With his peculiar tone of sweet weariness, Kurt Vonnegut Jr. rose cranelike from his perch and said, "I suppose the same people that are burning books now were burning people when I was a boy. Maybe we're making progress."

So it goes.

At the 48th PEN International Congress today, the gathering that drew the most interest was one on the various forms of censorship in the United States. Vonnegut was typical of the panelists in saying that while censorship in the United States is not to be compared with such suppression in Eastern Europe, China, Latin America and elsewhere, the issue is far from closed.

Outside of the United States, it was agreed, the situation is bleak. The PEN International Writers in Prison Committee reported that 441 writers worldwide are known to be imprisoned, detained, kidnaped and in some cases missing.

During the session on censorship, Vonnegut recalled a case in Drake, N.D., where the school board threw the school library copy of "Slaughterhouse Five" into a furnace and harassed one of the teachers, Bruce Severy, for teaching Vonnegut's works in the classroom.

"In a movie version of that case, people would have come up to Bruce and said something like, 'I support you but, of course, you know I can't really say anything,' " Vonnegut said. "They didn't even do that. People slashed his tires, shot his dog and smashed his windows. They threatened to give him such an awful job recommendation that he'd never teach anywhere again. No one took his side."

The American Civil Liberties Union successfully sued the school district. "And the funny thing was," said Vonnegut, "Bruce left there with the most glowing account of his teaching career."

Random House President Robert Bernstein, who chaired the session in a packed, nearly airless suite at the St. Moritz Hotel, read from a list of authors whose works had been banned at certain libraries. Besides the usual contemporary litany of Vonnegut, J.D. Salinger and James Baldwin, Bernstein also said Chaucer, Corneille, Dostoevsky, Orwell, Dickens, Hemingway and Fitzgerald had "met the censors."

Barbara Parker, executive policy director of People for the American Way, said that in 1985 there were efforts to censor literary works in 46 states, and "40 percent of those attempts resulted in books being removed from libraries or put on special, restricted shelves."

One school board restricted "The Diary of Anne Frank," calling it "depressing and a real downer." The editors of an anthology of literature for high school students excised 400 lines from Shakespeare's "Romeo and Juliet" because the passages were "sexually explicit."

"In American schools, the exchange of ideas is in danger of becoming an anti-American activity," Parker said.

Gay Talese, author of "Thy Neighbor's Wife," said he takes an "absolutist" position on issues of censorship. In his speech on pornography, Talese said, "Smut reflects America's erotic imagination, or lack of it" but should not be restricted by the government.

Talese spoke of how soldiers in the Civil War carried in their pockets imported erotic post cards of bathing beauties "with their soapy bows and sterns," and how this helped provoke Congress to pass laws in 1873 banning pornography from the mails.

Charles Rembar, an attorney who has defended Henry Miller's "Tropic of Cancer" and D.H. Lawrence's "Lady Chatterley's Lover," said that while the United States is among the least censored countries in the world, "We should try to make our freedom as perfect as we can. In this regard we are a chosen people." Rembar said that while only one book -- a bowdlerization of a government report on pornography -- has since 1966 been successfully prosecuted in federal courts, the opponents of censorship should monitor carefully the activities of local school boards, religious groups and others "who would attack freedom of expression."

As it has all week, the 1952 McCarran-Walter Act was a source of discussion. The cause of Margaret Randall, a writer who left the United States, became a Mexican citizen and now wants to return to this country, has been taken up by PEN. Because many of her books reflect a strong sympathy for the Sandanistas and other left-wing movements, Randall has been denied permanent reentry under the McCarran-Walter laws.

Talese asked Margaret Atwood, the Canadian poet and novelist, whether she, as a well-known feminist, felt that pornography in any form should be banned on the grounds that it is degrading to women. Atwood said any such restrictions would be unwise. "Women would probably be hurt first," she said.

"It's only too bad," said Bernstein, "that Russian Soviet authors weren't able to come to this congress and hear Americans discussing their problems out in the open. Why weren't they allowed to come? The days of exchanging musicians and dancers and calling it true 'cultural exchange' are over."

Before the seminar, PEN's assembly of delegates adopted resolutions appealing for freedom for two imprisoned poets, Mila Aguilar in the Philippines and Irina Ratushinskaya in the Soviet Union. Michael Scammell, chairman of the International PEN Writers in Prison Committee, said the 441 missing writers on its list include 94 who "disappeared" in Argentina during military rule and whose fates are unknown. Also listed were 46 elsewhere in Latin America; 104 in Europe, 89 in Asia, 39 in Africa and 69 in the Middle East.

Thursday night Mother Jones magazine hosted a party in Greenwich Village in Randall's honor. At the same time, PEN sponsored a reception at the Metropolitan Museum of Art for the more than 700 writers gathered here.