The Origin of the Distinction of Ranks is one of the major products of the Scottish Enlightenment and a masterpiece of jurisprudence and social theory. Building on David Hume, Adam Smith, and their respective natural histories of man, John Millar developed a progressive account of the nature of authority in society by analyzing changes in subsistence, agriculture, arts, and manufacture. The Origin of the Distinction of Ranks is perhaps the most precise and compact development of the abiding themes of the liberal wing of the Scottish Enlightenment. Drawing on Smith’s four-stages theory of history and the natural law’s traditional division of domestic duties into those toward servants, children, and women, Millar provides a rich historical analysis of the ways in which progressive economic change transforms the nature of authority. In particular, he argues that, with the progress of arts and manufacture, authority tends to become less violent and concentrated, and ranks tend to diversify. Millar’s analysis of this historical progress is nuanced and sophisticated; for example, his discussion of servants is perhaps the best developed of the "economic” arguments against slavery. John Millar (1735-1801) explored, through his works, the nature of English governance through a prism of the natural law tradition and Scottish philosophical history. Millar was a student of Adam Smith’s at Glasgow University and his most important immediate intellectual heir. His works provide an essential linkage to Smith. Aaron Garrett is Associate Professor of Philosophy at Boston University. Knud Haakonssen is Professor of Intellectual History and Director of the Centre for Intellectual History at the University of Sussex, England.