The original solar signification of Apollo is maintained among other eminent scholars by Creuzer, Welcker, and Gerhard, who appeal alike to ancient monuments and coins, and to vestiges of ancient Sun-worship found in various localities in Greece. "If we desire," says Creuzer, "in studying Greek mythology, to reach its ultimate roots, we must explore the ancient literatures of Persia and India. If from this point of view we investigate the original identity of the Sun-god and Apollo, we shall find in the figurative language of the Vedas the primitive occasion of the transition from the former to the latter."
One of the most striking features of the ancient Sun-worship was its dualistic character, founded upon the twofold aspect of the solar luminary, as at the same time a beneficent and a destroying power, as conquering and conquered, as dying, yet endowed with ever-renovated life; a conception which explains the enigma said to be uttered by the oracle of Apollo at Claros, in Ionia, "I am Jupiter Ammon in Spring, and black Pluto in Winter." In order to understand the more terrible aspects of the ancient Sun-god, we have only to remember the annual fevers occasioned by his scorching rays, and the danger of famine from failure of the crops: after the lightning of Zeus, there was no natural agent so destructive as the arrow of Helios; as calamity, moreover, was regarded in ancient times as the expression of Divine anger, expiatory and penitential rites formed an essential element of the ancient Sun-worship. This twofold aspect of Helios finds
