THE REAL LIFE OF ALEJANDRO MAYTA. By Mario Vargas Llosa. Translated by Alfred Mac Adam. Farrar, Straus and Giroux. 310 pp. $16.95.

OF THE WRITERS contributing to Latin America's current literary boom, Peru's Mario Vargas Llosa may well be the most difficult to classify. His work could never be lumped with that of Gabriel Garc,ia M,arquez, Manuel Puig, or other "magical realists." Its realism is of a solider sort, closer, except for its narrative inventiveness, to that of the great 19th-century novelists. Vargas Llosa does not attempt the metaphysical exercises of a Borges or the cosmic-historical confections of a Carlos Fuentes (at least the Fuentes of Terra Nostra). Yet, as he demonstrated in his last novel, The War of the End of the World, he is willing to treat such large themes as apocalyptical politics as long as they are grounded in down-to-earth circumstances. And while Vargas Llosa may not possess the satirical fury or sheer verbal brio of Puerto Rico's Luis Rafael Sanchez, his Aunt Julia and the Scriptwriter showed that he can work a lighter comic vein to often astonishing effect. Vargas Llosa has cut his own literary trail -- several different ones, in fact.

He is also something of a loner in his politics. A liberal in an intellectual world that lists decidedly leftward, Vargas Llosa has made a good many enemies, Garc,ia M,arquez among them, because of his sympathetic view of the United States and his criticisms of Castro's Cuba and of Sandinista extremists.

Quite understandably, the novelist Vargas Llosa has at times wished he were free of his region's political turmoil. "Why is it like this?" he asked in an essay several years ago. "Why is it that instead of being basically creators and artists, writers in Peru and other Latin American countries must above all be politicians, agitators, reformers, social publicists and moralists?" It is something of a surprise, then, that Vargas Llosa would have chosen the loaded subject of revolution and revolutionaries as the theme of his most recent novel. The choice alone throws him into the center of Latin America's current political debate.

The subject is a daunting one even without its obvious contemporary relevance. What, after all, remains to be said about that quintessentially modern hero -- or anti-hero -- after Dostoevsky's definitive depiction of the type in The Possessed? Consumed by a single passion, the revolutionary, moreover, lacks those complicating ambivalences that make for immediately interesting literary characters.

Shrewdly, Vargas Llosa has made the difficulties of writing about the revolutionary a central part of his novel. He sets his story in a Peru of the not-too-distant future, at a time when everyone is haunted by the specter of revolution. Terrorist violence has erupted throughout the country, and U.S. Marines have been called in to resist an invading Cuban-Bolivian revolutionary force. In the garbage-befouled city of Lima, the narrator, a novelist not unlike Vargas Llosa himself, attempts to put together the true story of Alejandro Mayta, an obscure Trotskyite who in 1958 led an abortive insurrection in the provincial Andean town of Jauja. The narrator wants the facts not so he can write a history or biography but so he can transform them into the stuff of a novel.

But why this minor figure, Mayta? The narrator wonders about that himself. Is it because Mayta's "case was the first that would typify the period? Because he was the most absurd? Because his person and his story hold something ineffably moving, something that, over and beyond its political and moral implications, is like an x-ray of Peruvian misfortune?"

This search for a clue to the national character, the national destiny, is told in a way that sometimes seems to obscure more than it does to clarify. The narrative technique consists of quick, unsignalled hops between the present (in which the narrator is usually engaged in interviewing Mayta's former acquaintances) and moments from Mayta's past. This quick-cutting montage forces the reader to wonder whether the scenes from the past are faithful renderings of what the narrator was told or whether they are already the reworked, fictionalized versions of those accounts.

Confusing it is, but at least it serves to make a legitimate, if not altogether original, point: that stories about the past are always reworkings, always fictions. Implicitly, furthermore, Vargas Llosa seems to support the Aristotelian argument that poetry (read fiction here) comes closer to truth than history (or more amateur recountings of events) because it strives after universals, whereas history, a lesser narrative genre, pretends merely to present the facts.

Then, it must be asked, does the narrator of this novel draw a "truer" picture of the revolutionary than mere facts might allow? I am not persuaded that he does. And yet here is an irony: I am not sure that Vargas Llosa intended him to.

The Mayta who gradually emerges in the narrator's picture belongs among the great romantics of literature. He is a type, a political Quixote, questing after the ideal society. Orphaned when young and brought up in Lima by his aunt, he is a good student and, for a time, a good Catholic. But the spectacle of poverty and suffering eventually drives him to Marxism and the promise of earthly salvation through revolution. Appropriately, he ends up a Trotskyite, among those most idealistic of revolutionary sectarians. And, as might be expected, the insurrection he leads turns out to be a catastrophe, the botched product of unrealistic expectations (most of Mayta's followers are mere schoolboys), inadequate planning, and poor execution.

But there is something else about Mayta, and this characteristic leads into the novel's all-important twist. Mayta is homosexual. At least that is what several informants say about him, and that is how the narrator chooses to present him. This characteristic, as it is revealed and developed, makes Mayta more vulnerable, complicated, and sympathetic. It doesn't fully explain his revolutionary fervor, although his attraction to a swaggeringly macho young lieutenant lies partially behind his decision to attempt the foolhardy insurrection in Jauja. For the most part, however, homosexuality is a wound that Mayta quietly carries, a wound from which he thinks he might suffer less in a better future world. It is a poignant detail and yet somehow too neat. And Vargas Llosa knows that it is.

That is why Vargas Llosa finally undercuts his elaborate fictional design at the end of the book -- or at least appears to. He does so by having the narrator meet the "real" Mayta, a much less complicated or sympathetic man than the one we have gotten to know. This real Mayta, now working in an ice cream parlor after having served several jail sentences for crimes which seem only remotely political, is disturbed and disgusted to learn that he has been depicted as a "queer." The narrator-novelist explains that he did so in order to heighten his character's "marginality." But then he confesses that he really doesn't know why he did it. I

T IS a strange moment in the novel,

and one that readers will doubtlessly

react to in different ways. But I don't

think Vargas Llosa is merely playing games with us. Instead he is attempting to dramatize his views about the problematic relationship between art and reality, particularly in the troubling realm of politics. His novel tells us a great deal about Peru's history, its mixed Indian and Spanish heritages (including the cruel, intolerant streak born of the Inquisition); it tells us muc about all classes of Peruvians, from the wretched and hopelessly poor who have no choice but to turn to crime or political violence, to the smugly well situated who, amid national chaos, can worry blithely about the dwindling coffee supply. His novel shows us, in other words, how a sensitive, intelligent man could be driven to the revolutionary faith, and it offers a sympathetic, even somewhat idealized, picture of just such a revolutionary. And yet finally Vargas Llosa draws up short before his own romantic portrayal. Indeed, in a subtle way, he denounces it as just that -- as romantic.

Vargas Llosa is too much of a political man to ignore what revolutionaries have brought upon others as well as upon themselves, to ignore, in other words, the disastrous consequences of their romanticism. So he arranges, in his novel, for "reality" (an imagined reality, of course) to puncture the romance. Unfortunately, this obtrusive ploy prevents The Real Life of Alejandro Mayta from having what mighthave been a more pleasing fictional shape. That is the price of writing a disturbing novel, one whose carefully contrived unpleasantness will keep readers from easily putting aside its harder truths.