Summa Th. II-II EN Qu.95 a.5

Whether divination by the stars is unlawful?

Objection: 1. It would seem that divination by the stars is not unlawful. It is lawful to foretell effects by observing their causes: thus a physician foretells death from the disposition of the disease. Now the heavenly bodies are the cause of what takes place in the world, according to Dionysius (Div. Nom. iv). Therefore divination by the stars is not unlawful.
2. Further, human science originates from experiments, according to the Philosopher (Metaph. i, 1). Now it has been discovered through many experiments that the observation of the stars is a means whereby some future events may be known beforehand. Therefore it would seem not unlawful to make use of this kind of divination.
3. Further, divination is declared to be unlawful in so far as it is based on a compact made with the demons. But divination by the stars contains nothing of the kind, but merely an observation of God's creatures. Therefore it would seem that this species of divination is not unlawful.

On the contrary Augustine says (Confess. iv, 3): "Those astrologers whom they call mathematicians, I consulted without scruple; because they seemed to use no sacrifice, nor to pray to any spirit for their divinations which art, however, Christian and true piety rejects and condemns."
I answer that As stated above (Articles [1],2), the operation of the demon thrusts itself into those divinations which are based on false and vain opinions, in order that man's mind may become entangled in vanity and falsehood. Now one makes use of a vain and false opinion if, by observing the stars, one desires to foreknow the future that cannot be forecast by their means. Wherefore we must consider what things can be foreknown by observing the stars: and it is evident that those things which happen of necessity can be foreknown by this mean,: even so astrologers forecast a future eclipse.However, with regard to the foreknowledge of future events acquired by observing the stars there have been various opinions. For some have stated that the stars signify rather than cause the things foretold by means of their observation. But this is an unreasonable statement: since every corporeal sign is either the effect of that for which it stands (thus smoke signifies fire whereby it is caused), or it proceeds from the same cause, so that by signifying the cause, in consequence it signifies the effect (thus a rainbow is sometimes a sign of fair weather, in so far as its cause is the cause of fair weather). Now it cannot be said that the dispositions and movements of the heavenly bodies are the effect of future events; nor again can they be ascribed to some common higher cause of a corporeal nature, although they are referable to a common higher cause, which is divine providence. on the contrary the appointment of the movements and positions of the heavenly bodies by divine providence is on a different principle from the appointment of the occurrence of future contingencies, because the former are appointed on a principle of necessity, so that they always occur in the same way, whereas the latter are appointed on a principle of contingency, so that the manner of their occurrence is variable. Consequently it is impossible to acquire foreknowledge of the future from an observation of the stars, except in so far as effects can be foreknown from their causes.Now two kinds of effects escape the causality of heavenly bodies. In the first place all effects that occur accidentally, whether in human affairs or in the natural order, since, as it is proved in Metaph. vi [*Ed. Did. v, 3], an accidental being has no cause, least of all a natural cause, such as is the power of a heavenly body, because what occurs accidentally, neither is a "being" properly speaking, nor is "one"---for instance, that an earthquake occur when a stone falls, or that a treasure be discovered when a man digs a grave---for these and like occurrences are not one thing, but are simply several things. Whereas the operation of nature has always some one thing for its term, just as it proceeds from some one principle, which is the form of a natural thing.In the second place, acts of the free-will, which is the faculty of will and reason, escape the causality of heavenly bodies. For the intellect or reason is not a body, nor the act of a bodily organ, and consequently neither is the will, since it is in the reason, as the Philosopher shows (De Anima iii, 4,9). Now no body can make an impression on an incorporeal body. Wherefore it is impossible for heavenly bodies to make a direct impression on the intellect and will: for this would be to deny the difference between intellect and sense, with which position Aristotle reproaches (De Anima iii, 3) those who held that "such is the will of man, as is the day which the father of men and of gods," i.e. the sun or the heavens, "brings on" [*Odyssey xviii, 135].Hence the heavenly bodies cannot be the direct cause of the free-will's operations. Nevertheless they can be a dispositive cause of an inclination to those operations, in so far as they make an impression on the human body, and consequently on the sensitive powers which are acts of bodily organs having an inclination for human acts. Since, however, the sensitive powers obey reason, as the Philosopher shows (De Anima iii, 11; Ethic. i, 13), this does not impose any necessity on the free-will, and man is able, by his reason, to act counter to the inclination of the heavenly bodies.Accordingly if anyone take observation of the stars in order to foreknow casual or fortuitous future events, or to know with certitude future human actions, his conduct is based on a false and vain opinion; and so the operation of the demon introduces itself therein, wherefore it will be a superstitious and unlawful divination. On the other hand if one were to apply the observation of the stars in order to foreknow those future things that are caused by heavenly bodies, for instance, drought or rain and so forth, it will be neither an unlawful nor a superstitious divination.

