The date of 4th July 1776 has other claims to fame, of course. But while Thomas Jefferson, John Adams, Benjamin Franklin and their fellow revolutionaries were meeting in Philadelphia to publish the Declaration of Independence and launch a new nation, across the Atlantic a private gathering of even greater intellectual distinction was in progress.
David Hume was dying. Slipping away fast; so fast indeed that in February he told his great friend Adam Smith that he had “fallen five compleat stones.” Hume had installed himself some years before in the New Town in Edinburgh, in a house big enough “to display my great Talent for Cookery, the Science to which I intend to addict the remaining Years of my Life.” Now, knowing he was near his end, he had gathered Smith and a few other friends around him for one last dinner in company.
But although Hume’s famous fleshy frame had gone, his sense of humour—no less renowned—had not. When Smith complained that evening at the cruelty of the world in taking him from them, Hume replied: “No, no. Here am I, who have written on all sorts of subjects calculated to excite hostility, moral, political, and religious, and yet I have no enemies; except, indeed, all the Whigs, all the Tories, and all the Christians.”
With Thomas Hobbes, Hume has good claim to be considered the greatest philosopher ever to have written in English, while Smith is widely regarded as “the father of economics.” But even these descriptions underplay the measure of their achievements, for Hume must also be counted one of the greatest of historians, and Smith with equal justice the father of sociology. John F Kennedy once remarked to a dinner of Nobel Prize winners that theirs was the most extraordinary collection of talent seen at the White House since Jefferson dined alone. But in intellectual terms even Jefferson is pretty thin gruel compared to the cornucopic abundance of Smith and Hume.
In many ways they were the original odd couple. Hume, the older man by 12 years, was worldly, open, witty, full of small talk, banter and piercing aperçus, a lover of whist, a gourmand and a flirt. Smith by contrast was reserved, private, considered and often rather austere in his public manner, though he could unwind among friends. Despite, or perhaps because of, these personal differences the two men became firm friends, and their ideas the central intellectual engine of the Scottish Enlightenment.
In The Infidel and the Professor: David Hume, Adam Smith, and the Friendship that Shaped Modern Thought, Dennis Rasmussen, an academic at Tufts University, tells the story of their friendship well. Fourteen nicely-judged chapters take the reader through the overlapping lives of the two men, including such incidents as Hume’s notorious falling-out with Rousseau, through to the natural climax of their friendship at Hume’s death, and Smith’s own demise 14 years later. At the same time, Rasmussen dextrously weaves in an account of the two men’s ideas that is, on the whole, accurate, meticulous and wide ranging. The result is not a work of original scholarship—for that, one should look to James Harris’s recent life of Hume, or to Ian Simpson Ross’s life of Smith 20-odd years ago—but a short and lively book that sustains the interest not merely of the general reader but the specialist to the end. That is a considerable achievement.
As the title suggests, within the narrow confines of 18th-century Scotland, Hume and Smith lived rather different lives. Hume was a philosophical prodigy. His first book, A Treatise of Human Nature—a masterpiece—was written when he was in his mid-twenties, and published in three volumes in 1738-40. In a last autobiographical memoir, Hume remarked sardonically that the work “fell dead-born from the press.” In fact, however, it was respectably received, especially given the youth and obscurity of its author, the astonishing intellectual ambition of its ideas, and their rich potential to give religious offence.
But the Treatise certainly did not discharge Hume’s hopes for it, or for himself, and such was his self-confessed “yearning for literary fame” that over the next 30 years he recast and extended many of its leading ideas in other works of philosophy, built a considerable reputation as an essayist on political, economic and moral topics, attracted a vast amount of religious scandal, was lionised in the literary salons of France, and made a fortune with his bestselling History of England in six volumes. And as he did so, first Edinburgh and then Glasgow universities achieved the notable distinction of turning down one of the greatest thinkers of this or any age for an academic job.
Smith’s life, by contrast, was the very pattern of academic uneventfulness. He went first to the University of Glasgow, then to Balliol College, Oxford—which he much disliked for its indolence and Scotophobia—then after a short interval back to Glasgow as professor. Later he toured France as tutor to the young Duke of Buccleuch, before finally taking a position as Commissioner of Customs. Over 40 years he published The Theory of Moral Sentiments (1759) and An Inquiry into the Nature and Causes of the Wealth of Nations (1776), and very little else.
Not that Smith was idle; far from it. He endlessly revised these books, and in his later years confessed to having “two other great works upon the anvil; the one is a sort of philosophical history of all the different branches of literature, of philosophy, poetry and eloquence; the other is a sort of theory and history of law and government.” But neither work satisfied him, neither was completed as old age and the grind of the customs business bore in on him, and near his death he instructed his executors to burn them, and perhaps other works unknown, which they did. Miraculously, two fairly full sets of students’ notes of Smith’s lectures on jurisprudence have survived. But Smith was almost as close-handed in the volume of his published output as Hume was lavish.
