Good bits. And bad: Gun nut. Drug fiend. Genius. William Burroughs is 80 tomorrow, and the legend lives on

The first American is gaunt, poker-faced, stooped. You might take him for a retired hanging judge or a small-town priest in mufti - a man of harsh views and finicky ways, at any rate. His hair is cut short, his tie juts precisely out from his collar, and in the lapel of his suit (dark hue, conservative cut) is the rosette of some distinguished order. He could hardly be described as loose-tongued, and when he finally does starts to speak, his tones are rasping and emotionless. Before long, you have gathered several unpleasant, if unsurprising things about this cadaverous being.

He seems to be a misanthrope and, even more strikingly, a misogynist - women do not so much offend as disgust him, and his favourite word for the gender is unfit for newspaper publication. Originally from a rich and high-toned family, he is only modestly wealthy now, and lives a reclusive life in a Midwestern city of almost proverbial dullness. His political opinions, while somewhat hard to pin down in the usual terms of left or right, are vehemently expressed and seldom humane.

The second American is a hero to freaks, rebels, misfits, delinquents and enrages around the planet. He has been a junkie and a queer (brandishing that tricky epithet years before it became politically OK); he has served time in prison and a psychiatric ward; he killed his wife with a pistol, and remains an enthusiastic marksman, or, more bluntly, a gun nut. He has lived in squalor and poverty for much of his life, supporting himself by grinding out pornography of exceptional vileness. He dabbles in crank religions and philosophies and occasionally the odd spot of black magic.

The third American is a famous novelist who has been described by Norman Mailer as the only one of his country's writers who may conceivably be possessed of genius. He is a member of the stuffy, but none the less august Academy and Institute of Arts and Letters. His influence, however, extends well beyond the world of literature: he has inspired or collaborated with any number of film-makers, musicians and performers, and in recent years has become a practioner of the visual arts himself. It is hard to think of any other writer of the second half of this century whose work has told so deeply in so many fields.

Other Americans could be mustered here, too - among them a nice old gentleman of impeccable manners and marked fondness for his cats - but each of them is simply another legendary facet of the same man: William S Burroughs, author of The Naked Lunch (1959) and other deranged novels, sometime heroin addict, godfather to the Sixties drug culture, elder statesman to several generations of the international avant-garde, actor and, imminently, octogenarian - Burroughs will be 80 tomorrow. How weird to reflect that the Jonathan Swift of smack withdrawal was drawing breath before the First World War. . .

To mark the event, the ICA is staging 'A Present for William Burroughs', a weekend of talks, screenings, performances and tributes. Among the highlights are the films Burroughs made in the mid-Sixties with the painter Brion Gysin and the director Antony Balch, and 'Burroughs in the Bewilderness', a talk by Peter Swales about Burroughs' treatment for psychiatric illness in the 1930s and 1940s, based on clinical notes Swales has recently turned up.

To the uninitiated and unconverted, all this fuss must seem baffling, if not downright repellent. Burroughs's CV alone is quite enough to set off many readers' taste alarms, but when it comes to the prose . . . well, Burroughs's writing squirms and seethes with almost unbelievably grotesque descriptions of hangings, mutilations, eviscerations, necrophilia and rape. Then it starts to turn ugly. ('As the author of Gold Coast Customs I can scarcely be accused of shirking reality, but I do not wish to spend the rest of my life with my nose nailed to other people's lavatories': Edith Sitwell on The Naked Lunch, 1963.) What do people see in the man?

David Cronenberg, who regards the writer as a genuine visionary, and who managed the considerable feat of bringing Naked Lunch to the screen in 1992, once explained Burroughs's main appeal to the young of the 1960s by saying that he was like an understanding uncle figure - the kind of black sheep who not only sets the precedent for your own bad behaviour but also slips illicit substances into your hand and invites you along to bizarre orgies. This sounds about right, all the more so since Cronenberg went on to wonder how many of the youths who liked the idea of Burroughs - including the Beatles, who with Peter Blake put his junk-sick face on the cover of Sgt Pepper - actually bothered to read him, and so to notice how savagely contemptuous this extremist would have been of any sugary notions about peace, love and understanding.

Even those who have read him carefully, and consider him in many respects admirable, can also be appalled by his talents. 'When I say that he's a hero of mine,' says the writer / actor / director / Lyric Theatre boss Neil Bartlett, 'I don't mean that I'd like to meet him, or that I don't find his writings horrific and disgusting. I wouldn't advise anyone to read Naked Lunch, or see the film. But I'm interested in artists whose mythical private lives have become indistinguishable from their equally mythical works.

'And I'm also interested in him because I live in a country where the public culture of being a gay artist is a desert, so I need people from outside with whom I can conduct a private fantasy relationship.' Burroughs's more general importance for writers, Bartlett thinks, is a technical one - 'He's made suggestions about what writing might be which we still have to deal with' - though he remains undecided as to what degree Burroughs' entire procedure might be akin to the con routines which recur in the fiction.

Few of those with the stomach to have read Burroughs' prose in much quantity would want to dispute the claim that he can be both hideously funny and eerily moving, at least in flashes. As Martin Amis once noted, Burroughs is a writer of good bits. Such a judgement, to be sure, sets him quite a way below the artistic pinnacle which legions of reputation-brokers have been reserving for him; but then, one of the most attractive aspects of the old curmudgeon is that he manifestly does not give a hoot what people say about him.

A Present for William Burroughs: ICA, various events this weekend and until 13 February (071 930 3647).

(Photograph omitted)