And fourthly: although to enter the soul belongs only to God, yet it is possible for a good or bad angel to enter the body and the faculties allied to the body, in the manner which has been shown above. And in this way hatred and love can be aroused in such a man. For the other argument, that the powers of the spirit are greater than the physical powers, which themselves cannot be changed by the devil, it is answered that the physical powers can be altered by the devil, in so far as they can be hastened or retarded in the flesh and bone. But he does this, not for the sake of impeding or stimulating the inner or outer perceptions, but for his own gain; since he derives his chief benefit by the deception of the senses and the delusion of the intellect.
Question VIII
Whether witches can hebetate the powers of generation or obstruct the venereal act.
Now the fact that adulterous drabs and whores are chiefly given to witchcraft is substantiated by the spells which are cast by witches upon the act of generation. And to make the truth more clear, we will consider the arguments of those who are in disagreement with us on this matter. And first it is argued that such a bewitching is not possible, because if it were it would apply equally to those who are married; and if this were conceded, then, since matrimony is God’s work and witchcraft is the devil’s, the devil’s work would be stronger than God’s. But if it is allowed that it can only affect fornicators and the unmarried, this involves a return to the opinion that witchcraft does not really exist, but only in men’s imagination; and this was refuted in the First Question. Or else some reason will be found why it should affect the unmarried and not the married; and the only possible reason is that matrimony is God’s work. And since, according to the Theologians, this reason is not valid, there still remains the argument that it would make the devil’s work stronger than God’s; and since it would be unseemly to make such an assertion, it is also unseemly to maintain that the venereal act can be obstructed by witchcraft.
Again, the devil cannot obstruct the other natural actions, such as eating, walking and standing, as is apparent from the fact that, if he could, he could destroy the whole world.
Besides, since the venereal act is common to all women, if it were obstructed it would be so with reference to all women; but this is not so, and therefore the first argument is good. For the facts prove that it is not so; for when a man says that he has been bewitched, he is still quite capable as regards other women, though not with her with whom he is unable to copulate; and the reason for this is that he does not wish to, and therefore cannot effect anything in the matter.
On the contrary and true side is the chapter in the Decretals (If by sortilege, etc.): as is also the opinion of all the Theologians and Canonists, where they treat of the obstruction to marriage caused by witchcraft.
There is also another reason: that since the devil is more powerful than man, and a man can obstruct the generative powers by means of frigid herbs or anything else that can be thought of, therefore much more can the devil do this, since he has greater knowledge and cunning.
Answer. The truth is sufficiently evident from two matters which have already been argued, although the method of obstruction has not been specifically declared. For it has been shown that witchcraft does not exist only in men’s imaginations, and not in fact; but that truly and actually in numerable bewitchments can happen, with the permission of God. It has been shown, too, that God permits it more in the case of the generative powers, because of their greater corruption, than in the case of other human actions. But concerning the method by which such obstruction is procured, it is to be noted that it does not affect only the generative powers, but also the powers of the imagination or fancy.
And as to this, Peter of Palude (III, 34) notes five methods. For he says that the devil, being a spirit, has power over a corporeal creature to cause or prevent a local motion. Therefore he can prevent bodies from approaching each other, either directly or indirectly, by interposing himself in some bodily shape. In this way it happened to the young man who was betrothed to an idol and nevertheless married a young maiden, and was consequently unable to copulate with her. Secondly, he can excite a man to that act, or freeze his desire for it, by the virtue of secret things of which he best knows the power. Thirdly, he can also disturb a man’s perception and imagination as to make the woman appear loathsome to him: since he can, as had been said, influence the imagination. Fourthly, he can directly prevent the erection of that member which is adapted to fructification, just as he can prevent local motion. Fifthly, he can prevent the flow of the vital essence to the members in which lie the motive power; by closing as it were the seminary ducts, so that it does not descend to the generative channels, or falls back from them, or does not project from them, or in any of many ways fails in its function.
And he continues in agreement with what has been treated of above by other Doctors. For God allows the devil more latitude in respect of this act, through which sin
