Colm Tóibín

It is hard to know who to love, or who to stay with. It is clear that the government or the BBC or someone in authority should help. In the absence of this, a simple rule of thumb is to ask everyone six questions and then decide whether you love them or not.

One: Philip Roth or Don DeLillo? Two: Stravinsky or Bartok? Three: Rio or Sao Paulo? Four: Billy Collins or John Ashbery? Five: Quentin Tarantino or Bela Tarr? Six: Andy Warhol or Joseph Beuys?

If those you love do not answer without hesitation 'The latter' to each of these questions, then you must say it is over and they have to go; you do not love them anymore; you must change the number of your mobile phone in case he, she or it wants to follow you or find you. From now on your real life begins.

While the first five of these questions are important, the last is the most essential. Joseph Beuys remains an image-make of integrity and mystery whose work has enormous implications not only for artists, but for anyone concerned with issues of memory, redemption, guilt and survival and also evasion, forgetfulness, nonchalance and utopian experiment.

He was born in Germany in 1921 which meant that he was old enough to take part in the Nuremberg rally in 1936 and, when the war broke out, to volunteer for the Luftwaffe. When his plane was shot down in 1944 over the Crimea, he claimed to have been protected by a nomadic tribe who used fat and felt to keep him alive, although there is not much evidence for this. Both fat and felt would become talismanic materials for him.

His work between the end of the war and his death in 1986 is an attempt, speculative and often hermetic, filled with humility and tact, to use any method and medium installation, for example, or sculpture, or photographs, or conceptual objects, or performances and lectures, or even paintings and drawings to explore obliquely the meaning of what he had suffered and what he had done. He became a pacifist and everything he did had an aura which was both deeply ambiguous and oddly spiritual. He was one of the founding members of the German Green Party.

His work was described by a colleague as 'simple-minded utopian drivel'; and there has often been wonder and worry that he did not confront his Nazi past directly, and that he seemed to blur fact and fiction; he seemed also content to self-mythologise; and, to the consternation of those who knew the danger of this, he seemed more interested in myth than in ideology.

It is easier to support these attacks on him if you don't actually look at Beuys's work. He is, in his way, an artist of some subtlety. There are times when he is worried about the implications of saying anything at all, and this gives his work an edge of great sadness; in other work, there is humour (his devotional card showing Jesus, with the caption 'the inventor of the steam engine', for example); in other works, there is something bloated and grand as though he wanted to contain all art history in a set of objects whose occult significance he alone understood.

His work, in all its uneasiness, is often best seen in bulk. I remember wandering through the seven rooms dedicated to him in the Hessisches Landesmuseum in Darmstadt in Germany and being overwhelmed and sometimes exasperated by the mystery of the objects in glass cases or lying on the floor or resting against the wall as though they were clear specimens from science or casual objects from life or the self-conscious ramblings of someone's wounded psyche.

It might be best, now that the dust has settled on Beuys, to see him as a sort of holy fool, a figure who wore his disturbed and beautiful mind on his sleeve, whose conscious and unconscious minds were closer than is entirely necessary. This means that when he tried to think he was an idiot, as his interviews make clear, but when he saw a room or a glass case or any space at all, he became a sort of genius and knew how to fill things with wonder, mystery, huge levels of emotion and a funny odd desperation. This means that any room he worked on, any space he re-imagined, any surface that attracted his eye, is worthy of our attention. Which is more than you can say for Andy Warhol.