Andy Warhol once said: "My work won't last anyway. I used cheap paint." It was an archetypal Warholism and, like many of the platinum-wigged enigma's celebrated utterances, it simultaneously embodied the most banal literalism and the most resonant metaphor. That paradox was at the heart of all of War-hol's work: he iconised the transient and trivial in a manner that rendered them monumental, while flattening the eminent and mighty into blurred, repetitive images reduced to their barest essentials and then decorated with garish, incongruous colour. Appropriately enough, the artist himself was a man whose affectless drawl was capable of turning phrases such as "Oh wow" and "Faaaabulous" into the most eloquent expressions of boredom imaginable.
Naturally, Warhol always fervently denied that his work expressed, or meant, anything at all. Most of all, he despised irony. "If you want to know all about Andy Warhol," he said, "just look at the surface of my paintings and films and me, and there I am. There's nothing behind it." Many have taken him at his word, without realising that he was telling them that lack of importance was precisely what was most important about his own work. His statement was that he didn't consider himself to be making one.
So has his work - his paintings, movies, photography and all the other varied manifestations of essential Andyness - "lasted"? The fact that, almost two decades after his death, a major exhibition is about to be dedicated to his 1980s photographic portraits (of everybody from Robert Rauschenberg and David Hockney to Diana Vreeland and Diana Ross via Demi Moore, Ozzy Osbourne and Mick Jagger) and to his little-seen cable TV shows suggests that it has: at least this far. What has enjoyed the greatest influence and longevity, however, has not been any specific work - not even the legendary Campbell's soup cans, Elvises, Marilyns or Maos - but the sensibility which created them and which now permeates the culture. What was once "camp", "trashy", "avant-garde", "banal" or just plain incomprehensible is now, quite simply, the mainstream. From Britart to Big Brother, we're all living, to one degree or another, in AndyWorld, and we'd better get used to it.
Warhol's best-known aphorism - "In the future everyone will be world famous for 15 minutes" - was as prescient a vision of today's reality-TV microcelebs as was J G Ballard's prediction, that one day every household would be a television studio, of the internet's webcam subculture. Warhol dubbed the street hustlers, drag queens, junkies and wannabe actors/poets/artists who served as the cast of his pioneering underground films as well as his off-screen entourage his "superstars". (In fact, the word had no history prior to Warhol's use of it.) He used them because they were there, in the same way as he used the common artefacts of the blue-collar kitchen - soup cans, Coca-Cola bottles, Brillo soap pad boxes - as the subjects of his paintings. "I paint these objects because those are the things I know best," he said; they were the mainstays of his mother's larder when he was a child in the low-income Pittsburgh of the 1930s.
Andrew Warhola was born in 1928 into an immigrant household. His parents were, by current geographical definition, Czech. He was small, sickly, effete, and had no visible talent except for drawing. As a teenager, he attended Carnegie Tech art school; in the late 1940s he arrived in Manhattan with his possessions in a paper bag, and set about establishing himself as a commercial artist and fashion illustrator. He stalked Truman Capote - whom he worshipped because Capote was not only young and gay, but also gilded, handsome and successful - until Capote's mother told him to stop. According to Capote, the young Warhol was "one of those helpless people you knew nothing's ever going to happen to . . . just a hopeless born loser, the loneliest, most friendless person I'd ever seen in my life". They later became close friends.
By the end of the 1950s, Warhol's distinctive style had made him one of the highest-paid fashion artists in New York. The acceptance as a fine artist he craved from the gallery world eluded him until his soup cans and Brillo pads - the urban, consumerist update of the still life, the mass-produced commercial object replacing the classicist depiction of the products of nature - catapulted him to the forefront of the pop-art movement, alongside Jasper Johns, Roy Lichtenstein and Robert Rauschenberg. Thus began the era of Classic Warhol: of films such as Chelsea Girls and Empire; of the Marilyn and Elvis paintings; of his sponsorship and packaging of Lou Reed's hugely influential band the Velvet Underground; of the life-meets-art-in-infinity-of-mirrors spectacle of his attempted assassination by the feminist activist Valerie Solanas; and the creation of the unique Warhol persona - the blank white mask, the silver-haystack wigs, the shades that served equally well as a barrier to keep Andy in and the world out.
The Andy of the 1970s straddled social strata: he indulged his worship of the rich - the idler and more vacuous, the better - and his voyeuristic inquisitiveness about the idiosyncrasies of street rats on the edge, while having no truck whatsoever with the dull conformism of the middle classes. For a man who, according to the critic Kenneth Silver, "made blue-collar gay American art", he delighted in becoming court jester to the financial and political elite, happily producing, or directing his assistants to produce, "Warhol" portraits of industrialists' wives for $25,000 a pop. He enjoyed hanging out at the White House and basking in the company of Imelda Marcos and the shah of Iran. (Ironically, when the shah fell, he went out owing Warhol money.)
Susan Sontag, for one, was less than impressed. "He said, 'I just loved rich people so much.' That's a political statement . . . he thought it was interesting to know a head of state. He thought it was glamorous. But he could not think [the shah] was a good guy. What he did think was, 'I don't have to worry about that question. That question is a boring question.' And it was not a boring question if you had feelings."
Warhol always said that he did not have feelings, and was furious whenever he inadvertently betrayed that he did. He wanted, he declared, "to be a machine", and it is much to his credit that sometimes he failed. His affectlessness was as much an artistic tool of his as were his graphic skills, or even his unique ability to see the surface that lay just beneath the surface. Despite the numerous memorable images he bequeathed during his almost ridiculously prolific career to a posterity he denied ever caring about, it is the Warhol "attitude" that will outlast any single painting, film or photograph: in the final analysis, he didn't so much reflect the culture as refract it through his own unique sensibility. Whether or not he was a charlatan, a hustler or a malign influence is still open to question; what isn't is that his impact on the media landscape we now inhabit was little short of seismic. Welcome to AndyWorld. Just remember that "Did you enjoy your stay?" is a boring question.
"Warhol's World: photography and television" is at Hauser & Wirth, 196a Piccadilly, London W1 (tel: 020 7287 2300), between 27 January and 11 March. www.hauserwirth.com