Adam Smith’s Rebuke of the Slave Trade, 1759

Interest in Adam Smith’s The Theory of Moral Sentiments (TMS, Smith [1759] 1976b) has soared during the past thirty-five years. Long eclipsed by The Wealth of Nations (WN, Smith [1776] 1976a), TMS now has a popular estimation more in line with Smith’s own estimation. Shortly after Smith’s death in 1790, a friend reported that Smith always considered TMS “a much superior work to [ WN]” (Romilly 1840, 1: 404).

The wonder and mystery of TMS is open-ended, but here we consider specifically two sentences, perhaps the most powerful passage in TMS. It comes in part V, titled “Of the Influence of Custom and Fashion upon the Sentiments of Moral Approbation and Disapprobation.” The part is curiously meandering and enigmatic; the passage is the key to the whole part. Once the passage is fully appreciated, the whole part achieves cogency and power. It is quite clear that the two sentences, appearing in the original edition of 1759 and maintained thereafter, were an inspiration to the early antislavery movement.

Smith says that from the regularities of experience and practice “the imagination acquires a habit” and that such regularities—custom among the society in general, fashion among those “of a high rank, or character” (TMS 194.3)—may cause “many irregular and discordant opinions which prevail in different ages and nations concerning what is blamable or praise-worthy” (194.1).¹ The part consists of two chapters. The first considers clothing, furniture, architecture, and other such inanimate objects and argues that, here, custom and fashion play a large role.

The second chapter turns to the influence of custom and fashion “upon Moral Sentiments”—that is, sentiments about the beauty or deformity of human conduct and character. Since the title of the entire part speaks only of “Moral Approbation and Disapprobation,” we may regard the first chapter, treating inanimate objects (or objects of nonmoral sentiment) as a warmup.

Less malleable, these: the moral sentiments, “though they may be somewhat warpt, cannot be entirely perverted,” for they “are founded on the strongest and most vigorous passions of human nature” (200.1). To the extent that moral standards do vary, they vary with circumstances. The variations follow different professions, different stages of life—young versus old—and different stages of society—barbarism