Book 5 — Revolutions and Their Causes

Book 5 begins with a theoretical framing. All constitutions are based on some notion of justice and equality, but each embodies a partial view: democrats think that because men are equal in freedom they are equal in all things; oligarchs think that because they are unequal in wealth they are unequal in all things. Both are partially right and partially wrong, and the mismatch between a citizen's expectations and the reality of the constitution generates the revolutionary feeling. The general cause of revolution is the desire of equality or the desire of superiority — inferiors revolt to be equal, equals revolt to be superior.

Aristotle then specifies seven particular causes that trigger this general disposition: insolence, fear, love of superiority, contempt, disproportionate increase of one part of the state, electoral intrigue, carelessness about small changes, and the dissimilarity of the citizen body. He illustrates each with historical examples drawn from his survey of Greek cities — Sparta's ephors, Athens's demagogues, the Syracusan tyrannies, the Macedonian monarchies — producing the most historically detailed section in the work. The empirical method is at its most visible here.

The second half of Book 5 examines how each constitution characteristically fails and what preserves it. Democracies are preserved by moderation in their treatment of the wealthy; oligarchies by not over-reaching; aristocracies by attending to merit rather than birth or wealth. The section on tyranny is the most unsettling: Aristotle describes, without endorsing, how tyrants maintain power — by humiliating subjects, creating divisions among the elite, preventing the formation of friendships and civic associations, keeping people poor and busy, and surrounding themselves with informers. He then argues that the most durable tyrannies have been those that practiced a kind of moderation — not because moderation is good but because it is more effective. Political science in Book 5 is not comfortable reading.