For public consumption Gerhart Hauptmann was Germany's greatest naturalist writer. Another, private existence is however revealed in and by the religious studies he undertook from ca. 1885 to 1945. His quest for that which underlies man's diverse perspectives of the supernatural and binds them into a whole leads him to study Christianity, eastern religions, the writings of Jacob Boehme, etc. Material from Hauptmann's notebooks, diaries, marginalia from his personal library, and a careful examination of the texts he actually read, show the effects of this preoccupation on his thinking and works, as well as explains his intense interest in German mysticism and the philosophies of the East.