This chapter examines John Stuart Mill's views on liberty. It first provides a short biography of Mill before discussing his revision of psychological hedonism in light of accusations by Thomas Carlyle, and Samuel Taylor Coleridge and his followers, that Mill's hedonistic naturalism is no better than a philosophy for ‘swine’. Mill addressed this charge by drawing a categorical distinction between higher and lower pleasures. The chapter also considers the equally problematic attempt to derive Mill's liberty principle from an act-utilitarian moral philosophy as well as the claim that Mill's religion of humanity involves a form of moral and philosophical coercion as great as anything he challenges. It concludes with an analysis of Mill's Considerations on Representative Government and shows that its defence of constitutional democracy reflects his philosophical liberalism.