"The Problem of the Puer Aeternus" is a book based on a series of lectures that Jungian analyst Marie-Louise von Franz gave at the C.G. Jung Institute, Zurich, during the Winter Semester, 1959–1960. In the first eight of twelve lectures, von Franz illustrates the theme of the puer aeternus by examining the story of The Little Prince from the book of the same name by Antoine de Saint-Exupéry. The remaining four lectures are devoted to a study of a German novel by Bruno Goetz, "Das Reich ohne Raum" ('The Kingdom Without Space'), first published in 1919. Of this novel von Franz says: