HEMINGWAY By Kenneth S. Lynn Simon & Schuster. 702 pp. $24.95

SO MUCH HAS been written about Ernest Hemingway in the quarter-century since his death that one approaches a new biography with trepidation. Is there anything left to say, any fresh and revealing way to assess this immeasurably influential writer and infinitely complex human being? Yes, there is, for in his quite monumental biography Kenneth S. Lynn has much to tell us that is new, provocative and convincing. His Hemingway is at once a distillation of all previous scholarship -- in itself no mean accomplishment -- and an excursion into territory that, though not precisely unexplored, has never before been examined with such care and insight.

This exploration involves a certain amount of Freudian speculation, with which I am generally uncomfortable, especially when it is practiced by an amateur. But Lynn gets away with it for two reasons: he is scrupulous about staying within the bounds presented by his evidence, and from that evidence he makes what seems to me a quite unimpeachable case. To anyone who has read Hemingway's fiction and observed his life with a degree of attentiveness, Lynn's conclusions will not come as a great surprise; but it remains that no one else has drawn these conclusions so boldly or argued them so effectively.

Lynn makes an elaborate argument, one that I summarize at the risk of oversimplification, the essential ingredients of which are as follows: that the dominant presence in Hemingway's life was his mother, "the dark queen of Hemingway's inner world," and that she compromised his sexual identity by dressing him as a girl when he was young and by "twinning" him with his older sister, Marcelline. Though Lynn does not go quite so far as to say emphatically that Hemingway emerged from this a repressed homosexual, he does contend that it made him especially sensitive to "the ambiguities of feminine identity" and that it invested him with a "sexual duality" that he attempted to overcome by wrapping himself in the mantle of exaggerated masculinity.

If there is an element of debunking in Lynn's argument -- he has no patience with the "Papa" mythology, is quick to point out the many forms that Hemingway's posturing assumed, and documents his treachery toward friends and rivals in unstinting detail -- it is secondary to what is in fact an admiring and deeply sympathetic portrait. As one who has long felt Hemingway the writer to be much overrated and Hemingway the man to border on the contemptible, I am persuaded by Lynn that Norman Mailer's judgment, as quoted by Lynn, is correct:

"It is not likely that Hemingway was a brave man who sought danger for the sake of the sensations it provided him. What is more likely the truth of his own odyssey is that he struggled with his cowardice and against a secret lust to suicide all his life, that his inner landscape was a nightmare, and he spent his nights wrestling with the gods. It may even be that the final judgment on his work may come to the notion that what he failed to do was tragic, but what he accomplished was heroic, for it is possible that he carried a weight of anxiety with him which would have suffocated any man smaller than himself."

Lynn's biography -- again I risk oversimplification -- is constructed around Mailer's hypothesis. He quotes a letter from Hemingway to Scott Fitzgerald -- "We are all bitched from the start and you especially have to be hurt like hell before you can write seriously. But when you get the damned hurt use it -- don't cheat with it. Be as faithful to it as a scientist" -- and then appends this comment: "Hemingway's hurt began in childhood and expanded until his death like ripples from a hand trailed in a sylvan lake. Uncertain to the point of fear about himself, he was compelled to write stories in which he endeavored to cope with the disorder of his inner world by creating fictional equivalents for it."

It is in Hemingway's stories that Lynn finds much of the evidence with which to substantiate his interpretation of the writer's "inner world," and he uses that evidence most persuasively. He believes, and certainly he is correct, that only Thomas Wolfe among Hemingway's contemporaries was so autobiographical a novelist; he therefore regards his fiction as legitimate corroboration of, and in some instances surrogate for, the facts. If anything, Lynn convinces me -- though he does not advance the argument himself -- that it is Hemingway rather than Wolfe who should get both credit and blame for the narcissistic currents that now course through American fiction; more than we have thus far realized, his influence lay not merely in style but in content.

THOUGH IT surely is unintentional, Lynn also persuades me that Hemingway's fiction is more interesting as autobiographical evidence than as fiction. His judgments about the work generally seem to me acute -- he admires the first two novels and a number of the stories, mostly the early ones, but dismisses most of the later work and is suitably contemptuous toward the "lachrymose sentimentality" of The Old Man and the Sea -- but he finds more to admire than I do in the celebrated Hemingway style and he is more patient than I am with Hemingway's literary mannerisms.

But that is of no moment. What matters is that Lynn has made the definitive case for Hemingway as a tortured man who sought to resolve his conflicts through literature and who fought a brave, honorable fight before succumbing at last to the same suicidal impulse that claimed both his father and his younger brother. In making this case he of necessity covers much ground that already has been traced to the point of extreme tedium, but to his immense credit he manages to breathe new life into all of it. More than any previous biographer -- more, in particular, than the well-intentioned but pedestrian Carlos Baker -- he places the events of Hemingway's life in proper perspective; he gives ample consideration to the crucial years with Hadley in Paris, for example, but dismisses the childish swashbuckling during World War II in a few pages.

Lynn is especially interesting on Hemingway's relationships with and attitudes toward women. Among Hemingway's critics it has for some time been assumed that, as I put it some years ago, "he regarded women as instruments of his own pleasure and discarded them when the purpose had been served." But Lynn contends that a legacy of his relationships with his mother and sister was "an ability to look critically at the insensitive ways in which men handled women" and that "the alienation of women from men (as well as vice versa) was one of his themes." Using in particular the testimony offered by Mary Hemingway's diaries and by the posthumous novel The Garden of Eden, Lynn makes an especially strong argument that Hemingway had a "helpless fascination with androgyny and sexual transposition," one that informed both his private life and his fiction.

What becomes clear above all else in Lynn's portrait is that Hemingway was a painfully haunted man: haunted by a mother whom he hated and did not understand, by a father whom he loved but did not respect, by a Midwestern childhood that inspired both nostalgia and loathing, by a sexual insecurity that drove him to outperform all men, by a longing for applause and celebrity, and in the end by the self-destructive image he created for himself -- the image of "Papa" -- that "would interfere with the free working of his creative imagination" and ruin him as a writer. It is, as Lynn well knows, a sad story and in many respects a peculiarly American one; he tells it with empathy and compassion, and with great admiration for the good heart that beat behind the pitiable facade.