t The New Yorker in the mid-1970's, it was still possible to hear editors debating which of the magazine's illustrious contributors had been the bigger jerk and the more impossible to deal with -- James Thurber or John O'Hara. Thurber usually won -- no small feat considering that O'Hara (when he was sober) was famously boorish, vain, petty, snobbish, quarrelsome and just plain hard to take. When he was drunk (which was often), he was apt to punch you out just for looking at him the wrong way -- even if you were a woman or, as on one memorable occasion at ''21,'' a midget. Yet history has chosen to forgive Thurber, an even nastier drunk, and he is now permanently enshrined as a lovable American original. In O'Hara's case, the taint of his personality somehow seeped into the way his books were received (the process of conflating the two was begun by the moralizing Orville Prescott, writing in this newspaper in the 1940's), and his literary reputation has suffered as a result. Fran Lebowitz once remarked that O'Hara was ''an underrated writer because every single person who knew him hated him.'' That's a stretch, obviously, but O'Hara was without a doubt his own worst enemy, with a genius, as the title of Geoffrey Wolff's fine new biography suggests, for burning his bridges behind him.

In a preface, Wolff writes that he began the book because he believed that O'Hara resembled his own father, the con man about whom he wrote so memorably in ''The Duke of Deception.'' (Wolff is also the author of several novels and of a biography of Harry and Caresse Crosby.) In fact, as he quickly discovered, Duke Wolff and John O'Hara couldn't have been more different; about all they had in common was the habit of cadging matchbooks or stationery from the Racquet Club, so that they could pretend to membership. Even so, Wolff persisted with the book, out of an impulse, he suggests, to redeem O'Hara both as a writer and as a human being.

The result is a biography that is both satisfying and pleasingly unconventional, and one that O'Hara would probably have hated. He would have wanted the full scholarly treatment, like Matthew J. Bruccoli's 1975 data dump, ''The O'Hara Concern.'' But ''The Art of Burning Bridges'' is from beginning to end not a scholar's book but one by a fellow writer: it's conversational and opinionated -- even autobiographical at times, with Wolff recounting his own experiences with rejection (''that particular pain, a stab of shame that something tended and tendered has been repulsed''), with editors and editing, with the indignities of writing for Hollywood. Sometimes Wolff relies on hunches instead of looking things up, and at a couple of moments he simply throws up his hands. Why did so many people find it pleasing to be in O'Hara's company? he asks. That's ''the major mystery'' of O'Hara's personality, and remains ''unexplained.'' At another point, he says in exasperation, ''Sometimes I just can't like this man.''

Yet the picture he paints of O'Hara is a frequently endearing one, suggesting the doubts and anxieties behind the abrasiveness. O'Hara is so needy and so transparent in his snobbery and social climbing -- with his Rolls and his tweeds, his collection of club ties and rosettes (many from clubs he didn't belong to) -- that you can't help forgiving him. And Wolff reminds us that in his later years O'Hara mellowed considerably. His second and third marriages -- to Belle Wylie, with whom he had a daughter, Wylie, and, after Belle died, to her friend Katharine Barnes (known as Sister) -- were extremely happy ones. Wealthy and more or less contented, O'Hara settled into a life of uxorious country squiredom, first in Quogue, on Long Island, and then in Princeton. He gave up drinking, on doctor's orders, and became so serene, Wolff gently proposes, that it was actually bad for his work. Like a lot of writers, O'Hara wrote best when he had something to prove.

