Dennis C. Rasmussen, The Infidel and the Professor: David Hume, Adam Smith, and the Friendship that Shaped Modern Thought (Princeton: Princeton University Press, 2017), 336 pp., $29.95.

IN AUGUST 1776, a large crowd gathered in front of a grand neoclassical mausoleum. It was designed by Scotland’s greatest architect, Robert Adam, and stood on Calton Hill in Edinburgh. One observer sardonically noted that it almost seemed as though the attendees had either “expected the hearse to have been consumed in livid flames, or encircled with a ray of glory.” To prevent the tomb from being desecrated by the devout, guards were stationed around the mausoleum for several days after the burial ceremony. A few years later, Adam Smith told a companion that the tomb was too ostentatious: “I don’t like that monument. It is the greatest piece of vanity I ever saw in my friend Hume.”

But this was an isolated reproach. No one went to greater lengths to defend David Hume’s posthumous reputation than Smith. Always more prudent than Hume—who was known as “the Great Infidel” and deemed unfit for tutoring the young—Smith, a venerated professor of moral philosophy at the University of Glasgow, was guarded in conversation about his religious skepticism. But after Hume’s death, Smith shed his habitual caution and composed a highly controversial supplement to Hume’s brief memoir My Own Life. It was called a Letter to Strahan. In it, Smith described Hume’s final months, emphasizing his affability and serenity in the face of illness and impending death. He observed,

Though Mr. Hume always talked of his approaching dissolution with great cheerfulness, he never affected to make any parade of his magnanimity. He never mentioned the subject but when the conversation naturally led to it, and never dwelt longer upon it than the course of the conversation happened to require.

Boswell, who visited Hume on his deathbed and wrote a famous account of it, was astounded by Hume’s phlegmatic acceptance of his demise. Dr. Johnson was not. After Boswell described his interview with Hume, Johnson, who was always beset by a profound fear of death and regarded Hume’s irreligiosity with abhorrence, commented that he had “a vanity in being thought easy.” Smith would have none of this. His aim was to counter the conviction that Hume could only be a moral reprobate. He concluded his letter by associating Hume with the greatest philosopher of them all, Socrates, echoing Plato’s epitaph in the Phaedo: “Upon the whole, I have always considered him, both in his lifetime and since his death, as approaching as nearly to the idea of a perfectly wise and virtuous man, as perhaps the nature of human frailty will permit.”

In The Infidel and the Professor, Dennis C. Rasmussen explores the bromance between David Hume and Adam Smith. They bolstered each other’s careers, belonged to the Select Society club in Edinburgh and corresponded regularly on a variety of topics, ranging from moral philosophy to history to economics. Both also lived for a time in France, where they were celebrities and where Hume briefly became friends with Jean-Jacques Rousseau. Rasmussen, a professor of political science at Tufts University, deftly examines not only Hume and Smith’s personal relationship, but also the indispensable part that they played in shaping the Scottish Enlightenment. The result is a valuable study of the rise of the liberal tradition.

ON THE face of it, Scotland was an unlikely candidate to spawn such intellectual titans. Hume himself said that Scotland had been “the rudest, perhaps, of all European Nations; the most necessitous, the most turbulent, and the most unsettled.” But Hume’s and Smith’s lifetimes coincided with a new era of economic prosperity and cultural glories. Edward Gibbon remarked in 1776—the year the first volume of his The Decline and Fall of the Roman Empire appeared, along with Smith’s The Wealth of Nations, not to mention Thomas Paine’s Common Sense—that he had “always looked up with the most sincere respect towards the northern part of our island, whither taste and philosophy seemed to have retired from the smoke and hurry of this immense capital.” Some of the leading luminaries included Adam Ferguson, William Robertson and Dugald Stewart. Most were employed by the university, the law, church or medicine. According to Rasmussen, this helps to explain why their “outlooks generally lacked the subversive edge that was so conspicuous among the Parisian philosophes, causing the more radical side of Smith’s and especially Hume’s thought to stand out in starker relief.”

