One of the key figures of the intellectual movement known as the Scottish Enlightenment, he is known primarily as the author of two treatises: ''The Theory of Moral Sentiments'' (1759), and ''An Inquiry into the Nature and Causes of the Wealth of Nations'' (1776). | One of the key figures of the intellectual movement known as the Scottish Enlightenment, he is known primarily as the author of two treatises: ''The Theory of Moral Sentiments'' (1759), and ''An Inquiry into the Nature and Causes of the Wealth of Nations'' (1776). |