Hugh Nissenson can go for six, maybe seven sentences without using one of the profanities that naturally season one's conversation if one grew up on the pregentrified West Side. He cannot, however, utter more than three sentences without quoting Keats, invoking Proust or alluding to Kafka, Joyce or Malraux.

By his speech, intense and quick and opinionated (and also by the sports jacket with suede elbows, the West Side apartment full of sunshine and art, the sheepdog at the feet and other credentials), ye shall know him: the New York Intellectual, subgenus novelist -- a prime specimen.

It takes considerable effort to imagine Nissenson methodically learning how to hurl a tomahawk, hunt with a flintlock rifle, trudge through the underbrush in fringed buckskins. Until one either opens the door to Nissenson's study -- where pelts, snowshoes and old muskets engulf the word processor -- or opens the resulting novel, "The Tree of Life." It took him seven years to research and write this diary of an invented frontiersman, now in its second printing and being received by critics with something like awe ("A strikingly original work, harsh and beautiful" -- Newsweek; "Searing and concentrated intensity" -- the Los Angeles Times). In it, the passion for authenticity and the challenge of finding a new form for the novel ("The 19th Century narrative is, of course, dead") intersect.

When he began work on "The Tree of Life," Nissenson says, leaning back on the sofa, "I had come to the end of a period, my mid-twenties to forties, which explored what it was to be a Jew in the 20th century." The author of four previous books, respectfully reviewed and rarely purchased, he had written about the shadow of the Holocaust, the immigrant experience, the state of Israel, "death and rebirth, a drama that obsessed me."

It was time, he decided, to address another lingering obsession: John Chapman, who as Johnny Appleseed has "been presented as a Walt Disney character" but was actually a religious mystic sowing Swedenborgian tracts along with his seeds.

"I was in a sense conflicted, and also scared, a first-generation American Jew [his father emigrated from Warsaw in 1907 and married a Brooklyn girl] confronted by the richness and power of the American tradition," he says of his abrupt change in subject matter, pausing to mention Melville, Poe and Twain. "I suppose you say to yourself, with the inhibitions and inferiority complex you feel, that you have to somehow make that tradition yours." (Here Nissenson quotes T.S. Eliot, "an anti-Semite and a great poet.")

Besides, he continues with animation, "you get bored. You want to try something new. Why do the same [expletive] thing when by an effort of the imagination perhaps you can try something different? Give it a shot!"

There follows a consideration, enlivened by references to Conrad and Flaubert, of whether there is "an innate drive in the artist which is reflective of evolution . . . an unconscious urge to make up something new for its own sake, for the joy, the fun of it. A creative person gets bored very rapidly."

Learning that Chapman/Appleseed was in Mansfield, Ohio, during the War of 1812, Nissenson began three years of research. "I knew nothing about American pioneer life. I went out to Mansfield, I don't know how many times, in all weather. I learned how to fire all the weapons, I went on a deer hunt. To make you" -- the reader -- "feel you were experiencing it, I had to experience it . . . It's like working with a palette knife: You lay on a daub of color, one at a time, an accretion of details."

Every high school English student hears how Stephen Crane wrote "The Red Badge of Courage" without ever serving in the Civil War. But Nissenson's "effort of imagination was much greater," he says, gesturing toward West End Avenue 20 stories below. "I mean, [expletive], look where I live."

To help him achieve the requisite "altered state of consciousness" he turned his study into what looks like a small-town museum, a hodgepodge created by the emptying of attics. Its shelves are full of history books, but written history, Nissenson says, "wasn't enough." He amassed a collection of reproduction weapons now laid across the Eames chairs: an American long rifle, "simple and deadly"; the Harper's Ferry rifle his diarist carried; the blunderbuss the Indians turned on the settlers. Wire hangers hold a Hudson Bay coat and several deerskin garments. Nissenson asked an Ohio taxidermist for a specimen of the rattlesnake that killed one of the novel's characters; the result sits coiled atop a file cabinet. Stuffed raccoons and horned owls, snowshoes and baskets, an Indian scalping wand and several scalps (wigs, actually) line the small room. Nissenson even obtained a human skull from an anatomical supply house.

"I used to come in here at night and light a candle," Nissenson says, eyeing the skull, "and in the flickering light think and feel, 'This is a human being. My God! Like myself.' And I'd be filled with the chill of death."

"The Tree of Life," though leavened by humor and even romance, evokes that chill, a time when Mansfield, Ohio, had 26 citizens and death could come by rattler, Delaware warrior, cholera or the bloody flux or childbirth. Nissenson reports that after initial skepticism about "some New York Jewish guy obsessed by the history of Ohio," Mansfield's latter-day residents are "thrilled" by the book and have invited him to address the Ohio Historical Society. But he is even prouder (citing Woolf, Mann, Pasternak et al.) of having incorporated his own paintings, drawings and poetry (ostensibly by his journal-keeping protagonist) into his artfully minimalist book.

"The whole thing is an attempt to push the novel into poetry," Nissenson explains. The classic narrative, whose death he has pronounced, "will still exist as middlebrow fiction, but for serious novels? Can I write better than Tolstoy? Dostoevsky? Jane Austen? Dickens? It's been done!"

Watching his contemporaries publish nonetheless, while he painstakingly crafted stories for The New Yorker, Commentary and Esquire, "I thought I'd be a short-story writer all my life. This juvenalia, these endless, onanistic novels of self-discovery, were just boring. Another Philip Roth novel and I'd cut my throat."

He calms himself long enough to say that actually, he thought "Portnoy" was brilliant. It's the repetitiveness of the form that he disdains. " 'Novel' means something new," Nissenson insists. "If a novelist forgets that, he's in the wrong business."

By that definition, it's suggested, there are rather few novelists around these days.

"You're not kidding," he says.

Nissenson believes that with "The Tree of Life" he took "perhaps the greatest risk of any writer of my generation," and he's basking in the exhilaration of having pulled it off. His next book, to be called "The Song of the Earth," will "go even further into the juxtaposition of written and drawn images." An anecdote: Faulkner once said he'd taken more risks than Hemingway. "Well, goddamit," Nissenson concludes, "I took more risks than William Faulkner."

It was a risk shared, as he readily acknowledges, by his wife Marilyn, a television producer whose earnings allowed him to write just five books in 25 years. "It's a shameful thing for a man to say at 52, I suppose, that he's never been able to support his family." Considering, he decides it's shameful only if he accepts the husband-as-breadwinner paradigm, which he does not. "It's never been an issue between us," he says. A love poem he wrote his wife on his 40th birthday has found its way, modified, into "The Tree of Life."

In fact, he says he owes his feminism to the "profound education" of living in "a house full of women" including daughters Kate, 15, and Kore, 9. "A wonderful experience," says Nissenson, who likes to quote Joyce on the virtues of being "a womanly man."

Marilyn Nissenson figured in a dream he had recently, a few days before the American Book Awards ceremony. "The Tree of Life" was one of three nominated novels (Don DeLillo's "White Noise" won) and in his dream, Nissenson and his wife were seated at a round table. They heard the master of ceremonies announce that this year, both the fiction and nonfiction categories had been swept by a single work, "I Was Hitler's Tennis Coach."

"I looked at Marilyn and we both started laughing," Nissenson says, shaking his head. He regrets that his laughter awakened him before he could leaf through the volume and see photos of der Fu hrer in his tennis whites.

He does not seem to regret much else.