But such a conclusion is not necessary.

Nations have often had an oral literature, existing only in the memories of men, and have handed down such a literature from generation to generation, through a long succession of ages.

The sacred lore of Zoroaster may have been brought by the Modes from the East-Caspian country in an unwritten shape, and may not have been reduced to writing till many centuries later.

On the whole it is perhaps most probable that the Medes were unacquainted with letters when they made their great migration, and that they acquired their first knowledge of them from the races with whom they came into collision when they settled along the Zagros chain.

In these regions they were brought into contact with at least two forms of written speech, one that of the old Armenians, a Turanian dialect, the other that of the Assyrians, a language of the Semitic type.