Reply Obj. 2: This objection has led some to say that what is necessary has no cause (Phys. viii, text 46). But this is manifestly false in the demonstrative sciences, where necessary principles are the causes of necessary conclusions. And therefore Aristotle says (Metaph. v, text 6), that there are some necessary things which have a cause of their necessity. But the reason why an efficient cause is required is not merely because the effect is not necessary, but because the effect might not be if the cause were not. For this conditional proposition is true, whether the antecedent and consequent be possible or impossible.
Reply Obj. 3: The science of mathematics treats its object as though it were something abstracted mentally, whereas it is not abstract in reality. Now, it is becoming that everything should have an efficient cause in proportion to its being. And so, although the object of mathematics has an efficient cause, still, its relation to that cause is not the reason why it is brought under the consideration of the mathematician, who therefore does not demonstrate that object from its efficient cause. _______________________
SECOND ARTICLE [I, Q. 44, Art. 2]
Whether Primary Matter Is Created by God?
Objection 1: It would seem that primary matter is not created by God.
For whatever is made is composed of a subject and of something else
(Phys. i, text 62). But primary matter has no subject. Therefore
primary matter cannot have been made by God.
Obj. 2: Further, action and passion are opposite members of a division. But as the first active principle is God, so the first passive principle is matter. Therefore God and primary matter are two principles divided against each other, neither of which is from the other.
Obj. 3: Further, every agent produces its like, and thus, since every agent acts in proportion to its actuality, it follows that everything made is in some degree actual. But primary matter is only in potentiality, formally considered in itself. Therefore it is against the nature of primary matter to be a thing made.
On the contrary, Augustine says (Confess. xii, 7), Two "things hast Thou made, O Lord; one nigh unto Thyself"—viz. angels—"the other nigh unto nothing"—viz. primary matter.
I answer that, The ancient philosophers gradually, and as it were step by step, advanced to the knowledge of truth. At first being of grosser mind, they failed to realize that any beings existed except sensible bodies. And those among them who admitted movement, did not consider it except as regards certain accidents, for instance, in relation to rarefaction and condensation, by union and separation. And supposing as they did that corporeal substance itself was uncreated, they assigned certain causes for these accidental changes, as for instance, affinity, discord, intellect, or something of that kind. An advance was made when they understood that there was a distinction between the substantial form and matter, which latter they imagined to be uncreated, and when they perceived transmutation to take place in bodies in regard to essential forms. Such transmutations they attributed to certain universal causes, such as the oblique circle [*The zodiac, according to Aristotle (De Gener. ii)], or ideas, according to Plato. But we must take into consideration that matter is contracted by its form to a determinate species, as a substance, belonging to a certain species, is contracted by a supervening accident to a determinate mode of being; for instance, man by whiteness. Each of these opinions, therefore, considered "being" under some particular aspect, either as "this" or as "such"; and so they assigned particular efficient causes to things. Then others there were who arose to the consideration of "being," as being, and who assigned a cause to things, not as "these," or as "such," but as "beings."
Therefore whatever is the cause of things considered as beings, must be the cause of things, not only according as they are "such" by accidental forms, nor according as they are "these" by substantial forms, but also according to all that belongs to their being at all in any way. And thus it is necessary to say that also primary matter is created by the universal cause of things.