Emphasizing his love for books and the country's need for wisdom, James H. Billington was sworn in by Chief Justice William Rehnquist yesterday as the 13th librarian of Congress.

"Our type of democracy has depended on knowledge and grown through books, which by their very nature foster freedom with dignity. Books do not coerce; they convince," Billington, 58, said at the morning ceremony.

President Reagan, in his remarks at the ceremony, called Billington "America's librarian," who will have the task of "not just administering this institution but ensuring that its vast resources are put to maximum use."

Billington's wife Marjorie and their four children were also present.

"This library serves both the working government of a free people and the scholarly frontiers of all people," said Billington. "It will not serve either well if it simply spreads information to other places without generating knowledge and distilling wisdom in its place."

Later, at a press conference in his office in the library's Madison Building, Billington said, "This society and the world need wise people. It sounds corny. There isn't that much true wisdom and if we could produce a little, that wouldn't be in electronic or book form, that would be in human form. And I do think a library is a place of wisdom."

Billington spoke mostly in general terms about his plans for the library, which include making its resources more widely available and having the library play a "catalytic role" in the development of imaginative ideas.

"There are, I'm sure, quite a number of problems and when I go to work tomorrow, I'm sure my colleagues will impress upon me which are the most pressing," Billington said with a smile.

However, Billington did identify a few areas of concern. One is conservation of books: "Most of the books printed in the last 150 years won't exist by the middle of the next century if we don't do something about the acidifying of paper." A second issue "relates to the organization of information more generally," Billington said. "How much difference is there if this material is machine-processed or in a book? With a book, you can turn pages, there's an interaction ..." There's also the question of "openness and access -- are books a little more open than a machine that someone controls?"

Billington, director of the Woodrow Wilson International Center for Scholars for the past 14 years, is a Sovietologist who has written several books, two of which were nominated for National Book Awards. He said yesterday that he plans to continue his writing while being librarian of Congress.