Lust or luxuria, one of the Seven Deadly Sins, was a rich and resonant term in the medieval Christian world, evoking a whole range of appetites and desires while speaking to penitential and other ecclesiastical discourses on human sexuality. Chaucer was an avid and inventive theorist and narrator of lust in its many emotional, affective and incarnate permutations, treating the category of lust with great ingenuity though with a surprising inconsistency inherited in part from scholastic discourses on the sin and its ramifications in human life. In Chaucer’s representations of Criseyde, Troilus, the Wife of Bath, and the Parson, among many others, lust functions as both a simple human desire for some end as well as a direct pathway to sin.