It was prescient advice. Haring would be dead within a few years but by then his estate was valued at $25m. He also left a foundation that bears his name, two stores - the Pop Shop, in New York and Tokyo - and an industry which rivals only that of Andy Warhol in turnover of diaries and keyrings. The "radiant baby" and the "bouncing man," the cartoonist's shorthand drawings for "happiness" and "vitality", have passed via Times Square billboard and Day-Glo fridge magnet into our popular culture. Symbols that everyone recognises.
Haring is seldom out of the news, nearly 10 years after his death. There were calls a couple of weeks ago in Wellington, New Zealand, for Paula Savage, the director of the city's main art gallery, to be fired. She made, it is claimed, a startling error of judgement in allowing a Family Fun Day Out to go ahead at the gallery during a show of a Haring's work, which the Christian Heritage Party leader attacked for, he said, featuring "masturbation, sodomy and bestiality". The "city censor" has been asked to step down, too.
"I never thought," the hapless Paula Savage says, "that I would be standing here fighting for freedom of speech. It brings to mind the quote about a society burning its books, then burns its people." The "commissioner for children", meanwhile, said he had been "hoodwinked" by Savage.
For the colleagues of Geldzahler, who could afford it back then, it's now said that a Haring original is as rare as a personally executed Warhol. It only took a short time for Haring's reputation to be sealed, which was just as well, for a short time is all that Keith Haring had. In a brief and hectic life, he drew his art on everything. He customised cars for BMW in Munich, he painted on the Berlin Wall, the sidewalks of Tokyo, and on the transept of the church of Sant'Antonio in Pisa, as well as on a dirigible in Calais for the celebrations of the bicentennial of the French Revolution. In Monaco he painted a mural for the Princess Grace Maternity Hospital and in Barcelona another one entitled Together We Can Stop Aids. And all that was in 1989 alone, a year before he died.
Nothing, it appeared, was beneath him - glasses, party invitations, wrapping paper, record covers, reproductions of which you can still buy today.
Above all, Keith Haring drew New York like no one else and in a life in thrall to its lunatic parade of disco freaks, art junkies, proto-celebrities, hustlers on the way up and burnt-out losers spiralling down, he scrutinised it with a fascination that a decade in the eye of its storm never quite dimmed. As he lay dying of Aids aged 31 in a bedroom decorated to resemble a suite in the Paris Ritz, he held himself up to the open window and, with the city displayed below him and the rooftops all the way to the Empire State Building in his sightline, he started to draw the familiar skyline. "Keith couldn't hold a marker anymore," said his friend John Gruen, "so he took my hand and with those smooth, graceful strokes that we know so well, we painted in the sky with all of New York as our backdrop."
Keith Haring drew over New York like no one else, too.
His psychedelic chalk drawings enlivened the walls of subway stations, of abandoned warehouses, of nightclubs, of municipal toilets and, on occasions, he drew his pulsing lines like tattoos over the city's inhabitants (most notably Grace Jones). He never expected much of it to last, if any at all, and for his painstaking and elaborate, transient muralling he was often arrested for the defacement of public property. At the recent retrospective at New York's Whitney Museum of American Art, a video showed him being cuffed and led away by the police. The installation also displayed, in an edition of one, a set of the artist's fingerprints direct from the forensic archives of the New York Police Department.
By the time he was being propped up in his bedroom, tracing the outline of his beloved city at the very end, he was hailed as the baddest of boy artists. The crown had belonged to his friend Jean-Michel Basquiat but he overdosed in 1988, so it passed to Haring, who wore it for two years. The Whitney show (for which he yearned more than anything - but it would take his death and seven more years to achieve) even came with the tag, "The Bad Boy of Graffiti". But in reality he couldn't really be bad even if he tried - and he did try: Ecstasy at the Paradise Garage, gay activism, getting arrested in the park. But his dopey, cartoon-like looks, heavy black-rimmed glasses, sticking-out ears and receding spun-sugar hair counted against him. He looked like a nerd, or at least the out-of towner he was (he came from Kutztown, Pennsylvania). He looked irredeemably nice.
What counted against Haring even more in the bad-boy stakes was that his art was also nice. He invested the lewdest of his tableaux with a sweetness that makes kids laugh. One critic said he was as American "as apple pie and angel dust". Even the most monstrous of phalluses, which he gave to his bouncing amorphous cartoon men or the hydra-headed, multi-penised grotesques have, in the end, all the sexiness of a primitive chalk drawing scratched into the hills of the Sussex countryside. It seems to have been this mixture of childlike execution, and the very different reality which underpinned it, which endeared him to the art establishment, as well as the public. "It was perfect," wrote one contemporary, "an artist with one foot in the seamy side and another - in the cradle." It guaranteed his celebrity and concomitant sales.
This week Lord Archer, not known until now for his championing of homoerotica, is putting on an exhibition of work from the Haring Foundation at his Mayfair gallery, the first British show of Haring's work since the artist's death. It promises to show prints, sculpture, ceramic pots and potentially a reproduction of the altarpiece in bronze with white-gold-leaf patina from New York's Cathedral of St John the Divine. One of these exhibits will be auctioned for the Terrence Higgins Trust. Haring devoted much of his energy at the end towards raising money for Aids awareness. Designing the First Day Cover to accompany a stamp issued by the United Nations commemorating 1990 as Stop Aids Worldwide Year was his last ever commission. He died shortly after completing it.
