Staring out from the jacket flap of many of his 18 books, Kirk Varnedoe looked the aristocrat. His forehead was high, his eyes a kind of flint. Here was a man who won the top curator's job in modern art over others more experienced. Here was a MacArthur genius hip enough to model an Ermenegildo Zegna suit for Barneys. Not many embodied so effortlessly the stereotype of the contemporary art world in all its unapproachable elan.

For years one of the Museum of Modern Art's most influential curators, Varnedoe is now on the faculty at Princeton's Institute for Advanced Study, which occupies a 500-acre wooded campus once home to Albert Einstein and Robert Oppenheimer. Manhattan cool has wrinkled into oxford shirt and old khakis. Varnedoe, too, is more of a rumple -- his smile warm, his hair not much combed. And on his desk, there is a bundle of dynamite.

"It's an amusing thing," says Varnedoe. "I used to have it on my desk at the Modern when I was always working on exhibitions and on deadlines -- it corresponded to my idea of time."

The realistic-looking dynamite is actually a clock that would be ticking, except Varnedoe has not had time to find new batteries for it. His immediate deadline is for the 52nd A.W. Mellon Lectures in the Fine Arts at the National Gallery of Art, which begin today. His title is "Pictures of Nothing: Abstract Art Since Pollock."

There is another deadline, another kind of dynamite. It is Varnedoe's inoperable cancer. "I always thought I'd make it through the Mellon Lectures," he says. "I always thought I'd be able to do that. But I just don't make any predictions about six months from now."

Seeking 'a Logic of Abstraction' Varnedoe, 57, spends Thursdays at Sloan-Kettering hospital in Manhattan receiving chemotherapy. A friend, New Yorker writer and art critic Adam Gopnik, often keeps him company. Over the course of the four hours, Varnedoe bounces his ideas about the abstraction lectures off his former student. Last fall, a young man who had just finished hours of treatment in the next cubicle poked his head around the partition. Gopnik remembers him telling Varnedoe, "I used to bring a book to read. Now I just listen to you."

Varnedoe's lectures are legendary. Before he joined MoMA, he taught art history at the Institute of Fine Arts at New York University for 13 years. Along with Gopnik, his former students include Jeffrey Weiss, head of the department of modern and contemporary art at the National Gallery, and Pepe Karmel, formerly a curator at MoMA and now an associate professor of fine arts at NYU.

"Kirk has been an inspiration to me and so many of his peers over the years," says Ned Rifkin, director of the Hirshhorn Museum and Sculpture Garden. "It's his acrobatic intelligence, his commitment to artists as creators of unique objects and his rigorous scholarship. There just aren't that many minds that work so hard on thinking and looking."

Five years ago, Varnedoe came to Atlanta when Rifkin was director of the High Museum of Art and lectured on Picasso. "I've heard really good lectures, and really not-good-at-all lectures," Rifkin says. Varnedoe "was nonstop insightful. I said to him afterward, 'Kirk, I wonder if you wouldn't mind, could I see your notes?' " Varnedoe handed Rifkin a piece of paper with four words on it -- roughly corresponding to the four main ideas of the lecture. "It was amazing. He did it all off the top of his head for one and a half hours."

Varnedoe was invited to give the prestigious Mellon Lectures three years ago. Why abstraction? Varnedoe was tempted to lecture on portraiture, an accessible, entertaining subject. The Mellon Lectures, after all, are aimed at a general audience.

Then, in "MoMA 2000," the museum's series of millennial exhibitions, Varnedoe curated the section called "Minimalism and After." One half of the show was sculptural -- a kind of "Variations on the Cube" that included the work of Tony Smith, Richard Serra, Donald Judd, Jackie Windsor, Giovanni Anselmo and Janine Antoni. The other half was abstract painting and conceptual art -- Cy Twombly, Jackson Pollock, Jasper Johns, Robert Morris, Felix Gonzalez-Torres and Sue Williams. "The experience of standing in front of that Twombly, the experience of looking at those cubes, I just felt there was something that was being achieved here that wasn't achieved in all the photography and figurative art elsewhere in the show," Varnedoe remembers. "This had such great dignity and such amazing austere power for me."

He realized too that abstract art was the "tougher nut to crack" for museum-going audiences. "The most vandalized pictures in museums are always monochrome abstractions. They're not nudes or provocative pictures," Varnedoe says. "People feel enraged by the sense that something's being pulled over their eyes. They're insulted."

To the highly sophisticated art world audience, says Gopnik, "abstraction is a dead letter. To the museum-going audience it still presents a challenge." Oddly, abstraction's place in current art practice roughly corresponds to representational art's place about 50 years ago when art historian E.H. Gombrich delivered the 1956 Mellon Lectures. "I always thought that one of the most impressive of the Mellon Lectures was Gombrich's," Varnedoe says.

