John Stuart Mill is one of the hallowed figures of the liberal tradition, revered for his defense of liberal principles and expansive personal liberty. By examining Mill’s arguments in On Liberty in light of his other writings, however, Joseph Hamburger reveals a Mill very different from the “saint of rationalism” so central to liberal thought. He offers this powerful challenge to conventional scholarship by drawing on the whole range of Mill’s philosophical writings and on his correspondence with, among others, Harriet Taylor Mill, Auguste Comte, and Alexander Bain. Hamburger reveals that Mill’s underlying goal was to replace the traditional religious basis of society with a form of secular religion that would rest on moral authority, individual restraint, and social control. Hamburger argues that Mill was not self-contradictory in championing both control and liberty. Rather, liberty and control worked together in Mill’s thought as part of a balanced, coherent program of social and moral reform that was neither liberal nor authoritarian.Based on a lifetime’s study of nineteenth-century political thought, this clearly written and forcefully argued book is a major reinterpretation of Mill’s ideas and intellectual legacy.