In this book, Stephen Buckle provides a historical perspective on the political philosophies of Locke and Hume, arguing that there are continuities in the development of seventeenth- and eighteenth-century political theory which have often gone unrecognized. He begins with a detailed exposition of Grotius's and Pufendorf's modern natural law theory, focusing on their accounts of the nature of natural law, human sociability, the development of forms of property, and the question of slavery. He then shows that Locke's political theory takes up and develops these basic themes of natural law. Buckle argues further that, rather than being a departure from this tradition, the moral sense theory of Hutcheson and Hume represents an attempt--which is not entirely successful--to underpin the natural law theory with an adequate moral psychology.