CLIFTON FADIMAN began reading books when he was 4 years old, and he was still absorbing them on audiotape in the final months of his life, which ended this week in his 96th year. His eyesight had faded, but books -- of which he was one of the century's great promoters -- have not, although they've taken on new forms and stranger subjects than even the imaginative Mr. Fadiman could have seen.

He was not so well known at the end of his long life as when he was book reviewer for the New Yorker, radio quiz show star and national literary "pitchman," as he called himself. In the '30s, '40s and especially in the buoyant postwar years -- when millions of veterans who'd gotten used to government-issue paperbacks along with their K-rations moved on to government-paid educations -- Mr. Fadiman was the country's most popular literary guide. A pre-Oprah arbiter of bestsellers, he was widely admired for his erudition, wit and remarkable memory.

He was the country's Great Introducer, writing introductions to some 65 books and anthologizing many more. For 50 years, beginning in 1944, Mr. Fadiman headed the selection panel for the Book-of-the-Month Club, making choices for huge numbers of people who either found his advice persuasive or simply forgot to return the card saying they didn't want that month's choice.

As a son of Russian-Jewish immigrants who was, by age 10, reading Homer, Sophocles, Dante and Milton, and who went on to graduate Phi Beta Kappa from Columbia, Mr. Fadiman represented a couple of 20th century American trends that he both advanced and profited from: the continuing increase of literacy and the democratization of education. He was probably about the only person who could presume to write a book called "The Lifetime Reading Plan" without being considered presumptuous. One of his Book-of-the-Month panelists described him as "the most civilized man I've ever met." Sadly, you have to wonder how much that would count for if he were starting out at the end of this century rather than its beginning.