Are books essential? Are they even important in the age of the videocassette, the news in pictures and the Gramm-Rudman Amendment?

We will presently know at least Congress's answer to these grave questions, because the Library of Congress is up against the wall. Eighteen million dollars has been cut from its budget.

Books don't bleed when you cut them, but librarians do. Librarian of Congress Daniel J. Boorstin made a most powerful lament before the House subcommittee on legislation about the cutbacks from his previous year's budget of $238.6 million: $8.4 million by Congress and $9.9 million by the mindless Gramm-Rudman process.

The Library's plight, Boorstin said, "could become tragic for our nation, the Congress and the whole world of learning. . . . It would be a historic irony -- the only analogy I can think of is the burning of the ancient Library of Alexandria in Egypt -- if the Congress should choose. . . to direct and promote the disintegration of this great institution."

He had always told the truth about the library's needs, Boorstin said, and Congress had believed him. They can't afford not to believe him now, he said.

"These are the times that try men's minds, that tax our consciousness, our resources of wisdom, knowledge and information. Threats from without and problems within demand every shred of the most ancient wisdom and the most recent information. . . . We, the greatest library on earth, serving the greatest republic, are needed as never before by an imprisoned humanity."

To Boorstin, it is obviously unthinkable that members of Congress, under what one of them called "the automatic buzz-saw of Gramm-Rudman", would wilfully tamper with the great treasure under his watch. He is a scholar of the American scene, a prolific author on the American character, and it is plain that he cannot credit a triumph for know-nothingism or a confession that Congress cannot decide for itself what is important.

The cuts will curb the library's collecting, curtail its services to the blind and shorten its hours.

"Historians will not fail to note that a people who could spend $300 billion on their defense would not spend $18 million on their knowledge -- and could not even keep their libraries open in the evening."

"These," said Boorstin, "are not the priorities of civilization and freedom . . . . Dare we say, simply, that our nation, perhaps the first nation on earth explicitly founded on knowledge, is now ready to disintegrate and destroy its own foundations?"

Chairman Vic Fazio (D-Calif.) said he shared the librarian's alarm but could not "dilute the reality of the atmosphere in the Congress."

"I am glad to hear you be so aggressive" was the most comfort he could offer.

And Rep. Lindy Boggs (D-La.) told Boorstin she was "very very pleased that you have given such an impassioned plea."

No one had any idea of what to do. Perhaps private contributions? As a matter of fact, one anguished reader wrote a letter to The Washington Post expressing a willingness to pay a dollar to enter the library, if only its doors could be kept open in the evening, the only time she was free to use its splendid reading-room.

Boorstin said he thinks it is "dangerous" to rely on private contributions because "this is a national library and can continue to provide its services only if the nation supports its activities."

Nor would it do for him to roam the country rattling a tin cup for the jewel in the crown of the country's public library system. Local libraries need money, too.

Fazio asked if we could acquire the books we "need" with the deep cuts.

"It is a most interesting question," said Boorstin. "It is a problem to decide what knowledge may be useful. Who would have thought that a book about the rainfall in Burma would be important? But we had it and during World War II we were the only place which had information which was a matter of life and death."

The cuts in the programs for the blind do not mean life or death, merely a narrower access to the joys of reading. Last year the library circulated 21 million books and magazines to its 646,300 talking-book patrons and 18,300 Braille readers. They will be deprived of 80,000 new books by Gramm-Rudman, or rather by a Congress which has abdicated its powers.

Congress doesn't see the Library of Congress as a symbol of our nation. The last time it intervened in the library's affairs was when it banned Playboy magazine from the reading material supplied the blind.

It's a little hard to see a body with that mentality throwing off the shackles of Gramm-Rudman to strike a blow for knowledge. Congress seems to think that the less it knows, the better off it is. It's obviously up to the rest of us to tell them that the country will be no stronger than its information.