Against Celsus 4.93

Hence, if I have admired anything else in Moses, I will declare this too worthy of admiration: that, having understood the different natures of animals, and whether he learned from the divine about them and the demons akin to each animal, or found it out himself, rising up by wisdom, in his ordinance about animals he said that all those thought prophetic by the Egyptians and the rest of humanity are unclean, and that, in general, those that are not such are clean. And among the unclean in Moses are the wolf, the fox, the serpent, the eagle, the hawk, and those like them. And in general, not only in the law but also in the prophets, you would find these animals taken as examples of the worst things, and never a wolf or a fox named for a good thing. It seems, then, that there is some fellowship between each kind of demon and each kind of animal. And just as among human beings some are stronger than others, not at all because of their character, in the same way some demons would be more powerful than others in matters indifferent; and some use these animals to deceive human beings, according to the will of the one called in our writings "the ruler of this age," while others foretell through another kind. And see how foul the demons are, so that even weasels are used by some to show the future. And do you judge for yourself which is better to accept: that the God over all and his Son move birds and the other animals to divination, or that those who move such animals, and not human beings though human beings are present, are wicked demons, and, as our holy writings have called them, "unclean."