The same is true of their private letters. For all their closeness—as Rasmussen notes, they moved over the years from “Dear Sir” to “Dear Smith” and “My Dear Hume” to “My Dearest Friend” at the end, an epithet uniquely reserved for each other—the two men never lived in the same city, and actually saw rather little of each other. In other circumstances one might expect that fact to be a spur to correspondence. Yet we have just 56 letters between them—almost three-quarters of them by Hume—and not much sign of many others lost.
It is a small and sometimes splendid correspondence, which ranges from gossip, political news and personal recommendations to brief moments of high philosophy. Among its gems is a wildly funny romp after the publication of The Theory ofMoral Sentiments, in which Hume in London alternately deflects and teases Smith in Glasgow as to how his book has been received. But 56 letters in 25-odd years of acquaintance is a meagre basis from which to write any biography of a friendship, let alone an intellectual one. Especially since, with a couple of modest exceptions, there is no place at which Hume and Smith engage in anything that might with any real justice be described as an argument.
So instead one must turn to the two men’s works themselves. Yet here too there is a problem, of a rather different kind. This is that, with the exception of his History of England, Hume had all but stopped writing and publishing by the time he first met Smith. Far more than any other thinker, Hume is Smith’s imagined interlocutor; there are few pages of Smith in which one does not sense the shadow, if not the influence, of Hume; indeed, it would not be too much to call Smith, for all their numerous points of difference, a disciple of Hume. Thus the flow is heavily in one direction.
Take the two problems together, and it is hard to escape this conclusion: we cannot tell from the letters how far the friendship by itself shaped Smith’s thought; and, at least as regards their published works, we can be pretty certain that Smith did not shape the thought of Hume.
Rasmussen’s book is not well served by its subtitle, then, catchy though it is; and the problem is all the more evident because one looks in vain for any substantial discussion of the ways in which modern thought has in fact been shaped by Hume and Smith. There is something that could, with some shortcuts and elisions, be called “Hume-and-Smith,” and that combined body of thought has had a profound influence on the way we think and act today. But this book barely addresses that influence, even in outline.
"Smith, for all his numerous points of difference with Hume, was his disciple. The flow is heavily in one direction"Let us briefly remind ourselves why this matters. At the heart of the two men’s thought is a—perhaps the—great Enlightenment project. This is to set out what Hume describes in the introduction of his Treatise as a “science of man”: a unified and general account à la Newton of human life in all its major aspects, derived from a few basic propositions, covering not merely mathematics and what would now be termed the hard sciences, but philosophy, religion, political economy, jurisprudence and the arts, and able in principle to serve as the basis for every other branch of human knowledge. Crucially, this science of man was to be based on observation and experience—not on natural law, divine inspiration or religious dogma.
In Hume’s coolly sceptical hands the test of observation and experience led to a series of devastating critiques and empirical reconstructions, notably of the ideas of a transcendental human self or soul, of unobservable laws of causation and of divine justice. Smith is less purely philosophical, more positive and constructive, and more focused on the unintended results of human action: TheTheory of Moral Sentiments argues that moral values are derived from human empathy working through interpersonal comparisons, The Wealth of Nations that markets, indeed commercial society, derive from the human instinct to truck and barter.
There are areas peculiar to each man, and real disagreements between them, notably over justice, in relation to which Hume emphasises utility and Smith injury. But their overall approach is the same: to deflate the claims of religion, if only by implication, and substitute for them general explanations based on recognisable human practices, emotions and habits. The result, a century before Darwin, is an evolutionary understanding of a vast range of moral, sociological, political and economic phenomena that is both recognisably modern and astonishingly powerful, marking every field it touches. Its full measure has yet to be taken.
Such ideas appeared to leave religion by the wayside, and it is not hard to see how they would excite the ire of the authorities. In fact Hume may have been more agnostic than atheist, but it made no difference at the time, and he was regularly denounced. The ever-circumspect Smith seemed to have escaped this fate, however, until “A single, and, as I thought, a very harmless sheet of paper, which I happened to write concerning the death of our late friend, Mr Hume, brought upon me 10 times more abuse than the very violent attack I had made upon the whole commercial system of Great Britain.”
As Rasmussen shows, Hume had the last laugh on his opponents. He died a philosopher’s death, cheerful and unperturbed to the last, and no one much begrudged him it, or the posthumous publication of his brilliantly subversive Dialogues Concerning Natural Religion. But Smith’s encomium of Hume, superbly written and full of pathos and paganism and Socratic overtones, brought the roof down on him. It was an act of love as well as of truth, perfectly befitting their friendship.