On the contrary, It is written (Deut. 18:10, 11): "Neither let there be found among you . . . anyone . . . that seeketh the truth from the dead": which search relies on the demons' help. Now through the observances of the magic art, knowledge of the truth is sought "by means of certain signs agreed upon by compact with the demons" [*Augustine, De Doctr. Christ. ii, 20; see above Q. 92, A. 2]. Therefore it is unlawful to practice the notary art.
I answer that, The magic art is both unlawful and futile. It is unlawful, because the means it employs for acquiring knowledge have not in themselves the power to cause science, consisting as they do in gazing certain shapes, and muttering certain strange words, and so forth. Wherefore this art does not make use of these things as causes, but as signs; not however as signs instituted by God, as are the sacramental signs. It follows, therefore, that they are empty signs, and consequently a kind of "agreement or covenant made with the demons for the purpose of consultation and of compact by tokens" [*Ibid.]. Wherefore the magic art is to be absolutely repudiated and avoided by Christians, even as other arts of vain and noxious superstition, as Augustine declares (De Doctr. Christ. ii, 23). This art is also useless for the acquisition of science. For since it is not intended by means of this art to acquire science in a manner connatural to man, namely, by discovery and instruction, the consequence is that this effect is expected either from God or from the demons. Now it is certain that some have received wisdom and science infused into them by God, as related of Solomon (3 Kings 3 and 2 Paralip. 1). Moreover, our Lord said to His disciples (Luke 21:15): "I will give you a mouth and wisdom, which all your adversaries shall not be able to resist and gainsay." However, this gift is not granted to all, or in connection with any particular observance, but according to the will of the Holy Ghost, as stated in 1 Cor. 12:8, "To one indeed by the Spirit is given the word of wisdom, to another the word of knowledge, according to the same Spirit," and afterwards it is said (1 Cor. 12:11): "All these things one and the same Spirit worketh, dividing to everyone according as He will." On the other hand it does not belong to the demons to enlighten the intellect, as stated in the First Part (Q. 109, A. 3). Now the acquisition of knowledge and wisdom is effected by the enlightening of the intellect, wherefore never did anyone acquire knowledge by means of the demons. Hence Augustine says (De Civ. Dei x, 9): "Porphyry confesses that the intellectual soul is in no way cleansed by theurgic inventions," i.e. the operations "of the demons, so as to be fitted to see its God, and discern what is true," such as are all scientific conclusions. The demons may, however, be able by speaking to men to express in words certain teachings of the sciences, but this is not what is sought by means of magic.
Reply Obj. 1: It is a good thing to acquire knowledge, but it is not good to acquire it by undue means, and it is to this end that the magic art tends.
Reply Obj. 2: The abstinence of these children was not in accordance with a vain observance of the notary art, but according to the authority of the divine law, for they refused to be defiled by the meat of Gentiles. Hence as a reward for their obedience they received knowledge from God, according to Ps. 118:100, "I have had understanding above the ancients, because I have sought Thy commandments."
Reply Obj. 3: To seek knowledge of the future from the demons is a sin not only because they are ignorant of the future, but also on account of the fellowship entered into with them, which also applies to the case in point. _______________________
SECOND ARTICLE [II-II, Q. 96, Art. 2]
Whether Observances Directed to the Alteration of Bodies, As for the
Purpose of Acquiring Health or the Like, Are Unlawful?
Objection 1: It would seem that observances directed to the alteration of bodies, as for the purpose of acquiring health, or the like, are lawful. It is lawful to make use of the natural forces of bodies in order to produce their proper effects. Now in the physical order things have certain occult forces, the reason of which man is unable to assign; for instance that the magnet attracts iron, and many like instances, all of which Augustine enumerates (De Civ. Dei xxi, 5, 7). Therefore it would seem lawful to employ such like forces for the alteration of bodies.
Obj. 2: Further, artificial bodies are subject to the heavenly bodies, just as natural bodies are. Now natural bodies acquire certain occult forces resulting from their species through the influence of the heavenly bodies. Therefore artificial bodies, e.g. images, also acquire from the heavenly bodies a certain occult force for the production of certain effects. Therefore it is not unlawful to make use of them and of such like things.
Obj. 3: Further, the demons too are able to alter bodies in many ways, as Augustine states (De Trin. iii, 8, 9). But their power is from God. Therefore it is lawful to make use of their power for the purpose of producing these alterations.