It was, however, among the cognate Iranian people that this antithesis acquired the greatest force, under the influence of the prophet Zarathustra. By a curious historic-religious process which cannot here be traced, the terms of the opposing forces were reversed. _Ahura_ (= _asura_) remained the name of the Supreme Power, with the addition of the term _Mazda_, "all-knowing," and the _daevas_ (= _devas_) became the evil multitude. In the oldest part of the Zend Avesta Ahura appears as the sole Creator, the God of light and purity and truth, who dwells on high in the Abode of Song. Beside him is his Good Mind, and the Holy (or beneficent, gracious) Spirit. But opposed to him in the realm of darkness beneath is "the Lie" (_drug_), with its correlates the Bad Mind and the Evil Spirit (_Añra Mainyu_, not yet a proper name). The world between is the scene of continuous struggle, and in this conflict man is called to take his {212} part. Ritual purity, appropriate sacrifice, and personal righteousness in thought, word, and deed, are his weapons in the fight. By these he helps to establish the sovereignty of Ahura, and to curtail the power of "the Lie." The earliest representations offer no account of the origin of the Drug any more than of Ahura himself. But later speculation, impressed with the contrasting elements of human life, began to ascribe to him, too, under the name of Ahriman (Añra Mainyu), creative power; all noxious animals and plants were due to him; plague and disease came from his hands; all agencies of cold, darkness, and destruction were his work; he was the _daeva_ of _daevas_, Lord of death, and author of temptation. And finally, in the long process of thought the two powers of good and evil had both issued from a still higher unity, Zervan Akarana, Time without bound. But long ere this the Persian character had responded to Zarathustra's teaching of warfare against "the Lie"; and Herodotus bears testimony to their repute for loyalty to truth. For from the earliest days the dualism of Zarathustra bound together morality and religion in the closest alliance. How the great demand for the ultimate victory of good was to be justified will be seen hereafter (p. 247).