The publication of a second volume of Sinclair Lewis’s 1920s novels by the Library of America may help to rescue the reputation of an author whose work is no longer taken seriously. Three decades ago, students of 20th-century American literature still read Lewis’s Babbitt along with Fitzgerald’s The Great Gatsby, Hemingway’s The Sun Also Rises, and Faulkner’s The Sound and the Fury as a kind of collective primer. But then Lewis’s writing fell out of favor, probably because the vernacular he replicates with such humor and precision — the language of boosterism, of the endlessly peppy go-getters of the automobile age — now sounds as foreign to our ears as, say, the nursery moralities of an Edwardian children’s story.

That’s a pity, because the quintet of novels Lewis turned out in this amazing decade — Main Street and Babbitt, which appear in the first volume, and Arrowsmith, Elmer Gantry, and Dodsworth, which make up the new one — are entirely remarkable. They present a commentary on social life in the first quarter of the American century that, in its wit and incisiveness, recalls Thackeray, Sheridan, and Twain. Lewis’s territory, as distinctive as Faulkner’s Yoknapatawpha County, is the prairie state of Winnemac, whose major metropolis is Zenith. Zenith is where Martin Arrowsmith, fresh out of medical school and newly married to Leora Tozer, sets up his initial practice. The charismatic preacher Elmer Gantry presides over his first big congregation there, and it’s the city where Sam Dodsworth makes his millions in the auto industry — the city he and his wife, Fran, their children grown, leave behind for Europe, setting out to create an adventurous new life for themselves. Lewis’s Midwest is a bastion of Yankee pride and Puritan rigidity. The men who preside over its cities and towns, with their scrubbed, bustling surfaces, are delighted to think of themselves as civilization’s most glorious exemplars, up-to-date yet still rough-hewn, preservers of an open-hearted, pioneer Christianity. What they are in truth is a society of vulgarian snobs and vicious conformists.

Lewis’s great subject is the struggle for authenticity in the face of conformity and hypocrisy. And for all the comedy he produces at the expense of Dickensian cheermongers and self-promoters like Doc Pickerbaugh, the jingle-spouting Health Department director ( " Boil the milk bottles or by gum/You better buy your ticket to Kingdom Come " ) who is Arrowsmith’s first boss, Lewis never makes the mistake either of underestimating the power and appeal of conformity or of simplifying the struggle to find a little independence of mind and spirit. In Elmer Gantry, his study of religious charlatanism, he explains how the title character, a broad-shouldered young lug " who would have been so happy in the prize-ring, the fish-market, or the stock exchange " but whose mother’s Christian fervor has sent him " poking through the cobwebbed corridors " of a local Bible college, winds up preaching a gospel he never really believes in:

They stood for the singing of " Shall We Gather at the River? " Elmer inarticulately began to feel his community with these humble, aspiring people — his own prairie tribe: this gaunt carpenter, a good fellow, full of friendly greetings; this farm-wife, so courageous, channeled by pioneer labor; this classmate, an admirable basket-ball player, yet now chanting beatifically, his head back, his eyes closed, his voice ringing. Elmer’s own people. Could he be a traitor to them, could he resist the current of their united belief and longing?

Elmer succumbs. So, intermittently, does Martin Arrowsmith, who has the blood of a true scientist in his veins. Leora, who represents his finest impulses, sizes him up:

You’re not a booster. You’re a lie-hunter. Funny, you’d think to hear about these lie-hunters, like [Martin’s most inspiring medical-school teacher] Professor Gottlieb and your old Voltaire, they couldn’t be fooled. But maybe they were like you: always trying to get away from the tiresome truth, always hoping to settle down and be rich, always selling their souls to the devil and then going and double-crossing the poor devil.

