Surgeon of the psyche profile; Ruth Prawer Jhabvala

EIGHT YEARS ago, Ruth Prawer Jhabvala decided to write a screenplay about Thomas Jefferson, author of the Declaration of Independence, third president of the United States, and all-round mythical American. One relatively quiet passage in Jefferson's epic life drew her: his service as American ambassador in Paris from 1784 to 1789. Exile and the exile's observation of foreign cultures had always interested Jhabvala, as had repressed, lonely characters; all of these themes were there in Jefferson's French stay when, between leading a revolution and leading a country, he witnessed another revolution inspired by many of his own ideas. He thought, he wrote, and he may have had an affair with one of his black American slaves.

As Jhabvala picked over his correspondence and worked through his biographies the latter question snagged her attention. Not in a prurient way - her writer's manners had been well-known since her elegant colonial India novel Heat and Dust won the Booker Prize in 1975, and famous since her buttoned-up script for A Room With A View won an Oscar 11 years later - but as a focus for examining the man's complexities. That the slavery- opposing Jefferson kept a slave at all was intriguing; that a man who wrote an essay about head ruling heart might have slept with that slave went to the centre of her preoccupations.

The film Jhabvala wrote, which opened recently, is made cautious, perhaps even choked, by these complexities. Jefferson In Paris is as lavish in its Versailles settings as we would expect from her long-time collaborators Ismail Merchant and James Ivory, but its drama is wordy and inward. Much of the story is voiceover, as Jefferson records his thoughts in letters, or set-piece debate, as he discusses politics and morality with his hosts. The start of his affair with his slave, the 15 year-old Sally Hemings, is shown solely by a brief shot of her empty bed.

Nevertheless, in America these two and a half stately hours have aroused fury. Jhabvala in particular, previously lauded for bringing subtlety and restraint to a dayglo film market, is now accused of creating a "historical travesty" and of being "thoughtlessly racist". The story she tells of Jefferson's affair with Hemings, her critics say, is an over-seasoned reheating of a 200-year-old rumour.

Jhabvala - who is 68, rarely leaves her apartment in New York, and speaks in a tiny, timid voice - is amazed: "I just put the story down the way I saw it. I had no idea it would stir up such a controversy." There is plenty of evidence to support her version, she says - the affair was widely discussed during Jefferson's presidency in the early 19th century, and resurfaced in a biography in 1974 - and, anyway, her intention was not to bury her subject, but to bring him to life. "I love Jefferson," she says. "He had human qualities - that's what made him a great man."

Americans may not want a "human" Jefferson. Such a nationalistic, self- consciously heroic country may not want its national heroes dissected. But this is what Jhabvala does. She dissects the sacred parts of cultures, revealing, for example, the stiflings of English class (without controversy - perhaps we're not as proud). Moreover, in all the 16 screenplays, six books of short stories, and 11 novels she has published over the last 40 years, Jhabvala has always done her dissection as an outsider. A German Jew of Polish extraction, married to an Indian architect, she has lived in three continents without putting down roots in any of them: "I've never been an insider anywhere," she says.

JHABVALA was born in Cologne in 1927. She deliberately remembers little of her childhood: "I started school in the year when Hitler came to power - one wipes these things out." In 1939 her entire extended family finally decided to flee. Some went to Palestine, others to America, France, and Holland. The latter group, 40 in all, were murdered in the camps; Jhabvala and her parents and brother fortunately chose England.

Within a week of arriving she was writing in English. "England is really the only background I have," she says, her vowels still carefully formed. "I identify far more with an English way of thinking." She went to school and university in London and then, aged 24, met an Indian architect called Cyrus Jhabvala. They married, and she followed him back to his practice in Delhi.

Again she started writing about what she saw, finishing her first novel in 1955. Soon she was getting the nuances of Indian life so right that people thought she was an Indian. When they found out otherwise, her sales dropped: "In India people don't like foreigners writing about them," she says. She kept writing, but "felt I was at the bottom of a deep abyss. I wrote these books; no one read them; no one cared ... but I enjoyed it."

