Summa Theologica, Part I (Prima Pars) From the Complete...

Reply Obj. 2: Although the angel's intellect is above that time according to which corporeal movements are reckoned, yet there is a time in his mind according to the succession of intelligible concepts; of which Augustine says (Gen. ad lit. viii) that "God moves the spiritual creature according to time." And thus, since there is succession in the angel's intellect, not all things that happen through all time, are present to the angelic mind.

Reply Obj. 3: Although the species in the intellect of an angel, in so far as they are species, refer equally to things present, past, and future; nevertheless the present, past, and future; nevertheless the present, past, and future do not bear the same relations to the species. Present things have a nature according to which they resemble the species in the mind of an angel: and so they can be known thereby. Things which are yet to come have not yet a nature whereby they are likened to such species; consequently, they cannot be known by those species.

Reply Obj. 4: Things distant according to place are already existing in nature; and share in some species, whose image is in the angel; whereas this is not true of future things, as has been stated. Consequently there is no comparison. _______________________

Objection 1: It would seem that the angels know secret thoughts. For Gregory (Moral. xviii), explaining Job 28:17: "Gold or crystal cannot equal it," says that "then," namely in the bliss of those rising from the dead, "one shall be as evident to another as he is to himself, and when once the mind of each is seen, his conscience will at the same time be penetrated." But those who rise shall be like the angels, as is stated (Matt. 22:30). Therefore an angel can see what is in another's conscience.

Obj. 2: Further, intelligible species bear the same relation to the intellect as shapes do to bodies. But when the body is seen its shape is seen. Therefore, when an intellectual substance is seen, the intelligible species within it is also seen. Consequently, when one angel beholds another, or even a soul, it seems that he can see the thoughts of both.

Obj. 3: Further, the ideas of our intellect resemble the angel more than do the images in our imagination; because the former are actually understood, while the latter are understood only potentially. But the images in our imagination can be known by an angel as corporeal things are known: because the imagination is a corporeal faculty. Therefore it seems that an angel can know the thoughts of the intellect.

On the contrary, What is proper to God does not belong to the angels. But it is proper to God to read the secrets of hearts, according to Jer. 17:9: "The heart is perverse above all things, and unsearchable; who can know it? I am the Lord, Who search the heart." Therefore angels do not know the secrets of hearts.

I answer that, A secret thought can be known in two ways: first, in its effect. In this way it can be known not only by an angel, but also by man; and with so much the greater subtlety according as the effect is the more hidden. For thought is sometimes discovered not merely by outward act, but also by change of countenance; and doctors can tell some passions of the soul by the mere pulse. Much more then can angels, or even demons, the more deeply they penetrate those occult bodily modifications. Hence Augustine says (De divin. daemon.) that demons "sometimes with the greatest faculty learn man's dispositions, not only when expressed by speech, but even when conceived in thought, when the soul expresses them by certain signs in the body"; although (Retract. ii, 30) he says "it cannot be asserted how this is done."

In another way thoughts can be known as they are in the mind, and affections as they are in the will: and thus God alone can know the thoughts of hearts and affections of wills. The reason of this is, because the rational creature is subject to God only, and He alone can work in it Who is its principal object and last end: this will be developed later (Q. 63, A. 1; Q. 105, A. 5). Consequently all that is in the will, and all things that depend only on the will, are known to God alone. Now it is evident that it depends entirely on the will for anyone actually to consider anything; because a man who has a habit of knowledge, or any intelligible species, uses them at will. Hence the Apostle says (1 Cor. 2:11): "For what man knoweth the things of a man, but the spirit of a man that is in him?"

Reply Obj. 1: In the present life one man's thought is not known by another owing to a twofold hindrance; namely, on account of the grossness of the body, and because the will shuts up its secrets. The first obstacle will be removed at the Resurrection, and does not exist at all in the angels; while the second will remain, and is in the angels now. Nevertheless the brightness of the body will show forth the quality of the soul; as to its amount of grace and of glory. In this way one will be able to see the mind of another.

Reply Obj. 2: Although one angel sees the intelligible species of another, by the fact that the species are proportioned to the rank of these substances according to greater or lesser universality, yet it does not follow that one knows how far another makes use of them by actual consideration.

