It is a perverse but almost inescapable phenomenon in the history of violent revolutions that after the first heroic days a colorless bureaucrat will inherit the mantle of leadership. In the Russian Revolution, Lenin was followed by a plodding Stalin rather than a dazzling Trotsky. Even after the American Revolution the celebrated Jefferson barely made it into office as president between two party regulars. The French Revolution was no exception. After the genius and idealism of Mirabeau, Danton, and others who had created the Revolution, it fell into the hands of an unscrupulous and...