In 1960 an Indian film director called Ismail Merchant who was living in Hollywood was given a paperback by a fellow director. It was The Householder; he was so impressed that he made a note in his diary to make a film of it. Then he and his collaborator James Ivory flew to India to find its author. Jhabvala was as shy of attention then as she is now. "She didn't want to meet strangers, and pretended to be her mother-in-law," says Merchant. Slowly, he convinced her. The partnership worked well: "She just goes out, and comes back with a fully-fledged screenplay," says Merchant. "Her first drafts are usually fine."

The spare, controlled style of Jhabvala's novels translated easily into film scripts. "I like it to be absolutely transparent," she says, "The words are not there for their own sake, so you can look through them, like glass." Her first collaborations with Merchant-Ivory - Shakespeare Wallah (1965) and Bombay Talkie (1970) were slow meditations on India and its interaction with foreigners. Critics and Western arts cinemas liked them, and Jhabvala kept quietly writing in Delhi until, in 1975, a novel of hers called Heat and Dust unexpectedly won the Booker Prize.

It was a brilliant book, telling the double story of a bored Englishwoman's affair with a Nawab in the 1920s and a young woman's attempt to uncover its details in hippie-trail India 50 years later, all in barely 180 pages,. The book made Jhabvala's reputation (and she later scripted its successful film), but that year she suffered a terrible asthma attack in Delhi's dusty, polluted air, and uprooted herself again, this time to spend three- quarters of her time in New York.

She moved into the same apartment block as Merchant and Ivory. At first her husband stayed in Delhi. "As long as I have a quiet room I don't really mind where I am," she says. Her second sudden success, the carefully written adaptation of E M Forster's A Room With A View, was a sunnier version of the films that the trio had been struggling to fund for decades. It was a Stallone-sized US hit, she won an Oscar for her script, and Merchant- Ivory films were promoted from the art house to the mainstream, the supposed saviours of cinema.

The partnership produced a line of successes: Howards End won Jhabvala another Oscar; her adaptation of The Remains of the Day (which elbowed aside Harold Pinter's script) wrought an exquisite and sellable melancholy from fellow exile-observer Kazuo Ishiguro's novel; Merchant-Ivory became shorthand for either empty heritage film-making or thinking popular drama.

What was often lost in this debate, and in the lush visuals, was the continuing singularity of Jhabvala's scripts. As Clare Monk, who writes for Sight And Sound, has pointed out: "There's a preoccupation with the inner self that is rather at odds with mainstream cinema." Jhabvala is not some hack adapter, turning out-of-copyright classics into seat-fillers; she is a novelist with particular preoccupations, only half-jokingly listing "writing film scripts" as her recreation in Who's Who.

NEXT month sees the publication of a new Jhabvala novel, Shards of Memory. Characteristically sparse, it covers a lot of ground quickly, tracking four generations of an Indian family across Hampstead and New York, and considers characters constrained by inward-looking exile, their repressed desires, and fate. Meanwhile, she is already thinking of her next novel, trying out possible characters in short stories in her small New York apartment.

"I don't do anything else whatsoever," she says in her small, distant voice. "I don't want to." She has three daughters, but they're in three different continents (the closest in Los Angeles); she doesn't go out much. "I have to live this way," she says, "Otherwise I'd be too distracted, and want other things, get other ambitions."

It's easy to see a path in all this, leading narrowly to the kind of friction that Jefferson In Paris has created, not least for her. Jhabvala just goes on digging, with her cold nomad's steel, into the worlds she's moved across, never worrying about sensitivities ("everything is instinctive"), and never reading what her critics say. "I have no sense of being what you call famous," she says. But then she chuckles quietly with self-awareness: "I know what unfamous is: when you go to a film premiere of something you've written, and they literally trample you underfoot to get to the star."