I answer that, The established order of things is for the higher beings to be more perfect than the lower; and for whatever is contained deficiently, partially, and in manifold manner in the lower beings, to be contained in the higher eminently, and in a certain degree of fulness and simplicity. Therefore, in God, as in the highest source of things, all things pre-exist supersubstantially in respect of His simple Being itself, as Dionysius says (Div. Nom. 1). But among other creatures the angels are nearest to God, and resemble Him most; hence they share more fully and more perfectly in the Divine goodness, as Dionysius says (Coel. Hier. iv). Consequently, all material things pre-exist in the angels more simply and less materially even than in themselves, yet in a more manifold manner and less perfectly than in God.
Now whatever exists in any subject, is contained in it after the manner of such subject. But the angels are intellectual beings of their own nature. Therefore, as God knows material things by His essence, so do the angels know them, forasmuch as they are in the angels by their intelligible species.
Reply Obj. 1: The thing understood is the perfection of the one who understands, by reason of the intelligible species which he has in his intellect. And thus the intelligible species which are in the intellect of an angel are perfections and acts in regard to that intellect.
Reply Obj. 2: Sense does not apprehend the essences of things, but only their outward accidents. In like manner neither does the imagination; for it apprehends only the images of bodies. The intellect alone apprehends the essences of things. Hence it is said (De Anima iii, text. 26) that the object of the intellect is "what a thing is," regarding which it does not err; as neither does sense regarding its proper sensible object. So therefore the essences of material things are in the intellect of man and angels, as the thing understood is in him who understands, and not according to their real natures. But some things are in an intellect or in the soul according to both natures; and in either case there is intellectual vision.
Reply Obj. 3: If an angel were to draw his knowledge of material things from the material things themselves, he would require to make them actually intelligible by a process of abstraction. But he does not derive his knowledge of them from the material things themselves; he has knowledge of material things by actually intelligible species of things, which species are connatural to him; just as our intellect has, by species which it makes intelligible by abstraction. _______________________
SECOND ARTICLE [I, Q. 57, Art. 2]
Whether an Angel Knows Singulars?
Objection 1: It would seem that angels do not know singulars. For the Philosopher says (Poster. i, text. 22): "The sense has for its object singulars, but the intellect, universals." Now, in the angels there is no power of understanding save the intellectual power, as is evident from what was said above (Q. 54, A. 5). Consequently they do not know singulars.
Obj. 2: Further, all knowledge comes about by some assimilation of the knower to the object known. But it is not possible for any assimilation to exist between an angel and a singular object, in so far as it is singular; because, as was observed above (Q. 50, A. 2), an angel is immaterial, while matter is the principle of singularity. Therefore the angel cannot know singulars.
Obj. 3: Further, if an angel does know singulars, it is either by singular or by universal species. It is not by singular species; because in this way he would require to have an infinite number of species. Nor is it by universal species; since the universal is not the sufficient principle for knowing the singular as such, because singular things are not known in the universal except potentially. Therefore the angel does not know singulars.