Summa contra Gentiles3.104 Chapter CIV. That the works of magicians result not only from the influence of heavenly bodies

Some there were who averred that such works as seem wonderful to us, being wrought by the magic art, are done, not by certain spiritual substances, but by the power of the heavenly bodies. This would seem to be indicated by the fact that those who practise works of this kind, observe the position of the stars: and are assisted by the employment of certain herbs and other corporeal things, for the purpose, as it were, of preparing matter of lower degree to receive the influence of the celestial power.

But this is in contradiction with the apparitions (in the works of magicians). For as it is impossible that an intellect be formed from corporeal principles, as we proved above, it is impossible for effects that are caused exclusively by the intellectual nature, to be produced by the power of a heavenly body. Now in these works of magicians, things appear that are exclusively the work of a rational nature; for instance, answers are given about stolen goods, and the like, and this could not be done except by an intelligence. Therefore it is not true that all such effects are caused by the mere power of a heavenly body.

Further. Speech is an act proper to the rational nature. Now in these works people appear to men and speak to them on various matters. Therefore such things cannot be done by the mere power of heavenly bodies. If, however, someone say that these apparitions are present, not to the sensorial organ, but only to the imagination:—this is, in the first place, apparently untrue. For imaginary forms do not seem real to anyone, unless his external senses be suspended: since it is not possible for a person to look on a likeness as areality, except the natural judgements of the senses be tied. Now these conversations and apparitions are addressed to those who have free use of their external senses. Therefore these apparitions and speeches cannot be imaginary.

Besides, no imaginary forms can lead a person to intellectual knowledge beyond the natural or acquired faculty of his intellect: this is evident in dreams; since even if they contain some indication of the future, it is not every dreamer that understands the meaning of his dreams. Now, in these apparitions and speeches that occur in the works of magicians, it frequently happens that a person obtains knowledge of things surpassing the faculty of his intelligence, such as the discovery of hidden treasure, the manifestation of the future, and sometimes even true answers are given in matters of science. Either, therefore, these apparitions or speeches are not purely imaginary; or at least it is the work of some higher intelligence, and not only of a heavenly body, that a person obtain the aforesaid knowledge through these imaginings.

Again. That which is done by the power of heavenly bodies, is a natural effect: since they are natural forms that are caused in this lower world by the powers of heavenly bodies. Hence that which cannot be natural to anything, cannot be caused by the power of the heavenly bodies. And yet some such things are stated to be caused by the aforesaid works: for instance, it is averred that at the mere presence of a certain person all doors are unlocked, that a certain man become invisible, and many like occurrences are related. Therefore this cannot be done by the power of heavenly bodies.

Further. ' The reception, through the power of heavenly bodies, of that which follows, implies the reception of what precedes. Now movement of its very nature, is the result of having a soul: since it is proper to animate things to move themselves. Therefore it is impossible for an inanimate being to be moved by itself, through the power of a heavenly body. Yet it is stated that by the magic art an image is made to move of itself, or to speak. Therefore it is not possible for the effects of the magic art to be caused by a celestial power.

And if it be said that the image in question is endowed with some vital principle by the power of the heavenly bodies; this is impossible. For the principle of life in all living things is the substantial form, because, as the Philosopher says (2 De Anima, iv.) in living things to be is to live. Now, it is impossible for anything to receive anew a substantial form, unless it lose the form which it had previously, since the generation of one thing is the corruption of another. But in the making of an image no substantial form is discarded, and there is only a change of shape which is an accident: since the form of copper or something of the kind remains. Therefore the image in question cannot possibly be endowed with the vital principle.

Further. If anything is moved by a principle of life it necessarily has sensation, for the principle of movement is sensation or understanding. But understanding is not found without sensation in things that come to be and pass away. Now there cannot be sensation where there is not the sense of touch; nor the sense of touch without an organ of mean temperature. Such a temperature, however, is not found in the stone or wax or metal out of which the statue is made. It is not possible, therefore, that statues of this sort should be moved by a principle of life.

Besides. Perfect living things are generated not only by a celestial power, but also from seed: for man and the sun generate man'A and such as are generated by a celestial power alone without seed, are animals formed by putrefaction, and such belong to a lower grade than the others. Accordingly if these images be endowed with the vital principle by a celestial power alone, so as to move themselves, it follows that they belong to the lowest grade of animals. And yet this would be false if they worked by an intrinsic principle of life: since among their operations some are of a high degree, for they give answers about hidden things. Therefore it is not possible that their operations and movements proceed from a principle of life.

Again. We find sometimes a natural effect produced 1 Aristotle, 3 Phys. viii. 2 2 Phys. ii.

by the power of heavenly bodies without the operation of art: thus, although one may produce frogs, or something of the kind by means of some artifice, frogs do happen to be produced without any artifice. Consequently if these images that are made by necromancy, are endowed with the vital principle by the power of heavenly bodies, it will be possible for them to be formed without the operation of art. But this is not the case. Therefore it is evident that such images have not the principle of life, nor are they moved by the power of heavenly bodies.

Hereby we refute the opinion of Hermes who, according to Augustine (8 De Civ. Dei xxiii.) expressed himself thus: As God is the cause of the heavenly gods, so man fashions the gods that reside in temples, being satisfied to live near men. I refer to those animal images, endowed with sense and spirit, that do great and wonderful things, images gifted with knowledge of the future, and who foretell by dreams and many other things; who afflict men with ailments and heal them, who bring sorrow and joy to them according to their merits.

This opinion is also refuted by divine authority. For it is said in the Psalm (cxxxiv. 15 seqq.): The idols of the Gentiles are silver and gold, the works of men’s hands. They have a mouth but they speak not... neither is there any breath in their mouths.

Yet seemingly we must not absolutely deny the possibility of some kind of efficacy being in these things through the power of the heavenly bodies: but only for such effects as certain lower bodies are able to cause by the power of the heavenly bodies.