Samuel Pufendorf is one of the most important moral and political philosophers of the seventeenth century. His theory, which builds on Grotius and Hobbes, was immediately recognized as a classic and taken up by writers as diverse as Locke, Hume, Rousseau, and Smith. Over the past twenty years there has been a renaissance of Pufendorf scholarship. On the Duty of Man and Citizen is Pufendorf's own epitome of his monumental On the Law of Nature and of Nations, and it served as a basic text in European universities throughout the Enlightenment. This edition has a lucid and historically sensitive translation by Michael Silverthorne, the first since the early twentieth century. James Tully's introduction sets the text in its context, summarizes the main arguments, surveys recent literature on Pufendorf, and shows how Pufendorf transformed natural law theory into an independent discipline of juristic political philosophy that dominated reflection on politics until Kant.