A boy who grows up reading Hemingway turns to Updike when he decides he is more likely to learn about girls at museums than bullfights. The works of both writers are driven by sexual vitality, but where Hemingway tends to strip it nobly bare, Updike dresses it, in various sophistications and accommodations. His Rabbit series launches into action when Harry Angstrom walks out on his pregnant wife and kid and drives away - a classic and negative bid for sexual freedom, which naturally fails, and quickly leads him into more and greater compromises. Urges born out of dissatisfaction mostly end in dissatisfaction, too. But the passion of Updike's prose, both sexual and religious, makes some of the moments in between worthwhile. "We don't even know what we're trying to do, is the humour of it," Harry's mother complains. "Have a few laughs," he offers, "have a few babies." But the scene ends on a heavier, and indeed more hopeful, note. "Pray for rebirth," she tells him. Updike is very good at making the tension between their positions sing. Even the pleasures we snatch along the way, just to get by, briefly suggest prospects of real happiness and true love - even redemption. Naturally, infidelities play their part in his stories; they prove both the joy of starting from scratch, and how short it lasts.

His new novel, Seek My Face, worries over familiar bones: art and sex. The great cricketer C B Fry gave his autobiography the title Life Worth Living; it could have served this book, if followed by a question mark. Hope Ouderkirk, an ageing artist and the widow of artists, tells her life's story in the course of a blustery spring day in New England. She is speaking to Kathryn D'Angelo, a young freelance journalist from New York who wants to write a piece on her career. Their conversation brings out several contrasts: between city and country types, and Americans and Europeans; between their generations; between their views on the role of women; between the freshness of the old modernism and the jaded youthfulness of postmodernism.

Updike has linked his heroine sexually to many of the major American artists of the 20th century: Jackson Pollock, Jasper Johns, Barnett Newman and Andy Warhol, among others, though they go mostly by fictional names - Zack McCoy is her first husband, and Guy Holloway her second - and Updike assures us that nothing in the book "is necessarily true". Some of the fictions, then, are necessarily teasing. Zack's breakthrough comes when he begins to drip his paintings, a practice he has the space for only when he converts the barn near their run-down Long Island farmhouse into a studio. Guy works by elevating the ordinary into art - Coke bottles, typewriters - and reproducing it endlessly, in silk-screen washes and with a factory of assistants.

The coat of fiction often runs thin, but it subtly shifts the emphasis from the academic, with its stubborn insistence on what actually happened, to the human. Updike can work with a loose hand, painting over a familiar print; and he can put a number of artists in the same bed, when virtuous history kept them from each other's temptations. In short, he can get Lee Krasner, the widow of abstract expressionism, to marry into pop and compare her husbands as a way of explaining an American century in art.

The book, consequently, feels somewhat second-hand: an old woman recounts her youth, a writer serves up a pastiche of history. Updike has always been brilliant at describing the press of sensations and preoccupations, the desires and frustrations that hold us in place and in time; he is very good at the passion of the moment, in both senses of the phrase. But the structure of Seek My Face allows little scope for this talent; the moments that matter have passed and been jumbled together. And though he does his best with the changing weather and the comfortable gloom of the farmhouse retreat where the interview takes place, these distract us from the main story, rather than pull us into it. But the conceit offers its own rewards: the contrast in weight between a life told and a life lived. The story takes up both an afternoon and a half-century, depending on the point of view; and Hope can handle with the light touch of memory what Kathryn calls "the historical moment, the explosion, when everything came together, and America took over from Paris, and for the first time ever we led world art. Why? How?"

Hope's answer to this question is mostly personal, and increasingly involves her in a kind of reproach implicit in Kathryn's line of questioning - a reproach that Hope has heard before, from her alienated daughter, an awkward, angry woman who accuses her mother of having lived her life through men. She offers two kinds of excuse, a practical and more fundamental version of the same justification: "But the art world then was almost all male; it was men who had the excess energy, the instinct for battle. This is terribly unpolitic to confess to you, but female artists have always struck me as hangers-on." A woman, she believes, can't "paint just out of nothing, out of herself, only a man would dare do that" - which also explains, perhaps, why Hope is still painting long after her more famous lovers have run dry or drunk themselves to death or both.

Updike has never been shy of essentialising the battles between the sexes; but it is hard to know what to make of this account. The line between the author's beliefs and Hope's is never quite clear, because Hope commands the point of view. Is this a story about the difference between men and women, or a story about one woman's view of her life's failures and successes? "Men do what they came for and then leave, and for the longest time this seemed heartless to Hope." That "longest time" suggests she has changed her mind, and the book at least leaves open the possibility that she changed it in recognition of the truth that women are just as tough and self- sufficient as men. Kathryn's visit has unsettled her into revisions.

Despite its grand inspirations, the novel is both pleasant and light, an afternoon's read. The plotlessness of Hope's remembered life is gently engaging, rather than gripping, but moving, too, as we are moved by distances, the broad spaces on either side of the tale's being told: where it took place, years before; and the months ahead of her, all the lonelier for loneliness's interruption. "Have a few laughs, have a few babies," Rabbit suggests as the reason for living. Hope has done both, though as usual, Updike leaves the question of rebirth hanging.

Benjamin Markovits's novel The Syme Papers is published next year by Faber and Faber