Killing the Ahriman creatures is killing Ahriman himself, and many sins can thus be atoned for, while killing Ormazdean animals is an abomination like the killing of the god. The struggle between the good and evil, however, is limited, for the world is not to last forever, and Ahriman will be defeated at last. There had been an old myth that the world would end in a fearful winter like that of the Eddic Fimbul, which would be succeeded by an eternal spring, but as a storm is the ordinary symbol of strife, the view which finally obtained in their mythology, is the prediction that the world will finally end in a battle of the elements. The Pārsīs came at last to a pure monotheism, and to a certain extent this change may have been influenced by the creed of the Moslem that “there is one God, and Mohammed is his prophet,” but the difference in sentiment cannot be ascribed to any one generation, for it is really deeper and wider than the movement which, in earlier times, brought the Magi from an imperfect form of dualism to one which was much more decided in its presentations.[176] THE GĀTHAS. The five Gāthas which have been attributed to Zarathuśtra are doubtless the earliest portions of the Zend-Avesta. They comprise seventeen sections of poetical matter, equal in extent to twenty-five or thirty hymns of the Ṛig-veda. They are composed in the ancient Āryan metre, and ascribe supreme power to Ahūra Mazda, who is opposed constantly by the spirit of evil. In these early songs, the kine, as the representative of the people, laments the burden which is laid upon Īrānian life. The effort to win their bread by honest labor is opposed, although not entirely frustrated, by the Deva-worshipping tribes, who still struggle with the Zarathuśtrians for the control of the territory. The kine, therefore, lifts her wail to Ahūra, who responds by the appointment of Zarathuśtra as the being who is entrusted with her redemption; and he, accepting his commission, begins his labors. We then have a series of lamentations and praises addressed by Zarathuśtra and his immediate associates to Ahūra; also exhortations which are addressed to the people. These hymns were composed amidst an agricultural people, many of whom were also herdsmen. Their land and their cattle being their most valuable property, the raids of the Deva-worshippers were looked upon as most terrible visitations. In the course of these invasions, we have also intimations of an organized effort on the part of the foe to overwhelm the Zarathuśtrians, and it appears that at times they very nearly accomplished their object, sanguinary conflicts being repeatedly alluded to. It may be inferred by the prevalence of the thankful tone in the Gāthas, that the Zarathuśtrians were not conquered during the Gāthic period, although at the time that the last hymns of the series were written, the struggle was by no means over.