Adam Smith is not who you think he is. Long hailed as the founder of modern economics and the father of capitalism, the 18th-century Scottish thinker was not only an economist and the author of The Wealth of Nations; he was also a moral philosopher and the author of The Theory of Moral Sentiments. Smith considered his work in moral philosophy every bit as important as his work in economics (if not more so), and he continually revised The Theory of Moral Sentiments even after he’d completed The Wealth of Nations.