Colin Davis focuses on the theme of evil in adaptations of Stevenson's The Strange Case of Dr. Jekyll and Mr. Hyde and how it relates to the original narrative. Davis argues that adaptations of the novella, in particular Jean Renoir's 1959 film Le Testament du docteur Cordelier, must adapt the idea and representation of evil to relate to the time and social atmosphere in which they take place. Davis explains that Stevenson also did this when the novella was written; the "evil" of the narrative correlated to what was happening in science and medicine at the time. Adapting the representation of evil in the story allows the narrative to continue. Davis discusses Immanuel Kant's types of evil (frailty, impurity, wickedness) and how they relate to the novella and its adaptations. Davis suggests