He inspired the Who to smash their guitars, refuses to be photographed and has a new art project in which a robot does all the work. Gustav Metzger tells Stuart Jeffries about six decades of political art and professional trouble-making
Gustav Metzger in 1962
'I had a choice: art or revolutionary politics' ... Gustav Metzger in 1962. Photograph: Ida Kar/National Portrait Gallery, London

Gustav Metzger didn't have to do much when it came to his latest art project. The renowned 86-year-old sat for 20 minutes looking blank and thinking about nothing. Then he wandered off. Don't pretend you haven't had working days like that.
The result is a sculpture entitled Null Object, which consists of a 50cm cube of 145 million-year-old fossilised Portland stone with a hole drilled in it. It's the hole that is important: this void is a three-dimensional representation of Metzger thinking about nothing. "My contribution was minimal," the artist admits. The hard work was done by robots drilling into stone, using biofeedback technology devised by cyberneticists at the Massachusetts Institute of Technology (MIT) and from databases compiled in Hackney, London.
As Metzger sat during a series of 20-minute sessions, trying not to think, readings were taken every two minutes of the electrical activity in his brain. The resulting electroencephalograms were used to create the instructions for a robot to work on the stone at a factory in Oxfordshire. The end product looks like a non-functioning washing machine. Perhaps this is a blueprint for art. In the future, machines will do the work, while artists stare gormlessly, 24/7.
"Gustav is the neurophysiological trigger," explains Bruce Gilchrist of artists' practice London Fieldworks; he and his collaborator Jo Joelson have created this sculpture questioning what happens to human subjectivity in an era of technological evolution and cybernetic augmentation.
Gustav Metzger - Null Object
Null Object, by Gustav Metzger. Photograph: London Fieldworks London Fieldworks/London Fieldworks
These are questions that have intrigued Metzger since he was a boy. He was raised by Polish-Jewish parents in 1930s Nuremberg, where he bore witness to what he describes as "machine-like" Nazi marches and rallies. In 1939, he and his brother came to Britain, two of about 10,000 children saved by the Kindertransport association. In 1943, Metzger's parents were murdered by the Nazis. "Facing up to the Nazis and the powers of the Nazi state coloured my life as an artist," he says.
Later, in 1969, the avant-garde artist became the first editor of the London-based Computer Art Society's journal, Page. "I swung the journal around from technological messianism into recognising technology as a threat," he recalls. Metzger's career has been about alerting us to the risks in our deluded pursuit of technological progress, and of humans being eclipsed by their machine selves.
Gilchrist and Joelson's original idea was that Metzger would sit in a gallery for 20 minutes a day, wired to a computer-brain interface. Visitors could stare at him as he stared at nothing in particular, like an exhibit in a transhuman zoo. Across the gallery, a robot drill would carve into the stone cube. But that proved impossible, not least because the industrial robot is so huge it would have necessitated removing the gallery floor. Just as well: it would have taken only one visitor pulling faces at Metzger to put him off his task of thinking about nothing. Instead, the show will consist of the cube with allied video and documentary material.
You could argue that Metzger's 20-minute spurts of creative inactivity are the culmination of his career. He is best known as the inventor of the auto-destructive art movement, which he launched in 1959. (Famously, the Who's Pete Townshend, who studied with Metzger, adhered to auto-destructive art's tenets when trashing his guitars on stage.) "When I saw the Nazis march, I saw machine-like people and the power of the Nazi state," he says. "Auto-destructive art is to do with rejecting power." In 1961, wearing a gas mask, Metzger performed one of the most famous acts of auto-destructive art when he threw hydrochloric acid at a sheet of nylon on London's South Bank. "The important thing about burning a hole in that sheet," he recalls, "was that it opened up a new view across the Thames of St Paul's cathedral. Auto-destructive art was never merely destructive. Destroy a canvas and you create shapes."
Auto-destructive art is also to do with rejecting art's egocentrism. Instead of being a narcissistic creator making stuff, he has often erased his work, or even himself, for the sake of an art he thinks must always have political purpose. He refused to have his picture taken for this article, even though with his kind eyes and funky hat he would have looked a treat. "I don't want my image to appear in the mass media," he says, in a gentle voice still inflected with German, "since it would detract from the project." Between 1977 and 1980, Metzger went on an art strike, refusing to labour for the exploitative Man.
Why did Gilchrist and Joelson want to harvest Metzger's brainwaves? One reason is that, while being one of Britain's most bracing art-world troublemakers, he knows a lot about nothing. In 2009, Metzger co-curated Voids, a retrospective at the Pompidou Centre in Paris. "We realised that there wasn't much literature on voids," Metzger says of that show. "So we decided to fill the gap." With, it should be added, nothing. Five rooms of Paris's premiere modern art temple displayed classic non-works such as Yves Klein's 1959 blank gallery wall and Art and Language's 1967 air-conditioned air in an empty gallery. The guards probably had difficulties ensuring visitors didn't touch the exhibits.
Metzger says he has always been interested in voids – an interest, it is hard not to think, that stems from his politically and ecologically charged disgust at adding to a world already filled with too many images and works of art. "I've always opposed two things in art: celebrity and commercialisation." That said, the 500-page exhibition catalogue for Voids cost €39 (£34). And Null Object, despite its central void, would have been an oddity in that show. It looks like a minimalist sculpture, a beautiful thing rather than anti-art provocation. It's not nothingy enough. It's not impossible that Charles Saatchi might want to acquire it.
As we sit over coffee in London Fieldworks' studio in Hackney, Gilchrist shows me a lump of wax. It's a scale model of the hole in Null Object: an absence has become a presence, something has been made from nothing. It recalls Rachel Whiteread's House, or a mutant Anish Kapoor, and is just the sort of thing hipsters might buy at a gift shop for their mantlepieces. (Work Gallery has no desire to commodify Metzger's brain activity. This, of course, would be very wrong.)
Metzger's art has often violently commented on the violence we do to the world and to each other. In his 2009 work Flailing Trees, for instance, 21 upended trees were plunged into concrete in Manchester's Peace Garden. In a retrospective at London's Serpentine Gallery the same year, technicians battered a car with sledgehammers until it resembled the wreckage in a news photograph of a street demonstration Metzger had once seen.
He has long campaigned against nuclear weapons. "Atomic physics," he once said, "was the worst thing that happened in the 20th century." As a member of the British anti-war group the Committee of 100, Metzger was jailed briefly for civil disobedience during CND protests in the early 1960s. Has living in the shadow of the bomb defined his art? "No. My fears about men and machines started in my childhood," he says. "My parents lived just off the main road between Fürth and Nuremberg. Thousands of people would march along that road to the Nazi rallies. I was frightened and disturbed by the Nazis."
At the Serpentine show, visitors had to crawl on the floor under a sheet to look at blown-up press photographs of Jews scrubbing the streets of Vienna during the Nazi era – Metzger's way of making us empathise more profoundly. "At the beginning I was confronted with a choice: move into art or revolutionary politics," he says. "I took the path of art at the age of 18." But the choice turned out to be more apparent than real: "I could see this possibility of using the ideas of social change within art."
Now, after decades of unmaking and undoing, Metzger is embroiled in making a sculpture. Two of his earliest influences, Henry Moore and Eric Gill, also sculpted holes in monumental stone. Metzger is no lone genius with a chisel, though. Null Object, by harnessing a creative inactivity, by showing an artist colonised by technology, and by then erasing him from his work, is perhaps his most radical move yet. "I find it very admirable," he says, examining a scale model as if the work had nothing to do with him. Which, in a sense, it doesn't.