 Ritsema then worked at odd jobs to support himself, but continued voraciously to read on his own, particularly in French and German literatures, Tibetan Buddhism, and in Jungian psychology.In 1944 Ritsema and Catherine Gris began psychoanalysis under Alwine von Keller, whom Ritsema had previously encountered at the Odenwaldschule (where she worked as an English-literature teacher).It was von Keller who would now introduce him to the "I Ching".