American arts and letters have been blessed with few great generalist critics over the years, and fewer still have written novels. The most obvious example, Edmund Wilson, wasn’t much of a novelist. The other fellow who comes to mind, Henry James, wasn’t much of an American.

In this regard, John Updike stands as America’s great man of letters of the past century.

“Evidently I can read anything in English and muster up an opinion about it,” wrote the author of Rabbit, Run in 1975, explaining why his second collection of criticism contained so many essays on fiction from abroad.

Three decades later Updike is reinforcing this fact with the energy of a much younger critic. Several times a year he files exquisitely textured reviews of art for The New York Review of Books, while The New Yorker carries a dispatch of his every few weeks. Introductions, riffs, op-eds, feuilletons and posthumous tributes pile up, too.

Entering his mid-70s, he remains the Iron John of criticism.

But stamina alone is for drudges. What makes Updike’s essays worth reading and owning in hardback is the intimate, frighteningly articulate voice that holds them aloft. Due Considerations, his sixth collection of criticism, showcases 701 pages of his descriptions of novels by Ian McEwan, the gimcrack imagination of Frank Baum, the sinking of the Lusitania and the value of a penny. Occasionally, it feels as if Emerson’s all-seeing invisible eye had picked up a pen.

The pleasure of reading his sentences is enormous. Better known for his lyrical cul-de-sacs, Updike is also a master of the declarative. “Ian McEwan, whose previous novels have tended to be short, smart and dark, has produced a beautiful and majestic panorama,” Updike wrote of Atonement. “The author of this bulky book offers more indignation than analysis in his portrait of post-colonial Africa,” he wrote of Ngugi wa Thiong’o’s Wizard of the Crow.

As he has aged, Updike has worked to keep up with the times — a not altogether successful effort. Even when bestowing a compliment he can reveal a tin ear for the best way to honor difference. Of Colson Whitehead’s John Henry Days, he wrote, “The young African-American writer to watch may be a 31 year old Harvard graduate.” To which Mr. Whitehead reportedly quipped, “I hear John Updike is a great white American writer to watch.”

Still, Updike carries on, determined to see and explore and explain to the best of his abilities, even if it requires a great deal of homework (and some self-chastening). In order to write a long essay on the complete works of Isaac Babel, he seems to have read deep into the margins of Babel’s life. Reviews of novels by Orhan Pamuk, the art of Francisco Goya, and the life of Marcel Proust baste in a wealth of knowledge lightly worn.

One of the most endearing qualities of Updike as a critic has been his solicitous modesty — he genuflects to contemporary realities rather than badger them with his own preferences. He takes nothing for granted, and yet manages to coax readers beyond typical shores without hectoring, all while refusing to be bullied by scholars.

“With a hundred pages to go,” Updike describes in an essay on Harriet Beecher Stowe’s Uncle Tom’s Cabin, he “switched from the wide-format, double-focused annotated version to the text as presented by the Library of America, where the feverish and nakedly exhortative climax is allowed to work its spell without editorial heckling.”

If there are signs of Updike aging, they are most evident in what he has chosen to write about. Who else but a novelist in his 70s could recall the Saturday Review, the value of small change, the introduction of mass market books, the “ominous blob on the horizon” that Philadelphia was in 1930 and 1940, let alone the particulars of E.B. White’s marriage?

The combination of this wide-ranging curiosity with such obvious nostalgia for the Americana of yore makes for a heady, unique, occasionally maddening perspective. In Updike, America possesses a quintessential voice of the Yankee abroad at home in his armchair, dreaming of the future. Perhaps, as he notes, the future may not even have books, as we now know them, but on this count, Updike remains guardedly optimistic.

“Such books constitute a pledge of an infinite future,” he writes in a piece about the books piled up in his study. “Books hold our beams down; they act as counterweight to our fickle and flighty nature.” A job, one might add, that’s well-performed by this keenly fired foundational brick.

John Freeman is president of the National Book Critics Circle.