In his lectures and a later book, "Art and Illusion: A Study in the Psychology of Pictorial Representation," Gombrich defended realism -- which Gombrich called "illusionism" -- as one of the major achievements of Western civilization. "It was a moment when, after World War II, modern art was being installed as the new humanism, and abstraction was the big hot issue," Varnedoe says. "Illusionism, which was everywhere, was taken to be banal. Gombrich wanted to . . . show that it had been an achievement, that it had been difficult to win."

Varnedoe realized he wanted to do the same for abstraction, to try to "come up with a logic of abstraction" that would explain why it, too, was a major achievement of Western civilization. In the last lecture of the series, "Abstract Art Now," he wants to show it is by no means "over," that younger artists are constantly regenerating it.

But the central idea of the lectures is that common explanations and justifications for abstract art are bankrupt. They just didn't work historically and they don't make sense logically. Even the explanations of artists themselves don't explain it. Its first practitioners, Mondrian, Malevich and Kandisky, for example, said abstraction was a search for spirituality, reaching ultimate absolutes, reforming the "new man," even part of a vast revolution. That revolution didn't happen. Under communism, abstraction was banished. Abstraction didn't make for new people and it didn't revolutionize consciousness, but it's pretty wonderful stuff. And it certainly changed visual culture and the way we saw the world. Varnedoe wants to give another explanation for abstraction that still allows for what's good and powerful about it, but on a more defensible basis, based on how it actually happened.

Some Tough Early Criticism Varnedoe was born in Savannah. His father was an investment banker; his mother one of the few women in her day to earn a master's degree in English literature. On his father's side were ancestors who fought for the Confederacy. Varnedoe's father and all but one of his father's brothers went to Yale. On his mother's side, way back when, there were Yankees. His mother and her sisters went to Smith. Varnedoe's parents opposed segregation, not an easy stance to take in the Deep South in those years. They traveled to Europe and New York frequently. They had three sons and a daughter; Kirk was the youngest.

His oldest brother, photographer Sam Varnedoe, 67, has a doctorate in philosophy, and he too has been listening to his youngest brother's thoughts on abstraction. " 'Art and Illusion' is an amazing book," says Sam Varnedoe, who taught at the University of Maryland for seven years and now lives in Astoria, N.Y. "It was certainly revolutionary. But I believe it was a badly built machine. I think it's terrific that Kirk's going to consider it again. He wants to come head to head with the book."

Sam left home for prep school when he was 14 and Kirk was 5. Sam didn't get to know his brother until years later, in 1971. Kirk was in Paris working at the Musee Rodin on his doctoral dissertation. They toured France on motorcycles. "I got an education about art from someone soon to be one of the most prominent art historians of his time," Sam remembers. By 1974, the pair was on the Upper West Side in Apartments 4B and 5B at 146 West 75th St. They shared a library, and sat talking about art for hours on Sam's terrace. Sam came to see abstraction was not really abstraction: "For example, Pollock is about the tangled part of the universe. Mondrian, I think, is about the carpentered part of the universe."

Sam, asked what has driven his brother over the years, answers, "I guess I have to say he's one of the most competitive people I've ever met. I've played squash with him and you would not want to give up a point needlessly when you play Kirk Varnedoe. He is 57 places in the court at once."

It was not always so. One of the stories that gets told about Varnedoe was how he was, as his brother puts it, "a roly-poly little guy as a kid. He was very passive. He watched an awful lot of television." When Kirk hit adolescence, Sam says, "he made up his mind he was going to be a different person." To his family's surprise he became an athlete and graduated valedictorian of his class at St. Andrew's prep school in Delaware. He played football at Williams, and then earned his doctorate in art history from Stanford at 26.

Varnedoe, while a young art professor at Columbia and then the Institute for Fine Arts, curated shows and wrote catalogues on French impressionist Gustave Caillebotte at the Museum of Fine Arts in Houston and 19th-century Scandinavian painting at the Brooklyn Museum of Art. In 1984, the year Varnedoe won a MacArthur Foundation grant, the head of MoMA's painting and sculpture department, William Rubin, invited him to help curate "Primitivism in 20th-Century Art: Affinity of the Tribal and the Modern." The show took the long-standing notion that tribal art had influenced modernism and traced exactly how that had occurred.

Thomas McEvilley, writing in Artforum in 1984, trounced the show, saying "something important is at issue here, something deeply, even tragically, wrong. In depressing starkness, 'Primitivism' lays bare the way our cultural institutions relate to foreign cultures, revealing it as an ethnocentric subjectivity inflated to co-opt such cultures." A heated exchange of letters among Varnedoe, Rubin and McEvilley ensued the following year in Artforum. It signaled a continuing conflict between Varnedoe and the left wing of the academic establishment. Rubin, however, thought highly of Varnedoe, and appointed him adjunct curator. In 1986, Varnedoe curated "Vienna 1900: Art, Architecture and Design" at MoMA. In 1988, Rubin announced that Varnedoe would succeed him.