O'Hara had three great themes: class, sex and drinking. The last two he taught himself; the first was his birthright. He was born in 1905 in Pottsville, Pa., the eldest of eight children in a prosperous and prominent local family. His father, Patrick, was a hot-tempered but accomplished physician, legendary for his skill at skull surgery. The O'Haras lived on Mahantongo Street, the town's fanciest address, in a mansion that formerly belonged to the Yuengling brewing family; they owned five automobiles, a show farm and a string of horses; they were members of the Pottsville Club and the Schuylkill Country Club. Yet they were Irish and they were Catholic, and this -- in O'Hara's mind, anyway -- meant that they never quite belonged. He grew up with an acute awareness of all the tiny indicators of rank in the social hierarchy -- the clothes, the slang, the fraternity pins and handshakes -- and he studied them the way the Duc de Saint-Simon studied the wigs and the chair placement at the court of the Sun King. He also grew up with that most precious of writerly gifts: a sense of place. He learned every inch of Pottsville and the surrounding coal country and eventually recreated it, lovingly and fastidiously, in his fictional Gibbsville -- a miniature world as complete as Yoknapatawpha, only without the mythologizing.

What Princeton was for Fitzgerald, Yale was for the young O'Hara -- the magical, beckoning realm where he believed he would finally come into his own. But he was a wretched student, bouncing from one second-rate prep school to another until, in 1925, his father died intestate and left the family virtually penniless. O'Hara reluctantly gave up his dreams of New Haven -- he saw no point in going unless he could go in the proper style -- and for the rest of his life he fantasized about which Yale clubs he might have belonged to, which secret society would have tapped him; amazingly, as late as 1935, when he had already published three books, he was still talking about enrolling as a Yale pre-med.

In fact, his non-matriculation probably saved him from becoming a truly insufferable snob (and not just a yearning wannabe). Instead of Yale, he got one of those classic, rough-and-tumble educations that have been the making of so many American writers. He was variously a railroad worker, a waiter on an ocean liner, a P.R. man, a hotel night clerk and, most crucially, a newspaper reporter, first in Pennsylvania and then in New York, where he worked for The Herald Tribune and The Daily Mirror. In many ways O'Hara was a terrible newspaperman -- he was always getting fired for being hung over or for disappearing on benders -- but the job taught him a reporter's reverence for facts. ''He had a feral appetite to know things, especially secrets,'' Wolff says, and in time an exactness of detail and preciseness of reference became one of the hallmarks of his writing, together with an acute ear for dialogue and a style so plain and so clear that it sometimes seemed like no style at all.

In 1928, while working at The Trib, he sold his first piece -- a ''casual,'' or humorous sketch -- to the then fledgling New Yorker, and thus began an association with the magazine that lasted almost 40 years. It was a vexed relationship on both sides, even though O'Hara, like Thurber, E. B. White, Wolcott Gibbs and Dorothy Parker, quickly became one of the magazine's big drawing cards. Harold Ross, the founder of The New Yorker, couldn't stand O'Hara personally, and published his work only grudgingly. Katharine White, the fiction editor, understood the value and importance of O'Hara's writing, but lectured and condescended to him. It wasn't until O'Hara began to work with William Maxwell in the late 30's that he finally had a New Yorker editor who loved and appreciated him, and by then it was too late. Out of defensiveness and self-importance, O'Hara had already cultivated the habits -- the lofty and imperious letters, the refusal to rewrite, the stubbornness about changing even a single mark of punctuation -- that made him so difficult to deal with.

Most of O'Hara's really bad behavior stemmed from drinking, and he wasn't alone. He belonged to that hard-living generation of American writers (especially well represented on the the New Yorker staff) for whom drinking meant not just a few cocktails after work; it meant disappearing for two or three days at a time and waking up with no recollection of what you had done and said. Reading Wolff's account of those long, woozy evenings at Bleeck's or ''21,'' you sometimes wonder how any writing got done at all. But for O'Hara, alcohol was also an essential part of what he wrote about: it's the volatile fuel that propels many of his novels, especially the first two, ''Appointment in Samarra'' and ''Butterfield 8.'' In those books, both of which are set during Prohibition, booze is, first of all, a dangerous solvent eating away at the very foundations of the social order -- because to be a drinker, no matter how proper you were, was by definition to be a lawbreaker, forced to associate with bootleggers or frequent speak-easies. Even the seemingly innocent mixing of a country club cocktail brought with it the faint whiff of corruption. For certain doomed characters, moreover -- people like the self-destructive Julian English in ''Appointment,'' and Weston Liggett, the bored stockbroker in ''Butterfield'' -- a drink (or five or six) is like the potion that turns Jekyll into Hyde; it literally transforms you, bit by bit revealing the monster lurking inside, from whom friends and family flinch and turn away.

