Madison’s reading convinced him that direct democracies—such as the assembly in Athens, where 6,000 citizens were required for a quorum—unleashed populist passions that overcame the cool, deliberative reason prized above all by Enlightenment thinkers. “In all very numerous assemblies, of whatever characters composed, passion never fails to wrest the sceptre from reason,” he argued in The Federalist Papers, the essays he wrote (along with Alexander Hamilton and John Jay) to build support for the ratification of the Constitution. “Had every Athenian citizen been a Socrates, every Athenian assembly would still have been a mob.”