The religion thus imposed on the Persians seems to have been imageless by reason of the simple defect of art among its cultivators; [221] and to have been monotheistic only in the sense that its chief deity was supreme over all others, including even the great Evil Power, Ahriman (Angra Mainyu). Its God-group included Mithra, once the equal of Ahura-Mazda, [222] and later more prominent than he; [223] as well as a Goddess, Anahita, apparently of Akkadian origin. Before the period of Cyrus, the eastern part of Persia seems to have been but little civilized; [224] and it was probably there that its original lack of images became an essential element in the doctrine of its priests. As we find it in history, and still more in its sacred book, the Zendavesta, which as we have it represents a late liturgical compilation, [225] Mazdeism is a priest-made religion rather than the work of one Zarathustra or any one reformer; and its rejection of images, however originated, is to be counted to the credit of its priests, like the pantheism or nominal monotheism of the Mesopotamian, Brahmanic, and Egyptian religions. The original popular faith had clearly been a normal polytheism. [226] For the rest, the Mazdean ethic has the usual priestly character as regards the virtue it assigns to sacrifice; [227] but otherwise compares favourably with Brahmanism. As to this cult being priest-made, see Meyer, i, 523, 540, 541. Tiele (Outlines, pp. 167, 178) assumes a special reformation such as is traditionally associated with Zarathustra, holding that either a remarkable man or a sect must have established the monotheistic idea. Meyer (i, 537) holds with M. Darmesteter that Zarathustra is a purely mythical personage, made out of a Storm-God. Dr. Menzies (Hist. of Relig. p. 384) holds strongly by his historic actuality. The problem is analogous to those concerning Moses and Buddha; but though the historic case of Mohammed bars a confident decision in the negative, the balance of presumption is strongly against the traditional view. See the author's Pagan Christs, pp. 286-88.