Reply to Objection: 1. Wherefore the Reply to the First Objection is evident.
2. That astrologers not unfrequently forecast the truth by observing the stars may be explained in two ways. First, because a great number of men follow their bodily passions, so that their actions are for the most part disposed in accordance with the inclination of the heavenly bodies: while there are few, namely, the wise alone, who moderate these inclinations by their reason. The result is that astrologers in many cases foretell the truth, especially in public occurrences which depend on the multitude. Secondly, because of the interference of the demons. Hence Augustine says (Gn ad lit. ii, 17): "When astrologers tell the truth, it must be allowed that this is due to an instinct that, unknown to man, lies hidden in his mind. And since this happens through the action of unclean and lying spirits who desire to deceive man for they are permitted to know certain things about temporal affairs." Wherefore he concludes: "Thus a good Christian should beware of astrologers, and of all impious diviners, especially of those who tell the truth, lest his soul become the dupe of the demons and by making a compact of partnership with them enmesh itself in their fellowship."
3. This suffices for the Reply to the Third Objection.

Whether divination by dreams is unlawful?

Objection: 1. It would seem that divination by dreams is not unlawful. It is not unlawful to make use of divine instruction. Now men are instructed by God in dreams, for it is written (Jb 33,15-16): "By a dream in a vision by night, when deep sleep falleth upon men, and they are sleeping in their beds, then He," God to wit, "openeth the ears of men, and teaching instructeth them in what they are to learn." Therefore it is not unlawful to make use of divination by dreams.
2. Further, those who interpret dreams, properly speaking, make use of divination by dreams. Now we read of holy men interpreting dreams: thus Joseph interpreted the dreams of Pharaoh's butler and of his chief baker (Gn 40), and Daniel interpreted the dream of the king of Babylon (Da 2,4). Therefore divination by dreams is not unlawful.
3. Further, it is unreasonable to deny the common experiences of men. Now it is the experience of all that dreams are significative of the future. Therefore it is useless to deny the efficacy of dreams for the purpose of divination, and it is lawful to listen to them.

On the contrary It is written (Dt 18,10): "Neither let there be found among you any one that . . . observeth dreams."
I answer that As stated above (Articles [2],6), divination is superstitious and unlawful when it is based on a false opinion. Wherefore we must consider what is true in the matter of foreknowing the future from dreams. Now dreams are sometimes the cause of future occurrences; for instance, when a person's mind becomes anxious through what it has seen in a dream and is thereby led to do something or avoid something: while sometimes dreams are signs of future happenings, in so far as they are referable to some common cause of both dreams and future occurrences, and in this way the future is frequently known from dreams. We must, then, consider what is the cause of dreams, and whether it can be the cause of future occurrences, or be cognizant of them.Accordingly it is to be observed that the cause of dreams is sometimes in us and sometimes outside us. The inward cause of dreams is twofold: one regards the soul, in so far as those things which have occupied a man's thoughts and affections while awake recur to his imagination while asleep. A such like cause of dreams is not a cause of future occurrences, so that dreams of this kind are related accidentally to future occurrences, and if at any time they concur it will be by chance. But sometimes the inward cause of dreams regards the body: because the inward disposition of the body leads to the formation of a movement in the imagination consistent with that disposition; thus a man in whom there is abundance of cold humors dreams that he is in the water or snow: and for this reason physicians say that we should take note of dreams in order to discover internal dispositions.In like manner the outward cause of dreams is twofold, corporal and spiritual. It is corporal in so far as the sleeper's imagination is affected either by the surrounding air, or through an impression of a heavenly body, so that certain images appear to the sleeper, in keeping with the disposition of the heavenly bodies. The spiritual cause is sometimes referable to God, Who reveals certain things to men in their dreams by the ministry of the angels, according Nb 12,6, "If there be among you a prophet of the Lord, I will appear to him in a vision, or I will speak to him in a dream." Sometimes, however, it is due to the action of the demons that certain images appear to persons in their sleep, and by this means they, at times, reveal certain future things to those who have entered into an unlawful compact with them.Accordingly we must say that there is no unlawful divination in making use of dreams for the foreknowledge of the future, so long as those dreams are due to divine revelation, or to some natural cause inward or outward, and so far as the efficacy of that cause extends. But it will be an unlawful and superstitious divination if it be caused by a revelation of the demons, with whom a compact has been made, whether explicit, through their being invoked for the purpose, or implicit, through the divination extending beyond its possible limits.

