Five hundred years after his death, Niccol Machiavelli still draws an astonishing range of contradictory characterizations. Was he a friend of tyrants? An ardent republican loyal to Florence's free institutions? The father of political realism? A revolutionary populist? A calculating rationalist? A Renaissance humanist? A prophet of Italian unification? A theorist of mixed government? A forerunner to authoritarianism? The master of the dark arts...