The political philosophy of liberalism was first formulated during the Enlightenment in response to the growth of the modern nation-state and its authority and power over the individuals living within its boundaries. Liberalism is now the dominant ideology in the Western world, but it covers a broad swathe of different (and sometimes rival) ideas and traditions and its essential features can be hard to define. This book offers a rich and accessible exploration of liberalism as a tradition of political thought. It includes chapters on the historical development of liberalism, its normative foundations, and its core philosophical concepts, as well as a survey of liberal approaches and responses to a range of important topics including freedom, equality, toleration, religion, and nationalism. The volume will be valuable for students and scholars in political philosophy, political theory, and the history of political thought.