Reply to Objection: 1. This suffices for the Replies to the Objections.

Whether divination by auguries, omens, and by like observations of external things is unlawful?

Objection: 1. It would seem that divination by auguries, omens, and by like observations of external things is not unlawful. If it were unlawful holy men would not make use thereof. Now we read of Joseph that he paid attention to auguries, for it is related (Gn 44,5) that Joseph's steward said: "The cup which you have stolen is that in which my lord drinketh and in which he is wont to divine [augurari]": and he himself afterwards said to his brethren (Gn 44,15): "Know you not that there is no one like me in the science of divining?" Therefore it is not unlawful to make use of this kind of divination.
2. Further, birds naturally know certain things regarding future occurrences of the seasons, according to Jr 8,7, "The kite in the air hath known her time; the turtle, the swallow, and the stork have observed the time of their coming." Now natural knowledge is infallible and comes from God. Therefore it seems not unlawful to make use of the birds' knowledge in order to know the future, and this is divination by augury.
3. Further, Gedeon is numbered among the saints (He 11,32). Yet Gedeon made use of an omen, when he listened to the relation and interpreting of a dream (Jg 7,15): and Eliezer, Abraham's servant, acted in like manner (Gn 24). Therefore it seems that this kind of divination is not unlawful.

On the contrary It is written (Dt 18,10): "Neither let there be found among you anyone . . . that observeth omens."
I answer that The movements or cries of birds, and whatever dispositions one may consider in such things, are manifestly not the cause of future events: wherefore the future cannot be known therefrom as from its cause. It follows therefore that if anything future can be known from them, it will be because the causes from which they proceed are also the causes of future occurrences or are cognizant of them. Now the cause of dumb animals' actions is a certain instinct whereby they are inclined by a natural movement, for they are not masters of their actions. This instinct may proceed from a twofold cause. In the first place it may be due to a bodily cause. For since dumb animals have naught but a sensitive soul, every power of which is the act of a bodily organ, their soul is subject to the disposition of surrounding bodies, and primarily to that of the heavenly bodies. Hence nothing prevents some of their actions from being signs of the future, in so far as they are conformed to the dispositions of the heavenly bodies and of the surrounding air, to which certain future events are due. Yet in this matter we must observe two things: first, that such observations must not be applied to the foreknowledge of future things other than those which can be foreknown from the movements of heavenly bodies, as stated above (Articles [5],6): secondly, that they be not applied to other matters than those which in some way may have reference to these animals (since they acquire through the heavenly bodies a certain natural knowledge and instinct about things necessary for their life---such as changes resulting from rain and wind and so forth).In the second place, this instinct is produced by a spiritual cause, namely, either by God, as may be seen in the dove that descended upon Christ, the raven that fed Elias, and the whale that swallowed and vomited Jonas, or by demons, who make use of these actions of dumb animals in order to entangle our minds with vain opinions. This seems to be true of all such like things; except omens, because human words which are taken for an omen are not subject to the disposition of the stars, yet are they ordered according to divine providence and sometimes according to the action of the demons.
Accordingly we must say that all such like divinations are superstitious and unlawful, if they be extended beyond the limits set according to the order of nature or of divine providence.

