What can one say about a movie that celebrates nonconformity by conforming to every Hollywood cliche in the book? Why must all movies about favorite teachers strike the same elegiac chord en route to the hero’s coronation? The movie’s cartoon notions of the ’50s and snooty Easterners say more about Hollywood cluelessness than about the period the film condescends to. The way the girls brazenly humiliate Katherine their first day in class is just one of many glaringly anachronistic details. And if Wellesley was such a stodgy bastion of anti-intellectualism, how did Vladimir Nabokov end up on the faculty in the ’40s?

The solid cast does what it can with the cut-and-dried material. Maggie Gyllenhaal is the self-destructive party girl (her open drinking would never have been tolerated); Julia Stiles, the smart girl who stifles her own ambitions for convention’s sake; Marcia Gay Harden, the prissy, pathetic professor of poise and elocution, and Dominic West, the womanizing Italian prof our heroine takes as a temporary lover.

What drew the usually astute Mike Newell (“Four Weddings and a Funeral,” “Donnie Brasco”) to this project? There are hints that the script (credited to Mark Rosenthal and Lawrence Konner) may once have had more shadings–a suggestion that Katherine’s idealism is a form of power-tripping; that she’s afraid of intimacy–but any ambiguity is quickly brushed aside to make way for the Julia lovefest. Newell, no hack, tries not to milk the cliches shamelessly, and that may be the movie’s final undoing. Lacking the courage of its own vulgarity, “Mona Lisa Smile” is as tepid as old bathwater.