Ingenious theorists have accounted for the Iranian philosophy of a universal war between Ormuzd (Ahuramazda) the Good, and Ahriman (Angromainyus) the Evil, by vast and terrible climatic changes, involving extremes of heat and cold, of which geologists find traces about Old Iran, from which a colony of Aryans migrated to New Iran, or Persia. But although physical conditions of this character may have supplied many of the metaphors in which the conflict between Good and Evil is described in the Avesta, there are other characteristics of that ancient scripture which render it more probable that the early colonisation of Persia was, like that of New England, the result of a religious struggle. Some of the gods most adored in India reappear as execrated demons in the religion of Zoroaster; the Hindu word for god is the Parsî word for devil. These antagonisms are not merely verbal; they are accompanied in the Avesta with the most furious denunciations of theological opponents, whom it is not difficult to identify with the priests and adherents of the Brahman religion. The spirit of the early scriptures of India leaves no room for doubt as to the point at which this revolution began. It was against pious Privilege. The saintly hierarchy of India were a caste quite irresponsible to moral laws. The ancient gods, vague names for the powers of nature, were strictly limited in their dispensations to those of their priests; [13] and as to these priests the chief necessities were ample offerings, sacrifices, and fulfilment of the ceremonial ordinances in which their authority was organised, these were the performances rewarded by a reciprocal recognition of authority. To the image of this political régime, theology, always facile, accommodated the regulations of the gods. The moral law can only live by being supreme; and as it was not supreme in the Hindu pantheon, it died out of it. The doctrine of 'merits,' invented by priests purely for their own power, included nothing meritorious, humanly considered; the merits consisted of costly sacrifices, rich offerings to temples, tremendous penances for fictitious sins, ingeniously devised to aggrandise the penances which disguised power, and prolonged austerities that might be comfortably commuted by the wealthy. When this doctrine had obtained general adherence, and was represented by a terrestrial government corresponding to it, the gods were necessarily subject to it. That were only to say that the powers of nature were obedient to the 'merits' of privileged saints; and from this it is an obvious inference that they are relieved from moral laws binding on the vulgar.