Reply to Objection: 1. According to Augustine [*Questions. in Genes., qu. cxlv], when Joseph said that there was no one like him in the science of divining, he spoke in joke and not seriously, referring perhaps to the common opinion about him: in this sense also spoke his steward.
2. The passage quoted refers to the knowledge that birds have about things concerning them; and in order to know these things it is not unlawful to observe their cries and movements: thus from the frequent cawing of crows one might say that it will rain soon.
3. Gedeon listened to the recital and interpretation of a dream, seeing therein an omen, ordered by divine providence for his instruction. In like manner Eliezer listened to the damsel's words, having previously prayed to God.

Whether divination by drawing lots is unlawful?

Objection: 1. It would seem that divination by drawing lots is not unlawful, because a gloss of Augustine on Ps 30,16, "My lots are in Thy hands," says: "It is not wrong to cast lots, for it is a means of ascertaining the divine will when a man is in doubt."
2. There is, seemingly, nothing unlawful in the observances which the Scriptures relate as being practiced by holy men. Now both in the Old and in the New Testament we find holy men practicing the casting of lots. For it is related (Jos 7,14, sqq.) that Josue, at the Lord's command, pronounced sentence by lot on Achan who had stolen of the anathema. Again Saul, by drawing lots, found that his son Jonathan had eaten honey (1R 14,58, sqq.): Jonas, when fleeing from the face of the Lord, was discovered and thrown into the sea (Jon 1,7, sqq.): Zacharias was chosen by lot to offer incense (Lc 1,9): and the apostles by drawing lots elected Matthias to the apostleship (Ac 1,26). Therefore it would seem that divination by lots is not unlawful.
3. Further, fighting with the fists, or "monomachy," i.e. single combat as it is called, and trial by fire and water, which are called "popular" trials, seem to come under the head of sortilege, because something unknown is sought by their means. Yet these practices seem to be lawful, because David is related to have engaged in single combat with the Philistine (1R 17,32, sqq.). Therefore it would seem that divination by lot is not unlawful.

On the contrary It is written in the Decretals (XXVI, qu. v, can. Sortes): "We decree that the casting of lots, by which means you make up your mind in all your undertakings, and which the Fathers have condemned, is nothing but divination and witchcraft. For which reason we wish them to be condemned altogether, and henceforth not to be mentioned among Christians, and we forbid the practice thereof under pain of anathema."
I answer that As stated above (Article [3]), sortilege consists, properly speaking, in doing something, that by observing the result one may come to the knowledge of something unknown. If by casting lots one seeks to know what is to be given to whom, whether it be a possession, an honor, a dignity, a punishment, or some action or other, it is called "sortilege of allotment"; if one seeks to know what ought to be done, it is called "sortilege of consultation"; if one seeks to know what is going to happen, it is called "sortilege of divination." Now the actions of man that are required for sortilege and their results are not subject to the dispositions of the stars. Wherefore if anyone practicing sortilege is so minded as though the human acts requisite for sortilege depended for their result on the dispositions of the stars, his opinion is vain and false, and consequently is not free from the interference of the demons, so that a divination of this kind is superstitious and unlawful.Apart from this cause, however, the result of sortilegious acts must needs be ascribed to chance, or to some directing spiritual cause. If we ascribe it to chance, and this can only take place in "sortilege of allotment," it does not seem to imply any vice other than vanity, as in the case of persons who, being unable to agree upon the division of something or other, are willing to draw lots for its division, thus leaving to chance what portion each is to receive.If, on the other hand, the decision by lot be left to a spiritual cause, it is sometimes ascribed to demons. Thus we read (Ez 21,21) that "the king of Babylon stood in the highway, at the head of two ways, seeking divination, shuffling arrows; he inquired of the idols, and consulted entrails": sortilege of this kind is unlawful, and forbidden by the canons.Sometimes, however, the decision is left to God, according to Pr 16,33, "Lots are cast into the lap, but they are disposed of by the Lord": sortilege of this kind is not wrong in itself, as Augustine declares [*Enarr. ii in Ps. xxx, serm. 2; cf. Objection [1]].Yet this may happen to be sinful in four ways. First, if one have recourse to lots without any necessity: for this would seem to amount to tempting God. Hence Ambrose, commenting on the words of Lc 1,8, says: "He that is chosen by lot is not bound by the judgment of men." Secondly, if even in a case of necessity one were to have recourse to lots without reverence. Hence, on the Acts of the Apostles, Bede says (Super Act. Apost. i): "But if anyone, compelled by necessity, thinks that he ought, after the apostles' example, to consult God by casting lots, let him take note that the apostles themselves did not do so, except after calling together the assembly of the brethren and pouring forth prayer to God." Thirdly, if the Divine oracles be misapplied to earthly business. Hence Augustine says (ad inquisit. Januar. ii; Ep. lv): "Those who tell fortunes from the Gospel pages, though it is to be hoped that they do so rather than have recourse to consulting the demons, yet does this custom also displease me, that anyone should wish to apply the Divine oracles to worldly matters and to the vain things of this life." Fourthly, if anyone resort to the drawing of lots in ecclesiastical elections, which should be carried out by the inspiration of the Holy Ghost. Wherefore, as Bede says (Super Act. Apost. i): "Before Pentecost the ordination of Matthias was decided by lot," because as yet the fulness of the Holy Ghost was not yet poured forth into the Church: "whereas the same deacons were ordained not by lot but by the choice of the disciples." It is different with earthly honors, which are directed to the disposal of earthly things: in elections of this kind men frequently have recourse to lots, even as in the distribution of earthly possessions.If, however, there be urgent necessity it is lawful to seek the divine judgment by casting lots, provided due reverence be observed. Hence Augustine says (Ep ad Honor. ccxxviii), "If, at a time of persecution, the ministers of God do not agree as to which of them is to remain at his post lest all should flee, and which of them is to flee, lest all die and the Church be forsaken, should there be no other means of coming to an agreement, so far as I can see, they must be chosen by lot." Again he says (De Doctr. Christ. xxviii): "If thou aboundest in that which it behooves thee to give to him who hath not, and which cannot be given to two; should two come to you, neither of whom surpasses the other either in need or in some claim on thee, thou couldst not act more justly than in choosing by lot to whom thou shalt give that which thou canst not give to both."

