Adam Smith’s The Theory of Moral Sentiments (1759) secured its author’s place as one of history’s most celebrated philosophers. Like all great works of moral philosophy, Smith’s book belongs to a tradition that dates to antiquity. The Theory of Moral Sentiments, however, is probably best understood in the context of the 18th-century Scottish Enlightenment, for its argument helps reconcile two otherwise conflicting ideas advanced by two of that era’s intellectual titans. Furthermore, The Theory of Moral Sentiments lays the foundation for Smith’s most famous book, An Inquiry into the Nature and Causes of the Wealth of Nations, published in 1776.

The Scottish Enlightenment produced two great moral philosophers who had a tremendous impact on Adam Smith. The first was Francis Hutcheson, Smith’s teacher at the University of Glasgow and the man whom Smith later succeeded as chair of moral philosophy. The second was David Hume, who also became Smith’s friend. While Hutcheson argued that man possesses a “moral sense” that inclines him to do good, Hume insisted that men are driven primarily by their passions. Smith’s Theory of Moral Sentiments occupies the vast middle between Hutcheson’s benevolence and Hume’s self-interest.

Plot Summary

The Theory of Moral Sentiments is divided into seven parts. To demonstrate that human beings are not merely the selfish creatures of Hume’s imagination, Smith establishes sympathy as the central concept of his moral philosophy. Modern students might think of sympathy as an expression of condolences, and it had this meaning in the 18th century as well, but it also meant, in Smith’s words, “our fellow-feeling with any passion whatever” (19). When we observe the behavior of those around us, we take note of how it makes us feel, and we use this feeling to form moral judgments, first of their behavior and later of our own. As Hume insists, however, our passions are indeed powerful, so it is not easy to form a correct judgment of our own behavior. To this end, Smith argues that human beings rely on an impartial spectator, an imaginary observer who acts as a kind of conscience (“the man within the breast,” or “the great inmate of the breast,” as Smith alternately refers to it) reminding us of how total strangers, unafflicted by the passions we feel at any given moment, would view our conduct. These two related concepts—sympathy and the impartial spectator—constitute two of the book’s major themes.

While Smith does not wholly embrace Hume’s view of self-interest, neither does Smith accept Hutcheson’s argument for a moral sense driving us toward benevolence. In fact, when we act first and foremost from concern for our own interest, we do so in accordance with God’s design. Universal benevolence is fine for sentiment, and when we consult the impartial spectator, we never dream of sacrificing the welfare of the many for our own private benefit. It does not follow, however, that virtue consists in benevolence alone, for we were not meant by nature to take onto ourselves the suffering of others, nor were we meant to see the world as God sees it. It is best, then, for us to keep to our own limited spheres of activity and influence. Thus, Smith locates Hume’s self-interest in divine will (ironically, for Hume was no believer), another of the book’s major themes. In so doing, Smith paves the way for the individual- and interest-centered economic arguments that later appear in Wealth of Nations.