Luhmann takes up the question of how a society divides itself, and declines the familiar answer that its parts are bound together by shared values.

Integration, on his account, is thin and momentary. Because everything that happens happens at the same time, a single event — a budget laid before parliament — is identified at once by politics, law, the media and the economy, and briefly limits the freedom of each. As soon as prehistory and consequences are counted in, the systems pull the event apart and each makes of it something of its own. Systems couple and uncouple continuously; the autopoiesis of subsystems is untouched.

Against that background he sets out the succession of differentiation forms — segmentary, centre and periphery, stratified, functional — and what each permits to develop inside it. A society moving from one principle of stability to another undergoes what he calls, in systems-theoretical terms, a catastrophe.