For students of the early American republic, James Madison has long been something of a riddle, the member of the founding generation whose actions and thought most stubbornly resist easy summary. The staunchest of Federalists in the 1780s, Madison would turn on his former allies shortly thereafter, renouncing their expansive nationalism as a threat to the Constitution and to popular government.

In a study that combines textual analysis with historical awareness, Gary Rosen stakes out important new ground by showing the philosophical consistency in Madison's long and controversial public life. The key, he argues, is Madison's profound originality as a student of the social compact, the venerable liberal idea into which he introduced several novel, and seemingly illiberal, principles.