The theme was "A Nation of Readers," and at times it seemed as if most of them were at the Library of Congress last night. The black-tie reception and five-course dinner for 100 was sponsored by the Book-of-the-Month Club to kick off the library's new exhibition, and was elegant enough to draw a caveat from Librarian Daniel Boorstin: "There's not a cent of appropriated funds."

As the cocktail crowd swirled under the vast vaulted splendor of the library's Great Hall, unlikely bibliophiles drew together. Charlton Heston ("I'm indeed a compulsive reader--a print freak" who will "even read the backs of cereal boxes") towered over Defense Secretary Caspar W. Weinberger ("I don't read much for pleasure anymore"), while five yards down the marble former CIA director Richard Helms enthused over a new spy novel, "Mole."

But there was no unanimity over the exhibition's theme. Frank Hodsoll, head of the National Endowment for the Arts, was skeptical, fearing a "larger and larger gap" between the market for best sellers and the audience for "serious creative books." The NEA, he says, is helping to "bring these ideas together" by "jawboning" with publishers.

Clare Boothe Luce, resplendent in black and purple, was equally circumspect, and was beginning an impassioned remark ("the minute you have a population that can't read, you have a slave poulation") when her train of thought was interrupted by the sudden sight of Heston across a parted cocktail sea. "I must see him," Luce said. "I think he would have been perfectly cast as MacArthur, in the movie, you know. In fact, I'm going to ask William Manchester." Which she did: interrupting the wall-leaning historian's conversation, returning briskly to announce, "Mr. Manchester agrees with me," and sailing off toward the general manque'.

Manchester, repairing to the bar, was adamant: "This is plainly not a nation of readers. If you have a book in hardcover which sells 300,000 copies, it's extraordinary. Yet that reaches only a fraction of one percent of the American people." Reflecting on his forthcoming project, a two-volume biography of Winston Churchill, he sighed, "I am, as authors go, a popular one. But my audience is limited to people who read. And most don't."

Historian Barbara Tuchman, in floor-length purple, felt that "nonfiction is now very lively, but fiction is now at an uninteresting stage," perhaps because "our century has been one of disappointment in mankind. We've lost our respect for ourselves."

After dinner, Boorstin's address was optimistic. "The pundits in every age have been quick with their premature obituaries," he said, including those who now "predict that television and computers will displace the book." But he cautioned against three "biases of our time" which interfere with reading: "presentism," the preoccupation with events "certifed by immediacy"; publicity of the sort accorded political figures ("every book reader is a refugee from the present"); and overemphasis on statistics and the "mathematicized homogeneity" of best sellers.

Boorstin was then to have turned the podium over to Chief Justice Warren Burger, who could not attend because of illness. So Heston stood in, warming up the crowd by mocking his Moses voice (looking toward the ceiling, he intoned, "Who is on the lord's side?") and then delivering an eloquent and humble toast, from one who "makes his living by mouthing the words of wiser men than I," to the invisible benefactors of it all: "To the readers of America!"