Part II, Question I, Chapter VIII
Of the Manner whereby they Change Men into the Shapes of Beasts.
But that witches, by the power of devils, change men into the shapes of beasts (for this is their chief manner of transmutation), although it has been sufficiently proved in the First Part of the work, Question 10, Whether witches can do such things: nevertheless, since that question with its arguments and solutions may be rather obscure to some; especially since no actual examples are adduced to prove them, and even the method by which they so transform themselves is not explained; therefore we add the present exposition by the resolution of several doubts.
And first, that Canon (26, Q. 5, Episcopi) is not to be understood in this matter in the way in which even many learned men (but would that their learning were good!) are deceived; who do not fear to affirm publicly in their sermons that such prestidigitatory transmutations are in no way possible even by the power of devils. And we have often said that this doctrine is greatly to the detriment of the Faith, and strengthens the witches, who rejoice very much in such sermons.
But such preachers, as has been noted, touch only the outer surface, and fail to reach the inner meaning of the words of the Canon. For when it says: Whoever believes that any creature can be made, or can be changed for the better or the worse, or be transformed into any other shape or likeness except by the Creator Himself Who made all, is without doubt an infidel. . . .
The reader must here remark two chief things. First, concerning the words “be made”; and secondly, concerning the words “be transformed into another likeness.” And as to the first, it is answered that “be made” can be understood in two ways: namely, as meaning “be created,” or as in the sense of the natural production of anything. Now in the first sense it belongs only to God, as is well known, Who in His infinite might can make something out of nothing.
But in the second sense there is a distinction to be drawn between creatures; for some are perfect creatures, like a man, and an ass, etc. And other are imperfect, such as serpents, frogs, mice, etc., for they can also be generated from putrefaction. Now the Canon obviously speaks only of the former sort, not of the second; for in the case of the second it can be proved from what Blessed Albert says in his book On Animals, where he asks: whether devils can make true animals; and still with this difference, that they cannot do so in an instant, as God does, but by some motion, however sudden, as is shown in the case of the Magicians in Exodus vii. The reader may, if he likes, refer to some of the remarks in the question we have quoted in the First Part of the work, and in the solution of the first argument.
Secondly, it is said that they cannot transmute any creature. You may say that transmutation is of two sorts, substantial and accidental; and this accidental is again of two kinds, consisting either in the natural form belonging to the thing which is seen, or in a form which does not belong to the thing which is seen, but exists only in the organs and perceptions of him who sees. The Canon speaks of the former, and especially of formal and actual transmutation, in which one substance is transmuted into another; and this sort only God can effect, Who is the Creator of such actual substances. And it speaks also of the second, although the devil can effect that, in so far as, with God’s permission, he causes certain diseases and induces some appearance on the accidental body. As when a face appears to be leprous, or some such thing.
But properly speaking it is not such matters that are in question, but apparitions and glamours, by which things seem to be transmuted into other likenesses; and we say that the words of the Canon cannot exclude such transmutations; for their existence is proved by authority, by reason, and by experience; namely, by certain experiences related by S. Augustine in Book XVIII, chapter 17, of the De Ciuitate Die, and by the arguments in explanation of them. For among other prestidigitatory transformations, he mentions that the very famous Sorceress, Circe, changed the companions of Ulysses into beasts; and that certain innkeepers’ wives had turned their guests into beasts of burden. He mentions also that the companions of Diomedes were changed into birds, and for a long time flew about the temple of Diomedes; and that Praestantius tells it for a fact that his father said that he had been a packhorse, and had carried corn with other animals.
Now when the companions of Ulysses were changed into beasts, it was only in appearance, or deception of the eyes; for the animal shapes were drawn out of the repository or memory of images, and impressed on the imaginative faculty. And so imaginary vision was caused, and through the strong impression on the other senses and organs, the beholder thought that he saw animals, in the manner of which we have already treated. But how these things can be done by the devil’s power without injury will be shown later.
But when the guests were changed into beasts of burden by the innkeepers’ wives; and when the father of Praestantius thought he was a packhorse and carried corn; it is to be noted that in these cases there were three deceptions.
First, that those men were caused by a glamour to seem to be changed into beasts of burden, and this change was caused in the way we have said. Second, that devils invisibly bore those burdens up when they were too heavy to be carried. Third, that those who seemed to others to be changed in shape seemed also to themselves to be changed into beasts; as it happened to Nabuchodonosor, who lived for seven years eating straw like an ox.
And as to the comrades of Diomedes being changed into birds and flying round his temple, it is to be said that this Diomedes was one of the Greeks who went to the siege of Troy; and when he wished to return home, he was drowned with his comrades in the sea; and then, at the suggestion of some idol, a temple was built to him that he might be numbered among the gods; and for a long time, to keep that error alive, devils in the shape of birds flew about in place of his companions. Therefore that superstition was one of the glamours we have spoken of; for it was not caused by the impression of mental images on the imaginative faculty, but by their flying in the sight of men in the assumed bodies of birds.
But if it is asked whether the devils could have deluded the onlookers by the above-mentioned method of working upon the mental images, and not by assuming aerial bodies like flying birds, the answer is that they could have done so.
For it was the opinion of some (as S. Thomas tells in the Second Book of Sentences, dist. 8, art. 2) that no Angel, good or bad, ever assumed a body; but that all that we read in the Scriptures about their appearances was caused by a glamour, or by the imaginary vision.
And here the learned Saint notes a difference between a glamour and imaginary vision. For in a glamour there may be an exterior object which is seen, but it seems other than it is. But imaginary vision does not necessarily require an exterior object, but can be caused without that and only by those inner mental images impressed on the imagination.
So, following their opinion, the comrades of Diomedes were not represented by devils in the assumed bodies and likeness of birds, but only by a fantastic and imaginary vision caused by working upon those mental images, etc.
But the learned Saint condemns this as an erroneous and not a simple opinion (though, it is piously believed, it is not actually heretical), although such appearances of good and bad Angels may at times have been imaginary, with no assumed body. But, as he says, the saints are agreed that the Angels also appeared to the actual sight, and such appearance was in an assumed body. And the scriptural text reads more as if it speaks of bodily appearance than imaginary or prestidigitatory ones. Therefore we can say for the present concerning any visions like that of the comrades of Diomedes: that although those comrades could by the devil’s work have appeared in the imaginary vision of the beholders in the manner we have said, yet it is rather presumed that they were caused to be seen by devils in assumed aerial bodies like flying birds; or else that other natural birds were caused by devils to represent them.