This is the first comprehensive exploration of ancient and modern tyranny in the history of political thought. Waller R. Newell argues that modern tyranny and statecraft differ fundamentally from the classical understanding. Newell demonstrates a historical shift in emphasis from the classical thinkers' stress on the virtuous character of rulers and the need for civic education to the modern emphasis on impersonal institutions and cold-blooded political method. The turning point is Machiavelli's call for the conquest of nature. Newell traces the lines of influence from Machiavelli's new science of politics to the rise of Atlanticist republicanism in England and America, as well as the totalitarian regimes of the twentieth century and their effects on the present. By diagnosing the varieties of tyranny from erotic voluptuaries like Nero, the steely determination of reforming conquerors like Alexander the Great and Julius Caesar and modernizing despots such as Napoleon and Ataturk to the collectivist revolutions of the Jacobins, Bolsheviks, Nazis, and Khmer Rouge, Newell shows how tyranny is every bit as dangerous to free democratic societies today as it was in the past.