Is pornography just a bit of fun or a cause for concern?

I DID not want to write about pornography today, but they made me. As a writer who tries to meld personal experience with abstract argument, I find this subject full of danger. Men, it has often been said, are "ambivalent" about pornography, meaning that they will look at it if it is available, but they are a bit ashamed that they are aroused by it. Like masturbation (with which it is, indeed, "intimately" linked) it is a topic to be discussed in the abstract, if at all.

But yesterday's call by James Ferman, outgoing director of the British Board of Film Classification, for a relaxation of the laws against certain kinds of video porn, is (said my bosses) too important a moment in our national conversation about sex and censorship for shyness to prevent publication. Give it, they implied, your best shot.

I first saw some pornography when I was 19, in the Bohemian household of a girlfriend. Her brothers were the sort of fearless madcaps who would walk straight into sex shops, look the greasy assistant full in the eye, and walk out with a brown paper bag. In a magazine that they had carelessly left lying around the place was a photo-story - entitled "The Plumber Calls"- concerning an improbably equipped man who rings the bell at the flat of a blonde lady and a dark-haired lady. In frame one they invite him in. In frame two they give him a drink. And in frame three... Everything, but everything, was depicted.

If James Ferman's recommendations were to be accepted, then the video version of "The Plumber Calls" would no longer be illegal, but would be available at licensed sex shops to anyone aged over 18 who wished to buy it. Such "scenes of homosexual or heterosexual intercourse and group sex" would be distinguished from nasty porn, which would be more strictly policed than it is now. The plumber could call again and again in the comfort of your own sitting-room. The Plumber with the Alsatian could not.

Mr Ferman's argument, based on the failure of the current anti-pornography laws, is very similar to that which calls for the selective legalisation of some of the less harmful hard drugs. First, those who want pornography which essentially depicts no more than what goes on in a Surbiton bedroom on Happy Night will not find themselves standing cheek by, er, jowl, with perverts asking for the horrid stuff. Secondly, the link between standard porn and organised crime will be severed, allowing legitimate, regulated porn to move in. Thirdly, the campaign against the most abusive and violent or degrading pornography will be made simpler and more effective as a consequence of narrowing the range of offending publications.

I have an innate sympathy with this argument, but the atmosphere in which we discuss pornography has changed a great deal in the last 10 years. The original rash of post-Sixties "all sex is fun" films and books was put into sharp perspective when Linda Lovelace revealed how badly she had been abused in the making of the notorious Deep Throat. Feminists seemed to have a good argument when they pointed out how exploitative much depiction of women was, and how diminished women were by it.

Could there, though, be an acceptable way of representing, on screen and in print, sexually exciting images? Some, such as the American anti- pornography crusaders Andrea Dworkin and Catherine Mackinnon, seemed to suggest that there could not. For Dworkin, all intercourse was essentially an assault with a blunt weapon. This position amounted to a criminalisation of the portrayal of sex.

Such puritanism came under assault from two unexpected quarters. Gay Liberation saw the widespread use of pornography for gay men. It clearly did not objectify or degrade women - 'cos there weren't any in it. And a new generation of confident feminists began to challenge the idea that women were inevitable victims in sexual encounters. In fact, said some of them, we quite like naughty stuff too.

Today, some porn seems almost respectable. The films Boogie Nights and The People Versus Larry Flynt have shown the porn industry in an amusing, almost tender light. Porn bestrides the Internet, where I discovered that the World Pornography Conference (held last week) was not a gathering of feminists, police chiefs and concerned psychology professors, but was - according to its organisers - "the defining porno event of the milinneum (sic)".

Helpfully, the conference website also gave a definition of its subject matter. "Pornography," it said, "is the presentation of sex for the purposes of entertainment, education or edification." The photographs that accompanied this statement could certainly be regarded as entertaining, would not usually be classified as edifying and could be conceived of as educational only by those who have never seen genitals before.

There is a lot of it about. In 1985, there were 77 million hard-core video rentals in the US. By 1996, the figure was 665 million. In the same year, American hotel guests spent $175m to rent porn in their rooms at the Sheraton, Hilton, Hyatt, and Holiday Inn ranges. (Source: US News and World Report, 10 February, 1997)

And we know why, don't we? Pornography is a sex aid. It is visual Viagra, used to make masturbation more interesting and (much more rarely) to spice up sex acts between partners. There is a strong argument that, in its more benign forms, it is a useful and enjoyable supplement to the - often disappointing - reality of many people's sexual lives. It helps.

But this is only part of the picture. For the weak and stupid, porn can also suggest a model of behaviour that does not in fact exist (or else I meet the wrong sort of plumbers); its easy availability and lack of complication can make it addictive; it may come to replace a relationship with a real human being; its manufacture could well involve the exploitation of women and men; and the sensations that it induces may dull the senses and thus lead to the use of stronger imagery.

In addition, if these videos are more easily available, then as sure as eggs is eggs, kids will see them - just as, all over Britain during these summer holidays, teenage boys are looking at scenes on their computers that would make your hair curl. And while none of this may be as damaging as some have suggested, neither is a lot of it a sign of a healthy, well- adjusted society.

There are, however, secret virtues in the liberal model suggested by Mr Ferman. For if part of our objective is to reduce, rather than increase, everyone's appetite for porn, then may I suggest the following system of classification which, if used, might lead to a diminution in its use. Instead of giving each dirty video an "R18" category, we should instead award it an "M-certificate". Making it quite clear, of course, that "M' stands for...

Need I go on? Just watch the sales fall.