<i> Paradise</i> by Donald Barthelme (Putnam’s: $16.95; 208 pp.)

The messages of modern life undermine life. The feedback is poisoned. Something has convinced the elephant that it can race like a gazelle; the gazelle that it can destroy leopards with its teeth; the camel that its natural habitat is the icy waters off Maine.

Donald Barthelme floats his protagonist along in a stream of reassuring messages, even as his life stands uprooted and perhaps destroyed. “Paradise” is a kind of dream where everything is seen naturally and logically. An apparent normality is tilted by absurdities which, because they seem normal, have actually declared the normal to be absurd.

Simon is a successful architect who has lived, we believe--Barthelme delivers his data in the form of unreliable clues--a comfortable life in Philadelphia with his wife, daughter and plenty of esteem. There may have been affairs; there have certainly been other troubles, and now the marriage has broken up.

Simon has moved to New York; his wife is suing him for everything he has; his daughter communicates by phone but keeps away. He has an apartment, a little work sent him by his Philadelphia associates, and, at age 53, he goes to single bars and practices mild swinging.

These are the kinds of moves recommended by a society that endorses personal freedom and fulfillment, making your life over, and becoming what you think you would like to become. Simon goes through the moves; but in fact, he is going through something between a profound depression and an outright breakdown.

You will not read this, specifically, in “Paradise.” It is to be gathered, perhaps approximately. Because what Barthelme gives us is not these particulars, but a kind of detached and drifting fantasy, in which every detail is absolutely solid and convincing, and quite unreal.

It could be, of course, that Simon really does meet three young models from Denver in a bar where they are demonstrating lingerie. It could be that they are broke and ask to move in with him, and he agrees. It could be that, having no real education or prospects, nothing, in fact, but good looks and heads full of fashionable notions and appetites, they stay on.

It could also be that this middle-aged man becomes a combined den-mother and domestic sex object to these gorgeous and insecure creatures. “Paradise,” as the title has it. “Hog-heaven,” as Dore, Veronica and Anne frequently tell him he’s in. Carefree sex, gourmet cooking and spacey talk; what else does the combined message of television, life-style sections, glitzy magazines and expensive advertising propose to us?

The tale of Simon and the three Bloomingdale’s houris who arrive, stay eight months, and leave with casual mutual regret--”Bye, guys,” he says--is funny, matter of fact and exact in every surface detail.

Yet Barthelme’s perfect numbers add up to hallucination. The sleeper is unwell, and his depression invades his buoyant dreaming with inexplicable messages. Everyone talks exactly right but in disconnected snatches, like something overheard on a bus.

Simon looks out of a window at 6 a.m., and two men are beating up a black policewoman. He looks out of another window, also at 6 a.m., and a naked couple are making love on the patio next door. At lunch in a restaurant, an armless man is seen drinking a cocktail with his toes. When Simon, momentarily unfaithful to his harem, goes to meet a woman poet at the airport, he presents her with a raw steak. In his last days in Philadelphia, someone puts a pipe bomb under his car. He dreams that a leper pursues him, spitting into his mouth.

Life inside the harem is vague, removed. Often, Simon hears his three visitors discuss him dispassionately, as if he were extra-planetary. They worry about his potency; should they put on a porn show for him? They speculate about his weight, his flabbiness, his temper.

“What are we going to do about this bozo,” one of them wants to know. “What’s to do?” another rejoins. “He hasn’t hurt anything.” “Yet,” says the third; and the voices jumble together; “He’s been very circumspect.” “I think too circumspect.” “I think he thinks he’s doing the right thing.” “I don’t think he’s a nut.” When Gulliver came groggily awake after being washed ashore, this was the way he heard the Lilliputians talking.

Everyone in Barthelme’s world moves like graceful shadows. They have lost their reality somehow; illusion has imperceptibly swindled them of it. Dore, Veronica and Anne are waifs in Guccis; they know nothing, can do nothing, and have no prospects. They talk about going to Harvard, about joining a fashion house in Paris, about studying music, about getting a job at Burger King, as if these things were all equally real or unreal. As with the television screen, occupied for equal time by a deodorant ad and an African famine, their minds democratically consist of 90-second segments.

Simon, with greater advantages and talents, has let his life be segmented too. He is the intellectual, not so much sold out as time-shared. He is uneasy, but all the uneasiness accomplishes is to get him to sessions with a doctor who pushes bowls of tranquilizers at him, and tells of his own bad dreams. “Paradise” is agile, witty and lightened by Barthelme’s canny disassociations, and it is one of the blackest things he has written.