By Troy Patterson
Updated February 06, 1998 at 05:00 AM EST

A fox-eyed philosophe (Poupaud) lends his copy of Diary of a Seducer, S %oslash; ren Kierkegaard’s treatise on love, to a bored belle (Mastroianni), and the book proves a love charm. The romances set off range from madcap kiss-kiss to blood-soaked bang-bang, but rest assured that whenever this purported comedy-thriller’s eccentricity spins toward lunacy, Mastroianni — a sort of sharp, Continental edition of Claire Danes — strides in to renew the enchantment. B+