Minimalist at Mid-Life : NATURAL SELECTION <i> by Frederick Barthelme (Viking: $18.95; 208 pp.)</i>

Our minimalist fiction writers, chroniclers of the young urban and suburban middle classes, use deflection to write of their fears and passions. Often ingeniously--some of our best writers are minimalists--they suggest the emotions by muting them: heat by coolness; outcry by silence. It is the silence of Sherlock Holmes’ celebrated dog that does not bark.

What would a minimalist dog sound like if it did bark? Frederick Barthelme, whose collection of short stories, “Moon Deluxe,” was a nearly perfect minimalist work, has made a fascinating and often moving attempt to find out.

“Natural Selection” is rich in the oblique ironies and the broken-field talking and thinking that we have come to expect of Barthelme, Ann Beattie, Mary Robison, the late Raymond Carver and so many others, but there is a rupture right down the middle. The skin of control is broken. Awkwardly--Barthelme himself can be awkward attempting it--his characters are turned to stare their anguish in the face instead of in smoked and angled mirrors.

A dozen years ago, Peter and Lily were singles. They lived outside Houston in rented poolside apartments with shag rugs and flimsy plasterboard ceilings. They drove to malls and fern bars and went at 11 p.m. for waffles or beer. Now they are married, have good jobs, an 11-year-old son, Charles--as knowing and rueful-witty as his parents--and a suburban house.

It is a tract house, with barbecue, garden shed and wood deck. But as Peter, the narrator, tells us: “The yard has worn patches you recognize. . . . And the deck looks as old as you are, you don’t mind sitting on it.”

It is, right at the start, one of those seeded sentences that hint at the transition the book is set in, and the transformations that lie ahead. Minimalist couple glimpse middle-age, and beyond that, growing old and dying.

There are no minimalist deaths; they are all the same size. The recognition and acceptance of time passing requires a wrenching alteration of the language we use for our lives. “Natural Selection” is about Peter’s painful struggle to learn that alteration.

The book takes place in Peter’s early mid-life crisis, with excursions into the past when life and love were easily taken on, and disposed of. Peter is restless, bored, rebellious. Lily and Charles are too precious to be disposed of; realizing this, he realizes he cannot dispose of himself; he feels imprisoned and desperate.

The desperation sways in a balance of acute detail and comedy that sometimes recalls Updike in his suburban period, and sometimes, when Peter’s comic soliloquy goes wild, Peter De Vries. The narrator jokes blackly with Lily and Charles and they gamely joke back, but something serious is going on.

The husband and father keeps up a litany of gallows-humor rant about the state of the world and the foolishnesses and conformities of American living. When a man does that, at some point his wife and child will get a different message: Are you angry at us? Fed up? Leaving?

Peter, in fact, is on the borderline of a breakdown, signaled when his intellectual rough-and-tumble with Charles edges past joking into a moment or two of real cruelty. He is not a cruel man; he is a decent man riding on the edge of trouble.

He moves tentatively out of the house, returning every day. To have taken that bit of action clarifies things for him; he is freer to own attachment to his life and to his family. He moves back, not quite as tentatively as he moved out; he may be OK. And then life, perhaps fed up with being learned so tardily and for such low, easy tuition, takes a tragic swipe at him.

It is tempting to spell out the tragedy. It would allow me to give an idea of the distance Barthelme is covering in his own evolution. I will only say that the last 20 pages of this brief but spacious book contain a tautly building horror, followed by a cry of despair and regret as powerful as it is astonishing.

I have stressed theme and form at the expense of detail; if Barthelme is breaking his own new ground with the first two, he is on beautifully cultivated home ground with the last.

Peter’s and Lily’s first date, in flashback, is a comical minimalist tour de force. Each pokes a tentative turtle head out of a protective shell; each says zingy things and apologizes for them. He suggests a movie: “I probably can’t be boring in a movie.” She hates people who say they’re boring, she tells him, and soon she is floundering too. “I do this. I need a verbal skill. Just one. Jesus.”

Somehow they get to his apartment; she has cleverly arranged for each to take a car so it will work out. Somehow they not only have sex but, without quite admitting it, they make love. The moment of truth comes in the morning when she has carefully arranged breakfast and is self-conscious about it.

“It was delicious,” he says. Turtle head retracts: Has he sounded patronizing? “I mean, I meant it was delicious but I didn’t mean the other part--you know what I’m talking about?” “The repellent part?” she asks. He knows they must grow old together.

That is no ending, of course, but a beginning; and it is the battle to grow old that Peter is fighting with himself 10 years later. Barthelme’s comedy of detail rarely wavers, but it goes deep until, without apparent transition, we are touched.

He manages to suggest, subtly but without deflections, the pain that Peter’s life-crisis is causing. His portrait of the 10-year-old Charles gamely trying to play along with his father’s moods while keeping his own independence are funny and moving. Even more remarkable is what he does with Lily.

Wonderfully well-voiced, she is fighting not altogether consciously to bring Peter into life. She will try anything: irony, sympathy, argument. She will even become him; at one point, she takes up his angry commentary on the state of the world and out-despairs him.

She will even dream for him; it is one of the best fictional dreams in a long time. It is a gathering of philosophers who argue by changing their pants. One dons a green pair; another studies it, reflects, and counters by putting on plaid. It is a rejoinder to Peter’s despairing vision of entropy. Lily’s vision: “The possibility of good fortune.”

Not quite everything works. The last 20 pages are breathtaking, but it is not quite the same breath we have been breathing up to then. Thematically, the shift is justified, but fictionally, though not unprepared, it makes the gears complain.

The main difficulty occurs, now and then, with Peter. His reflections about the state of the world and his own state represent, of course, the minimalist’s breakthrough. He is confronting, not evading. But these soliloquies are exceedingly rounded and complete. They can suggest Layman’s Sunday in church. The sermon, worked on so hard, is more brilliant than the minister’s own average effort, but it fights the occasion a little.

Barthelme’s battle with his own literary occasion has these roughnesses. No battle is ever tidy. Some, such as this one, are supremely worthwhile.