One generation’s faculty gossip is sometimes another’s cultural history. At the University of Chicago in the early 1950s, a professor stopped a teenage student leaving one of his classes. She was not properly enrolled in the course, but bureaucratic proprieties really did not have anything to do with it. She was stunning. He was smitten. They had lunch. And 10 days later, give or take, Philip Rieff was joined in marriage to a young woman who never actually did change her name to Susan Rieff, instead always being known as Susan Sontag.

They did not live happily ever after. The opening pages of Sontag’s last novel, In America, are written in a first-person voice that sounds very much like the author’s. The narrator mentions reading George Eliot as a young bride and bursting into tears at the realization she had, like Dorothea in Middlemarch, married Casaubon.

As you may recall, Dorothea is at first transfixed by the learning and gravitas of Casaubon, a scholar who is many years her senior. It soon dawns on her (as it does perhaps more quickly for the reader) that he is a bloodless pedant, joyless except when venting spleen against other bloodless pendants. And there are hints, as clear as Victorian propriety will allow, that Dorothea’s honeymoon has been disappointing in other ways as well.

Sontag’s allusion must rank as one of the more subtly devastating acts of revenge ever performed by an ex-wife. At the same time, it is in keeping with some durable and rather less literary attitudes towards professors -- the stereotype that treats them as being not just other-worldly, but also rather desexed by all the sublimation their work requires. This view really took hold in the 19th century, according to the analysis presented by A.D. Nuttall in Dead From the Waist Down: Scholars and Scholarship in Literature and the Popular Imagination (Yale University Press, 2003).

But a different cliché is emerging from Hollywood lately. The summer issue of The American Scholar contains an essay by William Deresiewicz called “Love on Campus” that identifies a “new academic stereotype” visible in popular culture. The sexually underachieving Casaubon’s day is over. The new stereotype of the professor has some notches in his bedpost (this character is almost always a male) and for the most part demonstrates his priapic prowess with students.

Universities in real life are “the most anxiously self-patrolled workplace in Ameican society,” writes Deresiewicz, “especially when it comes to relations between professors and students. This is not to suggest that sexual contact between college students and professors, welcome or unwelcome, never takes place, but the belief that it is the norm is the product of fantasy, not fact.”

Yet the fantasy is played out in numerous contemporary films. It merits examination for what it implies about how academe is perceived and (mis)understood.

The stereotyped character in question is often a professor of English or creative writing, as in "The Wonder Boys" or "The Squid and the Whale." But sometimes he teaches philosophy ("The Life of David Gale") or French ("Little Miss Sunshine"). He is consumed with ambition. But he is also a loser. Those condition -- academic ambition, abject failure -- are identical, at least given the implicit logic of the stereotype.

“In the popular imagination,” writes Deresiewicz, “humanities professors don’t have anything to be ambitious about. No one really knows what they do, and to the extent that people do know, they don’t think it’s worth doing.... It may be simply because academics don’t pursue wealth, power, or, to any real extent, fame, that they are vulnerable to such [criticism]. In our culture, the willingness to settle for something less than these Luciferian goals is itself seen as emasculating.”

So he neglects his family, or drinks, or both. Above all, he seduces his students. The latter is not so much an abuse of power as a symptom of having no real power at all. He is “a figure of creative sterility,” writes Deresiewicz, “and he is creatively sterile because he loves only himself. Hence his vanity, pomposity, and selfishness; his self-pity, passivity, and resentment. Hence his ambition and failure. And thence his lechery, for sleeping with his students is a sign not of virility but of impotence: he can only hit the easy targets; he feeds on his students’ vitality; he can’t succeed in growing up.”

At one level, this new character may look like the negation of earlier clichés about absent-minded and asexual professors. But that appearance is, in some ways, misleading. These more recent fictional figures are, so to speak, Casaubon on Viagra. Like his ancestor, the contemporary on-screen professor is empty and vain, and going nowhere fast. But he has another way to vent. “In both ‘Terms of Endearment’ and ‘We Don’t Live Here Anymore,’” notes Deresiewicz, “ ‘going to the library’ becomes a euphemism for ‘going to sleep with a student.’ ”

Deresiewicz offers a cogent analysis of how this stereotype may reflect the changing place of academe in American society and the contradictory attitudes it evinces. He also presents some thoughts on a dimension of education that popular culture for the most part ignores: the eros of learning, the way a student can fall in love with a teacher for reasons having nothing to do with sexuality. Combining them, as Sontag tried to do with Rieff, seems like a bad idea.

It is a remarkable essay -- cogent on many points, and adventurous in making some of them, given the inescapable risk of being misunderstood. (I half expect to see Deresiewicz on a cable program with the words "Professor Advocating 'Brain Sex' " at the bottom of the screen.) Rather than quote or paraphrase any more of it, let me simply recommend that you read the whole thing.