This study addresses the complex and often fractious relationship between liberal political theory and difference by examining how distinctive liberalisms respond to human diversity. Drawing on published and unpublished writings, private correspondence and lecture notes, the study offers comprehensive reconstructions of Immanuel Kant's and John Stuart Mill's treatment of racial, cultural, gender-based and class-based difference to understand how two leading figures reacted to pluralism, and what contemporary readers might draw from them. The book mounts a qualified defence of Millian liberalism against Kantianism's predominance in contemporary liberal political philosophy, and resists liberalism's implicit association with imperialist domination by showing different divergent responses to diversity. Here are two distinctive liberal visions of moral and political life.