"Naked in the Marketplace" is Henry James's phrase for George Sand's parading of her affair with Alfred de Musset in her fiction. James, needless to say, preferred more discretion in his aesthetic. Sand shocked and titillated her contemporaries even more when she took up with Chopin, a liaison that lasted nearly nine years, during which the composer produced half his works of genius.

Sand's fiction is not much read today, although her letters are now complete in 26 volumes, and yet her life is better recorded than that of any other woman in French history.

So what does Benita Eisler have to add? Mainly a wry wit and a compact narrative — although I was a bit distracted by her penchant for the passive voice. Her book sometimes reads as if it has been translated from the French.

Certain feminists have given Sand a hard time because she was, in Ms. Eisler's terms, an "exceptionalist" — meaning, in Sand's view, it was all right for her to act the part of a man, wearing pants and loving whom she pleased. But women in general ought to stay at home, she thought, and not bother about the right to vote. Sand got a divorce from Casimir Dudevant in 1844 but was against it for other women.

But Sand was hardly alone in rejecting feminism as a movement. Like other exceptional women, she saw herself as sui generis, and "more intelligent, more honest, more self-respecting" than other women. Margaret Fuller and Mary Wollstonecraft thought similarly, Ms. Eisler notes. "Only Sand's talent and success, trumped all the cards against her," she concludes. Why should Sand think that lesser, ordinary women could do the same?

So Sand's fiction, even though it was autobiographical, never included a woman as protean as herself. On the contrary, these women were, like her eponymous heroine, Lélia, frigid — not because of some psychological disorder but because a woman caught in a terrible marriage with an abusive man could not achieve orgasm. Patriarchal power relationships were such that a woman could not freely love, and without that kind of spontaneity in her life, she could not climax.

In an age when pregnancy was referred to by such euphemisms as "lying in," it is no wonder that Sand gave Henry James the vapors. The poor chap used to get enervated when Edith Wharton took him out for excursions in her driving machine. And Sand's contemporaries thought that she hastened Chopin's demise by her vampiric demands on his fragile libido.

Stuff and nonsense, of course. Sand nursed and mothered the invalid Chopin. He was grateful, although he never quite got over his conventional notion that she was a naughty woman.

Ms. Eisler's narrative proceeds so effortlessly that it was not until I had finished her book and began perusing her sparse notes that I began to feel a tad dissatisfied. Why did Sand write so much? Something like 90 novels (it is odd that different biographers come up with different counts), not to mention her memoirs, 20,000 letters, and copious journalism. Why did Sand write so rapidly? A typical day yielded 20 pages. And why didn't she revise?

Ms. Eisler explains that Sand always spent more than she earned, so she was always taking on more writing assignments. And she didn't revise because she didn't really think of herself as an artist — you know, like her friend Flaubert, who agonized over every word, not to mention that finicky perfectionist Chopin, taking the measure of every note.

Well, okay, but plenty of writers go into debt rather than chain themselves to their desks every night like Sand. And it is not only artists who feel the need to revise. And I was still left wondering why Sand always composed in a torrent.

I began to suspect that Ms. Eisler is one of those biographers who does not want her flow interrupted by inconvenient, disturbing questions. Yet some biographers earn their authority by asking the right questions, even when they cannot give definitive answers.

Now I have a confession to make: Many years ago I attended a brilliant talk about George Sand given by Elizabeth Harlan, then a member of a biography seminar at New York University. She published her "George Sand" in 2004 — a fact mentioned once in Ms. Eisler's note (the only one) to chapter 3: "We owe the reconstruction of Sand's discovery and subsequent suppression of evidence relating to her parentage to the archival labors of Elizabeth Harlan."

In other words, although Ms. Eisler does not exactly acknowledge it, much of chapter 3 owes its existence to Ms. Harlan's groundbreaking work. And this "reconstruction," by the way, is not only a matter of research, but rather, in Ms. Harlan's words, a product of the "tug of war between information and intuition."

Ms. Harlan had a hunch that Sand biographers had missed something: "What if, I came to wonder, an unverified but universally accepted assumption about George Sand's identity was placed in doubt?" In short, what if Sand's father was not the aristocrat Maurice Dupin but rather an unknown male who had coupled with Sand's mother Sophie during one of Maurice's absences?

There is no space here to recount how Ms. Harlan proved that Sand knew but covered up the fact that Maurice Dupin was not her biological father. But I second Ms. Eisler's belief that Ms. Harlan has proven her case.

And it matters, because the thrust of Sand's novels were about women who sought to legitimate themselves. At night, in a dreamlike reverie Sand would write these fables emanating from a deep inner hurt: Pages and pages would pour out, even though Sand often suffered pain in her writing arm and even experienced partial paralysis accompanied by periods of "near blindness," Ms. Harlan notes.

Composing at night, alone, gave Sand access to feelings that she could not recall the next day without rereading what she had just written. What was happening to Sand? In a footnote, Ms. Harlan quotes Helen Deutsch's essay on Sand: "There are mental disturbances in which the patient falls into so-called twilight states, in which he experiences things that are normally cordoned off from his conscious life."

Naked in the marketplace indeed! Fiction was not just thinly disguised autobiography for Sand. Fiction represented a kind of primal woman's story, an anchoring of the self in novels not governed by a Napoleonic code that gave women practically no rights.

Where to funnel all that energy — so much that no man could satisfy Sand for long — except in writing, in the font of her own creativity? In "A New History of French Literature" (1989) Naomi Schor suggests that in "Lélia" Sand demonstrated that the "war between the sexes is culturally constructed." Where to escape that construction — even as she wrote about it — other than in her own prose?

No wonder, as Ms. Schor argues, Sand rejected Balzac's realism in favor of her allegorical novels about the terrible choices women confronted.

The end of James's line about Sand and de Musset is that the lovers "perform for the benefit of society." So it seems in Ms. Eisler's account. But it does not in Ms. Harlan's, where Sand, it seems to me, comes into her own. ( )