Crazy for Sighing and Crazy for Loving You : BREATHING LESSONS <i> by Anne Tyler (Alfred A. Knopf: $18.95; 330 pp.) </i>

No Olympian or high-flying view for Anne Tyler’s art and the people it invents. She is a low-flyer, a crop-duster, zooming in at head-height and lifting hats; skimming the ordinary because it provides certain essential kinds of humanity, sometimes catching a wing tip on it or blowing its dust into her engine; and finally, with all the risks, accomplishing a gleeful astonishment.

Her people are arrayed in comic eccentricity. But Tyler waives the preservative chill customary to such a thing. They perform as close as possible to life temperature. They are soft, sometimes too soft.

In almost any Tyler novel there are moments when the reader worries about the low altitude, wonders whether the humor and sentiment are getting perilously close to shtick, suspects that the characters are becoming so comfortable in their quirks as to forfeit movement.

It is Tyler’s idiosyncratic form of authority. She gives her people no freedom to be anything but themselves. She never stops imagining them or listening for their possibilities. Sometimes she can’t hear them and improvises--we sense a kind of shuffling--but it’s not long before they are back in her ken and under orders: Your soil will not change; grow in it. Grow any way you want.

And how they grow. “Breathing Lessons” turns a fraying middle-class household into a mixture of picture palace and puzzle palace; a familiar place made new.

It is set in the 28-year marriage of Maggie and Ira Moran and told in the course of a day trip from their Baltimore home to the funeral of the husband of an old school friend. The marriage is the soil I mentioned, more thin than fertile, and seared by dry spells.

The story is about what grows there: a man and a woman who are two versions of the human condition, two different stories in the same story, like the old tales in which a father sends two children out in opposite directions to seek their fortunes and misfortunes. But Ira and Maggie are never apart. It is their opposite spirits that make their common life a painful, provident slog for the one; and a painful, cloudy passage of dragons and treasures for the other.

We start with what in another author’s hands might be two stock figures. Ira is careful and methodical and conceals his warmth beneath a mystique of competence; Maggie is emotional, impulsive, interfering and sloppy.

Each is in a kind of mid-life anguish; Ira, because he gave up his hopes of being a doctor to run the family picture-framing business on behalf of his half-invalid father and two sisters; Maggie, because her two children are grown up and her granddaughter lives with her son’s former wife.

Maggie’s stock figure is only a starting point. When a friend counsels Maggie to learn to let go, she retorts: “I don’t feel I’m letting go. I feel they’re taking things from me.” In her quixotic and far-fetched efforts to fight life’s depredations, and in the repercussions these have on Ira’s effortful equanimity, we get not only some of Tyler’s most exuberant humor but two of her most moving and penetrating portraits.

The trip to Deer Lick, Pa., begins as it is to continue--in a comedy that, based as it is on a mixture of misadventure, misapprehension and unregenerate originality, is invariably a comedy of character.

Dressed to the nines, but already beginning to come unfastened, Maggie picks up the family car at the auto body shop. Hitting the accelerator instead of the brake, she has her fender mashed by a passing truck. Maggie, and everything she possesses or attempts, will always have dents.

She was distracted, of course. A talk show was playing on the car radio; she thought she heard her former daughter-in-law, Fiona, announce that she was about to marry again--this time for security instead of love.

The mis-hearing sets off a fever of schemes. Maggie tells a reluctant Ira that on the way back from the funeral, they will stop at Fiona’s and offer to take care of their granddaughter, Leroy, during the honeymoon. Beyond that notion floats the word “love.” Perhaps, after all, she can reunite Fiona, before it is too late, with her son.

The thought makes one of many more dents in the trip. Along the way, they stop at a diner where Maggie, as is her habit, confides all her troubles to the waitress. A little further on, she judges from Ira’s choice of a tune to whistle--”Crazy”--that he is criticizing her and climbs out of the car, determined to start a new life in the nearest small town. Like many of her decisions, it is as absolute and brief as a firefly’s light.

Eventually, they get to the funeral. Serena, the widow, has arranged it to be a replay of her youth and that of her former classmates. Each is assigned to sing one of the pop songs of their day; later, at the reception, a movie of her wedding is shown. The sequence is a remarkable blend of farce and poignancy beneath which we are made to feel the bareness of time and its dwindling choices.

The funeral scenes are intercut with the recollection of Maggie’s and Ira’s courtship, a phenomenon largely precipitated by another chain of Maggie’s misapprehensions and impulses. It was a successful chain, as it happened.

On the other hand, Maggie’s campaign to get Fiona back to Baltimore, which occupies the last third of the book, is an inverted pyramid of stratagems and illusions. It comes toppling down once more in an outrageous blend of comedy and pain.

There are moments when Maggie’s klutziness seems overloaded, when she is just too funny and inept. But they are minor defects in a portrait that is triumphant because Tyler neither judges Maggie and Ira nor indulges them. Comedy of her sort is the supreme form of kindness; it brings out an extraordinary depth of feeling.

Maggie and Ira--whose portrait is more sparing but equally vivid and compassionate--are not heroes, but they are, in a sense, heroic. It is the heroism of enduring. Each does a number of unforgivable things, but in a marriage that lasts, forgiveness is not the point. Going on to the next day is.

“Breathing Lessons” may not be Tyler’s best book; it is not a comparison I am easy with. The flashbacks sometimes slow down her matchless way with the present tense. The softness is sometimes too noticeable.

On the other hand, it may be her funniest book. Maggie’s extraordinary encounter with an old black motorist whose flamboyant disassociations outbid her own is one of the funniest sustained sequences of contemporary writing that I can think of. And there are moments when the struggle among Maggie, Ira, and the melancholy of time passing forms a fiery triangle more powerful and moving, I think, than anything she has done.