 It is here that he sets forth a famous characterization of "the peculiar form which it [courtly love] first took; the four marks of Humility, Courtesy, Adultery, and the Religion of Love"—the last two of which "marks" have, in particular, been the subject of a good deal of controversy among later scholars.In the second chapter, Lewis discusses the medieval evolution of the allegorical tradition in such writers as Bernard Silvestris and Alain de Lille.The remaining chapters, drawing on the points made in the first two, examine the use of allegory and personification in the depiction of love in a selection of poetic works, beginning with the "Roman de la Rose".