Reply Obj. 3: The appetite of the brute does not control its act, but follows the impression of some other corporeal or spiritual cause. Since, therefore, the angels know corporeal things and their dispositions, they can thereby know what is passing in the appetite or in the imaginative apprehension of the brute beasts, and even of man, in so far as the sensitive appetite sometimes, through following some bodily impression, influences his conduct, as always happens in brutes. Yet the angels do not necessarily know the movement of the sensitive appetite and the imaginative apprehension of man in so far as these are moved by the will and reason; because, even the lower part of the soul has some share of reason, as obeying its ruler, as is said in Ethics iii, 12. But it does not follow that, if the angel knows what is passing through man's sensitive appetite or imagination, he knows what is in the thought or will: because the intellect or will is not subject to the sensitive appetite or the imagination, but can make various uses of them. _______________________

Objection 1: It would seem that the angels know mysteries of grace. For, the mystery of the Incarnation is the most excellent of all mysteries. But the angels knew of it from the beginning; for Augustine says (Gen. ad lit. v, 19): "This mystery was hidden in God through the ages, yet so that it was known to the princes and powers in heavenly places." And the Apostle says (1 Tim. 3:16): "That great mystery of godliness appeared unto angels*." [*Vulg.: 'Great is the mystery of godliness, which . . . appeared unto angels.'] Therefore the angels know the mysteries of grace.

Obj. 3: Further, the prophets are enlightened by the angels, as is clear from Dionysius (Coel. Hier. iv). But the prophets knew mysteries of grace; for it is said (Amos 3:7): "For the Lord God doth nothing without revealing His secret to His servants the prophets." Therefore angels know the mysteries of grace.

On the contrary, No one learns what he knows already. Yet even the highest angels seek out and learn mysteries of grace. For it is stated (Coel. Hier. vii) that "Sacred Scripture describes some heavenly essences as questioning Jesus, and learning from Him the knowledge of His Divine work for us; and Jesus as teaching them directly": as is evident in Isa. 63:1, where, on the angels asking, "Who is he who cometh up from Edom?" Jesus answered, "It is I, Who speak justice." Therefore the angels do not know mysteries of grace.

I answer that, There is a twofold knowledge in the angel. The first is his natural knowledge, according to which he knows things both by his essence, and by innate species. By such knowledge the angels cannot know mysteries of grace. For these mysteries depend upon the pure will of God: and if an angel cannot learn the thoughts of another angel, which depend upon the will of such angel, much less can he ascertain what depends entirely upon God's will. The Apostle reasons in this fashion (1 Cor. 2:11): "No one knoweth the things of a man [*Vulg.: 'What man knoweth the things of a man, but . . . ?'], but the spirit of a man that is in him." So, "the things also that are of God no man knoweth but the Spirit of God."

There is another knowledge of the angels, which renders them happy; it is the knowledge whereby they see the Word, and things in the Word. By such vision they know mysteries of grace, but not all mysteries: nor do they all know them equally; but just as God wills them to learn by revelation; as the Apostle says (1 Cor. 2:10): "But to us God hath revealed them through His Spirit"; yet so that the higher angels beholding the Divine wisdom more clearly, learn more and deeper mysteries in the vision of God, which mysteries they communicate to the lower angels by enlightening them. Some of these mysteries they knew from the very beginning of their creation; others they are taught afterwards, as befits their ministrations.

Reply Obj. 1: One can speak in two ways of the mystery of the Incarnation. First of all, in general; and in this way it was revealed to all from the commencement of their beatitude. The reason of this is, that this is a kind of general principle to which all their duties are ordered. For "all are [*Vulg.: 'Are they not all.'] ministering spirits, sent to minister for them who shall receive the inheritance of salvation" (Heb. 1:14); and this is brought about by the mystery of the Incarnation. Hence it was necessary for all of them to be instructed in this mystery from the very beginning.

We can speak of the mystery of the Incarnation in another way, as to its special conditions. Thus not all the angels were instructed on all points from the beginning; even the higher angels learned these afterwards, as appears from the passage of Dionysius already quoted.

Reply Obj. 3: Whatever the prophets knew by revelation of the mysteries of grace, was revealed in a more excellent way to the angels. And although God revealed in general to the prophets what He was one day to do regarding the salvation of the human race, still the apostles knew some particulars of the same, which the prophets did not know. Thus we read (Eph. 3:4, 5): "As you reading, may understand my knowledge in the mystery of Christ, which in other generations was not known to the sons of men, as it is now revealed to His holy apostles." Among the prophets also, the later ones knew what the former did not know; according to Ps. 118:100: "I have had understanding above ancients," and Gregory says: "The knowledge of Divine things increased as time went on" (Hom. xvi in Ezech.). _______________________