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
Christian views on Hades the souls of the wicked are in a state the reverse of this." The Latin word "infernus" or "infernum" (underworld) indicated the abode of the dead and so was used as the equivalent of the Greek word "ᾅδης" (hades). It appears in both the documents quoted above, and pointed more obviously than the Greek word to an existence beneath the earth. Later, the transliteration "hades" of the Greek word ceased to be used in Latin and "infernum" became the normal way of expressing the idea of Hades. Though "infernus" is usually translated into English as "hell", it did not have