Niccolo Machiavelli taught that political leaders must be prepared to do evil that good may come of it, and his name has been a byword ever since for duplicity and immorality. Is his sinister reputation deserved? In answering this question Quentin Skinner focuses on three major works, "The Prince", "the Discourses", and "The History of Florence", and distils from them an introduction to Machiavelli's doctrines of exemplary clarity.