Obj. 7: Further, according to some, the Pope cannot commit simony: yet he can buy or sell something spiritual. Therefore simony is not the will to buy or sell something spiritual or connected with a spiritual thing.
On the contrary, Gregory VII says (Regist. [*Caus. I, qu. i, can. Presbyter, qu. iii, can. Altare]): "None of the faithful is ignorant that buying or selling altars, tithes, or the Holy Ghost is the heresy of simony."
I answer that, As stated above (I-II, Q. 18, A. 2) an act is evil generically when it bears on undue matter. Now a spiritual thing is undue matter for buying and selling for three reasons. First, because a spiritual thing cannot be appraised at any earthly price, even as it is said concerning wisdom (Prov. 3:15), "she is more precious than all riches, and all things that are desired, are not to be compared with her": and for this reason Peter, in condemning the wickedness of Simon in its very source, said (Acts 8:20): "Keep thy money to thyself to perish with thee, because thou hast thought that the gift of God may be purchased with money."
Secondly, because a thing cannot be due matter for sale if the vendor is not the owner thereof, as appears from the authority quoted (Obj. 1). Now ecclesiastical superiors are not owners, but dispensers of spiritual things, according to 1 Cor. 4:1, "Let a man so account of us as of the ministers of Christ, and the dispensers of the ministers of God."
Thirdly, because sale is opposed to the source of spiritual things, since they flow from the gratuitous will of God. Wherefore Our Lord said (Matt. 10:8): "Freely have you received, freely give."
Therefore by buying or selling a spiritual thing, a man treats God and divine things with irreverence, and consequently commits a sin of irreligion.
Reply Obj. 1: Just as religion consists in a kind of protestation of faith, without, sometimes, faith being in one's heart, so too the vices opposed to religion include a certain protestation of unbelief without, sometimes, unbelief being in the mind. Accordingly simony is said to be a "heresy," as regards the outward protestation, since by selling a gift of the Holy Ghost a man declares, in a way, that he is the owner of a spiritual gift; and this is heretical. It must, however, be observed that Simon Magus, besides wishing the apostles to sell him a grace of the Holy Ghost for money, said that the world was not created by God, but by some heavenly power, as Isidore states (Etym. viii, 5): and so for this reason simoniacs are reckoned with other heretics, as appears from Augustine's book on heretics.
Reply Obj. 2: As stated above (Q. 58, A. 4), justice, with all its parts, and consequently all the opposite vices, is in the will as its subject. Hence simony is fittingly defined from its relation to the will. This act is furthermore described as "express," in order to signify that it proceeds from choice, which takes the principal part in virtue and vice. Nor does everyone sin against the Holy Ghost that sins from choice, but only he who chooses sin through contempt of those things whereby man is wont to be withdrawn from sin, as stated above (Q. 14, A. 1).
Reply Obj. 3: The kingdom of heaven is said to be bought when a man gives what he has for God's sake. But this is to employ the term "buying" in a wide sense, and as synonymous with merit: nor does it reach to the perfect signification of buying, both because neither "the sufferings of this time," nor any gift or deed of ours, "are worthy to be compared with the glory to come, that shall be revealed in us" (Rom. 8:18), and because merit consists chiefly, not in an outward gift, action or passion, but in an inward affection.
Reply Obj. 4: Simon the magician wished to buy a spiritual power in order that afterwards he might sell it. For it is written (I, qu. iii [*Can. Salvator]), that "Simon the magician wished to buy the gift of the Holy Ghost, in order that he might make money by selling the signs to be wrought by him." Hence those who sell spiritual things are likened in intention to Simon the magician: while those who wish to buy them are likened to him in act. Those who sell them imitate, in act, Giezi the disciple of Eliseus, of whom we read (4 Kings 5:20-24) that he received money from the leper who was healed: wherefore the sellers of spiritual things may be called not only "simoniacs" but also "giezites."