In his work Love in the Western World (L’Amour et l’Occident), Denis de Rougemont examines the theme of courtly love expressed in the poetry of the 12th century troubadours and found in the courtly novels of the 13th century. According to Rougemont, this new and deeply influential definition of love originated from religious dissidents, the Cathars, transposing the contours of this religious movement to the lived experience of the lover facing his beloved. Rougemont sees in this medieval creation the origin of many facets of the “passion” which has since become familiar in the West. Relying on previously undisclosed archival documents (Marrou, Gilson, Massignon), the present article sheds light on the beginnings of the polemic sparked by the book. It distinguishes two levels in this debate, on the historical method as well as on the permeability between the religious and profane strata in society.