Shannyn Sossamon tries to tempt Josh Hartnett from his celibacy vow in the comedy 40 Days and 40 Nights

That character is Matt Sullivan (Josh Hartnett), a young dot-commer who is heartbroken after his girlfriend Nicole (Vinessa Shaw) dumps him. Matt tries to get over her by having a series of meaningless sexual flings, only to find himself panicking at every attempt. He is finally pushed over the edge when he discovers Nicole has gotten engaged. It's too much to take - he needs a cleansing, a way to purge himself of all sexual and romantic thoughts until he can regain his focus. Turning to his brother (a Catholic priest) for help, Matt decides that the only way he can get his head straight is to forego sex during the 40 days of Lent. That means no intercourse, no touching, no kissing, and no masturbation. Not even his brother thinks Matt can pull this off.

Initially, he starts off okay, spending his time putting together model cars while his roommate Ryan (Paulo Costanzo) tries to tempt him with one promiscuous hottie after another. Matt somehow fends off Ryan's advances. Then - at a laundromat - he meets Erica (Shannyn Sossamon) and is immediately attracted to her. They go out on a date, but to avoid closeness, he only takes her for a ride around the city on a public bus. When Erica finally learns about Matt's vow of celibacy, she feels somewhat tricked. Is this guy really interested in her or just pulling some sort of cheap scam? As the movie progresses, Matt becomes more and more desperate; he wants to show Erica how much he cares, but he also wants to live up to his promise.

40 Days and 40 Nights understands one of the major rules of comedy: desperation is funny. By exaggerating a character's misery, you can milk big laughs. I don't want to ruin any good gags, but the movie uses some fantasy sequences to show just how preoccupied Matt's subconscious is with sex. (Sigmund Freud would have called this the movie of the year.) Hartnett, who until now has had only serious dramatic roles, shows a real flair for comedy. With every passing day of Matt's abstinence, Hartnett uses more and more contorted facial expressions and uncoordinated body movements to show just how badly the pressure is working on the character's system. He really made me laugh.

In the wrong hands, this plot could have been just a one-joke movie, but writer Robert Perez and director Michael Lehmann (Heathers, The Truth About Cats & Dogs) aren't interested in making just another sex comedy. They want to make a sex comedy with a brain. For all its outrageous humor, 40 Days and 40 Nights actually has something to say about the value of emotional intimacy over physical intimacy. Not that it's preaching abstinence, mind you, but it does suggest that the real connection between two people can be found in the kiss rather than in the bed.

I thought the story faltered somewhat in the final act, where Nicole returns and does something that, quite frankly, is a little creepy when you think about it. Mostly, though, I was entertained by the picture. It's light and breezy, but also a surprisingly witty movie about sex. And these days, that's a real rarity.

( out of four)

40 Days and 40 Nights is rated R for strong sexual content, nudity and language. The running time is 1 hours and 39 minutes.