John Berger “A house stands on one side of a square in which there are tall poplars. The house, built just before the French Revolution, is older than the trees. It contains a collection of furniture, paintings, porcelain, armour which, for over a century, has been open to the public as a museum. The entry is free, there are no tickets, anybody can enter.”

Tilda Swinton pauses and looks up at the packed rows of seats in the Queen Elizabeth Hall before resuming her reading from Bento’s Sketchbook, John Berger’s new collection of essays and drawings.

“Many of the paintings on display feature young women and shot game, both subjects testifying to the passion of pursuit. Every wall is covered with oil paintings hung close together. The outside walls are thick. No sounds from the city outside penetrate.”

From the broad leather chairman’s seat that I occupy in the centre of the stage I can easily tell that the large audience is already captivated by Tilda’s beautifully articulated, even slightly reverential, rendition of John’s little story about this modest museum and its remarkable guide.

“Everything she wore was black. Flat black shoes, black stockings, black skirt, black cardigan, a black band in her hair. She was the size of a large marionette, about four feet tall. He pale hands hovered or flew through the air as she talked. She was elderly and I had the impression that her thinness was to do with slipping through time.”

I’d carefully read John’s new book in preparation for this event so I knew that Tilda would now be going on to tell us more about this woman, would once again be demonstrating John’s very special humanist capacity to find the character of a person not just in such familiar novelistic features as face and personality, but also in their specific biography, their historical context, the manner in which their character had been formed by hard and often unregarded work.

This was, I reflected, as Tilda read on, not quite how I’d envisaged the evening. When I’d first been approached by the organisers I’d somehow assumed that I’d be required to conduct an extended interview with John Berger in which I’d be able to talk not just about his new book but also about the principal political, philosophical and aesthetic themes that have preoccupied him during his long literary and artistic career.

It seemed a safe assumption that this type of approach would be best suited to an audience that had surely turned out in such numbers not just to hear about a single new book but to acknowledge a rare visit to these shores by someone whose work over the last 50 years had made some sort of difference to their lives.

Many would surely be there because of their memories of his 1972 BBC television series Ways of Seeing, the wonderfully contextualised antidote to the timeless essentialist view of art promoted by Kenneth Clark’s Civilisation. Berger’s series controversially advanced the idea that the highly tactile depiction of things and events in oil paintings represented a desire to possess those things or the lifestyle they depicted. A landscape was not a pretty picture of nature but an announcement of the ownership of land. Depictions of women in painting had the same function. They were an announcement of male possession. In European art from the Renaissance onwards women are shown as being seen by a male observer. “Men look at women. Women watch themselves being looked at.”

Others, I suspected, would be in the hall because of memories of his fiction, the Booker prize winning novel G, also from 1972, or the 2008 Booker long-listed From A to X. And still others would be admirers of his more political and ethnographic work, the studies of migrant workers and the isolated rural communities they had left behind, and his well-publicised pronouncements on such issues as the war in Iraq and the Israeli treatment of Palestinians.

But my long list of the recurrent themes that might impose some coherence on this hugely diverse output never got any further than my clipboard. Berger, I quickly learned from a rapid conversation I had with him in the backstage green room, did not wish to go on stage and answer any questions at all. Indeed, as he explained, in between signing the copies of his book that were successively thrust in front of him by his energetic publicist, he saw little value in saying anything whatsoever about Bento’s Sketchbook. All anyone could possibly want to know about the book was in the book itself. That meant that the evening should be entirely devoted to reading from its contents. Once his old friend and artistic collaborator Tilda Swinton arrived they would agree on the most appropriate passages. If there were a few moments left at the end, then he would take questions from the audience. That, however, was the only concession.

I wasn’t inclined to argue. John may be celebrating his 85th birthday later this year but it was easy to tell from the way he strode into the green room, from his stocky muscularity and the deep weather-beaten tan acquired from his long years of farming in rural France, that he was not the sort of person to readily take instructions from the clutch of pale metropolitan administrators and TV people who awaited his arrival. We were somehow all outsiders.

Tilda Swinton by John bergerThat didn’t, though, extend to Tilda Swinton. I’d read a lot about the importance that John attached to collaborators. (Many will remember the remarkable results of his collaboration with photographer Jean Mohr in his studies of migrant workers.) And it was immediately clear that Tilda, whose commitment to working with artists goes back to the time she spent working with Derek Jarman on his film Caravaggio, was now a fully paid-up member of the club.

They greeted each other like long-lost relations. Two fellow artistic spirits in a room otherwise dedicated to the necessary but still slightly sordid commercial business of selling books. Indeed, their embrace went on for so long that I was beginning to think I might need to physically tear them apart if I wanted to establish the passages Tilda would read before we were all ushered on to the stage.

But now, I realised with a slight start, she was nearing the end of her first spell at the lectern. Nearly time for me to introduce the piece that John would read. I hoped that he hadn’t in any way been put off his task by my little piece of naughtiness.

For although I’d agreed not to interview him and simply allow the book to speak for itself, I’d found it impossible after I’d concluded my brief lectern introduction to the evening not to go and sit by his side centre stage and ask him about the origins of his new book. How did it come to be inspired by the 17th-century philosopher Baruch Spinoza, also known as Bento de Spinoza?

There was a long pause before he answered. For one awful moment I thought that he’d decided to deal with my change to the agreed script by keeping completely silent. But then he leant forward, ran his fingers through his shock of white hair, slowly sat back up again and spoke.

