On Friday the press were exasperated to find that taking photographs of the artist was not permitted. Metzger said that "the personality of the artist was of no consequence: the work was the only thing that mattered". Such hermitic behaviour is a little disconcerting in a time when the stars of British art are sharing the most intimate details of their private lives in the name of confessional art. But Metzger is of the old school of manifestoes and political activism, when artists believed that art had a social purpose.
Unlike the current generation of aesthetic annihilators (The Chapmans, Matt Collishaw), who portray violence with a dash of frivolity, Metzger is deadly serious in his message of self-destruction for mankind. There is no doubt that his early experiences, growing up as a polish Jew in Nuremberg - a rallying ground for National Socialism - are the basis of his art.
Metzger has suffered for his beliefs. He was sent to prison, along with Bertrand Russell, for his actions as a member of the Committee of 100, which committed acts of civil disobedience on principal. He has always stood outside the establishment, at a safe distance from the commercial art world.
In 1962 he denounced galleries as "boxes of deceit", capitalist institutions which must be destroyed. In 1974 he declared that all artists must go on strike. Of course no one else did, so he declared that all artists were "disgusting bastards". In the Eighties, he publicly withdrew from the art scene and went to Germany where he studied Vermeer, and Fascism in art.
Between 1962 and 1992, Metzger sold virtually nothing. Auto-destructive art was a public art, meant to incite political action. When he sprayed hydrochloric acid onto a series of red, white and black paintings at the South Bank to demonstrate man's inherent self-destructive tendencies, during the time of the Vietnam war, the effect - a battered view of St Paul's and the Stock Exchange through the disintegrated canvas - was not something that could be bought or sold. And of all his fantastic monuments to auto-destruction, the plans of which are on display (including a giant plastic cube which was to be inflated with exhaust fumes until it exploded), not one has been commissioned.
Metzger has never concealed his disgust with the media and the art establishment (who he denounces as "stinking, cigar smoking bastards and scented fashionable cows" ). And he is not a man to overturn 30 years of principal for a quick bit of publicity. He would not agree to an interview, only an "informal chat", and the interviewer first had to be "interviewed" by the artist.
Metzger has been specific about his reasons for "returning to the fold" with his recent work, Historic Photographs, which he admits has caused "inner conflict". It was a moment in November 1990, when he witnessed on television the slaughter of Muslim civilians by the Jewish police in Jerusalem, that inspired him to get back to work. "Massacre on the Mount" is the first in the series of Historic Photographs which you can "walk into": the photograph of crawling bodies is shrouded by a hessian cloth and you have to sidle right up to the image to view it and pass through.
You have to crawl across the picture of the Jewish Viennese during the Anschluss, scrubbing the streets of their own blood, which is covered by a cloth of silk. The familiar image of the fireman carrying a baby from the wreckage of the Oklahoma bombing is totally walled up in the far corner of the gallery, which serves as a mausoleum for the victims of terrorism. A scene from a Hitler Youth rally will be welded together between two pieces of steel on the opening night. Through being concealed, the photographs take on a new realism.
Metzger is ever the prophet of doom, and time has only fortified his beliefs that Man is on the fast track to oblivion. "I have no doubt that with Auto-destructive art I was working in a prophetic mode", he remarks on his old manifesto in the display case, yellowing at the edges. The dangers of the autobahn, traffic gridlock in the city streets, air pollution and the destruction of natural forests which he railed against have all escalated.
"Thirty years ago, the phrase self-destruct was not so widespread. Now even governments and politicians are said to `self-destruct'. Even cars and fridges are designed with their ultimate waste disposal in mind."
The man who was credited with inventing Machine Art has turned against the machine dream since the Sixties. "Technology is a danger as long as it is allied to Capitalism: it is the speed at which we are relentlessly hurtling towards our own destruction."
Metzger will be warning people against the tyranny of the machine in a series of lectures at MoMA, "like I warned against the War and Mutual Assured Destruction". Genetic engineering ("the new H-Bomb"), the destruction of the environment, computer chips in the brain - these are all things which he says bear the marks of our self-destruction. The very word "environment" he considers is a "technoid double" for the nature we have abused, foisted upon us by politicians.
Metzger says, matter-of-factly: "I was not appreciated in my time. I was very isolated". He still feels helpless and frustrated today when he tries to discuss art's role in politics. "If I did not bring it up in conferences nobody would be discussing what is going on. In Russia, for example, how can we stand back and let it be destroyed by capitalism?... In the Thirties , the artists and intellectuals gathered to save Spain from Fascism."
While he admires the work of Damien Hirst ("Very interesting those little sheep") and Cornelia Parker, who will be speaking with him at the Hand in the Fire conference next week, he thinks their self-interest is unhealthy. "They are the Thatcher generation. It is vital that artists start entering the political arena again, before it is too late". He intends to use this as a subject of debate at The Whitechapel art gallery next week, but "too late" for what, he doesn't say.
He feels strongly enough about it to emerge from two decades of oblivion to bring it to our attention. "I was an angry young man back then. Now I am better at communicating," he jokes. His recent inclusion in major shows in Paris (Live/Life at the Musee de Arte Moderne) and Speed at The Whitechapel shows that the world is belatedly waking up to his important contribution to British art.
He hopes that, like Rodin, he may get to see one of the visions of his youth erected in his dotage (he is 76). "The main thing is, I want to work again."
From 25 Oct to 10 Jan at MoMA,
Oxford (01865 722733)