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
Hades dead (also called Erebus) where all mortals go when they die. Very few mortals could leave Hades once they entered. The exceptions, Heracles and Theseus, are heroic. Even Odysseus in his "Nekyia" ("Odyssey", xi) calls up the spirits of the departed, rather than descend to them. Later Greek philosophy introduced the idea that all mortals are judged after death and are either rewarded or cursed. There were several sections of the realm of Hades, including Elysium, the Asphodel Meadows, and Tartarus. Greek mythographers were not perfectly consistent about the geography of the afterlife. A contrasting myth of the afterlife concerns