Movie adaptations of the works of famous authors can serve as a form of literary criticism. That's not to say that one can fairly judge the writing of Philip Roth based on the movies that have been made from his books.

But boiling down the books to their most basic, and seeing on screen the lecherous (and now old) men the old semi-autobiographical novelist paired with the cinema's reigning beauties can make the guy, his sexual obsessions and his recent writing seem ridiculous.

"The Human Stain," which had the accomplished old academic Anthony Hopkins hiding his racial history behind an affair with a most trashy Nicole Kidman, made for an odd coupling. The attraction can seem pretty one-sided, even if the leading man is a fit 70-something.

The new film, "Elegy," taken from another Roth work, puts Ben Kingsley in bed with the stunning Penélope Cruz. It's a lot less jarring than "Human Stain," at least in the sense that a gorgeous, unsure of herself Cuban-American student could fall for her brilliant, celebrated and ever-on-the-make professor. But it lacks both sexual heat and romantic warmth.

Kingsley is David Kepesh, a cultural philosopher-historian, a PBS and NPR staple, who narrates his pondering of the one nagging question that dominates his life.

"Why can't an old man act his age?"

He walked out on a marriage, something his grown son (Peter Sarsgaard in a too-small role) never forgave. He has a decades-long uncomplicated fling with sexy, successful businesswoman Carolyn (Patricia Clarkson).

And at school, David plays by the "sexual harassment" rules, never seducing students who are actively taking classes from him. But he makes it a point of throwing a cocktail party for his classes after they're done. That's when he makes his move on Consuela (Cruz).

She's sensitive, sexy without making the effort to be, and in his view, a little unsophisticated. He'll bed her, show her the finer things in life, theater, music, wine. And then she'll find somebody more her speed, closer to her own age.

Except this time, David gets jealous. He is struck by feelings he's never had. He can make his crude confessions to his academic pal (Dennis Hopper, very good), but he can't do the right thing. He can't break it off and he can't commit.

Director Isabel Coixet did the wonderful, melancholy "My Life Without Me," but despite her stellar cast and an engrossing, interior-monologue rich script by Nicholas Meyer, who does a better job adapting this than he did "The Human Stain," Coixet can't get past the lack of chemistry between her leads.

Cruz's Consuela seems more resigned to this affair than genuinely smitten. Kingsley's David can swagger all he likes, but we're never convinced that he's convinced he has enough to offer, physically or temperamentally, either of these gorgeous women who share nude scenes with him.

Occasionally touching, always interesting, "Elegy" may capture the essence of Roth, but it never lets him off the hook for being the eternal dirty old man, playing out some dirty old man's wish-fulfillment fantasy.