YOU WOULD have to look like Sarah Silverman to get away with the things she says. The cuteness rises off her like heat waves from a stove. She's such a Disney chipmunk, the freckliness not covered with powder, the toothiness the result of alarming amounts of orthodontia. Is there such a thing as prenatal braces? As a comedian, Silverman's secret lies in her mannerisms. She does a brilliant imitation of a person eager not to offend as she wrings her shoulders and casts her eyes down.

Just as the most arousing actresses were helpless captives of their own appeal—"I'm not to blame," sang Dietrich—the Silverman character is hilarious because she doesn't understand how a person can really be guilty of saying ridiculously offensive thing, so long as they're well bred and apologetic about it. Her face says: I'm sorry I feel this way. In fact, there's virtue in the fact that I'm honestly coarse and stupid enough to express such deep thoughts. As in the case of an ethnic who took offense at her—"He has to learn to love himself, before I can learn to stop hating his people."

This film of a live show in North Hollywood isn't a triumph of translation between the stage and the screen. Director Liam Lynch shoots from what looks like two cameras, with a few half-hearted cuts to the audience reacting. Some musical sequences by Silverman and her band, the Silver Men, aren't quite there, though she looks very fetching dressed as a 1960s fun girl, a Marlo Thomas. If Silverman has broken through as a comedian, maybe it's because she's been working on her acting. You can see her progress in the fictional framing sequences, where the coldhearted, selfish Silverman sneaks out from behind the mask of the entertainer. In a burst of self-love, she makes a torrid pass at her mirror, then breaks it up at the last minute before she goes too far and does something she'll regret later: "No, no ... not like this ..."

What's marvelous about the film is Silverman's astonishing aptitude for the sugar-coated slur and the pornographic story. While never doing strictly political humor, she is adept at the self-righteous neoconservative corrective: "Martin Luther King Jr. was a litterbug." Comedians sometimes justify reactionary jokes by saying that the real enemy of Lenny Bruce—the 1950s pioneer of Silverman's style of attack—was liberal self-satisfaction. Still, Bruce never forgot who the real enemy was. In Bruce's fiercest pieces, such as his lobbing racial stereotypes in the audience, he had cleansing in mind. The idea is that if we used these forbidden words, they'll become meaningless by repetition, they'll lose their power to hurt.

No one could possibly believe that today. Words change their meaning with each new generation. They mutate like viruses, bringing fresh fevers and pains. Past its hopes of improving others, Silverman's comedy is almost serene, fighting ignorance by embodying it. Before she performs "Amazing Grace" in three-part harmony. she tells a particularly wicked joke with the punch line, "You can't smell yourself." Silverman's comedy is about a woman who can't smell herself. I can't blame walkouts, but I think it's clear that the barb of her humor is aimed inward, not outward.

Sarah Silverman: Jesus Is Magic (Unrated; 72 min.), a film by Liam Lynch, opens Friday at selected theaters.

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