Reply to Objection: 1. 2. This suffices for the Reply to the First and Second Objections.
3. The trial by hot iron or boiling water is directed to the investigation of someone's hidden sin, by means of something done by a man, and in this it agrees with the drawing of lots. But in so far as a miraculous result is expected from God, it surpasses the common generality of sortilege. Hence this kind of trial is rendered unlawful, both because it is directed to the judgment of the occult, which is reserved to the divine judgment, and because such like trials are not sanctioned by divine authority. Hence we read in a decree of Pope Stephen V [*II, qu. v., can. Consuluist i]: "The sacred canons do not approve of extorting a confession from anyone by means of the trial by hot iron or boiling water, and no one must presume, by a superstitious innovation, to practice what is not sanctioned by the teaching of the holy fathers. For it is allowable that public crimes should be judged by our authority, after the culprit has made spontaneous confession, or when witnesses have been approved, with due regard to the fear of God; but hidden and unknown crimes must be left to Him Who alone knows the hearts of the children of men." The same would seem to apply to the law concerning duels, save that it approaches nearer to the common kind of sortilege, since no miraculous effect is expected thereupon, unless the combatants be very unequal in strength or skill.


We must now consider superstition in observances, under which head there are four points of inquiry:

(1) Of observances for acquiring knowledge, which are prescribed by the magic art;

(2) Of observances for causing alterations in certain bodies;

(3) Of observances practiced in fortune-telling;

(4) Of wearing sacred words at the neck.

Whether it be unlawful to practice the observances of the magic art?

