Mention Hubert Selby (now minus the "Junior") to any reasonably well-read person and they will say, "Yes - Last Exit to Brooklyn. Brilliant. Excellent. A classic!" They remember the film, they may even recall the UK prosecution of the book, in 1967, under the Obscene Publications Act, during which the judge demanded an all-male jury (women must not be exposed to this). The jury found the book so impenetrable as to be unreadable. Apparently bored to distraction, they voted "guilty", presumably out of pique. The conviction was reversed on appeal.

Yet mention any of Selby's other great books to your literary friends and they will look blank. They may just about have heard of The Room (1972). As for The Demon (1976) and Requiem for a Dream (1978), the verdict is "No Sale". Their pilot lights are out. Despite his relative obscurity, this dazzling quartet of novels - four works of genius - was to prove more prescient, more prophetically powerful and more influential over subsequent generations of writers than any other work of the time, including that of William Burroughs and Thomas Pynchon.

Last Exit was the forerunner of every hip, street-wise US novel of later decades. The Room was the harbinger of all the violence, obscenity and squalor that was to erupt with such tremendous force in so-called "transgressive" work in literature and other media during the 1980s and 1990s. Additionally, it draws an early map of the theories of contradiction in fiction between "reality" and "fantasy" that came to obsess so many contemporary authors. It was also the only book in my life ever to make me physically sick (at breakfast, too). I was impressed.

The Demon has as its main character and anti-hero the prototype fictional yuppie, Harry White. An ambitious accountant who murderously flips out under sexual pressure, he presages Bret Easton Ellis's homicidal yuppie in the celebrated American Psycho. Requiem for a Dream is, arguably, the best novel about heroin (and other addictions) ever written. Better even than Trainspotting? Well, very possibly. Indeed, Irvine Welsh owes much - probably without knowing - to Selby. And the foul facial pimple that so preoccupies the occupant of The Room is a close, viscid relative of the tapeworm in Welsh's recent Filth. They both contain the poison.

Influence, however insidious, pertinent and widespread, is not quite enough. I submit Hubert Selby as my author of the century for other reasons - for his impeccable literary technique and his dazzling, innovative mastery of style and dialogue. It took Selby six years to write Last Exit to Brooklyn; he has a horror of all the lazy cliches in fiction and treats adverbs like viruses. "What bugs me in fiction," he once said, "[is]'Harry said' and 'Tommy said'. Who can read a book like that?"

So Selby, through endless, agonising application, wrote almost entire books or novellas without attributing or describing speech. And yet, reading a piece like "The Queen is Dead" in Last Exit - the story of poor, tragic Georgette, "the hip queer"- one is always fully aware, through Selby's use of rhythm and emphasis, exactly who is speaking, even though the characters share the same background, ethnicity, demotic, inclinations and manner of speech. This applies to the entire quartet, and stands as a hugely impressive feat of literary control.

Selby tends to eschew physical description, too. He is interested in the interior life of the individual personality. "We don't live and die on the outside," he says. His main task was "to squash my ego . . . the ego has no place [in literature] . . . I have no right as an artist to interpose myself between the people in the book and the reader. They should be able to communicate directly. They should not have to go through a middleman."

Selby, a self-styled "frustrated preacher", is not interested in realism or naturalism, but in transmitting moral essences, moral choices. His characters fail "not because they are immoral . . . but because they lack control . . . all these people are looking for outside sources to do something for them. Not one of them wants to know what he can do for somebody else." These characters may sometimes be archetypes, but never, in Selby's delicate, caring hands, are they stereotypes.

There is a strong strain of spiritualism, even religiosity, in Selby's work. Most of his epigraphs are biblical. Consider Requiem for a Dream, a more melodramatic and vengeful novel than the others. It concerns blue-collar bum Harry; his Jewish mother Ada, who is addicted to television soaps and prescription diet pills; bebopping black Tyrone; and Marion, Harry's girlfriend, a wincingly accurate portrait of the educated, artistic, wealthy, middle-class, young, female addict (a portrait unique in fiction). Harry and Tyrone start dealing heroin to support their habits and those of their girlfriends; they obsessively dream, too, of becoming wealthy drugs criminals. Scuffling by on ten-dollar deals, they fantasise about buying "a pound of pure" - and then cutting it. But Selby's epigraph reads, "The only pound of pure [is] Faith In a Loving God".

Selby has suffered appalling ill-health throughout his life, and never earned a living wage from his books. Since cleaning up through, I think, AA and NA, he has produced much less powerful work. This raises a disturbing question: was it only by indulging his capacity for extremity that he was able to produce great work?

I once spent time with Selby, when he toured the UK with Henry Rollins, and found that he had all the humility of the great artist. As Gilbert Sorrentino writes: "He's a pure artist . . . interested in the art of literature and the perfection of art." The discerning Marion Boyars holds the UK rights in his work. It's time, surely, for this towering quartet of novels to be republished, and assume their rightful place in the postwar literary canon.

Elizabeth Young is compiling a book of her essays for Serpent's Tail