Shaky Hold on Verities of the Middle Class : PLAN B FOR THE MIDDLE CLASS<i> by Ron Carlson</i> ; W. W. Norton $19.95; 208 pages

As you might lean out an attic window at an exaggerated angle to check your roof’s soundness--somebody is holding your feet--Ron Carlson uses touches of fantasy that get agreeably out of hand for a better view of the virtues and verities of his middle class. Most of the time someone is holding his feet, yet the grip is disturbingly shaky.

Sometimes the fantasy comes down on the reassuring side. In Carlson’s short story “Sunny Billy Day,” a baseball player is unstoppable; not because he bats well, but because his charm gets umpires to call his strikes balls, his fouls fair and his base-running invariably safe. This sickens everyone, including the player himself; at a crucial World Series moment, he charms the umpire into calling him out and promptly goes off to live in the South Seas.

The piece falls a little frail and flat; sharper and more ambiguous is “On the U.S.S. Fortitude.” A mother frets philosophically about her children getting home late for supper, leaving their stuff scattered around and being rude when she helps them, and about her difficulty in keeping the place clean.

But the place is an aircraft carrier, the children are out flying jet fighters with their playmates, and when they do get home, they grumble about having to put their planes away. It’s hard to keep the flight deck neat; a neighbor, who stops by on her own aircraft carrier, gives her a tip about removing unsightly skid marks.

It’s a comically extravagant displacement; its effect is more playful than absurdist. In an ambiguous way, it seems to affirm American family values, yet where are the fathers? And is our safe suburban world perhaps as alien as the China Sea, a tidy house as dehumanized as an aircraft carrier? Are our children adrift, in fact, at stratospheric altitudes and supersonic speeds?

Several of the pieces are brief spoofs. One, about subliminal advertising, is pretty much of a dud. Another blithely re-creates what went on at the Last Supper by means of a scientific examination of the stains on the table cloth. Judas was nervous; there are bits of disgorged food at his place setting. California Red was served (“A full-bodied red”), the narrator claims. Does this mean it’s a fake? No, he argues solemnly: “It simply means that civilization in California is older than some people now think.”

Other pieces in “Plan B for the Middle Class” are more fully developed. “Hartwell” is about a scholarly and abstracted professor of Victorian literature who makes a fool of himself over a seductive student. It is almost surprisingly predictable, but it is enlivened by Carlson’s comments.

In his bookworm state, Hartwell stays in his room, living on “a steady diet of the kind of food eaten with ease while reading, primarily candy.” In love, he spiffs up his wardrobe and loses weight, “the way men do when they spend the energy necessary to become fools.”

Hartwell gets his appropriate if pathetic comeuppance. There is another appropriate, if more cheerful affirming of verities--a kind of tribute to married love--in the title story. Carlson makes it a mix of balances lost and balances found. With something close to the inspired, he uses sexual desire as an image for--of all things--true love.

Lew, the protagonist, is a man on the edge. He has lost his job as a columnist, he is tormented by a skin rash, and his two small children’s omnipresence makes it impossible for him to have wild and protracted sex with his willing wife, Katie. Harry, not quite 3, roams the house naked with a pair of binoculars and invariably turns up in the doorway when Lew and Katie are trying to lie down.

On a plane to Hawaii--the couple has arranged a four-day escape with grandparents as baby sitters--Lew imagines their house that night. “Harry is going to pad west in his bare feet, looking for us with his glasses, but the surf is going to stop him. He’ll be mad for a moment at the Pacific Ocean. . . . But then he’ll turn and go back to his room.”

That is close to sublime. The rest of the story--Harry draws on memories of his first sexual observation of his parents and of the strong sexual bond that underlay his parents’ happiness--is simply very good.

In a darker story, comically mordant, a husband invests all his money in his brother-in-law’s golf course, only to find it is built over a landfill. Fumes and sharp bits of metal work their way up through the grass. Financial salvation, of a sort, is achieved when customers pay $5 each to prospect for scrap.

Carlson’s stories sometimes fall short of the ingenious turns and phrases he develops them with. Under a shrewd condimenting, some are bland or cursory. At their best, though, they tilt the world just enough to give us a sense of how much we need it to stand upright.