Whether his subject was the Empire State Building or a sleeping friend, Andy Warhol was able to give it undivided attention. Doctors call it scopophilia. Social historians might link it with an approach to reality that permeated 50s culture in the United States. Look at John Cassavetes or Brando and Steiger alone in the car in On the Waterfront (1954); watch Ed Murrow's TV interviews, where he talked to a picture on a wall, then disappeared as that framed image expanded to fill the screen as he violated the privacy of his interviewee; listen to the changes of gear in a long Frank O'Hara poem or a Charles Mingus improvisation... In each case, the pressures and directions that events take seem not to be fictionalisations, nor even dramatisations but heightenings of the rhythms and pressures of daily life. By the time Lenny Bruce stood up and spoke honestly about his life using the language of the street, he, like Cage, like Pollock, was redefining an event. Who could have foretold the trouble that that would cause? But that was the 50s you reply, Warhol was a 60s animal; he changed as the decade changed. Before that he was drawing effeminate young men naked, sometimes with roses or stylised kisses over their bodies, and was selling them in uptown coffee-shops. His sexual preferences were never concealed. The 60s equivalent might have been the 'most beautiful boys' he portrayed one by one. In fact, it was probably the star of Blow Job (1964), whose almost immobile expression is recorded as shadowy activities take place below. The genre was still the idyll; instead of gods, angels or putti, denizens of the Factory would disport themselves. Paul America in My Hustler (1965); Tom Hompertz in Lonesome Cowboys (1967); Eric Emerson in Chelsea Girls existed to be watched: easy looking, Warhol's equivalent to easy listening. And to match the solos there were duos: Viva and Joe Spencer in Bike Boy (1967) or Louis Waldron and Viva in Fuck [Blue Movie] (1969). Warhol's approach to these films was anything but flippant. Asked by interviewers about the meaning of Fuck, he answered that it was 'about the war in Vietnam', a remark quoted in Victor Bockris' biography as if it were untrue. (In fact, as the two stars fool around, a television set opposite them is giving news of the fighting.) Warhol was quite conscious of what he was doing; his subject matter was the present and he could capture it in many different ways. Warhol's status as a historian is evident from the paintings, spanning high and low, famous and infamous, adopting a style and tone that no critic has yet been subtle enough to describe. For Warhol had a knack for turning the literal into something subtle and often potentially highly volatile. Take the largest of the Mao paintings, a version of the official portrait which Mao himself had banned, fearing the idolatry that would ensue if he became a cult figure. Made and shown in the West, does this become a satire, a copy of the original and therefore a 'faithful' likeness, or as abstract an image as it is possible to make? Or take the three-part portrait of the weeping Jacqueline Kennedy, as near a Catholic altarpiece as any contemporary image could be. The technique is also evident in the Oxidations or 'Piss Paintings'. Early in the Factory's history, Warhol's idea was to lay a canvas on the Factory floor and have guests urinate on it. The idea did not work but was resuscitated in the late 70s, when guests or staff making water onto copper sheets produced stains which resembled 50s Italian foyer decoration or, conversely, an accurate portrayal of pools of stale urine. On a list of the most popular Warhol paintings, they might rank lower than the portraits of rich people's dogs. Pornography, one might think, is beyond such subtleties or vicissitudes. Yet because the visual diet is so meagre, detail takes on an almost frightening importance. Clothes and hair-styles matter a lot, and styles of photography change gradually as the centuries progress. Are they copied from magazines or drawn from life? Probably neither; the stories are that friends and employees picked up boys, brought them back to the Factory where Warhol photographed them enjoying sex. Participation, it seems, never occurred. The drawings which resulted seem almost topographic: lines describe contours or shadows in diagrammatic fashion, and areas of complex detail are balanced by acres of empty space. Divisions are made by means of straight lines and shadow is indicated by primitive markings. While bare skin is blank, body hair is indicated by a cross between stylised foliage and a freestyle flocculence that could pass for thick soapsuds. Large areas can be so sparsely marked that matter and space are confused, and Warhol uses the lack of variety of marks to play spatial games. Points of view are often unusual and the drawings seem quickly executed. Grabbing and rough handling is common, and display seems a prime motive. In one drawing of a single, dangling penis, the pubic hair is rendered in a way that is almost electric, or the shading is so elaborate that it makes less and less sense the more there is. 'I do not like the Gide that exalts the body,' wrote Albert Camus, 'He asks it to hold back his desire in order to make it more intense.' The manic twiddles are not without parallels in Warhol's other work. (After all, in his paintings he used camouflage patterns.) But is it possible that the pubic hair that resembles the top of a Greek column or the open backsides which look like vaginas are evidence of holding back in a Gidean sense? And if so, could it be that the sexual elements in his work provide a kind of intensity which results from serious repression?