The week of the announcement, the full-page Barneys ad of Varnedoe modeling the suit -- part of a campaign featuring "real" people -- appeared in the New York Times Magazine. (The modeling fee went to charity.) For some at MoMA, it reinforced perceptions that Varnedoe had a more-than-healthy ego. His high profile heightened resentment that someone who had never run a museum department was now running the most important modern art department in the world.

"I think people misunderstood who Kirk was," says Rifkin. "He had to learn to play on a team, and immediately after that, he was given the captain's job. But he regained his balance."

But not at first. New York Times art critic Roberta Smith called Varnedoe's first major show, "High and Low: Modern Art and Popular Culture" (co-curated by Gopnik), "a textbook case for the maxim that an exhibition top-heavy in masterpieces can still be a disaster." Fellow Times critic Michael Kimmelman called it "in principle, a brave undertaking" but "in reality a disappointment, not least because it shirks the very issues it promised to confront."

The same year "High and Low" opened, Varnedoe published "A Fine Disregard: What Makes Modern Art Modern," an important study that challenged prevailing (and largely pretentious) thinking about modern art's origins. He argued great art arose not because of sociopolitical ferment but from the genius and innovation of individual artists such as Rodin, Degas, Boccioni, Balla, Gauguin and Picasso. Varnedoe's curation returned to individual artists as well; he staged retrospectives of Twombly in 1995, Johns in 1997 and Pollock in 1998.

"Kirk Varnedoe has given us a humane and liberal account of the crucial passages in the history and origins of modern art," says Gopnik. It's an account, he explains, that does not accept Marxist ideas that art can be explained in terms of larger social and economic forces and how artists react to them. But it's also an account that rejects the narrowly formal ideas of MoMA founder Alfred Barr or of postwar critic Clement Greenberg, who saw art as far removed from the realities of history, and as moving relentlessly and inevitably toward pure abstraction.

In "A Fine Disregard," Varnedoe describes how the sociopolitical account, for example, would take Seurat's "Sunday Afternoon on the Island of La Grande Jatte" as a critique of the "starchy rigidity of the middle-class strollers." He describes how the formal account, on the other hand, saw modern painting as "stripping itself of illusionism and literary reference to arrive at an unadulterated presentation of color and shape on a flat plane." Varnedoe tries for some middle ground between the two positions: The birth of modern art, he believes, depended on the creative reactions of specific gifted individuals to the precise artistic and historical context they were working in. There was nothing inevitable about the stylizing course of modern picturemaking: It was directly contingent on these few artists' "fine disregard" of the status quo, and on their constant willingness to rewrite the rules of art.

Living Scan to Scan In 1996, Varnedoe thought he caught an intestinal virus from a vacation in India. His recovery was agonizing and eventually his doctors found he had colon cancer. He underwent surgery and chemotherapy. A week after the fifth anniversary without a recurrence, a routine X-ray disclosed that the cancer had spread to his lungs, and later, his adrenal glands.

That was the summer of 2001. Doctors told him there were four drugs they could try that would manage, though not ever cure, the cancer. "It's a real dice throw how your particular metabolism and constitution react to a particular drug," Varnedoe says. "I've managed to keep my hair. I've kept my appetite. I have not suffered unduly from fatigue. I have not suffered unduly from nausea. I've just been lucky in that regard.

"On the unlucky side, my cancer has adapted to the drugs at a fairly rapid rate. One of them didn't work at all. Two of them worked for a while and exhausted themselves and I'm on the fourth. The game that I'm playing now is to try to string out the drugs that are available until new ones become available."

For now, Varnedoe says, "I live six weeks to six weeks, scan to scan." He doesn't expect to get to the book he has wanted to write for years about the South and "how Rauschenberg, Johns and Twombly, three Southern boys, changed the world." (Robert Rauschenberg is from Port Arthur, Tex., and Lafayette, La. Johns came from Allendale, S.C. Twombly, from Lexington, Va.)

"I went along the week before last when he got the news about the latest scan. It's extraordinary to know that somewhere in this world, in a doctor's office, there's a place where you're going to hear whether you live or die," says Varnedoe's brother Sam. "These may be his last lectures, that's incontestable. But, oh my, I hope they're not."

Kirk Varnedoe's lectures are on Sundays at 2 p.m. in the East Building Auditorium of the National Gallery of Art. The lectures are free; seating is first come, first served. The series includes the lectures "Why Abstract Art?," March 30; "Survivals and Fresh Starts," April 6; "Minimalism," April 13; "After Minimalism," April 27; "Satire, Irony, and Abstract Art," May 4; "Abstract Art Now," May 11.

Despite his struggles with inoperable cancer, Kirk Varnedoe will explore abstract art in the A.W. Mellon Lectures, beginning today at the National Gallery.Kirk Varnedoe, for years one of the Museum of Modern Art's most influential curators, will address abstract art since Jackson Pollock in his Mellon Lectures, which run through May 11.