Both Left and Right claim visionary Adam Smith for their cause. James Buchan suggests they read his works first.
In the transfer of knowledge from the specialist to the public, or from the academy to the street, something is lost as well as gained, and never more so than in the territory of philosophy. Machiavelli, the great Florentine theorist of republican government and aristocratic liberty, is to the public an immoral schemer. David Hume is merely a fatty.
Adam Smith, the most brilliant and readable philosopher ever to write and lecture in these islands, is famous today for things he never said or did. A thinker whose purview took in everything from Italian verse to hedge topiary, with pins, taxes and ethics in between, the Scotsman is revered all over the world as the founder of the doctrine of laissez faire in business. Something he invented called the Invisible Hand is supposed to convert the selfish propensities of businesspeople into national benefits.
Neoconservative think-tanks and right-wing blogs appeal to Smith against the sins of Big Government.
The odd thing is that, since at least the 1920s, this view has had no respectable following in the historical or philosophical departments of the university. Laissez faire long predates Smith and never, in all the voluminous and lucid philosophy that has come down to us, does he use the phrase. The famous Invisible Hand so beloved of economists is a mere circumlocution for Providence. The very name economist was applied in Smith's day only to a sect of French agricultural theorists of whom he disapproved.
As for government, Smith's problem was that in those days the British Government was in thrall to the sectional interests of businesspeople.
Of all the classes that could do injury to Great Britain, Smith thought that the merchants and manufacturers were by far the most dangerous. At the very least, any proposal "which comes from this order ought always to be listened with great precaution". In other words, beware of the Adam Smith Institute.
Smith prospers at the university for quite different reasons. He is the object of vigorous study in his home country, in England, Germany, the US and Canada as perhaps the ultimate representative of what, for better or worse, is called the Enlightenment of the 18th century.
Smith was among the last men to know everything. That does not mean he knew everything there was to know, just that he probably knew most things that could be known at that time. For a world of knowledge that has fissured into surly and monoglot specialisms, his is a golden age.
Why is there such a discrepancy between the Adam Smith of the quadrangle and the Adam Smith of the boardroom and Bourse?
The problem is that ever since John Maynard Keynes in 1946 began to despair of his own philosophy, and prayed for an "invisible hand" to save the British Empire, Smith has been the plaything of economists and politicians.
Unlike philosophers, still baffled by what baffled Socrates, economists believe themselves to be like physicists and medical doctors, with nothing to learn from the past. History is just so much quackery. They are interested in the likes of Smith only in so far as the poor man had premonitions of modern doctrines.
Left or Right, they have selected from Smith only those passages that correspond to their beliefs. As for politicians, the public does not select its parliamentary representatives on the basis of their literary education.
Does the distortion of Smith matter? Perhaps not. The struggle between Right and Left in the 1970s and 1980s over the proper or appropriate role of the state was a real political struggle. It was a battle that perhaps needed to be fought to end a sort of political stalemate in the principal English-speaking countries.
While a real distortion of the doctrine and memory of both Keynes and Smith, the great simplifying slogans of the later 20th century made for a battle in which everybody could take part.
All that laissez faire and all those Invisible Hands were like the primordial elements in ancient physics of earth, air, fire and water, which, as Smith put it, "with all their imperfections, could enable mankind to think and to talk, with more coherence, than without them they would have been capable of doing".
All this writer would say is this: if Adam Smith were alive today he would cry out, with Gotthold Lessing, " Weniger erhoben, fleissiger gelesen " - praise a little bit less, and read just a little bit more.
James Buchan is the author of Adam Smith and the Pursuit of Perfect Liberty , published this week by Profile Books, £15.99.