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 "to change allegiance, status, ownership". Cognates could include Greek ὄρφνη ("órphnē") "darkness", and surely Greek ὀρφανός ("orphanós") "fatherless, orphan", from which comes English "orphan" by way of Latin. Fulgentius, a mythographer of the late 5th to early 6th century AD, gave the unlikely etymology meaning "best voice," "Oraia-phonos". The earliest literary reference to Orpheus is a two-word fragment of the sixth-century BC lyric poet Ibycus: "onomaklyton Orphēn" ("Orpheus famous-of-name"). He is not mentioned in Homer or Hesiod. Most ancient sources accept his historical existence; Aristotle is an exception. Pindar calls Orpheus "the father of songs" and identifies him as a