The 250th-anniversary edition of the influential treatise on social responsibility that has shaped leaders from Bill Gates to Barack Obama Best known for his revolutionary free-market economics treatise The Wealth of Nations , Adam Smith was first and foremost a moral philosopher. In his first book, The Theory of Moral Sentiments , he investigated the flip side of economic self-interest: the interest of the greater good. Smith's classic work advances ideas about conscience, moral judgment, and virtue that have taken on renewed importance in business and politics.