A Love Story Tough as a New England Winter : ISAAC AND HIS DEVILS, <i> By Fernanda Eberstadt (Alfred A. Knopf: $22; 368 pp.)</i>

Fernanda Eberstadt has given us a beautiful novel, as tough as New England in winter, alive with braided ideas and passions. The reader feels the characters’ thoughts, thinks their emotions and cheers with both admiration and gratitude: Here is a book for grown-ups to relish.

The story is deceptively simple. Sam Hooker was to be a Ph.D. in literature while his sexy, driving, working-class wife, Mattie, was to find the American dream and nurture it for them both. Prisoners of poverty and their own limitations, pinned in rural New Hampshire, they fail their hopes and each other. Sam becomes a thwarted high school teacher while Mattie edges from adoring him to finding her fulfillment in founding her own business.

Their sons, Isaac and Turner, are the victims of their parents’ history of frustrations. Turner becomes a lover of guns and hunting, cars, and everything else that neither Sam nor Isaac, his first-born, can manage. Turner is a complex young man, though, with insecurities, aspirations and generosities that flesh him out beyond stereotype; he is a captive, and he senses his limitations, and he chafes at them sorrowfully.

Isaac becomes Sam’s surrogate, the repository of his failed hopes. Whether this story were set in New Hampshire, Brooklyn or San Francisco, it would (given my summary) sound familiar. Inasmuch as we do imprison our children, and do spend so much of our lives seeking to escape the imprisonments our parents have made for us, it is familiar. Perhaps it is archetypal, a central story in the coming-of-age of children and parents.

And Eberstadt does examine each parent, each child. She weaves the examinations of their lives just as she judiciously weaves each character’s past into his teeming present. The novel, by the time we reach its remarkably moving last lines, is a miracle of texture.

One reason for this achievement is Isaac. His devils--the family history that fights its civil wars within him; the surge of giant intellect, vast passions; the need to build a world of words--provide the book with its title and with a profound suspense. We come to care so deeply about the fate of this big, shaggy, noisy, intrusive, disturbed, galvanic boy-man that the details of his love affair, and of his youthful decisions, matter immensely.

Since Isaac is a genius, and a sometimes-enchanting fool, and is loved by Miss Agnes Urquhart, a skinny redhead who refuses to be a joke about spinster schoolteachers but instead emerges as one of our smartest, most enchanting literary heroines, we seek out and savor these details.

The details live not only because Eberstadt loves her characters and their story. They shimmer on the page because this author’s language does. Here’s Isaac, a dropout after two years of Harvard:

“Today Isaac came bounding in like a pink-and-gold baby elephant, giant head rolling a little on its bearings, blind eyes dancing behind three-inch-thick glasses, plump dimpled fingers spread and waving like underwater plants, beaming and laughing before he’d even got his foot in the door. A bumpkin, a village idiot in high-top sneakers and baggy patched trousers, pockets bulging with books, magazines, pipe, tobacco, chess set. Ragged flannel shirt missing so many buttons it showed the golden hair on his pot belly.�

Only a lover, a mother or a superbly attentive artist would have remarked upon the belly’s golden hair.

Imagine this behemoth as he mourns crazily in the country cabin that he and Agnes occupy. She has loved him for years, and in him she has found her challenge and repose. Finally, they are together, and his problematic father dies: Isaac’s sorrow makes him mad.

Watch--and admire--how cunningly Eberstadt depicts this brilliant woman whose house has gone “putrid with the smell of cooped-up, airless misery�: Agnes faces the possibility that “their love affair was not a birth into healthy bliss but a sign of his sickness, that a cured Isaac might be cured of her as well.�

Although “Isaac and His Devils� is about romantics and romanticism, it is, we’re reminded, about people with brains. How long has it been since you read a love story about smart people whose minds put on an instructive, entertaining show?

There are too many grand scenes to quote or list, but let me alert you to the brilliant, harrowing description by Sam, who doesn’t want to tell it, of the story of the biblical Abraham’s willingness to sacrifice his Isaac. Be aware, too, of the offer by Sam--books are sacred to him and his son--of “The Columbia Encyclopedia,� which Isaac refuses. Then look forward to the moment when, as he mourns Sam, Isaac breaks into his widowed mother’s house to steal the encyclopedia his father had tried to give him.

Turner, thinking he hears an intruder, comes downstairs and turns on the lights:

“ ‘Daddy . . . ‘ he whispered in dread, transfixed, and then he looked again and it was Isaac . . . standing barefoot in the middle of the wooden floor, hair on end, white shirt bloodied . . . and in his hands, cradled, a big book.�

The long development of the biblical tale pays off, and wonderfully, as Eberstadt sets up the final confrontation of Agnes and Isaac in a tent filled with a state fair’s prize sheep. Here, we recall Abraham and his Isaac: The trusting boy, as his father prepared the sacrifice, asked where they would find the lamb to slaughter for God, not knowing that he was to be God’s lamb.

Because Eberstadt is possessed of gorgeous language, she is, like most excellent writers, sometimes possessed by it. It seems that she often cannot resist the writing of charming, clever, not-quite-relevant digressions--as if her ability to say them so well prevents her from relinquishing them. Thus: A teacher who influences Sam teaches English literature, described as “Herbert’s shivery winged fevers . . . Marvell’s . . . ticklish aromatic hay and sweaty mowers and gelid serpentine rivers. . . .�

On the other hand, Mattie’s seduction of Sam yields this, as she removes her clothes: “Sam watched rolling masses of olive flesh unfold like farmland seen from an airplane.� One description demonstrates Sam’s perception and Mattie’s wonderful earthen surface; the others show off mostly Eberstadt’s large talent. On balance, I am glad to experience the one in order to get to the other.

We have here a novel that actually explores learning, but through such sensuously rich, dramatic action that the story of Isaac and his devils, contemporary in language and material, is also quite like a splendid 19th-Century eponymous novel: The man is the book, born at the start, graduated by the end into the rest of his life.

This is a novel of education, then, as well as of humor, sexuality, sacrifice, generosity, appetites and art--the sort of education you might wish for your child, or yourself. Greet Isaac and his Agnes with applause.