Traugott Konstantin Oesterreich  Traugott Konstantin Oesterreich (15 September 1880, in Stettin (Szczecin) – 28 July 1949, in Tübingen) was a German religious psychologist and philosopher. Oesterreich was also interested in parapsychology. He argued against the philosophy of materialism. He was the author of "Die Besessenheit" (1921), a book on demonic possession. It was translated into English in 1966. William Peter Blatty, author of "The Exorcist", was influenced by the book.