Scotland’s enlightened philosophers did not on the whole have an exciting time of it. Some piquant stories told about them – the infant Adam Smith kidnapped by gypsies, Adam Ferguson leading the charge at the Battle of Dettingen – seem just to have been invented by later admirers. David Hume is an exception: he had a taste for the good things of life, and during his years in Paris he made sure to enjoy them, from the cuisine that fattened him up to the flattering attentions of the licentious hostesses in the intellectual salons.

Did he have sex? It is a question readers of the twenty-first century like to get an answer to. In contrast to his bosom buddy Smith, who even in The Theory of Moral Sentiments scarcely mentions women, Hume did at least write about them and give advice on how to chat them up. From a passing remark he made to Robert Dundas of Arniston, he seems to have enjoyed risqué jokes. In this excellent biography, James Harris allows himself a number of other legitimate speculations about a Hume whose private life remains largely hidden from us, as he himself wanted it to be. But I do not see why the speculation should not have not extended to sex. There is nothing in the mind, said Hume’s philosophical predecessor Gottfried von Leibniz, that was not previously in the senses. So there should be a place for sex even in an intellectual biography.

Still, that is about the only criticism I have to make of a book which seems sure to revolutionise our views of one of the greatest Scots, yet a man who up to now has been hard to see in the round. While for us he stands at the fountainhead of modern western philosophy, his immediate intellectual environment in Scotland largely rejected what he had to say. Only gradually in Europe did he find the receptive audience that would carry his impetus forward. Meanwhile in Edinburgh, Hume stopped publishing works of philosophy or at best postponed their publication till after his death.

Instead he spent much time writing essays, beautifully polished and on a wide range of subjects from astronomy to politics. They are good to read, if not always easy to relate to the hard core of his strapping empiricist philosophy. Yet that is what the present generation of academics has sought to do, in an effort to create round this body of work an intellectual structure that does not really exist. In fact their interpretative efforts can be rather harder to follow than the original writings they seek to elucidate.

Harris at last resolves these dilemmas and moves us on. He sees the philosophy, epoch-making though it was, as only one part of a life’s work, in which the life itself was really the work as a whole. Hume set out, after deciding he would be useless for anything else, to make himself a man of letters, and that was what he did. Fine for him that he was anyway endowed with a most muscular intellect, but he found that his first and greatest book, A Treatise of Human Nature (1741), only frightened his punier contemporaries off. So, not without regret, he afterwards set out to give readers what they wanted, smoothly crafted pieces on items of topical interest. Today he would have been a renowned columnist, perhaps a tele-pundit. Like the ablest of such people, he made a fortune.

A service Harris performs for us, never done so well before, is to winkle out Hume’s attitude towards his own nation. He has won some notoriety for his determination to rid his literary style of Scotticisms, but this was really a necessary marketing tool. More revealing is the stance he took in his historical works, which could be quite anti-English, at least in the sense of debunking the fond myths the English cherished about their ancient constitution, the idea that they had brought their concept of liberty with them from the German forests and defended it ever since against all comers, from Normans to Scots. Yet the Tudors, the most English of monarchs, were despots as harsh as any in Europe – so what was all his blather about liberty? "I am delighted to see the daily and hourly progress of madness and folly in England,’ Hume wrote in 1769." The consummation of these qualities are the true ingredients for making a fine narrative in history, especially if followed by some signal and ruinous convulsion, as I hope will soon be the case with that pernicious people.’