"I don't need no man," is the woman's firm answer in the folk song quoted above, which is played over the sound system before the show and between the acts of "Rapture, Blister, Burn," a deep-delving comedy about contemporary relationships between the sexes, now at Theatre on the Square through Saturday. As a social movement, American feminism has not been able to come up with so categorical a dismissal of the male sex, tempting though that must be at times. It's probably more vital for women to advance their interests and accommodate their longings to the male power structure in their actual lives. Besides, the Woody Guthrie song is about a particular rejection; it's not a policy agenda, though it may do as a pleasant fantasy. Gina Gianfriddo 's play probes the vulnerability of Catherine Croll (Carrie Ann Schlatter), a romantically unattached feminist scholar who takes time out from her celebrity as a public intellectual to come home to her...