IN EARLY 1977, Argentine political journalist and short story writer Rodolfo Walsh wrote an open letter to the junta that had come to power in Buenos Aires the year before. It's a brief document, only five pages long, and in another time and place wouldn't have been noticed. After all, writers have been issuing jeremiads against the state for as long as there have been writers or states.

Argentina in the late '70s, however, was one of those places -- like the Soviet Union under Stalin and Nazi Germany -- where the usual rules didn't apply. Thousands of people were being snatched out of their homes and off the streets, disappearing without a trial, without explanation, without reason. By government directive, "to report, comment on, or make reference to" these incidents was strictly forbidden.

Walsh broke that rule. He told the junta it had spread "the most savage reign of terror Argentina had ever known," creating "virtual concentration camps in all the principal military bases . . . The original objective of extracting information through the use of torture is subordinated in the perverted minds of those who administer it to the need to utterly destroy their victims, depriving them of all human dignity, which both the torturers and yourselves have already lost."

Unlike, say, Salman Rushdie, the 50-year-old Walsh knew exactly what he was doing. He closed his letter saying he was writing "without hope of being listened to, in the certainty of persecution, but faithful to the commitment I made a long time ago to be a witness in difficult times."

The day after releasing the letter, Walsh was abducted. He is believed to have died within hours. His body was never found.

There's no dispute about the writer's courage: He placed the notion of bearing witness above his own survival. It's with the living Argentine writers that the furious arguments begin. Just who was the bravest in the Dirty War? IF THE TAXI DRIVERS know your name, immortality is within reach. Even so, the driver couldn't find Ernesto Sabato's house, which is in a working-class suburb about 40 minutes from the city center. So he stopped and inquired of a pedestrian where a certain street number could be found. "Ah, you're going to see Sabato!" the fellow said. "Go left, then down four blocks, then turn right, and you'll be there."

This public familiarity has nothing to do with Sabato's fiction, all of which is serious literature of the most uncompromising nature. The association is instead with human rights. After the military government permitted the return of elections in 1983 -- a situation it was forced into by first, ruining the economy and second, losing the Falklands War to Britain -- the democratic government of Raul Alfonsin set up a commission to look into the 10,000 disappearances. At its head: Ernesto Sabato.

The report the team produced was called Nunca Mas, which means Never Again. It was a huge bestseller, probably the most famous book in Argentine history. And it solidified Sabato's reputation as a champion of liberty.

He's 83 now, relatively robust except for a fading eyesight that caused him to give up writing in favor of painting. (He's also had to give up reading, although he mentions with pleasure "a very good writer" whose work has been read to him: Paul Auster.)

It's an unfortunate but, as Sabato acknowledges, oddly appropriate affliction: His masterpiece, the brain-busting 1961 novel On Heroes and Tombs, revolves around a "Report on the Blind," which claims the sightless have formed a secret society that rules the world. And in The Outsider, an early existentialist-flavored work about a painter who murders his lover -- the only person who understands him -- a key character is blind.

Sabato wrote more than a dozen novels, but burned all except three in his backyard grill. They weren't good enough. "I have regrets sometimes, but in general my tendencies are pyromaniacal. If a writer can really achieve something with one book, if it resists dying like Don Quixote and The Divine Comedy, that's sufficient."

His three novels, he feels, form a trilogy -- essentially one book. "Personally, I consider my books so disagreeable, so hard, that when I find someone who likes them . . . " He shrugged. "I don't recommend them."

Others do: Sabato is generally considered, with the arguable exception of Adolfo Bioy Casares, the most important living Argentine writer. Although barely known in the United States and Britain, he's long been famous in Europe as one of the dozen or so most significant figures of the '60s Boom in Latin American literature.

If modest about his literary talents, Sabato showed more vanity when the conversation turned to the Dirty War. "Writers had a special responsibility to speak out, but very few did. And the few who did suffered threats of death and torture. I was not afraid for my own life, but for my sons and nieces. Many times the messages were, We're going to kill one of your nieces.' "

Nevertheless, Sabato declined to go into exile. "A writer has a lot of privileges but at the same time, and for the same reasons, he has a lot of moral obligations. The poor people couldn't leave. How could I?"

Many Argentines not only didn't want to leave, they didn't notice much amiss. Before the junta took over, the country had been in chaos. Both left-wing terrorists and right-wing death squads battled the marginal government headed by Isabelita Peron, widow of the general who was the dominant figure in Argentine politics for 30 years. The country was politically and economically in tatters.The generals took over without much of a struggle. Argentina's greatest writer, Jorge Luis Borges, spoke for many when he said, "Now we are governed by gentlemen."

This attitude, apparently shared by Bioy Casares, caused a rift with their colleague Sabato. "Neither raised his voice to say anything," Sabato complained. "And while others did speak, they did so from abroad." That, he made clear, wasn't much better than not speaking at all. "My situation," he concluded, "was a solitary one."

