ended, as among the Hebrews, by separating themselves from the rest
of the nation and forming a special tribe, that of the Magi, which was
the last to enter into the composition of the nation in historic times.
All the Magi were not necessarily devoted to the service of religion,
but all who did so devote themselves sprang from the Magian tribe; the
Avesta, in its oldest form, was the sacred book of the Magi, as well as
that of the priests who handed down their religious tradition under the
various dynasties, native or foreign, who bore rule over Iran.

The Creator was described as "the whole circle of the heavens," "the
most steadfast among the gods," for "he clothes himself with the solid
vault of the firmament as his raiment," "the most beautiful, the most
intelligent, he whose members are most harmoniously proportioned; his
body was the light and the sovereign glory, the sun and the moon were
his eyes." The theologians had gradually spiritualised the conception
of this deity without absolutely disconnecting him from the material
universe.

[Illustration: 012.jpg THE AHURA-MAZDA OF THE BAS-RELIEFS OF PERSEPOLIS]

Drawn by Faucher-Gudin, from Flandin and Coste.

He remained under ordinary circumstances invisible to mortal eyes,
and he could conceal his identity even from the highest gods, but he
occasionally manifested himself in human form. He borrowed in such case
from Assyria the symbol of Assur, and the sculptors depict him with the
upper part of his body rising above that winged disk which is carved in
a hovering attitude on the pediments of Assyrian monuments or stelae.

[Illustration: 012b.jpg HYPOSTYLE OF HALL OF XERXES: DETAIL OF
ENTABLATURE]

In later days he was portrayed under the form of a king of imposing
stature and majestic mien, who revealed himself from time to time to the
princes of Iran.*

* In a passage of Philo of Byblos the god is described as
having the head of a falcon or an eagle, perhaps by
confusion with one of the genii represented on the walls of
the palaces.

[Illustration: 013.jpg AN IRANIAN GENIUS IN FORM OF A WINGED BULL]

Drawn by Boudier, from a photograph.

He was named Ahuro-mazdao or Ahura-mazda, the omniscient lord,*
_Spento-mainyus_, the spirit of good, _Mainyus-spenishto_** the most
beneficent of spirits.

* _Ahura_ is derived from _Ahu_ = _Lord_: Mazdao can be
analysed into the component parts, _maz = great_, and _dao