Perhaps we have here a recognition of the anarchic character of evil, whose attacks are like those of a huge undisciplined host--casual, fitful, irregular--destitute wholly of that principle of law and order which gives to the resisting power of good a great portion of its efficacy.
To the belief in a spiritual world composed of all these various intelligences--one half of whom were good, and the other half evil--the early Zoroastrians added notions with respect to human duties and human prospects far more enlightened than those which have usually prevailed among heathen nations.

In their system truth, purity, piety, and industry were the virtues chiefly valued and inculcated.

Evil was traced up to its root in the heart of man; and it was distinctly taught that no virtue deserved the name but such as was co-extensive with the whole sphere of human activity, including the thought, as well as the word and deed.

The purity required was inward as well as outward, mental as well as bodily.

The industry was to be of a peculiar character.