Plutarch, De Iside et Osiride
Frank Cole Babbitt, Ed.

The great majority and the wisest of men hold this opinion : they believe that there are two gods, rivals as it were, the one the Artificer of good and the other of evil. There are also those who call the better one a god and the other a daemon, as, for example, [p. 113] Zoroaster¹ the sage,² who, they record, lived five thousand years before the time of the Trojan War. He called the one Oromazes and the other Areimanius³; and he further declared that among all the things perceptible to the senses, Oromazes may best be compared to light, and Areimanius, conversely, to darkness and ignorance, and midway between the two is Mithras ; for this reason the Persians give to Mithras the name, of ‘Mediator.’ Zoroaster has also taught that men should make votive offerings and thank-offerings to Oromazes, and averting and mourning offerings to Areimanius. They pound up in a mortar a certain plant called omomi, at the same time invoking Hades⁴ and Darkness ; then they mix it with the blood of a wolf that has been sacrificed, and carry it out and cast it into a place where the sun never shines. In fact, they believe that some of the plants belong to the good god and others to the evil daemon ; so also of the animals they think that dogs, fowls, and hedgehogs, for example, belong to the good god, but that water-rats⁵ belong to the evil one ; therefore the man who has killed the most of these they hold to be fortunate.