Lord Archer said in The Independent last month that he thought his show would "scandalise" traditionalists with some of its eroticised images, but it seems unlikely that there will be the same furore here as there is in New Zealand at the moment. Any risks Haring took were in his private life, after hours in the gay clubs of Manhattan, in the Palladium or Paradise Garage. His art never really threatened to mirror his life. His zig-zagging displays of animals and flying saucers, hazy, comical assemblages of eyeballs, disembodied limbs, lurid toned creatures, his dancing lines and jiving crowds are in the end much like him, charming and funny, by most accounts.
So sweet is his oeuvre, in fact, that New York's Parks Department is frantically battling time and natural erosion to preserve the graffiti it tried to remove with solvents barely 15 years before. In July 1997, the parks commissioner unveiled 13 steel sculptures by Haring on traffic islands up and down Fifth Avenue, nowhere near the subway stations where it all began, but not so far from the Whitney which has belatedly put him back on the map. The process of conservation, by the way, also involves the eradication of the efforts of all those graffiti artists who have followed in Haring's footsteps, who still run the same risk of prosecution that Haring did all those years ago. Even more so, in the era of zero tolerance.
Only with death approaching did Haring ever get serious in his art. His paintings of dead or dying friends, collaged with photographs, are sombre and heart-breaking. His work, Pile of Crowns for Jean-Michel Basquiat (1988) is a poignant valediction for his doomed friend.
By the summer of 1982, Haring had left the subways and the downtown scene behind (at least during daylight hours) and moved a little further up and along to the Tony Shafrazi gallery in SoHo. Haring became an emblem of his strange times - you could go from zero to hero in minutes by pestering Andy Warhol and Geldzahler in a restaurant (like Basquiat did) or just plainly entrancing one of them in your downtown studio, like Haring did. (Actually he ended up entrancing both but not at the same time.) Haring became a pop icon - the pop icon - when Warhol, his friend and mentor, (and fellow oddity from Pennsylvania) died. He learnt a little about art from Warhol and a lot about business. "I think," Warhol once mused, "that somebody should be able to do all my paintings for me ... " And then the franchising began.
As a determined and heartfelt populist, Haring's intention was always to take his art out of the galleries and salons of rich collectors and give it back to the masses on the streets where he started. But there was the other, commercial, side to this. As one commentator put it, "Haring paid a residual allegiance to the ethic that says you have to earn your daily bread - though the more bread the better."
The New York Pop Shop he founded still thrives. It sells licensed souvenirs of the artist's considerable oeuvre and brings, at a price, his art to the masses. Indelibly stamped on to the public's psyche his dancing stick figures are as recognisable as Warhol's soup cans, though a lot more cuddly. The market is also full of fake Harings and unauthenticated, possibly genuine pieces, too. Much of the subway art he thought was gone has been reclaimed, and scratched and rusting panels are regularly offered for sale. The Foundation as a matter of principle refuses to validate this industrial detritus that Haring assumed was lost for ever.
Haring was astute enough to know that America likes its bad boys to stick to harmless fun, to fall short of killing people or making art too abstract to assimilate in about three seconds. And though he cast himself as a daring subversive, a champion of the people with whom he shared "oppression and struggle", he made an awful lot of money, much of which to his credit went on to fund Aids research.
And still his industry thrives. The Haring Foundation's tentacles spread long and far, and it appears to possess as many eyeballs as the most graphic of its benefactor's Day-Glo monsters. In Hong Kong this week a case comes to court brought by the Foundation against counterfeiters of Haring's work. They had been trying to bring Haring's art to the masses in the form of pirated children's T-shirts.
Haring's Andy Mouse may not be his abiding emblem - that belongs to the radiant baby, the amorphous jiving man or the barking dog - but the hybrid of Mickey Mouse and Andy Warhol, one of which appears in Archer's show, is a potent motif for all that has gone before and perhaps all that is still to come. These few, elegantly drawn lines stand for the fusion of art and commerce on the grandest scale. Back in Kutztown PA, all Haring ever wanted in the world was to draw cartoons for Disney. "What all these three [Haring, Warhol and Disney] have in common," wrote Liz Jobey in these pages several years ago, "is dollars. And T-shirts."
Though Lord Archer likes Haring's work a lot, but not enough to own one, yet, to hang up alongside his Lowrys and Picassos, he knows a thing or two about what's commercial. This is the man, after all, who made a modest fortune disposing of his collection of Andy Warhols, also through the his West End gallery. Death jacked up Haring's prices, like it did for Jean-Michel Basquiat, and clearly for Warhol, too.
Yet the relentless manufacture of souvenirs diminishes Haring's voice - when he transcended cartoon doodling, he sang louder than any other graffiti artist. He was perhaps in the end the only designer of Swatch watches and giftwrap to acquire trans-global fame. A fuller retrospective in London would help us to discover if his art is, as the critic Henry Lehmann has put it, "just part of the packaging"
Keith Haring, May 14 to August, Peter Gwyther Gallery, 29 Bruton Street, London W1 (0171-495 4747). Facing page: `Apocalypse', silkscreen (1988). This page, clockwise from above: painting a section of the Berlin Wall (1997); `Self-portrait', aluminium (1989); church transept, Sant'Antonio, Pisa (1989); the Pop Shop, New York