The City of God by Augustine

Augustine of course knew that demons appeared in the scriptures as well as angels and at several junctures in the city of God he is compelled to deal with Christianity's second string divine beings. To Augustine, angels were divine because they could see the divine plan behind the material world whereas demons could not. The pursuit of happiness through means of demonic intermediaries to Augustine was doubly misguided as the only intermediary really needed between humanity and God was Christ. While Augustine had issues with latter day Platonists going on and on about angels and demons, he had another problem with them. And this was their writings about a practice called Theurgy, ritual practices designed to bring humans closer with God. This