De Malo, qu. xvi. art. 9: "The devils can do what they do, 1st, Because they know better than men the virtue of natural agents. 2d. Because they can combine them with greater rapidity. 3d. Because the natural agents which they use as instruments can attain to greater effects by the power and craft of the devils than by the power and craft of men."
Alexander Hales, Sum., pars 2, qu. 42, art. 3, says that nothing, however wonderful, "is a miracle which takes place in accordance with the natural or seminal order, but every miracle holds of the causal ratio (creative cause) only," (L.C. qu. 43). He admits that these marvels of the seminal order are miracles secundum modum faciendi—a term equivalent to S. Thomas' quoad nos.
Albertus Magnus, Op., tom. xviii. tract viii. qu. 3, art. 1, points out that the miracles of Pharao's magicians are called lies, "not because they are unreal (falsa in se), but because the devils have always the intention of deceiving in those works which they are allowed to do."
To sum up, the doctrine of the scholastics on the subject of the devil's power comes to this: The devil is a great artist, who can present incomparable shows to the senses and the imagination, and a supreme chemist, who can combine natural agents indefinitely, and can elicit in a twinkling the virtual contents of each combination; but he can create, and, strictly speaking, originate, nothing external to himself. They knew that, in mercy to mankind, Almighty God was ever restraining the devil in the exercise of this power; but they conceived that the power itself continued unaltered. It was generally admitted that the devil could not raise a dead man to life, or restore a sense, as the sight, when really destroyed. But such acts were regarded by the scholastics as precisely instances of the creation or origination of such a mode as could not be the outcome of any mere combination of natural agents, and which, therefore, must require the fiat of the Creator. At the same time, it must be admitted that they often found it difficult to distinguish in fact between the operation of the limits of the devil's finite nature and the result of the habitual reservation of Almighty God.
And here it may not unnaturally be objected that the large allowance I have made to natural powers, and to the devil's power of manipulating them, tends to lessen the effect of the argument from miracles. No doubt it tends to reduce a considerable number of miracles from the category of logical proof to that of rhetorical argument. Where the miracle is supposed wholly above nature, it is a proof that God is with those who work it; but where it is not beyond the sphere of universal nature, it can, for the most part, only offer a greater or less persuasion dependent upon circumstances. However, such natural miracles, so to call them, approximate more or less closely to logical cogency in proportion as they manifest themselves as the victors in a war of miracles; for it cannot be supposed that in such a war God should allow himself to be worsted, or that Satan should be divided against himself. When God first presented himself as a wonder-worker before human witnesses, it was as developing and modifying in a supernatural manner the powers of nature—nay, of local, Egyptian nature—and outdoing and discomfiting the magicians "who did in like manner." A recent Catholic commentator, Dr. Smith, in his very learned work, The Book of Moses, points out in detail "the analogy which most of the plagues present with the annual phenomena of the country."[127] Of the prelude to the plagues, the conversion of the rod of Moses into a serpent, he says: "Even at the present day, the descendants, or at least representatives, of the Psylli ... can change the asp into a rod stiff and rigid, and at pleasure restore it to flexibility and life by seizing the tail and rolling it between their hands."
In his treatment of the first plague, he gives the following account of the annual phenomenon: "For some time before the rise, the Nile assumes a green color; it then becomes putrid and unfit to drink. Gradually, about the 25th June, a change comes on; the green color and putrid odor disappear; the water becomes clear again, then takes a yellow tinge, which passes into an ochreous red; until for ninety days before the inundation gains its greatest height, it is popularly called the red water. 'On the first appearance of the change,' says an eye-witness, 'the broad, turbid tide certainly has a striking resemblance to a river of blood.'[128] ... At the moment foretold by Moses, the miraculous rod is lifted up and waved over the stream; instantaneously the red attains all its intensity of color; the fish, which in ordinary years live on through the gradual habituation to a different state, now perish in numbers from the very suddenness of the change; and the putrid odor, which usually exhales from it before the rise, comes back again in consequence of this mortality. The blood-red hue is not confined to the spot where Pharao and his magicians stood. It spreads at once into the various channels into which the river divides itself, into the canals which are carried through the land for irrigation, into the lakes and ponds which served as reservoirs, into all the collections of Nile-water, and the very vessels of stone and wood which were commonly used both in town and country for private cisterns. The consequence is that at the very time the water begins to sweeten, it becomes again undrinkable; the Egyptians loathe the water, a draught of which is esteemed one of the greatest luxuries they can enjoy; and, as the inhabitants still do when anything prevents them from drinking of the river, 'they digged round about the river for water, for they could not drink of the water of the river.'"
Of the plague of frogs, the same author remarks: "Such a nuisance was not unknown in some other countries, and there are instances of the inhabitants being in consequence driven from their settlements, as Athenæus remarks of the Pœonians and Dardanians, Diodorus of the Antariats of Illyria, and Pliny of some Gaulish nation. But in Egypt they are not unfrequently equivalent to a plague. Indeed, Hasselquist believes that every year that would be the result, were it not for the species of stork, called ardea ibis, which in the month of September comes down in large flocks to feed upon the small frogs then beginning to swarm over the country."
As regards the third plague, that of the ciniphs, or Egyptian mosquito, Dr. Smith thinks that the magicians could not produce them, because at that time of the year they were not yet out of the egg. This, as we have seen, is not the doctrine of the scholastics, and is hardly consistent with the idea that the magicians were anything more than conjurers. I would suggest that the mosquitoes had to do something more than show themselves and crawl in order to vindicate their reality as plagues. Doubtless the magicians and their familiars hatched the eggs; and there the effete creatures were, with knock-knees, and flaccid trunks, and languid appetites; but they were as though they were not when the orthodox mosquitoes sounded their horns for the banquet, and put in their stings with all and more than all their native vigor. Well might the magicians exclaim in anguish, "This is the finger of God."[129] Abbot Rupert, a writer of the XIIth century, gives precisely the same rationale of the magicians' failure, whilst maintaining that their successes were of the nature of phantasmagoria.
Of the remaining plagues, the fourth, that of flies, was too like the third for the magicians to hope for success; and when at the sixth plague they seem again to take heart, behold, they cannot "stand before Moses for the boils that are upon them." The dreadful sequel, closing in darkness and death, would seem to have simply swept them away in its tide of horror.
So far, then, from there being any reason for shrinking from the idea of a miraculous competition, in which the spirit of man, the demon, and Almighty God enter the lists together, we ought rather to rejoice at the recurrence of the very conditions which God is wont to choose for the scene of his most triumphant manifestations.