Objection: 1. It would seem that it is not unlawful to practice the observances of the magic art. A thing is said to be unlawful in two ways. First, by reason of the genus of the deed, as murder and theft: secondly, through being directed to an evil end, as when a person gives an alms for the sake of vainglory. Now the observances of the magic art are not evil as to the genus of the deed, for they consist in certain fasts and prayers to God; moreover, they are directed to a good end, namely, the acquisition of science. Therefore it is not unlawful to practice these observances.
2. Further, it is written (Da 1,17) that "to the children" who abstained, "God gave knowledge, and understanding in every book, and wisdom." Now the observances of the magic art consist in certain fasts and abstinences. Therefore it seems that this art achieves its results through God: and consequently it is not unlawful to practice it.
3. Further, seemingly, as stated above (Article [1]), the reason why it is wrong to inquire of the demons concerning the future is because they have no knowledge of it, this knowledge being proper to God. Yet the demons know scientific truths: because sciences are about things necessary and invariable, and such things are subject to human knowledge, and much more to the knowledge of demons, who are of keener intellect, as Augustine says [*Gen. ad lit. ii, 17; De Divin. Daemon. 3,4]. Therefore it seems to be no sin to practice the magic art, even though it achieve its result through the demons.

On the contrary It is written (Dt 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 Question [92], Article [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" [*Augustine, De Doctr. Christ. ii, 20; see above Question [92], Article [2]]. Wherefore the magic art is to be absolutely repudiated and avoided by Christian, 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 (1R 3 and 2Ch 1). Moreover, our Lord said to His disciples (Lc 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 1Co 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 (1Co 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 I 109,3. 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 to Objection: 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.
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."
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.

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.
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.
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.

On the contrary Augustine says (De Doctr. Christ. ii, 20) that "to superstition belong the experiments of magic arts, amulets and nostrums condemned by the medical faculty, consisting either of incantations or of certain cyphers which they call characters, or of any kind of thing worn or fastened on."
I answer that In things done for the purpose of producing some bodily effect we must consider whether they seem able to produce that effect naturally: for if so it will not be unlawful to do so, since it is lawful to employ natural causes in order to produce their proper effects. But, if they seem unable to produce those effects naturally, it follows that they are employed for the purpose of producing those effects, not as causes but only as signs, so that they come under the head of "compact by tokens entered into with the demons" [*Augustine, De Doctr. Christ.; see above Question [92], Article [2]]. Wherefore Augustine says (De Civ. Dei xxi, 6): "The demons are allured by means of creatures, which were made, not by them, but by God. They are enticed by various objects differing according to the various things in which they delight, not as animals by meat, but as spirits by signs, such as are to each one's liking, by means of various kinds of stones, herbs, trees, animals, songs and rites."

Reply to Objection: 1. There is nothing superstitious or unlawful in employing natural things simply for the purpose of causing certain effects such as they are thought to have the natural power of producing. But if in addition there be employed certain characters, words, or any other vain observances which clearly have no efficacy by nature, it will be superstitious and unlawful.
2. The natural forces of natural bodies result from their substantial forms which they acquire through the influence of heavenly bodies; wherefore through this same influence they acquire certain active forces. On the other hand the forms of artificial bodies result from the conception of the craftsman; and since they are nothing else but composition, order and shape, as stated in Phys. i, 5, they cannot have a natural active force. Consequently, no force accrues to them from the influence of heavenly bodies, in so far as they are artificial, but only in respect of their natural matter. Hence it is false, what Porphyry held, according to Augustine (De Civ. Dei x, 11), that "by herbs, stones, animals, certain particular sounds, words, shapes and devices, or again by certain movements of the stars observed in the course of the heavens it is possible for men to fashion on earth forces capable of carrying into effect the various dispositions of the stars," as though the results of the magic arts were to be ascribed to the power of the heavenly bodies. In fact as Augustine adds (De Civ. Dei x, 11), "all these things are to be ascribed to the demons, who delude the souls that are subject to them."Wherefore those images called astronomical also derive their efficacy from the actions of the demons: a sign of this is that it is requisite to inscribe certain characters on them which do not conduce to any effect naturally, since shape is not a principle of natural action. Yet astronomical images differ from necromantic images in this, that the latter include certain explicit invocations and trickery, wherefore they come under the head of explicit agreements made with the demons: whereas in the other images there are tacit agreements by means of tokens in certain shapes or characters.
3. It belongs to the domain of the divine majesty, to Whom the demons are subject, that God should employ them to whatever purpose He will. But man has not been entrusted with power over the demons, to employ them to whatsoever purpose he will; on the contrary, it is appointed that he should wage war against the demons. Hence in no way is it lawful for man to make use of the demons' help by compacts either tacit or express.

Summa Th. II-II EN Qu.95 a.5