THE GENERAL IN HIS LABYRINTH By Gabriel Garcia Marquez Translated from the Spanish by Edith Grossman Knopf. 285 pp. $19.95

ADVANCE INTEREST in this new novel by Gabriel Garcia Marquez has been uncommonly and understandably high, for the simple reason that the subject of The General in His Labyrinth is Simon Bolivar. Latin America's great novelist writing about Latin America's great hero: It seemed, in anticipation, an inviting combination. But now that the book itself is here, a surprisingly mixed judgment must be tendered; although there are passages that give hints of Garcia Marquez at his most lustrous and that therefore will give his admirers much pleasure, by and large The General in His Labyrinth is an uncharacteristically flat and uninspired performance.

What Garcia Marquez has done in this novel is to take the magic out of magical realism. Why he has done so is open to any number of explanations, but the most likely is twofold: He has been daunted by the challenge of rendering in fiction an historical figure of mythic proportions, and he has felt constrained by the obligations imposed by fact from taking all the liberties offered by fiction. The General in His Labyrinth is presented as a novel, but in truth it is neither fish nor fowl: It plays too loosely with historical fact to be either history or biography, yet it fails to make the imaginative leaps that fiction entails -- leaps, it need scarcely be said, that few novelists have made so boldly as did Garcia Marquez in his earlier work.

Among that work, the novel with which this must be compared is The Autumn of the Patriarch, Garcia Marquez's somewhat neglected masterpiece about despotism at its most paradigmatic. It is a difficult but hardly inaccessible novel in which Garcia Marquez manages to locate humanity at the heart of evil, to give totalitarianism something approximating a personality; but in The General in His Labyrinth, he has been cowed into cautiousness by a figure who approaches, if he does not entirely achieve, epic goodness.

Garcia Marquez tries, heaven knows, to give Bolivar a human face, to endow him with weaknesses that make him a man rather than a saint. His Bolivar is, in his own words, "old, sick, tired, disillusioned, harassed, slandered and unappreciated," an unheroic hero who is not incapable of self-pity and who resorts daily to emetics in hopes of allaying his "persistent constipation." Now in the last days of its life, his is "the most ravaged body one could imagine: the meager belly, the ribs pushing through the skin, the legs and arms reduced to mere bone, all of it enclosed in a hairless hide as pale as death except for the face, which was so weathered by exposure to the elements that it seemed to belong to another man."

Combine this with what Garcia Marquez presents as Bolivar's compulsive interest in the opposite sex -- "despite all the value he placed on his life and his cause, nothing tempted him more than the enigma of a beautiful woman" -- and you would seem to have a well-rounded portrait of an entirely human hero. Yet Bolivar never really comes to life in Garcia Marquez's hands -- never, that is, flings aside the bonds imposed on him by history and emerges as a fictional character in his own right. He is the beneficiary of some lovely prose, but even the best of it never reaches the magical stratosphere occupied by its author's several masterpieces. To wit:

"He always considered death an unavoidable professional hazard. He had fought all his wars in the front lines, without suffering a scratch, and he had moved through enemy fire with such thoughtless serenity that even his officers accepted the easy explanation that he thought himself invulnerable. He had emerged unharmed from every assassination plot against him, and on several occasions his life had been saved because he was not sleeping in his own bed. He did not use an escort, and he ate and drank with no concern for what was offered him, or where. Only {his lover} Manuela knew that his disinterest was not lack of awareness or fatalism, but rather the melancholy certainty that he would die in his bed, poor and naked and without the consolation of public gratitude."

That is a handsome passage, notwithstanding the translator's misuse of "disinterest," and the unmistakable imprint of Garcia Marquez is firmly upon it, but it is more expository than inventive; it is the author as historian or biographer rather than as novelist, barely tiptoeing beyond the limits that convention sets for him. The same is true of the narrative itself. Garcia Marquez seems to feel obliged to give the reader of this novel the same information that the reader would expect were it a biography; thus in the beginning he takes forever to set the stage, introducing various minor characters who rarely if ever reappear, and throughout the story he continues to divert attention from his main business with what, as a novelist, he should recognize as unnecessary clutter.

His Bolivar is trying, weeks before the end of his life, "to purge his body and spirit of twenty years of fruitless wars and the disillusionments of power," but this is an insight that any competent biographer or historian could reach. You will search without success in this tale for the Garcia Marquez who gave us, in The Autumn of the Patriarch, an "age-old animal who blinked with open eyes in a space of his own reserved in another age of the world" and who delivered up an enemy "ready to be served at a banquet of comrades by the official carvers to the petrified horror of the guests as without breathing we witness the exquisite ceremony of carving and serving, and when every plate held an equal portion of minister of defense stuffed with pine nuts and aromatic herbs, he gave the order to begin, eat hearty gentlemen."

Not another human on earth could have written that passage; but any number of professional writers could have composed much of The General in His Labyrinth, so bogged down is it for so much of its course in the dutiful business of being faithful to what, in his prodigious researches, Garcia Marquez learned about his subject's life. He tells us nothing we do not already know when he writes that Bolivar had "the fantastic dream of creating the largest country in the world: one nation, free and united, from Mexico to Cape Horn," or that "the General's dream began to fall apart on the very day it was realized." This is mere historical fact; Garcia Marquez declines in the end to embellish it with whatever stabs into the unknown his extraordinary imagination might permit.

This is a pity. The General in His Labyrinth simply is not the book that Garcia Marquez's previous work had led us to hope for and expect. It's anything except a bad book, and the reader will find in it more pleasure than most contemporary fiction provides, but by contrast with One Hundred Years of Solitude and The Autumn of the Patriarch and Love in the Time of Cholera it is oddly, and most disappointingly, pedestrian.