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 death, although Euripides' play ""Alkestis"" states fairly clearly that Thanatos and Hades were one and the same deity, and gives an interesting description of Hades as being dark-cloaked and winged; moreover, Hades was also referred to as "Hesperos Theos" ("god of darkness"). When the Greeks propitiated Hades, they banged their hands on the ground to be sure he would hear them. Black animals, such as sheep, were sacrificed to him, and the very vehemence of the rejection of human sacrifice expressed in myth suggests an unspoken memory of some distant past. The blood from all chthonic sacrifices including those to