So what exactly did Andy do?

Andy Warhol's films of people (and buildings) doing their own thing got the Sixties art world talking. Some of the later works are even watchable - thanks mainly to his director, Paul Morrissey. By Ryan Gilbey

You may not have seen any of the films that Andy Warhol made, or lent his name to, in the 1960s and 1970s, but you will doubtless have had a discussion or an argument about one of them. Probably Sleep. That comprised six hours of footage of a man sleeping. Or Empire, in which the camera unblinkingly documents a day in the life of the Empire State Building from a single static point. Or the half-hour Blow Job, which really needs no explanation.

It seems now that this was the purpose of those films: to be debated and bickered over at parties; to attract myths and gossip. But to be seen? Fifteen minutes of Sleep or Empire might hold a certain hypnotic allure, but linger with the films any longer and the concept quickly becomes more appealing than the reality.

Warhol was using these films to challenge cinema's temporal laws, and to make explicit the scopophilia - the sexual pleasure in looking - which underpinned the medium. He shaved his films to the bone in terms of action, making the viewer blatantly aware of time and image, forcing us to reconsider the boundaries and purposes of cinema just as his silk-screen prints had altered the way we looked at art. It was revolutionary, and ceaselessly exciting, just so long as you didn't have to actually watch one of the movies from start to finish.

It's debatable whether Warhol approved of his work being digested as theory rather than cinematic experience. We have accepted that he may not have had very much to do with the films beyond their conception and financing. His collaborator, Paul Morrissey, who exerted an influence on Warhol's film output from 1965 and directed all of the "Andy Warhol" films from 1968 onwards, confirms this.

"Andy operated the camera, because there was nothing else for him to do," Morrissey says. "Anything in the movies which looks like a direction or an overall pattern, I put in."

Was Warhol satisfied with the films he gave his name to? "He was very happy that people were paying to see films like [the 1968 gay western] Lonesome Cowboys, and enjoying themselves. I think he was just so happy that anything was getting done at all."

Ronald Tavel, Warhol's sometime scriptwriter, recalls the director being transfixed throughout the full 24-hour cut of Couch, which consisted of assorted people meeting and having sex on a sofa: "He would sit and watch it with such contentment that I felt I was in the presence of a Buddhist who had achieved the desired transcendent state." A conflicting story has a friend binding Warhol to a cinema seat with a length of rope to make him endure one of his own movies. Warhol slipped the knot a short way into the picture.

He had publicly exhibited around a hundred of his own films, and was rumoured to have made double that number, by the end of the 1960s. The later works such as My Hustler and Lonesome Cowboys even had vestiges of narrative planted there by Morrissey ("I started saying to Andy, 'We can't let the camera roll for 30 minutes any more - it's a waste of film!' "), and pointed to a future where this underground form would adopt the conventions of mainstream cinema, creating a kind of Warhollywood.

"People are so fantastic," Warhol enthused. "You can't take a bad picture." He sought to render a pure cinema untainted by technique or affectation, and driven by the camera's act of surrendering itself to its subject. The actors were everything - the way they moved, spoke, slept, screwed. The camera simply revered, and revealed.

Warhol's vision of cinema as a monument to the star remained intact even as the films began to alter irrevocably. In 1968, he was wounded in a near-fatal shooting by Valerie Solanis, a deranged hanger-on. At this point, Morrissey assumed full creative control over the movies - or rather, his full creative control over the movies was finally made explicit. And while purists have argued that Morrissey was refining, and therefore compromising, his producer's work, the transition was ripe with the sort of incongruous juxtapositions that had long fuelled Warhol.

Morrissey brought with him two vital additions that shifted the Warhol movie into a new phase. Firstly, a different shape: the new movies were built around the more ordered narrative structure of Hollywood melodrama. The stories were minimal (1968's Flesh follows a hustler as he rustles up the money for a friend's abortion, though in the final reel she decides to keep the baby anyhow). But at least they existed.

This is what separates the two periods in Warhol's film-making career: the early films, which nobody saw but everyone ranted about (Warhol called these "my art films"); and the sex comedies made between 1968 and 1973 - Flesh, Trash, Women in Revolt, Heat; and the two horror spoofs Blood for Dracula and Flesh for Frankenstein, which hilariously transposed New York accents and attitudes to rustic Italy. You can watch these films, and enjoy them. In real life, not in theory.

The second change that Morrissey brought with him was the introduction of a new star for the camera to worship. Joe Dallesandro ("Little Joe" from Lou Reed's "Walk on the Wild Side") had wandered into an apartment where Morrissey was filming, and hung around. He was young and pretty; mostly he moved like a panther; sometimes he had a galumphing awkwardness. He had time to kill. Morrissey had an unused reel of film, and a hunch about this beautiful kid. Suddenly, his movies had a centre.

Dallesandro won a part in Lonesome Cowboys, but it was with Flesh, Trash and Heat that he actually became the subject of the films. He was celebrated, fetishised. And, for the most part, naked. David Thomson has called him "obdurately impassive and unable to animate his beauty". His allure is buried in this frustrating impenetrability. The camera wanted him, and he gave himself obligingly. But Morrissey is keen to stress that, despite the loose feel of Dallesandro and co-stars like Holly Woodlawn and Jackie Curtis, the actors were not, as has been suggested, interchangeable with their characters.

"If a person is in front of a camera, they're acting," he says. "It's not possible to live in front of a camera. What I always believed in was the truthfulness of artificiality. You can't have the real thing on camera - that's the nature of cinema. When you see people like Daniel Day-Lewis and Ralph Fiennes screaming and hyperventilating, you're seeing the phoniest kind of bad acting. You may as well have a 'men at work' sign. It's not acting if you can see it."

Did Andy subscribe to this?

"He didn't have many points of view. He didn't have many ideas at all, actually. Maybe three. If you're gonna make a movie, hopefully it will be funny. And hopefully people will pay to see it - that was another of his ideas. But he had no good sense. If he made a choice, it was almost always the worst possible choice in the world."

n 'Flesh', 'Trash', 'Women in Revolt', 'Heat', 'Blood for Dracula', 'Flesh for Frankenstein' and 'Madame Wang's' are available on First Independent at pounds 12.99 each