When film censors in the United States drafted the now defunct Hays Code in 1930, they came up with some simple rules of thumb: married couples must be shown sleeping in twin beds, and if couples really must be on the same bed, at least one of them must have a foot on the floor. One can only wonder what the censors might have made of Matthew Barney’s contribution to a new series of seven short films, Destricted, which opens at Tate Modern today. In what way is it offensive to see a naked man slathered in moss rubbing himself against the axle of a deforestation truck? And is it more or less offensive if the gentleman has a large purple blossom protruding from his mouth and what looks like a root vegetable stuck up his behind?

It seems that even today’s film censors have been foxed by this conundrum, as Destricted has been released with the longest sequences of explicit sex yet passed by the British censor. It will come as no surprise that Larry Clark is involved: his short documentary invites a few young hopefuls to talk about their experiences of pornography before a “lucky” winner gets to do it on a lime-green sofa with a porn star. But Destricted also features the contribution of an artist as respectable as Sam Taylor-Wood, although you could play her contribution, involving a man masturbating in Death Valley, all day while filing your tax return without making any errors.

Destricted was devised by three producers, Neville Wakefield, Andrew Hale and Mel Agace, and it is the first in a planned series of projects that explore the intersection between art and pornography. Wakefield says: “It’s an opportunity to think about the representation of sex and violence. Apparently, it’s OK to watch someone being eviscerated, but not to watch them having sex.” Hale points out that although the fantasy of sex is used to sell almost everything, its representation as an aspect of real life is encircled by a thicket of prejudices and taboos.

Screening sex and screening porn may, however, be two different things. Some contributions clearly cross the line: Richard Prince’s House Call recycles a 1970s film that tells of a poorly young lady who calls the doctor to examine her chest, etc. Prince rerecorded the footage again and again to degrade its quality, and he matches it to a droning and strangely elevated soundtrack. Similarly, Marco Brambilla has edited down hours of footage into a filmic flick-book of classic porn shots.

At the heart of Destricted is the tendentious proposition that there is an overlap between art and pornography. Obviously, drawing hard distinctions between one and the other has always been difficult, but Wakefield points out that “pornography tends to be non-narrative, and that is a characteristic of a lot of contemporary art”.

Clark’s film explores the remarkable fact that a generation of children has now grown up with hitherto unprecedented access to pornography. Typically, the director draws no conclusions from this; he just lets the kids describe their own mental world.

However, if you’re looking for any emphatic denunciation of pornography in these films, you’ll look in vain. “What I am saying,” Wakefield says, “is that pornography is a fact, and it’s where a lot of our information about sex comes from.”

What nobody seems prepared to say is that the overwhelming majority of pornography is inherently sexist, and violently so. And that leaves it up to one of the young men on Clark’s couch to state the awful truth about where pornography gets you: “She was so small and he was so big, it was like he broke her in half. I really got off on that.”

Destricted is at Tate Modern, London SE1 (020-7887 8888), from today, before nationwide cinema release on Sept 15 and a DVD release on Sept 25 (Revolver, £19.99)