I’m generally left a bit cold by art with no sex in it. Not that every work of art need preoccupy itself with meditations on the subject or be confined to representations of the various physical acts. Quite the contrary; the world is already overstuffed with cliched recreations of the blunt and bland doings of the flesh.

What I mean is that I find it hard to rouse any interest in art or literature that relegates the life of the body to some lesser status than the goings-on of the mind or emotions.

Sex isn’t everything, of course, but it’s certainly something. The impulse towards and away from it sits at the root of enough of the cataclysms that shake and shape our lives as to warrant a far deeper degree of attention than the titillating/slightly embarrassed/deeply embarrassed/hygienically challenged digression from the main event that it’s frequently consigned to.

After all, sex runs right through our lives. The older they get, the more awareness children acquire of the often indefinable but rarely undetectable sonar of the sexual selves of the adults around them.

Typically, these adult selves have, in their turn, been forged not only by personal experience but by their own wrestlings with the cumulative, intergenerational attitudes that have been transmitted down to them. It’s as if there’s a knot of complex sexuality right at the centre of each of us.

In the past, societies laboured under the delusion that self-discipline could keep this knot of sexuality forever tied and that a socially enforced orderliness - whatever its frustrations – was far preferable to the inevitable catastrophe resulting from any unsanctioned unravelling.

This is a simplification, because it assumes an equality in attitudes towards sexuality when, as we know, some sexualities have always been more equal than others.

For me, part of the challenge, but at least half the pleasure, of examining or watching others examine sexuality through the prism of art is the satisfying knowledge that, whatever discoveries are made, there will be, and can be, no definitive conclusions. In this way, art and sexuality present themselves as an almost perfect symbiosis of form and content.

The range, shape and intangibility of sex and sexuality make claims of any certitude tantamount to an admission of, at best, ignorance and, at worst, arrogance. Art at its best, like sex at its best, is an invitation into God-knows-where. This is why they get along so well.

Their shared seedbed has long been acknowledged. “Sex and art are the same thing,” Picasso said. “All art is erotic,” said Klimt. Others have regarded both acts of creation as fundamental to one another.

In a 2001 interview, Beryl Bainbridge admitted a concern for her ability to continue writing having decided to give up sex: "At first I was worried - because all my life I'd believed that the creative impulse was sexual, and if you lost that, then blimey, could you write any more?"

The American fashion and portrait photographer Terry Richardson, famous for the sexually explicit nature of his work, says of his choice to appear naked in his own photographs: "The thought of people masturbating to me, or to pictures I take, is great. That's a wonderful inspiration to give someone."

Even those blatantly on the make have recognised the intrinsic sexual draw of art. Saul Bellow was of the opinion that: "All a writer has to do to get a woman is say he's a writer. It's an aphrodisiac."

Given these quotes are merely the tiniest tip of the iceberg of possible illustrations available to anyone typing “sex and art quotes” into Google, the lofty distaste to which work exploring sexuality is so often subjected by those in the critical sphere seems oddly coy.

At this point it’s probably worth mentioning that, generally, this particular form of prudishness is far more visible in male than female critical work, for reasons that my word count won’t permit me to do justice to here.

As Peter Bradshaw pointed out in his review of Michael Winterbottom’s 2005 film 9 Songs, which featured the first on-camera ejaculation by a mainstream actor and unsimulated sexual acts, including full – and fully visible – penetrative sex.

Traditionally, objectors to this sort of thing airily claim that it is “boring”. This is the acceptable unshockable-sophisticate alternative to condemnation on moral grounds. 9 Songs will undoubtedly have a chorus of pundits ostentatiously stifling their yawns in print.

To which I can only say - boring? Gosh, really? Is that why all those male journalists in the audience were gulping and surreptitiously recrossing their legs? Because they thought it was boring?

Bradshaw goes on to ask if the film is pornographic. Initially he suggests it is “in the sense that the sex act is shown on screen, complete with money shot”. On reflection, he concludes it is not, because “it doesn’t have the porn tropes of transgression and exhibitionism. The people are too ordinary and the sex is too straightforward.”

The “is it porn?” question is probably the toughest and most loaded of any confronting an artist whose work is, or contains material that is graphically sexual in nature. Whatever one thinks of 9 Songs as a fully realised piece of work, its role in setting up a debate about sex in art versus sex in porn is undeniably significant, with Winterbottom’s decision to strip out almost every other aspect of the couple’s relationship being additionally fortuitous for this purpose. While I’m inclined to agree that 9 Songs isn’t pornographic, this is for quite a different reason: intention.

Pornography sets sex outside the lives, or the characters’ lives, of those engaged in it. Sex in the pornographic context exists as a hermetically sealed experience bearing no relation to the pasts or inner lives of the performers/ characters, nor will it have any consequences for their future. For sex to be pornographic, it must be created with the intention of inducing sexual arousal in its target audience.

Porn’s simplification of sex necessarily eliminates honest exploration of the true natures, physical responses, emotions and thoughts of the people/characters performing it, whether on screen or on the page.

Pornography is created by using various stimuli to manipulate sexual reactions from bodies. Using sex as a means of exploring the human is what art is for. The confusion stems from the fact that bodies never stop behaving like bodies and therefore tend to react to sexual material sexually, no matter what the intention.

That’s a simple truth, a byproduct even, and that responses will inevitably vary merely indicates the diversity of erotic proclivities. For example, it’s highly likely the explicit sex scene in the 2015 BBC drama London Spy provoked sexual arousal in its viewers but it also served as both an incredibly beautiful piece of film-making and a vital source of information about both characters involved in it.

It’s hard to imagine how imparting the same information verbally would have been as emotionally impactful for the viewer. No matter how gussied up the sex in Fifty Shades of Grey may present itself as, it serves no meaningful purpose beyond the desire to make masturbatory material more publicly visible, more socially acceptable and, therefore, ever more lucrative.

So, to my theory of “intention” being the dividing line between art and pornography, I could add “necessity”, but that would be redundant; porn can never compete in those stakes. It doesn’t want to and it doesn’t have to.

Of my own area, literature, it’s always said that good sex scenes are notoriously difficult to write. This is true. Why, is less frequently reflected on. To a large extent, it’s probably attributable to explicit descriptions of sex being considered, until the mid- to late-20th century, too outrageous to public decency to be legally permissible.

Even that battle being fought and won failed to bring about the moral acceptability of such work in the wider public consciousness for many years. This limited the reach of sexually explicit literary work and hindered the natural evolution of a more imaginative and nuanced sexual vocabulary.

Even when explicit writing began to find its place, the continued unacceptability of female, homosexual or any non-straight-male sexualities still hobbled its development. Today’s go-to sexual lexicon remains so straight, po-faced and crassly misogynist that any writer with half an ear for language falls into paroxysms of mortification at the thought of having to conjure a recognisably human experience from between its “pump and thrust” endpapers.

We may live in sexually liberated times, but as the media moralises, the internet demonises and pornography compartmentalises almost every form of sexual expression, how liberated do any of us really feel?

In the sexual realm, vulnerability, imperfection, naivety and the search for joy have become the new taboos. Fortunately, they remain the basic tools of art.

Keeping sex and art together, to push against humanity’s increasing alienation from itself and the physical world, looks likely to soon become the most transgressive act of all.

Guardian Service

The Lesser Bohemians, by Eimear McBride, is published by Faber