What Dreams May Come in the book are derived from my wide range of reading." One of Matheson's influences was Harold W. Percival, an adherent of Theosophy, a belief system with a strong Eastern and Hindu influence. The story also shares the same theme of the ancient Greek myth Orpheus and Eurydice, in which the gifted musician makes a challenging journey to Hell to retrieve his wife. One character quotes from the writings of 18th century Christian mystic Emanuel Swedenborg. Matheson bases his descriptions of the death experience itself on studies by Elisabeth Kübler-Ross and Raymond Moody. When reading these accounts, Matheson found that
Orpheus of Demeter Chthonia and that of the "Kóres Sōteíras" (Greek "Κόρες Σωτείρας" "Saviour Maidens"). Also in Taygetus a wooden image of Orpheus was said to have been kept by Pelasgians in the sanctuary of the Eleusinian Demeter. According to Diodorus Siculus, Musaeus of Athens was the son of Orpheus. The "Argonautica" () is a Greek epic poem written by Apollonius Rhodius in the 3rd century BC. Orpheus took part in this adventure and used his skills to aid his companions. Chiron told Jason that without the aid of Orpheus, the Argonauts would never be able to pass the Sirens—the same