Nicene and Post-Nicene Fathers, Vol. II:
City of God: Chapter 9

Chapter 9.—Of the Illicit Arts Connected with Demonolatry, and of Which the Platonist Porphyry Adopts Some, and Discards Others.

These miracles, and many others of the same nature, which it were tedious to mention, were wrought for the purpose of commending the worship of the one true God, and prohibiting the worship of a multitude of false gods.  Moreover, they were wrought by simple faith and godly confidence, not by the incantations and charms composed under the influence of a criminal tampering with the unseen world, of an art which they call either magic, or by the more abominable title necromancy, 403 or the more honorable designation theurgy; for they wish to discriminate between those whom the people call magicians, who practise necromancy, and are addicted to illicit arts and condemned, and those others who seem to them to be worthy of praise for their practice of theurgy,—the truth, however, being that both classes are the slaves of the deceitful rites of the demons whom they invoke under the names of angels.

For even Porphyry promises some kind of purgation of the soul by the help of theurgy, though he does so with some hesitation and shame, and denies that this art can secure to any one a return to God; so that you can detect his opinion vacillating between the profession of philosophy and an art which he feels to be presumptuous and sacrilegious.  For at one time he warns us to avoid it as deceitful, and prohibited by law, and dangerous to those who practise it; then again, as if in deference to its advocates, he declares it useful for cleansing one part of the soul, not, indeed, the intellectual part, by which the truth of things intelligible, which have no sensible images, is recognized, but the spiritual part, which takes cognizance of the images of things material.  This part, he says, is prepared and fitted for intercourse with spirits and angels, and for the vision of the gods, by the help of certain theurgic consecrations, or, as they call them, mysteries.  He acknowledges, however, that these theurgic mysteries impart to the intellectual soul no such purity as fits it to see its God, and recognize the things that truly exist.  And from this acknowledgment we may infer what kind of gods these are, and what kind of vision of them is imparted by theurgic consecrations, if by it one cannot see the things which truly exist.  He says, further, that the rational, or, as he prefers calling it, the intellectual soul, can pass into the heavens without the spiritual part being cleansed by theurgic art, and that this art cannot so purify the spiritual part as to give it entrance to immortality and eternity.  And therefore, although he distinguishes angels from demons, asserting that the habitation of the latter is in the air, while the former dwell in the ether and empyrean, and although he advises us to cultivate the friendship of some demon, who may be able after our death to assist us, and elevate us at least a little above the earth,—for he owns that it is by another way we must reach the heavenly society of the angels,—he at the same time distinctly warns us to avoid the society of demons, saying that the soul, expiating its sin after death, execrates the worship of demons by whom it was entangled.  And of theurgy itself, though he recommends it as reconciling angels and demons, he cannot deny that it treats with powers which either themselves envy the soul its purity, or serve the arts of those who do envy it.  He complains of this through the mouth of some Chaldæan or other:  “A good man in Chaldæa complains,” he says, “that his most strenuous efforts to cleanse his soul were frustrated, because another man, who had influence in these matters, and who envied him purity, had prayed to the powers, and bound them by his conjuring not to listen to his request.  Therefore,” adds Porphyry, “what the one man bound, the other could not loose.”  And from this he concludes that theurgy is a craft which accomplishes not only good but evil among gods and men; and that the gods also have passions, and are perturbed and agitated by the emotions which Apuleius attributed to demons and men, but from which he preserved the gods by that sublimity of residence, which, in common with Plato, he accorded to them.

Footnotes

Goetia.