The Cycle of Constitutions

Anacyclosis is the theory that political systems spin through a fixed cycle: kingship decays into tyranny, which yields to aristocracy, which curdles into oligarchy, which gives way to democracy, which collapses into mob rule (ochlocracy) — and then the wheel starts over. The idea is seeded in Herodotus' 'Constitutional Debate' (5th c. BCE), but the Greek historian Polybius (2nd c. BCE) built it into a full doctrine to explain the rise of Rome. Rome, he argued, escaped the wheel by blending all three good forms into a single mixed constitution.