“You never know how something begins,” he said, “when you’re to trying to create. I’ve read Spinoza since the age of 20. He’s very difficult because he’s so condensed. But there is one thing. He did away with, and transcended, the Cartesian division between the material and the spiritual, between the body and the soul. He proposes that they’re one thing. They’re inseparable. You can look at what exists and interpret it in all its materiality and yet realise that the sacred lies in that materiality. One day I read that he used to draw, that he often had a sketchbook with him. And he was, of course, a contemporary of Vermeer. I don’t imagine his drawing was great. But he liked the idea of drawing. And that sketchbook was lost. I started thinking, well, suppose it was found, that one could find the eyes behind that disciplined and marvellous brain. I’m not trying to draw like Spinoza in my book. My sketchbook has Spinoza as a companion and as I wrote he became more and more of a companion. It became more difficult to separate us.”

He turned away. My interview was over. But I had at least captured one of the recurrent themes of Berger’s work, his persistent sense of the importance, the sacredness of the material world. Bento’s Sketchbook abounds in examples. In the very first essay, Berger writes about the quetsch plum trees in his garden. “When ripe those purple plums acquire a bloom the colour of dusk … blueberries are the only other fruit which are as blue, but their blue is dark and gem-like, whereas the quetsch blue is like a vivid but vanishing blue smoke.”

This insistence on difference is at the heart of so much of Berger’s writing. It is what Louis MacNeice once described in a poem as “the drunkenness of things being various”. And it has an ideological import. Berger wants to tell us about how a world increasingly dominated by capitalist consumerism is one that obliterates difference by making everything into a commodity that is only answerable, only capable of being evaluated, in terms of the cash nexus.

Bento Spinoza by John bergerI’d have liked to ask him so much more. I wanted to know in what way his own commitment to nature and to rural life could be understood as a manifestation of Spinozan pantheism, the belief that God is manifested in nature rather than in some supernatural realm. I also wanted to know how much Berger shared Spinoza’s commitment to reason as the only method for understanding the world and his consequent denigration of experience. I also wondered how Berger might manage to reconcile his own insistent exploration of the workings of consciousness, the ways for example in which the mystery of another person’s subjectivity initially attracted him to the novel, with Spinoza’s almost complete neglect of notions of the individual and the self.

But as the evening stretched past the hour point, I could see that any doubt I might have about the audience’s readiness to sit through an evening of readings was totally misplaced. Everyone seemed to be listening intently to every word, and I could hardly count a single instance of those bouts of coughing that have become such an integral feature of English concert halls.

There were good intrinsic reasons for such a resounding silence. You need to listen hard, for example, to take in the unexpected, even paradoxical, way in which Berger describes the activity of drawing: “There is a symbiotic desire to get closer and closer, to enter the self of what is being drawn, and simultaneously, there is the foreknowledge of immanent distance. Such drawings aspire to be both a secret rendezvous and an au revoir! Alternatively and ad infinitum.”

But there’s also the silence commanded in these banal coalition days by the profession of strong, optimistic political views.

“Every profound political protest is an appeal to a justice that is absent, and is accompanied by a hope that in the future this justice will be established; this hope, however, is not the first reason for the protest being made. One protests because not to protest would be too humiliating, too diminishing, too deadly. One protests (by building a barricade, taking up arms, going on hunger strike, linking arms, shouting, writing) in order to save the present moment, whatever the future holds.”

I realised as I sat on stage listening to these words that they were doing something to subvert the view of the evening that had crept unbidden into my head during the rest of the proceedings. There was, however much I tried to ignore the thought, something slightly unreal, almost comic, about all these eager liberal urbanites assembling to listen in rapt silence to good old-fashioned socialist strictures delivered by someone whose authenticity was somehow guaranteed by his very absence from the urban round, by his assumed rootedness in non-alienated nature. While we’d all been busily getting and spending and arguing inconsequentially around our dinner tables about the need for change, John had been keeping the flame of freedom burning brightly for us in his foreign hermitage.

What stopped such thoughts in their tracks was the realisation that I’d just been reminded by the last passage read out on stage of my own long-lasting debt to Berger. It was the phrase “save the present moment” that did the trick. Suddenly I was back in the spring of 1968, sitting in the Senior Common Room at the University of York and having to endure some of the customary taunts from colleagues about the inefficacy of the regular demonstrations in which I’d been participating.

It was after one such session that I picked up the SCR copy of New Society. And there was a lengthy essay with the definitive title “The Nature of Mass Demonstration”. The author, John Berger, was then unknown to me but after only a few paragraphs I realised that here was a writer whose capacity to capture the ambiguous meaning of an experience marked him out from the usual over-literal polemicists of the left. Berger began his argument by going along with those who argued that demonstrations rarely influenced anyone in authority to any significant degree. But then came the twist: “The truth is that mass demonstrations are rehearsals for revolution: not strategic or even tactical ones, but rehearsals of revolutionary awareness … a demonstration, however much spontaneity it may contain, is a created event which arbitrarily separates itself from ordinary life. Its value is the result of its artificiality, for therein lie its prophetic, rehearsing possibilities.”

Jacket of Bento's Sketchbook by John BergerIt was only as I remembered that article that I also recalled the number of times I’d used the argument it employed against all those who either chose not to take part in subsequent demonstrations or took part in bad faith.

There was little time for questions at the end of the evening. One man asked John about his hopes for the future while another invited him to make a public renewal of his support for a cultural boycott of Israel. He readily obliged.

Backstage there was the usual cluster of congratulatory remarks. It had, it seemed, all gone so very well. And what a large audience. And so quiet. Respectful even. “Yes, who’d have thought it,” I said. Unnecessarily.

This event took place at the Queen Elisabeth Hall, South Bank Centre, London on 25 May, 2011. Bento's Sketchbook by John Berger is published by Verso. Images by kind permission of Verso and the author.