“Mutual Coercion, Mutually Agreed Upon” (the phrase comes from Garrett Hardin's classic essay "Tragedy of the Commons") sees the democratic reforms and social reorganization of Attica by the Athenian statesman Cleisthenes in 508 BCE as a case study in systems leveraging. Cleisthenes’s reforms are situated in a nexus of Presocratic (Pythagorean) thinking about limit (peras) and in the context of ideas that circulated at the time under the banners of isonomy (isonomia) and harmony (harmonia). The ancient Athenians, newly freed from political tyranny and the social upheaval of 508, recognized the intrinsic value of limits and restraint and built them into the structures of democratic life. Their example, I argue further, stands as a challenge to environmental and social problems faced by democratic regimes today.