If America had a Novelist laureate, it would probably be John Updike. That’s not, of course, unadulterated praise. Poets Laureate are usually not the best poets of their time. Whatever their other talents, they ‘re usually chosen for being graceful, agreeable, eloquent, sage. They tell the nation as much of the truth about itself as the nation is ready to hear, and they do it in the native idiom. Clearly Mailer is too fiercely physical for that role; Bellow too philosophical; Pyncheon too fantastical; Roth too farcical. They’re all either too cosmopolitan or too earnest or too intellectual. But Updike is just the right balance of stimulating and unthreatening, and as familiarly American as high-school basketball or suburban adultery.

Still, limits do not only limit; they also liberate. Updike has concentrates on domestic life in mid-century middle America, mostly among the middle and lower-middle classes. This narrowness of focus has allowed him to map his chosen territory in exquisite detail. For some artistic temperaments familiarity breeds not contempt but a more intense, almost mystical appreciation. The mid-Atlantic region and suburban New England, the settings of nearly all his major novels, are appropriated, so thoroughly and intimately that they sometimes seem to be suffused with hints of something beyond, with gleans of pathos, heroism, or even (in the case of his loveliest novel, The Centaur) myth. More than any of his contemporaries, Updike is the lyricist of the American commonplace.

Roger’s Version is a departure for Updike, in a couple of ways. For one thing, it has an academic setting (not identified by name but, in fact, Cambridge). More important, it is a novel of ideas. Updike is a superb literary critic, and his gift for metaphor is itself a species of intelligence. But ideas have never played a prominent role in his fiction. The theological banter in A Month of Sundays is mainly for characterization and comic relief; The Witches of Eastwick, which is about witchcraft as feminism, is an elaborate joke, a jeu d’esprit. But in Roger’s Version ideas-- extended arguments, even-- are at center stage.

Roger Lambert is a middle-aged divinity school professor, ensconced in the comfortable indefiniteness of liberal Protestantism. Into his office strides a raw young evangelical computer programmer from the Midwest, Dale Kohler, bringing two unwelcome messages. Roger’s 19-year-old niece, Verna, has moved into the area with her illegitimate child; and Dale has hit on a scientific proof of the existence of God. Moreover, Dale wants Roger’s help in getting a grant to finance his research. So much fervor and energy have a depressing effect on the blasé Roger. But he listens; and the subsequent relations, sexual and intellectual, among Roger, Verna, Dale, and Roger’s wife Esther, make up the novel’s plot.

There’s a lot of fun to be had with this situation, and Updike makes the most of it: the professor of religion aghast that something about God may actually be demonstrable; the callow computer programmer who divides the Bohr atomic radius by the Hubble cosmological radius and is thunderstruck at the result -- 666, the number of the Beast in the Book of Apocalypse; mental soliloquies, laced with Latin, on the early Christian writers Tertullian and Marcion that segue into visions of unholy ecstasy:

"Weary of translating, I closed my eyes. I pictured a white shaft: tense, pure, with dim blue broad veins and darker thinner purple ones and a pink-mauve head like the head of a mushroom set by the Creator upon a swollen stem nearly as thick as itself, just the merest little lip or rounded eaves, the corona glandis overhanging the bluish stretched semi-epiderm where pagan foreskin once was, and a drop of transparent nectar in the little wide-awake slit of an eye at its velvety suffused tip. Esther’s studious rapt face descends, huge as in a notion picture, to drink the bitter nectar and then to slide her lips as far down the shaft as they will go, again and again, down past the corpus spongiosum to the magnificent twin corpora cavernosa in their sheath of fibrous tissue and silk-smooth membrane, their areolar spaces flooded and stuffed stiff by lust…"

There is another, allegorical layer of fun. Roger’s Version loosely parallels The Scarlet Letter an ardent young preacher (Dale/Dimmesdale) commits adultery with the sensuous wife (Esther/Hester) of a sour, cynical older man (Roger Lambert/Roger Chillingsworth), who in turn gradually undermines the younger man’s spirits. The joke is that this time around we’re getting Roger’s version. We see how grating naive piety can be, especially on someone who’s made his peace with the world and the flesh, who knows that virtue is a straw to the fire in the blood.

And for Boston-Cambridge readers, there are still other pleasures, incidental but considerable. As Roger Lambert shuffles through the novel, Updike limns Brattle Street, Central Square, and Cambridgeport in his usual languidly witty, uncannily vivid way. There’s a sentence about the subway ride from Kendall to Charles that begins underground and ascends to the sun, and is almost long enough and full enough to make the passage seem leisurely:

"Lifted up suddenly out of a subway tunnel on one of the bridges -- an old bridge, say, of sandstone hacked into big rough blocks and set there as if by a race of Titans, with buttresses and quaint conical towers and floriate lamp standards -- the metropolitan transit passengers wince at the splendor of the sudden view, of the hotels and emporia of glass and anodized metal which glitter at the city’s commercial center, of the roseate and powder-blue skyscrapers of the financial district that hovers above the brick silhouette of the old residential neighborhoods built on rubble-filled marsh a century ago, of the recently condominiumized warehouses and deserted churches, of the ribbon of Olmstead park along the riverbank and the bandshell and planetarium and the rented sailboats tilting on the river’s sparkling plane, all these man-created wonders thrown into brilliant visibility by the impressive slant of our local star, the sun."

But there are arguments in Roger’s Version too, and earnest ones. Dale is convinced that a number of physical coincidences and improbabilities, individually striking and collectively mind-boggling, rule out randomness as a cosmological principle. For example: if the mass of the neutrino were different by a factor of only one in five hundred, there would be no atoms and the universe would consist entirely of elementary particles. Two apparently unrelated magnitudes, the energy density of the universe at the time of the Big Bang and its expansion rate, had to be equal to within one part in ten to the fifty-fifth power, i.e., ten followed by fifty-five zeros, or the universe would have collapsed back into a point mass aeons ago. The probability that life evolved spontaneously from the primordial chemical “soup” was recently estimated by a distinguished physicist at one in ten to the forty thousandth. Few readers (certainly not this one) will have any idea whether these “facts” are accurate, or as significant as Dale claims. But despite his breathlessness and occasional lapses into crude numerology, he does manage to suggest plausibly that there are more things in heaven and earth than are dreamt of in Roger ‘s modern, secularized Protestantism.

In the end Dale is refuted, partly by a scientific colleague of Roger’s, but mainly by what one might think of as Updike’s reality principle: the primacy of the libido. Over the course of a sizzling affair with Esther, Dale’s focus blurs and his certainty falters; he desublimates. This concession to the flesh makes him more sympathetic, more human, but also less interesting. As an arrogant evangelical know-it-all, Dale had a certain piquancy, even a perverse charm. But magnificent obsessions don’t thrive in the worldly, cozy atmosphere of Updike’s fiction; they’re undercut by his ubiquitous mild irony.

For all the high-voltage philosophizing in Roger’s Version, it is this irony -- ostensibly Roger’s, since he’s the narrator, but recognizably Updike’s-- that poses the book’s most intriguing problem. It lends even to this, Updike’s most intellectual novel, an anti-intellectual flavor. Not that he hasn’t been conscientious about assimilating and reproducing the scientific terms and concepts he deploys. And he’s clearly fascinated by the questions they suggest. But within the novel, those questions never come to seem urgent or threatening; his tone defuses them. Whatever Updike may feel, on pretty much any subject, by now he can’t help sounding equable, judicious, slightly amused. Detachment is an indispensable virtue for a novelist, especially a comic novelist. But it’s overdone here; Updike seems finally, detached.

Near the close of the novel, Roger Lambert is brooding gloomily. He uses a phrase that may go some way toward explaining why Updike wrote Roger’s Version and, at the sane time, why it feels a bit bloodless. Roger refers to “our Godless freedoms that become, with daily use, so oddly trivial.” This remark immediately brings to mind another, a well-known adage about the literature of contemporary Eastern Europe: “In the West, everything goes and nothing matters; in the East, nothing goes and everything matters.” It is difficult to imagine a more civilized, tolerant, humane sensibility than Updike’s, which surely has much to do with his having been steeped in an exceptionally rich, free society during its long golden age. But this achievement provokes some troubling questions. What if the price of Updike’s marvelous, inexhaustible irony is weightlessness? What if the fruit of our indubitably precious freed is a certain moral and aesthetic lightness of being? What if the absence of illusions, religious or political, entails in the long run an absence of intellectual passion? Updike has long been one of America’s foremost fictional wizards. But in Roger’s Version, the literary equivalent of the law of gravity catches up with him.