For the piece at the Tate (When Robots Rule...) he brought along a little kit plane and said he wanted it to be mass-produced in the gallery: to be made at the rate of one every minute (and given an inaugural flight) all day long for a hundred days. Andy Everett of Studio S in London was then commissioned by the Tate to create the necessary production line. I asked Burden if he would have liked to solve that problem himself, and he said yes, in that it would have increased his technical knowledge; but no, in that it would have taken him three to five years to do it. Even Studio S can only achieve one plane every two minutes.
Burden values the miracle of a technology which can save many thousands of "person hours": normally, you'd need three hours and some dexterity to build each one. It's a plane he particularly likes: it uses simple materials (balsa wood, tissue, rubber band, etc) as efficiently as possible; it's a damn good flier. I think that's an aesthetic he likes: the beauty of the impeccably rightly constructed object. He calls it the "internalised" aesthetic of the engineer. And he enjoys the microcosm of industrial capitalism inherent in the piece. Thinking about it at the planning stage, he wondered, "Suppose the price is wrong? Suppose they don't sell? What's to be done with 20,000 aeroplanes?" After all, it might be like "The Sorcerer's Apprentice" in the Disney's Fantasia; planes spiralling upwards like swarming ants into the vastness of the Tate's Duveen Gallery.
Burden talks about people nowadays being "cybersised" - engineers, for example, often have no hands-on experience at all in their training. He's astonished that his fine art students in Los Angeles often have only a hazy notion of, say, what something might weigh just by looking at it. He attaches a lot of importance to physical experience: our bodies and our senses are our best guide to anything. Intuition grows from that physical experience. When Burden famously had someone shoot him through the arm as a performance piece in 1971, it was because that was the only way he could ever truly know what it felt like to be shot.
Burden is very committed to not being committed. Art is about "unfettered enquiry". But art is being subsumed by education: the training of artists is increasingly academic, the presentation of art is increasingly dictated by the need to educate the viewer. We so much want our artists to have opinions, and we want to know their motivations. There are so many taboos (racism, militarism, sexism, right-wingery etc) and we want to be reassured the artist is steering a safe course amongst these dangerous rocks.
In 1979 Burden had 50,000 nickels set out across a gallery floor, each with a matchstick placed on it. Each nickel represented a Soviet tank. He titled the piece The Reason for the Neutron Bomb and received a bashing from people convinced he was being gung-ho or crassly male; that he was naively supporting US militarism. In fact, he wanted to take something which everyone reads in Newsweek but which remains so abstract, and he wanted to make it real. His tactic is confrontational but it isn't propagandist: to advocate pacifism he regards as propagandist as well. He wants us to make our own decisions. In contrast, for The Other Vietnam Memorial - made at the time of the Gulf War, and with that in mind - Burden had 12 sheets of copper inscribed with the names of three million Vietnamese people who died in the war there. He's less happy with that piece, though many people would have fallen eagerly on it to show that yes, Chris is OK, you know - he's on the right side.
Burden is my generation: we "came of age" (as people used to say on reaching 21) around 1968. It doesn't follow, as I've been at pains to point out, that Burden is permanently radical, an ageing revolutionary - but it does mean that he's standing at the gallery window looking out, not standing outside eager to come in. He doesn't make art about art. He's interested in the forces which shape us, in power and money, in the forces we can control if we want to, in the choices we can make. He wants us to get a good feel of these things in our nice white galleries, once in a while.
Taking the art outside the museum isn't necessarily progress: Burden is uneasy about "public art" because he feels often there's an undeclared agenda - the art is needed to distract from something, or it's there to decorate. This brings us back to where we began: Burden gives galleries problems because his instinct is that institutions need to be challenged. I think he feels an artist has an obligation to be absolutely an individual, to stay free - and, well, to take flight.
`When Robots Rule' is at the Tate Gallery, London until 13 June, sponsored by American Airlines.
Hugh Stoddart was director of the Ikon Gallery, Birmingham 1978-81, and is now a screenwriter and art critic