Sources.--The views generally current about the ancient religion of Persia are derived from late Greek writers, whose accounts will be noticed at the end of this chapter. A truer knowledge is now possible, since the sacred books of the religion are now open to the world. They were only obtained from the Parsis, who keep up their ancient religion on the soil of India, during last century, and the study of them has been very laborious and difficult, and has given rise to great controversies which are not yet settled. These ancient books are furnished with Eastern translations and commentaries. Is the Western scholar to place himself under the guidance of these, which no doubt are part of the historical tradition of the religion, or may he claim that he is himself in as good a position as the Oriental commentator for understanding the original meaning of the texts; and will he best interpret them by comparing them with the Vedas? What is their age; in which of the lands of Iran were they written; was any part of them written by Zoroaster, or is Zoroaster to be regarded as an historical personage at all? On all these questions and on many others, scholars are not yet agreed; and while so much is uncertain about the books, there must also be great uncertainty about the history and the very nature of the religion. In what follows we are guided mainly by the scholars who have taken charge of the volumes connected with Persia in the _Sacred Books of the East_.[1] In the last of these volumes (xxxi.) a new clue is given to the subject, of which we shall gladly avail ourselves. [Footnote 1: Zend-Avesta, _S. B. E._, vols. iv., xxiii., xxxi.]