Arrowsmith and Elmer Gantry are very different books, because for Gantry capitulation comes quickly and completely. His story is an explication of American religious hypocrisy, and Gantry, whose sexual vibrancy and gift for salesmanship turn out to be the ideal tools for a successful — if utterly fraudulent — ministry, is a genuine American type no one before Lewis had ever put on the page. (That’s equally true, I’d say, of George Babbitt and Sam Dodsworth.) Eugene O’Neill adapted him for Theodore Hickey, the antihero of his great play The Iceman Cometh, though in O’Neill’s version he exhibits a self-awareness Elmer is incapable of. In the most fascinating scenes in Elmer Gantry, Lewis juxtaposes him with Sister Sharon Falconer, a popular evangelist for whom he goes to work and with whom he falls in love. Sharon is an even more powerful religious drummer than Gantry because she believes her own tripe. " I can’t sin! I am above sin! " she insists. " Whatever I may choose to do, though it might be sin in one unsanctified, with me God will turn it to his glory. " The " incalculable " Sharon — " sometimes ... a priestess and a looming disaster, sometimes ... intimidating in grasping passion, sometimes ... thin and writhing and anguished with chagrined doubt of herself, sometimes ... pale and nun-like and still " — strides to her death in a burning tabernacle, confident that God will save her. Gantry fights his way out of the flames. He’s a survivor; even a newspaper exposé of his adulteries is powerless to damage his career. (Lewis miscalculates by killing off Sharon in the middle of the novel; it never recovers from the loss of its protagonist’s most mysterious and challenging relationship.)

Of the three novels in this collection, Elmer Gantry is the most unorthodox, Arrowsmith the most traditional — a deeply satisfying bildungsroman about a young man who discovers his calling in the lonely, candle-burning laboratory and his ethic in opposition to everything that practical experience, and the self-interested self-made men he keeps running into, teach him. Lewis is no idealistic fool: when Max Gottlieb, the European-born scientist whose ruthless empiricism becomes Martin’s creed, has the chance to take over a research foundation, his single-mindedness turns it into a shambles. Martin places his work before everything else in his life, a position that Leora accepts but that drives his second wife, Joyce, away from him. He arrives at a Gottlieb-tutored insistence on pursuing a course of scientific study to its end despite the temptation to publish his findings early, but the journey is a tortured one: on a plague-ridden Caribbean island, he has to choose between employing his research to end the suffering before his eyes and waiting until it’s ready to be of some enduring use to humanity. At the end of the book, he’s located a comfortable home for himself within the four laboratory walls he keeps smashing up against. " I feel as if I were really beginning to work now, " he tells his colleague and kindred spirit, Terry Wickett. " We’ll plug along ... for two or three years, and maybe we’ll get something permanent — and probably we’ll fail! " The exclamation point that closes the narrative denotes good-humored resignation.

Dodsworth is the only novel Lewis wrote in the ’20s that’s set almost entirely outside America. As a piece of social commentary on the subject of Yankee Europhilia, it’s comparable to Twain’s The Innocents Abroad or James’s The American, but its focus is, unexpectedly, the disintegration of a marriage. In Sam and Fran Dodsworth, Lewis displays two attitudes toward travel that turn out to reveal an essential incompatibility. Fran, a fresh-looking 41, wants to find the cultivated youth she feels she threw away when she married Sam and buried herself in Zenith; she tries to deny the last 20 years of her life and remake herself as a continental. In their most rancorous exchanges, she scoffs mercilessly at her husband’s provincialism:

Oh, you’re like all the other American men! You speak no known language. You don’t know Rodin from Mozart. You have no idea whether France or England controls Syria.... But these are just symptoms!... The thing is that you haven’t the mistiest notion of what European civilization is, basically — of how the tradition of leisure, honor, gallantry, inherent cultivation, differs from American materialism. And you don’t want to learn.

But she’s as wrong about him as she is about herself. Nearly a decade her senior, Sam is content with himself, but his zeal for embarking on new experiences is undiminished by his financial success. He’s Lewis’s most moving portrait of American authenticity — the other end of the spectrum from Elmer Gantry. In this beautiful, bittersweet novel, the voice of pretension and self-delusion issues from the person Sam loves most in the world. By the time the Dodsworths set off for Europe, it’s already too late for them, but neither of them knows it. Lewis sets a domestic tragedy inside a comedy of manners — just as James, and Lewis’s underrated contemporary Booth Tarkington, did so well. It’s a glittering achievement.