Objection 4: Further, form is properly limited and perfected by matter. So the form which is not in matter is an infinite form. But the form of an angel is not infinite, for every creature is finite. Therefore the form of an angel is in matter.
On the contrary, Dionysius says (Div. Nom. iv): "The first creatures are understood to be as immaterial as they are incorporeal."
I answer that, Some assert that the angels are composed of matter and form; which opinion Avicebron endeavored to establish in his book of the Fount of Life. For he supposes that whatever things are distinguished by the intellect are really distinct. Now as regards incorporeal substance, the intellect apprehends that which distinguishes it from corporeal substance, and that which it has in common with it. Hence he concludes that what distinguishes incorporeal from corporeal substance is a kind of form to it, and whatever is subject to this distinguishing form, as it were something common, is its matter. Therefore, he asserts the universal matter of spiritual and corporeal things is the same; so that it must be understood that the form of incorporeal substance is impressed in the matter of spiritual things, in the same way as the form of quantity is impressed in the matter of corporeal things.
But one glance is enough to show that there cannot be one matter of spiritual and of corporeal things. For it is not possible that a spiritual and a corporeal form should be received into the same part of matter, otherwise one and the same thing would be corporeal and spiritual. Hence it would follow that one part of matter receives the corporeal form, and another receives the spiritual form. Matter, however, is not divisible into parts except as regarded under quantity; and without quantity substance is indivisible, as Aristotle says (Phys. i, text 15). Therefore it would follow that the matter of spiritual things is subject to quantity; which cannot be. Therefore it is impossible that corporeal and spiritual things should have the same matter.
It is, further, impossible for an intellectual substance to have any kind of matter. For the operation belonging to anything is according to the mode of its substance. Now to understand is an altogether immaterial operation, as appears from its object, whence any act receives its species and nature. For a thing is understood according to its degree of immateriality; because forms that exist in matter are individual forms which the intellect cannot apprehend as such. Hence it must be that every individual substance is altogether immaterial.
But things distinguished by the intellect are not necessarily distinguished in reality; because the intellect does not apprehend things according to their mode, but according to its own mode. Hence material things which are below our intellect exist in our intellect in a simpler mode than they exist in themselves. Angelic substances, on the other hand, are above our intellect; and hence our intellect cannot attain to apprehend them, as they are in themselves, but by its own mode, according as it apprehends composite things; and in this way also it apprehends God (Q[3]).
Reply to Objection 1: It is difference which constitutes the species. Now everything is constituted in a species according as it is determined to some special grade of being because "the species of things are like numbers," which differ by addition and subtraction of unity, as the Philosopher says (Metaph. viii, text 10). But in material things there is one thing which determines to a special grade, and that is the form; and another thing which is determined, and this is the matter; and hence from the latter the "genus" is derived, and from the former the "difference." Whereas in immaterial things there is no separate determinator and thing determined; each thing by its own self holds a determinate grade in being; and therefore in them "genus" and "difference" are not derived from different things, but from one and the same. Nevertheless, this differs in our mode of conception; for, inasmuch as our intellect considers it as indeterminate, it derives the idea of their "genus"; and inasmuch as it considers it determinately, it derives the idea of their "difference."
Reply to Objection 2: This reason is given in the book on the Fount of Life, and it would be cogent, supposing that the receptive mode of the intellect and of matter were the same. But this is clearly false. For matter receives the form, that thereby it may be constituted in some species, either of air, or of fire, or of something else. But the intellect does not receive the form in the same way; otherwise the opinion of Empedocles (De Anima i, 5, text 26) would be true, to the effect that we know earth by earth, and fire by fire. But the intelligible form is in the intellect according to the very nature of a form; for as such is it so known by the intellect. Hence such a way of receiving is not that of matter, but of an immaterial substance.
Reply to Objection 3: Although there is no composition of matter and form in an angel, yet there is act and potentiality. And this can be made evident if we consider the nature of material things which contain a twofold composition. The first is that of form and matter, whereby the nature is constituted. Such a composite nature is not its own existence but existence is its act. Hence the nature itself is related to its own existence as potentiality to act. Therefore if there be no matter, and supposing that the form itself subsists without matter, there nevertheless still remains the relation of the form to its very existence, as of potentiality to act. And such a kind of composition is understood to be in the angels; and this is what some say, that an angel is composed of, "whereby he is," and "what is," or "existence," and "what is," as Boethius says. For "what is," is the form itself subsisting; and the existence itself is whereby the substance is; as the running is whereby the runner runs. But in God "existence" and "what is" are not different as was explained above (Q[3], A[4]). Hence God alone is pure act.
Reply to Objection 4: Every creature is simply finite, inasmuch as its existence is not absolutely subsisting, but is limited to some nature to which it belongs. But there is nothing against a creature being considered relatively infinite. Material creatures are infinite on the part of matter, but finite in their form, which is limited by the matter which receives it. But immaterial created substances are finite in their being; whereas they are infinite in the sense that their forms are not received in anything else; as if we were to say, for example, that whiteness existing separate is infinite as regards the nature of whiteness, forasmuch as it is not contracted to any one subject; while its "being" is finite as determined to some one special nature.
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.
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.
Objection 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.
Objection 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.
Objection 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.
Hence it must be said that the angels, even inasmuch as they are immaterial substances, exist in exceeding great number, far beyond all material multitude. This is what Dionysius says (Coel. Hier. xiv): "There are many blessed armies of the heavenly intelligences, surpassing the weak and limited reckoning of our material numbers." The reason whereof is this, because, since it is the perfection of the universe that God chiefly intends in the creation of things, the more perfect some things are, in so much greater an excess are they created by God. Now, as in bodies such excess is observed in regard to their magnitude, so in things incorporeal is it observed in regard to their multitude. We see, in fact, that incorruptible bodies, exceed corruptible bodies almost incomparably in magnitude; for the entire sphere of things active and passive is something very small in comparison with the heavenly bodies. Hence it is reasonable to conclude that the immaterial substances as it were incomparably exceed material substances as to multitude.
Reply to Objection 1: In the angels number is not that of discrete quantity, brought about by division of what is continuous, but that which is caused by distinction of forms; according as multitude is reckoned among the transcendentals, as was said above (Q[30], A[3]; Q[11]).
Reply to Objection 2: From the angelic nature being the nighest unto God, it must needs have least of multitude in its composition, but not so as to be found in few subjects.
Reply to Objection 3: This is Aristotle's argument (Metaph. xii, text 44), and it would conclude necessarily if the separate substances were made for corporeal substances. For thus the immaterial substances would exist to no purpose, unless some movement from them were to appear in corporeal things. But it is not true that the immaterial substances exist on account of the corporeal, because the end is nobler than the means to the end. Hence Aristotle says (Metaph. xii, text 44) that this is not a necessary argument, but a probable one. He was forced to make use of this argument, since only through sensible things can we come to know intelligible ones.
Reply to Objection 4: This argument comes from the opinion of such as hold that matter is the cause of the distinction of things; but this was refuted above (Q[47], A[1]). Accordingly, the multiplication of the angels is not to be taken according to matter, nor according to bodies, but according to the divine wisdom devising the various orders of immaterial substances.
Whether the angels differ in species?