So, here's Smith and Shakespeare, together again, in "Monarchs and Mongrels."
Adam Smith’s respect for literature as art and as example infuses all his work. Whether it is The Theory of Moral Sentiments and its use of the characters of Iago and Othello to discuss issues of human sympathy and fellow-feeling, the quotations from Milton and Dryden which begin his essay on “The History of Astronomy,” his references to Phaedra, the Aeneid, and the Illiad in his examination of the legal history of marriage in the Lectures of Jurisprudence, or the Lectures in Rhetoric and Belles Lettres, the notes from his most extended considerations of literature, Smith’s use of literature throughout his body of work is constant.
Charles Griswold’s Adam Smith and the Virtues of Enlightenment points to the strong appeal that literature had for Smith as a way to speak about important contemporary moral concerns: “Not only plays, novels, and poems but tragedies, in particular, intrigue Smith. Together they completely overwhelm his relatively rare references to properly philosophical texts. …The notion that we are to understand literature and drama as sources for moral theory and moral education is clearly and strikingly evident in The Wealth of Nations as well. (59).” This attraction towards the literary as source material for moral arguments is easily seen simply by leafing through the footnotes to any of Smith’s works. His references to literature are myriad and most have been well-documented. In addition, however, Smith’s writing--steeped in poetry, novels, and drama as it is--often draws from the storehouse of his memory to allude to literature without giving a specific reference to the work of which he is thinking. Discovery and examination of such an uncited reference can give careful readers the sense of Smith as a writer who instinctively turns to literature as a tool for his thought.
Very early in Adam Smith’s Wealth of Nations the reader encounters one such reference, previously unnoted in Smith scholarship, during Smith’s meditations on human nature as demonstrated in comparison with the nature of dogs. The section is a justly famous one. It is elegant in both its content and its diction as well as in its explication of the social advantages and “conveniency” that arise from the human ability to “truck, barter, and exchange,” with skills that dogs are able only to use to help themselves. Smith writes:
The passage has been analyzed often. What has gone unnoticed, however, is that Smith’s passage alludes to an equally well-known passage from Shakespeare’s Macbeth. (The play may have been suggested to Smith by his use of the word “porter” early on in the passage reminding him of Macbeth’s famous Act II “porter scene.”) Suborning Banquo’s murder in Act III, Macbeth discusses human nature with the murderers for hire in almost precisely the same terms that Smith uses in the above passage.
A much longer version of this argument is available here, with footnotes and everything.