In an adjoining studio, Sabato's oil paintings were on display. These often had science fictional or at least surreal motifs -- clusters of amoeba-shaped beings drifting through space, Franz Kafka as a human mole. No matter what the subject, the paintings all shared the same feature: huge eyes, staring at the viewer in reproach. WHEN I told Sabato I would also be seeing Osvaldo Soriano, he appeared noticeably chagrined. At first, it was hard to see why. The 52-year-old Soriano proved to be a Falstaffian sort, good-humored, ebullient, loquacious. An interview scheduled to last an hour stretched into three, and the table was piled with coffee cups when it was over.

Soriano's eight books of fiction -- and his work as a journalist covering World Cup matches -- have made him both popular and esteemed, although the critics find him too easy to be considered really top-drawer. Certainly his most recent book to be translated into English, the absurdist road-trip Shadows, revealed an engaging touch.

While Soriano is very popular in Europe, Shadows suffered the usual dismal fate of foreign fiction when it was published in the United States two years ago. "The majority of the people in the States believe their country is the whole world," the writer said a little sadly. "Maybe they don't even know there's human life outside the States."

But if the United States isn't interested in Soriano, he's interested in the United States -- particularly, as it happens, in the work of Paul Auster. "I'm about to write him a letter. I was very much moved by his Leviathan. That's a story that has much more to do with a generation, our generation, than with a country." Soriano looked shy. "Would Paul Auster lose five minutes of his time to have coffee with me?"

Soriano's interest in the wider world outside of Argentina was informed by his years in exile. He left when the generals took over. "It's clear I was at risk," he said. "I don't know how to shut my mouth." He mentioned someone else who had the same problem: "Rodolfo Walsh was the only writer in this country who was a hero."

But what, I asked, about Sabato?

"Sabato has constructed a reputation around the idea that he protested the dictators. Well, he did, but only after the dictatorship was gone." Soriano has had a long dispute with the senior writer about this topic. "There's no reconciliation possible. When both of us are invited somewhere, one doesn't go. We've made sure we've never met."

Early in the dictatorship, Soriano said, Sabato had been one of those invited to meet Gen. Videla, the member of the junta who was believed to be more "moderate." It seems someone at this lunch asked about a writer who had disappeared -- a dangerous inquiry indeed. That person wasn't Sabato, Soriano said, although he later took the credit.

Besides, wondered Soriano, what was Sabato doing dining with a dictator? That legitimizes the tyrant, and makes it more difficult to get rid of him later. "I would have said no." The only acceptable responses to a military junta is "either to attack them with weapons, or leave the country."

The credit Sabato has received for supposedly standing up to the dictators is typical of the ethical morass of Argentine society, Soriano said. "Everyone likes to garland his biography with flowers. This is not a country of the truth." DURING A TIME of terror, the natural impulse of any writer -- indeed, of any sane person -- is to keep his head down and pray. In May 1976, two months after the coup, Gen. Iberico Saint Jean, the governor of Buenos Aires, said: "First we will kill all the subversives; then we will kill their collaborators; then . . . their sympathizers; then . . . those who remain indifferent; and finally we will kill the timid." Faced with such madness, who would speak up? It's instructive to note that by the time Rodolfo Walsh wrote his letter, several of his friends and his daughter had been murdered. Perhaps he figured they were coming for him anyway.

Some Argentine writers indicated to me that Walsh was as suicidal as he was heroic. If you read entries like the one in Current Biography, Sabato fits a much more useful definition of courage: "A bold and outspoken critic of repression and violations of human rights, despite the repeated threats that were made against his life." Andrew Graham-Yooll's After the Despots goes even further, saying "If there was any one man among Latin American writers who fought the despots of the 1970s it was Sabato." In an interview, Graham-Yooll backed off a bit. Sabato was, he said, one of those who bravely asked about the missing writer Haroldo Conti at the lunch with Gen. Videla, but on the other hand "he did avoid comment on the regime when he traveled abroad. And he should have been more strident in his defense of the Mothers," the women who demonstrated about their kidnapped children.

"Sabato quite rightly feels Soriano went abroad and made a brilliant career, and is now admonishing those who stayed home and didn't have a brilliant career," Graham- Yooll said. "Meanwhile, Soriano feels resentful for being diminished for going abroad, and hits back hard."

In the United States and Britain, writers quarrel over money. In Argentina, the feuds are about history. Sabato was so concerned that his enemy would damage his reputation that he faxed me a list of human rights-statements he had made during the Dirty War.

"Sabato and Soriano are still fighting this war, but the society as a whole is no longer interested in discussing it," said Graham-Yooll. If you ask in any bookstore here for Nunca Mas, the heartbreaking official account of the regime's victims, you will be told it is out of print. CAPTION: OSVAIDO SORIANO CAPTION: ERNESTO SABATO