Canon to right of them, canon to left: 'Culture of Complaint' - Robert Hughes: Oxford, 12.95 pounds

IT HAS not always been easy to identify with those who bang on about the devilish threat to civilisation posed by political correctness. There never seems to be enough heat in all that word-whingeing to get under anyone's collar; and besides, it is painful hearing politicians stress the importance of reading Shakespeare's sonnets, when we all know they haven't the slightest intention of arranging their own busy schedules around anything so low-priority and namby-pamby as poetry. Sonnets] For God's sake.

But now Robert Hughes, the top-drawer art-critic and expert historian of the convict transports to Australia, has shown himself to be as hot and bothered about America's cultural spats as anyone. Culture of Complaint, three lectures hammered into a book, is a sober plea for reason stirred up with an alarming amount of fiery, before-it's-too-late zest.

Hughes swinges both ways. He takes plenty of jovial potshots at both the stealthy left-wing sappers of social change and the moral reactionaries who want to wheel America's family-value wagons into a no-surrender last stand. Villainy does not lie with one side or the other: it lies in the way that both have unleashed a schismatic, authoritarian impulse and turned American culture into a corny, polarised slanging match. Bad-faith politics have melted out of the Cold War mould and dribbled into the arena of culture. Hughes doesn't want to imply that art is not political - only that its political aspect is rarely the most interesting thing about it. Discrimination, which used to be a mark of refinement but is now (with reason) a slur, is becoming taboo even in the field of aesthetics. Hence the 'maudlin reaction against excellence.'

What is at risk? For Hughes, it is the anti-authoritarian, liberal principle of inclusiveness. It might well be that this idea has never been tried, but it is too soon to quit. Hughes describes an America splintering into special-interest pressure groups, each in keen pursuit of a 'culture' to call its own. But instead of culture, we get cults. It all springs, he thinks, from a low-level, narcissistic fantasy about self-esteem, which in turn has promoted a culture of moaning, of blaming, of scapegoats and name-calling.

Hughes digs his heels into the middle ground, but while he is never less than a splendid sight, he does not always seem comfortable. Gazing on the thought-annihilating recipes of the left, he shudders to see distorted versions of his own classy liberal tendencies taken to a quasi-logical conclusion. In his humorous, blustering way, he seems right about almost everything, but there is something fidgety about even his quips. His well-reasoned pitch for sanity trips over the unreasonable, hectic reflexes of his prose. A long-serving and inventive critic of high-level bigotry, he has to wriggle here to avoid seeming like a mere defender of the status quo.

He delivers arguments like someone slapping out writs, or just slapping wrists. You keep a sharp eye out for the next biting epigram. Luckily, there are hundreds: 'There's an intractable New World disorder, laced with Arms business as usual . . . The right has its own form of PC - Patriotic Correctness . . . Those who parrot phrases like 'dead white male' might reflect that, in writing, death is relative: Lord Rochester is as dead as Sappho, though by no means as moribund as Brett Easton Ellis or Andrea Dworkin . . . The Canon is not a fortress, but a permeable membrane . . . Students come away with the impression that the correct response to a text is to run a crude propriety meter over it and then let fly with a wad of stereotyped moralising.'

He is clear: both camps are phony. But while he takes it as axiomatic that right-wing politics are pernicious, he reserves his most expensive ammo for left-wing academics. He is tough on racism in a goes-without-saying sort of way, but when it comes to the Afrocentric view of slavery, he has lots to say: 'Only the immense moral and intellectual force of the Enlightenment was able - unevenly and with great difficulty - to bring the trade to an end. That we now have so-called historians who are prepared to gloss over this fact strikes me as remarkable.'

This is part of an argument about history, not about slavery; Hughes is not for one second trying to gloss anything over ('Slavery is one of the oldest and worst of human institutions'). But no desire for historical redress, however patent the provocation, justifies dressed-up history. Mythmaking on behalf of the disadvantaged doesn't throw off anyone's chains: it adds salt to the wound. So the Afrocentric historians who have sought to cast Africa, and in particular Egypt, as the abused cradle of Western culture, a Utopian nest fouled by the European cuckoo, get the full treatment.

Hughes points out that the Greeks invented slavery, sure, but their slaves were white - the word comes from Slav. The African slave market, run by Muslims, was booming centuries before the horrid white man arrived, and continued for years after the transatlantic trade was abolished.

Yet today, Hughes says: 'the entire blame for the invention and practice of black slavery is laid at the door of Europeans. This is profoundly unhistorical, but it's getting locked into popular consciousness.' It is not enough to say that zealous separatist urges are wrong, but understandable in the circumstances. Hughes insists that they are understandable, but wrong.

So much of the book is scorching, bright and keenly felt. But why did Hughes write it? What nerve was touched, what cherished sentiment outraged? The last of the lectures, and perhaps the most bouncy, addresses the clash of art and morality. Hughes narrates the row over the public funding of a Robert Mapplethorpe exhibition. He declined to write an enthusiastic puff for the catalogue on the understandable grounds that he found the work disgusting ('fist-fucking, heavy bondage, and a man pissing into another water-sporter's mouth'); but, of course, he was also scornful of the priggish zealots who wanted the show banned.

We can imagine how this left him feeling bereft and out of a job: whichever way he turned, there was no one to agree with. Perhaps from this came the sense that America had split into two extremes, both deluded and, as it were, de-moralised.

Hughes is, above all, a writer who likes words with a bit of mud on them, the sort you can chuck across the restaurant at your mates. It might be that his warm dislike of the right-left language police is just the indignation of a man whose marbles are being confiscated by some officious prefect. Of all the threats to freedom in the world, the arcane, abstract and easily denounced proscriptions of the American academy do not seem so very serious. But for Hughes, they are hitting him where it hurts.