Whence it is said (De Causis, prop. 16) that "intelligence is finite from above," as receiving its being from above itself, and is "infinite from below," as not received in any matter. _______________________
THIRD ARTICLE [I, Q. 50, Art. 3]
Whether the Angels Exist in Any Great Number?
Objection 1: It would seem that the angels are not in great numbers. For number is a species of quantity, and follows the division of a continuous body. But this cannot be in the angels, since they are incorporeal, as was shown above (A. 1). Therefore the angels cannot exist in any great number.
Obj. 2: Further, the more a thing approaches to unity, so much the less is it multiplied, as is evident in numbers. But among other created natures the angelic nature approaches nearest to God. Therefore since God is supremely one, it seems that there is the least possible number in the angelic nature.
Obj. 3: Further, the proper effect of the separate substances seems to be the movements of the heavenly bodies. But the movements of the heavenly bodies fall within some small determined number, which we can apprehend. Therefore the angels are not in greater number than the movements of the heavenly bodies.
Obj. 4: Dionysius says (Div. Nom. iv) that "all intelligible and intellectual substances subsist because of the rays of the divine goodness." But a ray is only multiplied according to the different things that receive it. Now it cannot be said that their matter is receptive of an intelligible ray, since intellectual substances are immaterial, as was shown above (A. 2). Therefore it seems that the multiplication of intellectual substances can only be according to the requirements of the first bodies—that is, of the heavenly ones, so that in some way the shedding form of the aforesaid rays may be terminated in them; and hence the same conclusion is to be drawn as before.
On the contrary, It is said (Dan. 7:10): "Thousands of thousands ministered to Him, and ten thousands times a hundred thousand stood before Him."
I answer that, There have been various opinions with regard to the number of the separate substances. Plato contended that the separate substances are the species of sensible things; as if we were to maintain that human nature is a separate substance of itself: and according to this view it would have to be maintained that the number of the separate substances is the number of the species of sensible things. Aristotle, however, rejects this view (Metaph. i, text 31) because matter is of the very nature of the species of sensible things. Consequently the separate substances cannot be the exemplar species of these sensible things; but have their own fixed natures, which are higher than the natures of sensible things. Nevertheless Aristotle held (Metaph. xi, text 43) that those more perfect natures bear relation to these sensible things, as that of mover and end; and therefore he strove to find out the number of the separate substances according to the number of the first movements.
But since this appears to militate against the teachings of Sacred Scripture, Rabbi Moses the Jew, wishing to bring both into harmony, held that the angels, in so far as they are styled immaterial substances, are multiplied according to the number of heavenly movements or bodies, as Aristotle held (Metaph. xi, text 43); while he contended that in the Scriptures even men bearing a divine message are styled angels; and again, even the powers of natural things, which manifest God's almighty power. It is, however, quite foreign to the custom of the Scriptures for the powers of irrational things to be designated as angels.