The British are finally casting off their mistrust of the new, but most of our art collectors still compare poorly with their counterparts in Europe or the US. That is why the collection of the late Alexander Walker makes such a spectacular display. The 200-plus works, on view at the British Museum, constitute the biggest and most significant modern bequest received by the Department of Prints and Drawings for more than 50 years.
How on earth did the film critic for the Evening Standard manage to display them all in his modest Maida Vale home? When I knew Walker best, as a warmly supportive colleague on the paper in the 1970s and early 1980s, he had bought only a fraction of the work exhibited here. He invited me round to see the collection, and his pride and pleasure in the pictures were gratifying to behold. But I then had no inkling that he would go on to acquire such a distinguished range of images.
I might have guessed. After emerging from his incessant round of daytime cinema screenings, Walker would invariably hurry off to the galleries. Whenever we met, he would be alive with enthusiasm about a current exhibition and eager to hear about any discoveries I had made. Sometimes he would phone me. "Richard, it's Alex," he would say, in his distinctively crisp Northern Irish accent. "I've just seen something marvellous and I'm wondering whether to buy it." The artists were all quite different - in age, nationality and style. They reflected the broad, ever-changing nature of Walker's restless and inquisitive vision. He took art very seriously and, by degrees, the images he acquired took over the entire flat.
Walker rejoiced in the diversity of his collection. A Keith Vaughan inspired by Shakespeare's great elegiac line "Fear no more the heat of the sun", was hung next to a frowning, anguished Chuck Close face. And unlike so many British collectors, he became wholly unafraid of extreme abstraction. The most exuberant cluster of images in the British Museum show were produced by Bridget Riley. A 1962 ink and collage study for Blaze is one of the most dynamic and arresting works in the collection. Riley's inscription on the large sheet of paper conveys her determination to make the final painting even more visually dazzling: "All angles as acute as possible."
On the crowded walls, the Rileys would have threatened to knock out any other artists displayed next to them. Walker placed some in his bedroom, and delighted in Riley's ability to "pop my eyes open with their concertina'd waves when I wake up". He also revelled in the most heretical juxtapositions, and did not care if important works ended up jostling for room in places that grander collectors, with elevated ideas about impressing their guests, would never have dreamt of using. Arcs from Four Corners, a sumptuous Sol LeWitt, was above the draining board and next to the stove. Judging by the video-tapes and magazines stacked on the electric rings, Walker did not believe in cooking at home. So these images surrounding the stove were saved from harmful exposure to heat, bubbling food or boiling water.
The bathroom, however, was quite another matter. Here, alarmingly, Sean Scully's magisterial Abstract Landscape and Rachel Whiteread's Pink were hung above the bath. Whiteread's work, a tough yet seductive ink and gouache taking as its springboard the herringbone pattern of the parquet floor in her Berlin flat, looks especially vulnerable to any steam rising from the nearby hot taps or shower spray. But Walker, who must have loved looking at such a potent image while he washed and shaved, saw no reason why art should be prevented from accompanying his daily ablutions. And he was right: the British Museum assures me that the bathroom pictures have remained unharmed.
As he grew older, Walker removed himself from the neo-romanticism of his youth. Many of the finest images in the bequest are by the rigorous minimalist masters Agnes Martin, Robert Ryman and Brice Marden. Even so, Walker never sold any of his earlier, figurative acquisitions, and believed that everything he had ever bought possessed its own validity.
His accelerating involvement with abstraction never ossified into a chilling orthodoxy. A row of scrutinised Lucian Freud etchings prove that, even as late as 1996, Walker responded to the rewards of penetrating observation.
We search in vain for cliched images of movie stars in this exhibition. Even so, he never treated the collection as an escapist enterprise. In his study, near a poised and lyrical sequence of minimalist colour woodcuts by Robert Mangold, he hung one of the largest and most unnerving prints: Philip Guston's baleful Room, a lithograph in which a heap of severed limbs and hobnailed boots transforms a clinical, claustrophobic chamber into a charnel house. The reference to the Holocaust, along with every other manifestation of humanity at its most savage, is inescapable. But Walker knew that artists, like film-makers, must confront the most traumatic subjects, and that collectors should be prepared to meditate on tragedy as well as the manifold consolations of delight.
Richard Cork is giving a lecture on the Walker Collection at 6.30pm on 16 September at the British Museum. Tickets can be booked on 020 7323 8181 or at www.thebritishmuseum.ac.uk