Writer-directors Peter and Bobby Farrelly (There's Something About Mary; Me, Myself & Irene) have been steadily eroding the filmmaking conventions that make work for good-looking actors, in part by exploiting our eagerness to gawk at freaks just as we gaze at gods and goddesses. Pointedly casting a character actor (Jack Black) as Hal, an average guy who's determined to date only exceptionally attractive women, the Farrellys reveal the deep, dark secret behind his aesthetic--that it's arbitrary--and nestle this insight in layers of comedy. Hypnotized by a well-meaning stranger, Hal comes to see spiritual beauty as physical beauty, and in this state he falls for Rosemary, a fat woman played with considerable nuance (and crafty point-of-view shots) by willowy Gwyneth Paltrow. If there's hypocrisy in the Farrellys' premise--teaching us to look at a thin person and imagine a fat one when for Hal the lesson works the other way--their great achievement is forcing those of us addicted to eye candy to see we have a problem. 113 min. Burnham Plaza, Century 12 and CineArts 6, Chatham 14, City North 14, Crown Village 18, Ford City, Gardens 7-13, Lake, Lawndale, Lincoln Village 1-6, Norridge, 600 N. Michigan, 62nd & Western, Village.