It seems to the present writer that no solution of this and of the numerous other difficulties of which this is but one example can be profitably suggested, until we know more than we do at present about the origin and dates of Zoroastrianism. Although this religion is still with us in the beliefs of the modern Parsis, there is none about the origin of which we know less, or concerning the antiquity of which there is greater discrepancy between ancient and modern writers. Thus, while Plutarch, quoting as is generally supposed Theopompos of Chios who flourished in the IVth century B.C., declares that Zoroaster himself wrote 5000 years before the Trojan War[26], modern writers of authority, like Prof. Williams-Jackson and Mdlle Menant, are inclined to bring down the date of the eponymous prophet or reformer of the Persian religion to 700 B.C.[27] The discrepancy is too great to be bridged over by any compromise, and the question has been further complicated by the discovery a few years ago of inscriptions which show that Mithras, the Persian god whose worship formed the most dangerous rival to that of the Christian Church immediately before its alliance with Constantine, was one of the most exalted deities of the presumably Aryan Hittites or Mitannians at a date not later than 1272 B.C.[28] Signs are not wanting that discovery in the near future may take this line of advance, and if it should turn out that the religion which Zoroaster reformed was established in Northern Mesopotamia before the Homeric age, we may have to reconstruct all our ideas of the origin of the Greek religion. There seems no use therefore in dilating upon hypotheses which the course of research may in a very few years prove to be entirely erroneous[29]. In the meantime, the thing of immediate importance seems to be to get the documentary evidence already at our disposal as far as possible before the public, and this is attempted in the pages which follow. The different religions are there arranged in the chronological order of their greatest activity in the West with the belief that this course will prove most convenient to the reader. Footnote 1: For the pre-Christian centuries, the rise of ethical religions like that of the Greek Isis (see Chap. II _infra_) and of Mithras (see Chap. XII) is perhaps sufficient proof of this. For the post-Christian, see Tertullian’s remarks as to the interest excited among the heathens by problems like the origin of evil (_de Praescript._ c. VII.). As to their striving after morality, see Eugène de Faye, “Formation d’une Doctrine de Dieu au IIme Siècle,” _Rev. Hist. Rel._ t. LXIII. (Jan.-Fev. 1911) pp. 1, 2, for authorities. See, too, Hatch, _Hibbert Lectures_, 1890, pp. 291, 292 and Harnack as there quoted. Footnote 2: W. M. Ramsay, _The Church in the Roman Empire_, 1893, pp. 263, 264. Footnote 3: