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 then a subscript marking (), and finally omitted entirely (). Perhaps from fear of pronouncing his name, around the 5th century BC, the Greeks started referring to Hades as Plouton ( "Ploútōn"), with a root meaning "wealthy", considering that from the abode below (i.e., the soil) come riches (e.g., fertile crops, metals and so on). Plouton became the Roman god who both rules the underworld and distributed riches from below. This deity was a mixture of the Greek god Hades and the Eleusinian icon Ploutos, and from this he also received a priestess, which was not previously practiced in Greece.