Books about the characteristic figures of the Scottish Enlightenment, unlike those about their French contemporaries, tend to concentrate on their ideas rather than their activities. A comparison of how they usually met their demise suggests why. Barnave wrote his Introduction to the French Revolution in 1792, while he was in prison awaiting trial and eventual execution for treason, after plotting counterrevolution with the royal family. Condorcet, also suspected of treason—although with rather less justification than Barnave—wrote his Sketch for a Historical Picture of the Progress of the Human Mind while in hiding during 1793, shortly before his death in captivity the following year. Contrast their fates with those of David Hume and his friend Adam Smith, both of whom, as far as we can tell, died peacefully in their beds. It is true that both men rejected the consolations of religion, and that their scepticism towards it was treated as no better than outright atheism by the Calvinist ‘Popular’ wing of the Church of Scotland; but the era was long gone in which a blasphemer could be executed in Edinburgh at the behest of the Kirk, as Thomas Aikenhead had been in 1697. The risks they ran were to career and reputation, rather than to life and limb.

The differences are partly to do with the divergent forms taken by the French and Scottish revolutions: the former the prototype for all subsequent revolutions from below; the latter the first ‘passive revolution’ from above—to which both Hume and (especially) Smith contributed as theorists. Perhaps because their distance from the immediate process of social change led to comparatively—and mercifully—uneventful lives, biographies of the Scots have been relatively few and far between. In the case of Smith, his disciple Dugald Stewart established the basic framework in 1794 with the long essay ‘Account of the Life and Writings of Adam Smith, lld’, which began the process of de-radicalizing his work. Between that point and the 1980s, when an era of modern scholarship addressing Smith’s life rather than his work commenced, there appeared precisely two biographies, published in 1895 and 1937. Hume has been even more poorly served. His five-page memoir, ‘My Own Life’, written in the knowledge of his impending death from cancer in 1776, provided the framework for Thomas Edward Ritchie’s An Account of the Life and Writings of David Hume (1807)—a volume otherwise consisting of extracts from his letters and unpublished essays. Only two treatments of his life followed, in 1836 and 1931, before the appearance of the standard biography, E. C. Mossner’s The Life of David Hume, in 1954. This remains the most valuable source of information on Hume’s life, but it deals with his ideas only in so far as they provide what Mossner called ‘the rationale of his actions’—an approach that was still being followed fifty years later in Roderick Graham’s The Great Infidel (2004), with diminishing returns. In short, discussions of Hume’s work tend to treat his biography as ‘background’, and biographies tend to focus on his work only to the extent that it relates to his personal circumstances.

His life is not without interest, of course, however uneventful it may appear by the standards of late-eighteenth-century France. Hume’s trajectory was emblematic of the intellectual during the period when Scotland was undergoing the transition to capitalism and Britain was establishing its paramountcy over France as the dominant European power—as his dates suggest. Born in Edinburgh in 1711, only four years after the Anglo-Scottish Treaty of Union had given birth to Great Britain, he died in the same city in 1776, as the outbreak of the American Revolution prepared the first setback for what was now a British Empire. As the younger son of a relatively minor landowner and advocate—John Home of Ninewells in Berwickshire, who died when his children were very young—Hume would have been expected to acquire a profession, most obviously in law, but he never did. (The change of vowel in his surname was another departure.) Although he attended the College of Edinburgh at what now seems to us the extraordinarily young age of ten (the normal age was fourteen at the time), he never graduated and would maintain himself through a diverse series of posts. He worked as a clerk in Bristol in the early 1730s and acted as tutor and companion to the mentally unstable Marquis of Annandale in 1745–46, before taking up several posts in Britain’s military and diplomatic bureaucracy, first as secretary to the British General James St Clair during his campaigns against the French, then as secretary to the British embassies in Turin and Vienna. His last official post was as under-secretary of state for the Northern Department (that is, Europe north of France) between 1767 and 1768. Despite being one of the leading intellectuals of his time, Hume applied—or was proposed by his friends—for only two academic posts, one as professor of Moral Philosophy at Edinburgh (1745), which he was denied following a petitioning campaign by the local Kirk ministers, the other as professor of Logic and Metaphysics at Glasgow (1751), for which he was never seriously considered because of the heterodoxy of his religious views. The only one of his positions in any way connected to academic life was that of Keeper of the Edinburgh Faculty of Advocates’ Library between 1752 and 1757.

