The Caryatid of Existentialism SIMONE DE BEAUVOIR A Biography<i> by Deirdre Bair(Summit Books: $24.95; 749 pp.) </i>

Jean-Paul Sartre and Simone de Beauvoir were sometime lovers, lifelong companions and literary and political collaborators. In her vigorous and deeply researched biography of Beauvoir, Deirdre Bair advances and argues with a recurrent image. Sartre as statue, Beauvoir as pedestal: Bair struggles with the problem of detaching them.

Through the ‘40s and ‘50s, when existentialism was the most vital intellectual current in France, Sartre was its field marshal and Beauvoir was chief of staff. She went over his writing with him, she argued and clarified, she grasped what he wanted to say and helped him say it. She was evangelist and partner.

They hiked together, ate ham, drank whiskey and took vacations together. In his appearances around the world, she was nearly always beside him, even in the later years, when they’d moved somewhat apart. Despite the intelligence and success of her own writing, Parisian wits--four parts malice to one part wit--would call her such things as La Grande Sartreuse.

Yet Beauvoir was a brilliant figure in her own right. Her “The Second Sex” was a kind of Old Testament in the feminist movement, even if many feminist writers later found it out of date. “The Blood of Others” was an early major novel about the Resistance, and provided a powerful fictional representation of existentialist doctrine. As for “The Mandarins,” Bair argues that it is one of the most underrated novels of the century.

Bair, author of a biography of Samuel Beckett, was drawn to her new subject by vast, though not uncritical, admiration. In interviews over the last five years of Beauvoir’s life, she kept pressing her: Wasn’t her pedestal too big for Sartre’s statue?

Which, she tells us in an end-note, made Beauvoir highly indignant. “Well, I just don’t give a damn,” the septuagenarian would reply. “It’s my life and I lived it the way I wanted. I’m sorry to disappoint all the feminists, but you can say that it’s too bad so many of them live only in theory instead of in real life. It’s very messy in the real world, and maybe they should learn that.”

Bair has patiently and sometimes brilliantly assembled a statue in its own right. But it’s a statue that insists on its supporting role. Call it a caryatid. Sartre, Bair tells us, was the book’s “secret sharer.” He keeps intruding. Beauvoir’s fundamental sense of intellectual identity and self-esteem--and for a French intellectual, that is the deepest kind of identity and self-esteem--was in the partnership.

Which means that one of the book’s most moving and revealing passages comes near the end. In his last years, with new intellectual fashions and heroes taking over--notably, deconstruction and such figures as Lacan, Derrida and Levi-Strauss--Sartre hated being a statue. He wrote a study of Flaubert on principles quite different from his earlier ones. Old and ill, he gave a series of interviews to Benny Levy, a young Maoist adept whom many of the old Sartrians saw as an evil genius, in which he notably reversed the existentialist notion of the autonomous man.

The pedestal felt herself abandoned. Beauvoir wept tears of rage when she read the manuscript. For her, the ideas she and Sartre had worked on were her life. For him, they were a corset that made him look stiff and old. “I need to rub against everything that puts me in question,” Sartre often said. Beauvoir felt that she had been put in question.

“All he ever wanted,” Bair writes, “was to be . . . a French Peter Pan flying forever in eternal youth.” There are philosophical issues at stake, of course, but it is like a story about an aged couple where, one day, the husband tells the wife that he is tired of the pea soup they’d invented and eaten for 50 years; and that he’s up for a Big Mac.

Beauvoir was the daughter of a family with upper-bourgeois assumptions and less than lower-bourgeois means. The dowry that was supposed to cushion it fell through when Simone’s maternal grandfather, a provincial banker, went bankrupt and was jailed. The family lived in a cramped upper-floor apartment; Georges, the would-be bon vivant father, had to carry down the slop pail each evening.

Georges was interested in culture and books, and he encouraged Simone to read and discuss them. A beautiful, cosseted little girl, she grew into a stringy, awkward and compulsively hard-working adolescent with a fierce temper. Awkwardness never quite left her, but she became a star at the Sorbonne, where she virtually tied for first place in the prized agregation examinations with the class culture-hero: the ugly, wall-eyed, macho intellectual, Jean-Paul Sartre. Having to make a choice, the professors awarded him first place; but some regretted it, and one later said that Beauvoir was clearly the better philosopher.

Clearly they had to pair off. It was like the star quarterback and the homecoming queen. Bair gives us the comedy of their courtship. It was wary at first--when Sartre invited her out for the first time, she sent her sister instead--but it turned ardent. They became lovers, bound themselves to each other by a series of compacts, and lived and worked in Normandy, and then in Paris.

The compacts were both porous and enduring. They called for a kind of spiritual fidelity; sex was something else. Sartre was a prodigious seducer; among his conquests were Beauvior’s friends and pupils. In part, it was his fame. In France, it was more seductive to be the No. 1 intellectual than to be a Beatle. But there was something else. “Sartre conquered young girls by explaining their souls to them,” one of his friends remarked.

Beauvoir didn’t mind as long as the affairs were mainly sexual and romantic. It was threats to her role as intellectual intimate and partner that upset her. When Sartre became deeply involved with Dolores Ehrenreich, Beauvoir began a relationship with Nelson Algren, whom she called her “husband” and her one great amorous passion. Bair provides wonderful tragi-comic detail about the affair, which fell apart after a number of ecstatic trips both ways across the Atlantic.

Algren could not understand that Beauvoir had a deeper loyalty to Sartre, even though they no longer slept together and had never really lived together. He wanted her to move to Chicago. He could not see that a Parisian writer is a public figure, that “public” is as intrinsic as “writer,” and that without her milieu, Beauvoir--who, like Sartre, wrote her books in cafes for the sake of being interrupted--couldn’t survive. And that to leave Sartre would be a breakup not of lovers, but of duo-pianists.

We get as vivid a portrait as we are likely to have of this extraordinary personage. We also get a painstaking history and appraisal of her work. In particular, Bair discusses her role as a feminist world figure over the last 15 years of her life. Writing “The Second Sex” represented part of Beauvoir’s distancing from Sartre, who had turned more and more to a political activism that she did not fully share.

That was one kind of distancing--Sartre took little interest in feminist thought--but there was another. Arlette Elkaim, a young student, became his protege; then, he adopted her. It was a bitter blow to Beauvoir, and it made a rift. Beauvoir felt herself excluded and, in fact, she was. Arlette became his literary executor.

Nevertheless, the old couple continued to see each other several times each week, and to spend summers together. When he was dying, Sartre told Beauvoir that he loved her, and raised himself to be kissed; when she saw him dead, she tried to get into the hospital bed with him.

Bair fails to overcome some real problems in organizing her extensive material. She gives us virtually a month-by-month account; and the ups and downs of this stormy life, dependably recurring, tend to flatten out. They also involve a great deal of wasteful repetition. But she has given us a book that is beautifully detailed, and infused with a passion for the subject, her causes and her contradictions; and with no hesitancy at all in holding them up for examination and argument.