Hume, who was born in 1711, entered Edinburgh University at the age of ten, where he studied Latin, Greek, logic, metaphysics and the natural sciences. Religious precepts infused his courses. Hume was unimpressed. He instructed a friend in 1735 that “there is nothing to be learnt from a Professor, which is not to be met with in Books.” Upon graduation, he devoted eight years to private study, then spent three years in France, where he wrote the first two volumes of A Treatise of Human Nature. His early works, however brilliant, fell flat. Hume decided to focus on more accessible essays, deeming himself an “Ambassador from the Dominions of Learning to those of Conversation.” Hume’s luminous essays quickly earned him both applause and notoriety, not least his sallies against miracles. “A skeptic to the end,” writes Rasmussen,

Hume never claims that miracles are impossible; to insist on their impossibility would be nearly as dogmatic as to insist on their reality. Rather, he “merely” argues that it is never reasonable to believe a report of a miracle having occurred.

Hume also knew what he was about. Years later, he admitted to a friend that a “Tincture of Deism” could readily promote book sales since “the Clamor, which it raises, commonly excites Curiosity, & quickens the Demand.” Hume’s greatest offense was to maintain that, far from being a beneficent force, religion was actively pernicious, prompting its adherents to adopt overzealous habits and practices that were contrary to the true interests of society. As Boswell reported from Hume’s deathbed, “He then said flatly that the morality of every religion was bad, and, I really thought, was not jocular when he said that when he heard a man was religious, he concluded he was a rascal.”

If the genial Hume reveled in controversy, Smith was more restrained. Smith, who was born in 1723 in the port town of Kirkcaldy, entered Glasgow University at the age of fourteen, where he studied with what he called “the never to be forgotten Dr Hutcheson.” He spent another six years at Balliol College. Like Gibbon, he found Oxford an intellectual backwater: “It will be his own fault if anyone should endanger his health at Oxford by excessive Study, our only business here being to go to prayers twice a day, and to lecture twice a week.” After entering his chambers unannounced, several dons discovered Smith poring over Hume’s Treatise and severely reprimanded him. At Oxford, Smith wrote a work titled The Principles Which Lead and Direct Philosophical Enquiries. Like Hume, Smith was fascinated by human nature and the working of the human mind. Both Smith and Hume located the origins of religion in human nature, ascribing it not to reason but ignorance and credulous superstition. According to Rasmussen, “Smith’s and Hume’s first works both convey deeply skeptical assessments of the power and scope of human reason, and both served as prolegomena of sorts to their more constructive works.”

In 1759, Smith published The Theory of Moral Sentiments, which is often overlooked in favor of The Wealth of Nations. But Rasmussen quite rightly emphasizes its importance. Contrary to the popular image of Smith as a kind of proto-Gradgrind of modern capitalism, he was very much concerned with morality. “For Smith as for Hume,” Rasmussen writes, “our moral sentiments are acquired and developed over time, not written directly into human nature.” Rasmussen also suggests that, in some important instances, Smith’s views diverge from, and indeed are more sophisticated than, Hume’s. Smith states, for example, that a true moral judgment must contemplate not merely the effects of an action, as Hume maintained, but also the circumstances in which it transpired. Nor did Smith take as dim a view of religion as Hume. He adopted the more conventional view that religion, with its emphasis on punishment or reward in the afterlife, tends to buttress rather than subvert traditional morality. Nevertheless, Rasmussen demurs from the view that Smith harbored latent religious convictions. He notes that Smith’s more approbatory comments about religion are loaded with qualifiers. Hume was smitten by the Theory of Moral Sentiments, writing Smith privately to congratulate him as well as penning an anonymous review that lauded him for theorizing with “that boldness which naturally accompanies genius.”

