Zen Master : DUCHAMP: A Biography.<i> By Calvin Tomkins (Henry Holt: $35, 550 pp.)</i>

Marcel Duchamp was a computer virus in the Modernist program, a graceful saboteur of the cult of artist as hero-creator-prophet that ran from the Romantic movement up through Renoir and Manet, Van Gogh and Gauguin, Matisse and Picasso and the Abstract Expressionists.

Early in the century he painted a handful of exquisite Cubist works (“The King and Queen Surrounded by Swift Nudes,” “The Bride”) and a lesser Cubist piece, “Nude Descending a Staircase,” that won him scandalous fame at the 1914 Armory show in New York.

It was not an angry, Paris-style scandal, though, but the sunny American kind. He gave witty interviews, the newspapers were delighted--”The Rude Descending a Staircase” was the caption of a subway rush-hour cartoon--and he was perfectly content to provide an excuse for New Yorkers to laugh at modern art. His own smile--complex and with a hint of premonitory mourning--was in the making.

For 10 years, beginning in 1912, he attended on and off--mostly off--to what is widely held to be his masterpiece: a series of shapes worked on or into two plates of glass and entitled “The Bride Stripped Bare by Her Bachelors, Even.” At the same time, in whatever mode is opposite to a storm of creativity--dismantling sunniness?--he began to turn out his series of subversions.

He drew a mustache and goatee on a postcard reproduction of the Mona Lisa and presented it as a new work entitled “LHOOQ” (sounded in French, the letters are cheerfully obscene). Years later, he displayed another Mona Lisa postcard, this one unaltered, and called it “LHOOQ (shaved).” He signed a snow shovel and named it “In Advance of the Broken Arm”--one of a number of “ready-mades” that, he argued, became works of art by the act of signing. He proposed converting a Rembrandt canvas into an ironing board, thus turning the process around. For years he spent most of his time playing chess or working on chess problems.

If Rene Magritte, who painted a pipe and inscribed it “This Is Not a Pipe,” had done a portrait of him, Duchamp would happily have agreed to call it “This Is Not an Artist.” Patently, he was one. Collectors and museums have vied for his work. The bulk of it is in the Museum of Art in Philadelphia and all but reverses the joke about first prize being a week in that city and third prize, three weeks--except that it is not a great deal of work and one week ought to be enough.

Beyond that, Duchamp is a grandfather of influence. Born in 1887, he stood apart from the Cubists he grew up with (they found him frivolous though charming) and the Dadaists and Surrealists who revered him (he found them portentous though charming). The Abstract Expressionists of the next generation, both the stormy God-in-me gestural painters (Pollock, De Kooning) and the priestly not-me-but-God color-field painters (Rothko, Barnett Newman), had little in common with him. It was in the Postmodern generation of Warhol, Rauschenberg and Jasper Johns that Duchamp’s elusive virus propagated.

“In the years since his death in 1968,” Calvin Tomkins writes, “Duchamp has come to be considered a forerunner of Conceptual art, as well as Pop art, Minimal art, Performance art, Process art, Kinetic art, Anti-form and Multimedia art, and virtually every Postmodern tendency; the great anti-retinal thinker who supposedly abandoned art for chess has turned out, in fact, to have had a more lasting and far-reaching effect on the art of our time than either Picasso or Matisse.”

In calling Duchamp the most influential artist of the century, Tomkins’ lucid and judicious biography does not claim that he is the greatest. Even so, the assertion raises a question. The most influential figure in the play, it could be argued, is the man who turns off the lights. Many critics, even those sympathetic to Duchamp and the Postmodernists, see the end-of-art in their divorce of art from personal statement and in the concept that “the goal of art is not the work itself but the freedom to make it.” Or, perhaps, unmake it.

One of the great virtues of Tomkins’ book, in fact, is that it lights up the controverted debate in the arts: Is Postmodernism a burial of the dead and a move onward or is it the assassin? Tomkins praises the wit and gaiety of the wake, has no doubt that the body was already defunct but feigns no certainty about the move onward.

He writes of Duchamp with exhilaration--the artist’s work does not so much ravish the eye as make the brain fizz--but without undue panegyric. He is acid about the search for meaningful profundities on the part of those he calls “Duchampions,” “hagiologists” and “critical constabulary.” His book buoyantly navigates the paradoxes and contradictions of a figure who decided 80 years ago that art was dying and forged ahead in the possibly Gallic belief that the best bons mots are obtained at the deathbed.

One of the paradoxes is the biographical enterprise itself. Duchamp was a smiling enigma even to those who knew him. Tomkins has amassed a vast testimony, but there is not much of a voice from the subject himself. In the scenes of his Norman childhood, his early art life in Paris, his moves back and forth between France and the United States--since 1942 he was a permanent resident here--his friends, his many affairs, two or three real loves and a late, flowering marriage, he is a kind of Zelig. His face is in every gathering, but who is he?

This is wonderful as haunting characterization. We can sense him if not quite see or hear him. “I am a breather,” he once defined himself to Tomkins, who, as a young reporter, interviewed him presumably expecting something more clangorous. On the other hand, it can make the detailed narrative rather choppy: a list of comings, goings, encounters, parties, collectors, minute stretches of work and long stretches of chess and, as one chapter heading puts it, “silence, slowness and solitude.”

What Tomkins cannot narrate, though, he conveys. Duchamp bore the empty stretches with gaiety and style. Over and over we hear accounts of his smile and seductive bearing. Those who knew him remarked on the beauty of his face--in the cover photo, he looks like a cross between Rudolph Valentino and Buster Keaton--and Georgia O’Keefe was impressed by his elegant handling of a teacup.

Would a squat, bulbous-nosed Duchamp have made art history by mustaching the Mona Lisa? Would the Bartleby of modern art--”I prefer not to”--have left such a mark had he possessed less wit and allure? Opposed as he was to the “retinal” or visual aspect of contemporary art and arguing instead for ideas--he explained his long fallow periods by a lack of them--he imparted an elegance not only of concept but of execution to everything he touched.

He died at 81 after an excellent meal prepared by Alexina, his wife of 14 years and the former daughter-in-law of Henri Matisse. “He had the most calm and pleased expression on his face,” she told the author. For a man whose art lay in fashioning negations of the creative “I,” death was a decided artistic success.

He had already written the epitaph to be inscribed on his tomb in Rouen: “Besides, it is always the others who die.” But of course. If Duchamp was not the author of his work, then the death of the author of his work would in no case be his.