Drink, even in moderation, also makes O'Hara's people libidinous. ''Appointment'' was a scandalously sexy book when it first came out, in 1934, and even today it has a surprising raciness, as when Julian recalls the sound his wife, the well-bred Caroline, makes during orgasm: ''He knew, and not another human being knew, that she cried 'I' or 'high' in moments of great ecstasy.'' Even more remarkable is the novel's opening, when Luther Fliegler, the story's Everyman character, and his wife make love, while slightly hung over, on Christmas morning. This is, I'm pretty sure, the first explicit sex scene between a married couple in all of American literature. Before O'Hara nice girls didn't have sex -- not in polite fiction -- and even married ones weren't supposed to like it. His great revelation -- though it seems obvious now -- was that women are sexual creatures every bit as much as men. In some of his later novels he took this notion too far and made a caricature of it -- in characters like the nymphomaniacal Grace Caldwell Tate in ''A Rage to Live,'' or the rapacious lesbian Lovey Childs in the novel of the same name -- but in the earlier books and in the stories it had a liberating effect and enabled O'Hara to create unusually complex and sympathetic female characters.

Wolff is hard on the later novels, and in particular on the jumbo doorstoppers -- like ''A Rage to Live'' ''Ten North Frederick'' and ''From the Terrace'' -- with which he made his fame and fortune in the 40's and 50's. O'Hara's first two novels are better, it's true (so much so that they give his career a backward-looking trajectory), but the late ones are still intensely readable and they have a certain documentary fascination. Wolff gets some factual things wrong: William Maxwell's older brother lost a leg, not an arm, in a carriage accident, for example, and The New Yorker's system of bonus payments, though it was insanely complicated, never took into account the amount of fan mail an author received. But Wolff's only serious failing, if you're already an O'Hara fan, is that he tends to undervalue -- or, at any rate, to undersell -- the importance of O'Hara's short stories, an enormous body of work that constitutes his real claim on our attention. It's not just that a good number of these stories -- pieces like ''Graven Image,'' ''The Doctor's Son'' and ''Over the River and Through the Woods'' -- are classics, worthy of inclusion in any serious anthology of 20th-century short fiction. O'Hara was also a formal innovator, who liberated the story from the formulas of popular magazine fiction of the 20's -- the reliance on surprise climaxes; the elaborately articulated structure of beginning, middle and end. Perhaps because he began by writing sketches, O'Hara discovered a kind of story that had no ending at all, and sometimes no proper beginning either -- a story in which nothing ''happens'' necessarily, but in which a line of dialogue or even a single observed detail indicates that something crucial has changed. Hemingway typically gets credit for this revolution in story writing, but among practitioners O'Hara was probably more influential. He created what later came to be called ''the New Yorker story'' -- one that turns on a tiny alteration in tone or mood -- and he paved the way for Salinger, Cheever, Updike and even Carver.

Where did O'Hara come from, artistically speaking? In part, obviously, from Hemingway and Fitzgerald, who were friends and contemporaries. But he's less mannered than the former (the simplicity of his language never calls attention to itself), less high-flown and romantic than the latter. Is it possible that what we're hearing, filtered into the American idiom, are echoes of Chekhov and Turgenev? Wolff doesn't say, and it's likely that O'Hara wasn't aware of it. Like Cheever, a fellow dropout and autodidact, O'Hara was an artful but unreflective writer. He was so busy keeping a jealous eye on what his competitors were up to that he seldom bothered to analyze what he was doing himself. He wrote, he turned in his manuscripts and he waited impatiently for the checks -- which to his mind were never big enough.