During this time, Hume produced over sixty essays and pamphlets and, aside from the collections in which these appeared, four substantial books, two of them multi-volume in scope. In James Harris’s new intellectual biography, we finally have a work which integrates discussion of this oeuvre within the context of what is known about his life, without privileging either at the other’s expense, in a way similar to, but more developed than, Nicholas Phillipson’s approach to Hume’s friend in Adam Smith: An Enlightened Life (2010). This fine balance is not the limit of Harris’s achievement, but it is the starting point for it. As he notes in the preface, very few new facts have emerged since the revised edition of Mossner’s book appeared in 1980. However, unlike Mossner, whose groundless speculations are notorious among Hume scholars, Harris usually alerts the reader when there is a lack of conclusive evidence—about, for example, which books Hume was reading or in which debates he was intervening—and is clear when he is making defensible inferences rather than presenting facts.

But in any work of this sort, however scrupulous the historical account or accurate the theoretical exposition, the real interest is likely to be whether an author gives a plausible new interpretation of at least some aspect of their subject. As we shall see, Harris does so, but also shows that Hume was a deeply unreliable narrator on his own account, continually downplaying the extent to which he was personally admired by many of the leading European minds of his day, and how, from the start, his work was taken with great seriousness, even by those who disagreed with it. There may have been psychological reasons for this, including, as Harris suggests, the fact that ‘he was rather more sensitive as regards hostile criticism than he was as regards praise’, but more generally, ‘there seems to have been something in Hume that prevented him from acknowledging, perhaps even to himself, the success he undoubtedly had.’ Hume did concede in a very late letter to one of his friends that he had, as the Scots say, ‘a good conceit of himself’, to which Harris adds: ‘And there might have been vanity also in, precisely, this refusal to acknowledge that what he had achieved had not, in fact, gone completely unrecognized.’ ‘Not completely unrecognized’ is an understatement, and Harris’s caution against treating ‘My Own Life’ as an accurate assessment of Hume’s impact during his own lifetime is well taken. Beyond this properly critical attitude to his subject’s own utterances, Harris offers two major shifts in perspective regarding Hume’s work.

First, he challenges the dominant conception of Hume, in which he is primarily a philosopher who produced one great work, A Treatise of Human Nature (1739–40), at the early age of 26. The Treatise is a much discussed and controversial classic of Western philosophy, scarcely susceptible to summary in a few sentences, but for our purposes the following aspects are most relevant. Hume argued that we cannot truly understand causal relationships through reason, but only assume them on the basis of ‘certain principles’ that are inherent in our minds. Unlike Locke, he rejected the notion of mind as a passive tabula rasa that receives the impress of experience, claiming instead that it is the site of innate ideas and propensities—particularly in relation to explaining events. Broadly, because we observe a chain of events ending in a particular way, we assume that they always will, but this is at best only a probability. As Harris summarizes Hume: ‘On the demonstrative, mathematical conception of rationality that philosophers had been most interested in since the start of the scientific revolution, it was, Hume saw, actually irrational to believe anything at all on the basis of experience alone.’ The level of existential uncertainty to which this degree of scepticism tends might appear profoundly destabilizing, but Hume argued that it need not be, since societies can and should survive by relying on habit or custom as a guide to everyday life. We respond to external stimuli in certain ways because of our human nature, which is expressed through the passions, or ‘original existences’, which are quite separate from each other and not amenable to rational analysis. They are best understood as being ‘needs’ or ‘desires’. The contrast between reason and the passions is of course a venerable one, extending back to the ancient world, but it acquired a heightened significance during the Enlightenment, when the task of establishing the powers and limits of human reason took on a new urgency in the face of several varieties of confessional obscurantism. Pascal invoked it during the 1650s in the Pensées (‘the heart has its reasons of which reason knows nothing’), as did Spinoza shortly afterwards in the Tractatus Politicus, but Hume was perhaps the first thinker to devote so much attention to the distinction. What is most striking about his position—expounded in one of the first great works of the Scottish Enlightenment—is the limits he set on human rationality. As he wrote in the Treatise: ‘Reason is, and ought only to be the slave of the passions, and can never pretend to any other office than to serve and obey them.’

There are two versions of what happened once Hume had published this groundbreaking work. In the first, he is seen as continuing to pursue his philosophical interests but mostly, as it were, by other means: in this account, everything he writes on whatever subject is infused with the positions he established in the Treatise. In the second, associated above all with Lytton Strachey, Hume was so dispirited by the hostile reception of his first book, and the subsequent reluctance of anyone to republish it, that he abandoned his true philosophical vocation for writing about a series of unrelated subjects, driven by his desire for literary fame rather than any deeper intellectual purpose. Harris rejects both versions.