Philip Hensher: Is it safe to revisit the harems?

Timidly, one step at a time, a much-maligned artistic mode comes creeping out of the cupboard where it has been consigned for decades. Thirty years after Edward Said's Orientalism, his case seems to be losing its grip on the academy; after decades in which orientalist works seemed to possess no respectability whatsoever, their appeal and interest seem to be returning.

Tate Britain's exhibition The Lure of the East is devoted to Western, principally British, paintings of middle Eastern scenes from the early trading years to the First World War. It's a thrilling show. Some are wild and implausible oriental fantasy, fancy-dress portraits either openly or covertly, in the form of fantastic scenes from an imagined harem. Others are rich and picturesque, but completely plausible and well-observed scenes of oriental life.

Said's case against the corruption and falsity of such occidental depictions is well known, and still influential. Certainly, when you look at some of the more imaginative scenes here, such as a lecherously imagined market of nude female slaves in Cairo, by Gérôme, you have to say that there's little attempt to depict the society with respect or accuracy.

But is accuracy in the portrayal the only, or the principal, measure of a work of art? Is there no such thing as fantasy and invention? I don't suppose that even the most scrupulous of scenes in the exhibition are without the arranging touch of the picturesque. As for Gérôme, or William Holman Hunt's The Lantern-Maker's Courtship, an audience would have had to be extraordinarily naive to have thought that these scenes bore any relationship whatsoever to urban reality in Cairo, or anywhere. They declare themselves to be exactly that wild fantasy which Said's followers denounce them for being.

I saw the exhibition in New Haven, Connecticut before it came to London. In both places, the anxiety about Said's case had to be dealt with. In New Haven, the curators took care to express their respect for the cultures traduced by some of these painters. It proved rather a theoretical respect, however; I didn't meet anyone who seemed really familiar with the locations of some very famous Cairo street scenes included in the exhibition. Not going to Cairo seems a more effective way of sidelining its culture, really, than going there and painting it in detail, however Orientalist the endeavour.

In London, many of the paintings are labelled with commentary from scholars outside the Western tradition. The intention is no doubt contrapuntal, but often the effect of these sharp-tongued paragraphs being placed next to a slightly silly painting is, not unpleasingly, one of violent heckling.

It's interesting to note, however, that in some cases the heckling breaks down. As everyone has noted in writing about this exhibition, the series of paintings of Cairo scenes by the Victorian John Frederick Lewis are orientalist in the best sense – unprejudiced responses to the beauty of the culture. Not reporting, exactly, but plunging with a love and respect into an exotic world.

Said has probably kept us from appreciating a wonderful painter like Lewis. In recent years, Said's case has been pulverised by scholars from East and West, notably by the pseudonymous Ibn Warraq in Defending the West and Robert Irwin in For Lust of Knowing. We ought now to be able to see the difference between an accurate observer of domestic Ottoman life like Lewis, and a fantasist like Gérôme, obsessed with Turkish baths, harems and slave markets.

And an odd fact about Western Orientalist paintings ought to give even the most fervid of Said's admirers pause for thought; some of the most outrageously excessive paintings in this exhibition have been borrowed from collectors in the Middle East and the Gulf, including, I believe, Frank Dicksee's Layla. What ought to make a Western observer hesitate before abandoning what, after all, has never been anything but a European cultural tradition is the peculiar fact of its popularity in the very regions meant to recoil from it in horror.

Tate is doing a very interesting thing with this show. Where international exhibitions generally travel between the established centres, this one is going to Istanbul and to one of the Emirates, Sharjah. Sharjah is trying to become the cultural capital of the Gulf, and it will be fascinating to see how supposedly meretricious portraits of a culture go down in one of the new centres of that culture. I'm hoping to go there next year to find out; in the meantime, I would bet that a culture whose elite love and treasure Frank Dicksee's Layla will respond with fascination and perhaps even respect.

The English Orientalists loved what they painted; now, we shouldn't be surprised if what they painted starts to love them in return.