Philip Hensher: The art of breaking down barriers

Monday's was an unusual press view at Tate Modern. Normally these affairs are quite sedate experiences, with a useful talk by a curator, an opportunity to wander around in peace and quiet before the paying crowds descend, perhaps a free cup of coffee and a bun and a chat with a colleague.

Yesterday, the Turbine Hall was echoing with howls of terror and unfamiliar whoops of delight, as quite distinguished art critics and well-known blaggers found themselves deposited, rumpled, on the rubber-coated floor. The Times's much-admired critic couldn't resist leaping up and performing an exuberant gymnastic salute, but even the less energetic among us emerged in fits of giggles.

The artist Carsten Höller has responded to a commission in the running Unilever series to fill the Turbine Hall with a charming idea; a set of five covered slides, running from the second, third, fourth and fifth floors of the gallery to its base. As sculptural objects, they have some appeal, curling through space with baroque abandon, like steel and plastic ribbons caught in flight.

But there's no doubt that the real attraction here is to go up to the fifth, or the fourth floor - the fourth, I think, is more terrifying with its abrupt drop, sit on a sack and slide uncontrollably through a 55-metre-long tube, falling 26 metres in a few heart-stopping seconds.

You could defend this in aesthetic terms, and Höller certainly does. The wild ride introduces you to the immense space of the Turbine Hall in ways that can't be repeated, and their shape articulates the hall quite effectively. (It would have been more effective, though, if there had been more tubes, a whole spaghetti-tangle of vomitoria). But, really, the point of the experience is the ride, which isn't far from a fairground experience, and, like a lot of art in museums recently, it has gone for the popular option of the interactive experience.

It's quite interesting to trace the rise of the interactive through the various Turbine Hall commissions since Tate Modern opened. I remember being rather struck by the invitation to climb up one of Louise Bourgeois's sinister towers; they were so very sculptural, you felt a distinct licence in being permitted to clamber over them in such a way.

By Olafur Eliasson's immense trompe-l'oeil sunset, probably still the most successful of these commissions, the invitation to interact had gone very firmly into the mind of the audience. People lay down on the floor to observe their distant reflections in the mirrored ceiling, or dragooned their friends and acquaintances into forming giant shapes and even words.

In a way, there is nothing but interaction in any work of art; it doesn't exist until it is looked at. But the degree of physical interaction invited by Höller's piece is quite exceptional; you can't begin to appreciate it until you place your body, feet first, into one of the tubes, and then you find that "interaction" is hardly the word, since you've relinquished, for a few seconds, all possible physical control.

Contemporary artists have been breaking down the conventional museum barriers between artwork and removed observer since the 1960s at least. But I think Höller's piece reflects not just a contemporary-art phenomenon, but a growing self-belief in audiences everywhere; one not altogether to be welcomed.

Newspapers at the weekend were discussing the growing lack of decorum and respect in museum visitors in London generally. The example that was produced is one where the bad behaviour, now, is extremely striking; the Egyptian galleries at the British Museum.

The last time I was there, a couple of months ago, I was absolutely horrified to see numerous visitors running their oily hands over ancient sculptures, literally climbing over ancient temple statuary, and sitting not at, but on the feet of statues. I remonstrated with one woman who was allowing her child to try to climb on the back of a stone beast, and was abused in return; the guards didn't seem to be doing anything. They, apparently, see this all the time.

It's a question both of physical damage and of lack of respect for the antiquity. In the case of the British Museum, it's a particularly worrying phenomenon, since so much of the case for retaining treasures away from their origins is the superior care that can be offered by the museum. But the tendency is widespread and growing; museums, which for decades have been trying to get away from a glass case and a label, to involve visitors directly, are now having to deal with visitors who can't see why they shouldn't be able to handle anything they choose.

It was very striking, at Rachel Whiteread's glacial installation last year in the Turbine Hall, that many visitors started tapping or feeling her boxes, even inviting their children to climb on them in quite inappropriate ways.

In an age that thinks that fame or artistic achievement, or even significance, are matters of chance selection, things to be won on a TV talent show, it can't be a surprise if audiences start insisting on their own importance, and start inflicting themselves in the most crass ways on works of art which ought to be listened to in silence and observed at a respectful distance.

Works of art such as Carsten Höller's, which invite the gallery-goer to join in with yelps of pleasure, are still unusual, but really he is issuing an invitation to a gatecrasher who is already in the room. It's all very well, but it will end with the punters writing their names on a Joseph Beuys.