There has been much harrumphing this week over the fact that works of fiction are not always forensically exact in their historical detail.

Conservative MSP Alex Johnstone's motion in Parliament to reinstate the reputation of King Macbeth as a perfectly decent bloke rather than the weak, paranoid and manipulative killer of Shakespeare's grisly play might have set medieval historians cheering, but it was a dark day for the creative arts. If the likes of Johnstone were in charge, it seems, novelists and dramatists would have to take an oath on the bible to tell the truth, the whole truth and nothing but the truth before setting down a word.

On the other side of the Atlantic, meanwhile, newly opened documents have revealed that Truman Capote, who touted his masterpiece In Cold Blood as the first-ever non-fiction novel, would appear not only to have embellished the facts but also his handling of them. Some of the details he purported to have uncovered about the slaying of the Clutter family, and their murderers, are now exposed as half-truths, or inaccurate.

Loading article content

As a result, some are questioning Capote's genius, and others his claims to literary innovation. The less excitable among us, however, are not in the slightest surprised. Reshaping tedious or awkward facts into a more satisfying and powerful story is, after all, what writers of fiction do. That's why novels and plays are acts of imagination, not of stenography or dictation. Were they merely to report the facts, novelists and playwrights might as well become journalists and settle down with a steady income.

So where will it end? Must we live in dread that someday it will be revealed there never was a spider called Charlotte who span a web to save a pig from slaughter? That Dumas's musketeers are not so honest and true a portrait of King Louis XIV's guardsmen d'Artagnan, Aramis, Athos and Porthos that they might as well have been painted by Rembrandt?

As one sage letter writer to The Herald has remarked, were it not for Shakespeare's depiction, Macbeth would have been consigned to historical oblivion as just another medieval despot. In fact, he should perhaps be grateful to the bard for elevating his profile above the common ruck. Because while he may never have committed murder, like all monarchs of his times he will almost certainly have been party to deeds that to the modern eye are foul.

Yet whether or not the real Macbeth was anything like the fictional character is, artistically speaking, irrelevant. It is interesting, though, that while Shakespeare's grasp of 11th-century Scottish politics would not have won him a history O Level, his understanding of the machinations of power in the middle ages, the almost diabolical forces that preyed upon those in high positions, and the psychological damage they wrought, was eerily accurate.

Were it not for him, then, not only would Macbeth be a nobody, but the early Scottish court would be a blank sheet on which only academics and historical novelists would doodle. So too Richard III, bones not withstanding, whose feverish reflections the night before the fatal battle of Bosworth Field, as voiced in Shakespeare's play, give an insight into a beleaguered royal mind that carries an emotional truth that, for this reader at least, outweighs historical fact.

There are many, of course, who accord Shakespeare a great deal more respect than does Mr Johnstone. One such is American humorist James Thurber who, in an article in 1943, suggested that Macbeth is actually a crime novel. Poring over it for clues, he realised who the true murderer was. A fellow detective-novel addict was convinced she had unearthed the criminal, but Thurber knew better: "'You mean it wasn't Macduff?' she said. 'Macduff is as innocent of those murders' I said, 'as Macbeth and the Macbeth woman.'"

No, he went on, the miscreant was none other than Lady Macbeth's father, who, having killed Duncan, stuffed him under the bed and jumped under the bedclothes, thereby fooling his daughter. Having settled this, Thurber went off to reread Hamlet and unmask its culprits. If only all historical mysteries were as simply solved.