All have their logic, philosophy, stories, legends, or myths to elaborate. Many believe that evil exists in the universe and many confine it, some in vague terms, to the human world. Zarathushtra observes the universe as a good creation of God and sees no evil in it. However, there are indications that he sees the universe in its infancy, complete in every form but growing to perfection and immortality. As regards good and evil, he confines both to human mind, not outside, not in the cosmos.
Man thinks and thinks constantly.
His thoughts are either good or bad, beneficial or harmful. The two represent the duality only and only in the human mind and within the human society. The dualism in the Gathas is pure ethical in nature. The Gathas advocate a free, peaceful, prudent, and progressive society, both in spirit and matter. It makes them conceive God.