Bergstrom examines the differences between Lang and Pabst's uses of "psychological explanation" in their films in order to show the wide spectrum of Weimar film's emphasis on psychology. She notes that while Pabst in such films as Pandora's Box and Secrets of the Soul emphasizes "'realistic' characters who are carefully individuated through psychological depth," Lang's characters are abstract types set up in contrast to institutions (163). Bergstom is not interested in psychoanalysis but in "how psychology is used at the narrative level" (164). Bergstrom reads Secrets of the Soul as didactic/educational film whose project is to legitimate psychoanalysis by showing how it works to diagnose and cure the film's central character. But she notes that the film is the least satisfying of those she examines because, while the main character is shown to have great psychological depth, the secondary characters are devoid of such depth.