BOTH HUME and Smith found a most receptive audience in France, where what passed as heresies in London were mere commonplaces in Paris. If anything, the philosophes thought Hume wasn’t radical enough. Hume first visited the City of Light in 1763 in the capacity of private secretary to Lord Hertford, Britain’s newly appointed ambassador to France. There Hume was treated like a conquering hero. “Royalty, aristocrats, public officials, salon hostesses, men of letters—everyone who was anyone tripped over themselves,” Rasmussen reports, “to meet Hume, to extol him, and above all to be seen with him.” Hume soaked it up. “I eat nothing but Ambrosia,” he wrote a friend,

drink nothing but Nectar, breathe nothing but Incense, and tread on nothing but Flowers. Every Man I meet, and still more every Lady, wou’d think they were wanting in the most indispensable Duty, if they did not make to me a long & elaborate Harangue in my Praise.

The most fateful acquaintance that Hume made in Paris was in December 1765 with Jean-Jacques Rousseau. Baron d’Holbach warned Hume that “you are warming a viper in your bosom.” In an instance of flagrantly bad judgment, Hume ignored the warning and invited Rousseau to return with him to Great Britain. Rousseau, who was, to borrow from Donald Trump’s lexicon, something of a nutjob, soon turned on Hume, accusing him of spearheading an international conspiracy to traduce his reputation. In a thirty-eight-page epistle, Rousseau said, among other things, that Hume’s charitable acts on his behalf were simply a ruse to win control over him. Smith warned Hume not to respond: “To write against him, is, you may depend upon it, the very thing he wishes you to do.” Hume ignored this sage advice and wrote a pamphlet that sought to vindicate his name. After Rousseau departed England for Calais, Smith asked, “What has become of Rousseau? Has he gone abroad, because he cannot continue to get himself sufficiently persecuted in Great Britain?”

By now, Hume had decided that his book-writing years were over “because I’m too old, too fat, too lazy, and too rich.” It was Smith who earned widespread acclaim with The Wealth of Nations in 1776. Rasmussen emphasizes the intellectual contribution that Hume made to Smith’s thinking about political economy. He notes that Smith’s claim that commerce helps to promote personal liberty and security and abate the prospect of strife, as well as the case for the merits of free trade, was anticipated by Hume. The idea that trade is a zero-sum game, Hume thought, was bunk. Rasmussen rightly notes that in his essay “Of the Jealousy of Trade,” Hume declares that he prays for the prosperity of Germany, Spain and “even FRANCE itself.” Both Hume and Smith were also opponents of colonial adventures, with Hume noting that “extensive conquests, when pursued, must be the ruin of every free government,” and Smith concluding The Wealth of Nations with a ringing condemnation of the fiscal folly of imperialism. At the same time, Smith was definitely more alive to the shortcomings of commercial society than Hume. He condemned the “mean rapacity” of merchants and their propensity for collusion for personal gain. According to Rasmussen,

Even as Smith agreed with Hume that the benefits of commercial society—liberty, security, prosperity, and the rest—vastly outweigh the costs, he was far more willing to acknowledge that there are costs involved, and to seek ways to ameliorate them.

Unlike Hume, Smith’s death in 1790 excited little attention. The obituaries that appeared tended to cast aspersions upon Smith: the Times, for instance, took a swipe at him for having “published such a labored eulogium on the stoical end of David Hume.” Consistent with his modest personality, he only had a small tombstone, tucked away in a corner of the Canongate Kirkyard.

But he may have exercised an even more decisive influence on modern liberal thought than his lifelong friend. At a moment when enlightenment values are once more under assault from within the West, their work has acquired a fresh relevance.

Jacob Heilbrunn is editor of the National Interest.

Image: Statue of Scottish Philosopher David Hume (1711 to 1776) by Alexander Stoddart at one of the prominent landmarks on the Royal Mile in Edinburgh, Scotland.​ Wikimedia Commons