How can another book on John Stuart Mill be justified? In spite of the mountain of commentary, there are several reasons justifying a new look. First, all too often, and especially in the first century after Mill’s death, interpretations have been based on a mere selection of his writings. This runs the risk of getting him wrong in all decades of his life, and is fatal for his last. Mill drafted and published no new books between 1865, when he entered parliament, and 1873 when he died; therefore any study of his big publications in isolation fails to do justice to the final evolution of his thought. For that and for the whole of his career we must turn to his letters, speeches and occasional articles. There is no excuse for ignoring these, for the Mill scholar today is blessed with a superb complete edition of thirty-three volumes: there is so much meat in it that only a dullard would be unable to find fresh perspectives.