in 1876. Set during the winter of 1812–13, in and around Berlin, it explores the decisive historical moment when Prussia changed sides—breaking out of its forced alliance with France in order to side with Russia in the anti-Napoleonic war. Yet the dialectic of the moment was such that Germans could join in the rout of the French while nonetheless embracing aspects of the French revolutionary legacy. Thus near the conclusion of the novel, the Prussian General von Bamme, commenting on social changes around him, a reduction in traditional structures of hierarchy, speculates, “And where does all this come from? From over yonder, borne on the west wind. I can make nothing of these windbags of Frenchmen, but in all the rubbish they talk there is none the less a pinch of wisdom. Nothing much is going to come of their Fraternity, nor of their Liberty: but there is something to be said for what they have put between them. For what, after all, does it mean but: a man is a man.” Mensch ist mensch.

As Mao euphemistically remarked, revolutions are not dinner parties. Violence is to be expected when political regimes are overturned. But the violence that accompanied modern revolutions is remarkable for the fact that it targeted fellow revolutionaries almost as often as declared opponents. Why is this? In this essay, I suggest that the reason has to do with a specific feature of revolutions that abandon constitutional forms of political legitimacy. These revolutions, following the precedent of the French “revolutionary government” (1793–94) and Marx's model of a “revolution in permanence,” tend to base the authority of their governments on the fulfillment of revolutionary expectations. This creates a political culture in which authority derives from the power to define what these expectations are, and what “revolution” means (much like Hobbes's sovereign had the power to set the meaning of words). But revolutionary culture does not leave room for Rawlsian pluralism. “There can be no solution to the social problem but mine,” proclaims the revolutionary ideologue in Dostoyevsky's The Possessed, expressing the law of the Red Leviathan. Such a system does not allow for loyal opposition. Accordingly, the specter of counterrevolution always hovers above disagreements between fellow revolutionaries. The purge thus becomes the necessary method for settling ideological differences.