Literature: JOHN BERGER ICA, London

John Berger is staring up at the elegant Nash ceiling, biting his lips, struggling to find the words. Words have always been a struggle, he explains, whether it be for an article, or one or another of the 13 books of his that are currently in print and on sale at the ICA bookshop. (A full list has been left on every seat for our convenience.) Today he is struggling to explain the new novel, To the Wedding, the impulses behind it, how it came to be what it is.

The book is the story of the journey of two people who are converging on a wedding in northern Italy from different parts of Europe. One, the father, is travelling from the Pyrenees on a motorbike (motorbikes are one of Berger's great passions); the other, the mother, is travelling on a coach from Bratislava. The wedding itself is something of a pitiful charade - the bride is HIV positive, a discovery that is made as the story unfolds. Tragically, Berger discovered that his own daughter-in-law was HIV positive during the writing of the novel.

"This one was a quick book," says Berger, thrusting both hands back through his tousled grey hair, an aid to concentration that he repeats over and over again. "By that I mean it took me just two and a half years to write... You see, all the first things I write are so bad." He smiles broadly, self-deprecatingly. The audience smiles back, indulgently disbelieving. "It's a constant process of correction, of trying to get closer, of trying to interfere less with what is being narrated. I couldn't even start it until I had the voice of the old Greek who tells the story, and for him, and for the Athens that he comes from, I have my friend here to thank." Berger looks across at Nicos Papastergiadis, the young critic who is cross- questioning him, and an old friend with whom he has played a lot of table tennis in the Pyrenees.

Suddenly, Berger leans forward as if he's about to leap out of the chair and make a meal of us. "The whole secret of fiction, isn't it, is to do with Heisenberg's uncertainty principle - as soon as you begin to observe, the very act of observing itself affects the events. There are, of course, certain kinds of narrative, and certain poems, that manage to avoid that and leave the events intact. This is what I wanted to do. In the character of Gino, the husband-to-be, for example, there is almost no psychology."

Nicos interjects. "You seem to have wanted to clasp the nowness of things in an almost cinematic way."

"I think that's absolutely right," breathes Berger, closing his eyes appreciatively.

n `To the Wedding' is published by Bloomsbury (pounds 13.99)