Reply Obj. 1: A perfect thing participating any nature, makes a likeness to itself, not by absolutely producing that nature, but by applying it to something else. For an individual man cannot be the cause of human nature absolutely, because he would then be the cause of himself; but he is the cause of human nature being in the man begotten; and thus he presupposes in his action a determinate matter whereby he is an individual man. But as an individual man participates human nature, so every created being participates, so to speak, the nature of being; for God alone is His own being, as we have said above (Q. 7, AA. 1, 2). Therefore no created being can produce a being absolutely, except forasmuch as it causes "being" in "this": and so it is necessary to presuppose that whereby a thing is this thing, before the action whereby it makes its own likeness. But in an immaterial substance it is not possible to presuppose anything whereby it is this thing; because it is what it is by its form, whereby it has being, since it is a subsisting form. Therefore an immaterial substance cannot produce another immaterial substance like to itself as regards its being, but only as regards some added perfection; as we may say that a superior angel illuminates an inferior, as Dionysius says (Coel. Hier. iv, x). In this way even in heaven there is paternity, as the Apostle says (Eph. 3:15): "From whom all paternity in heaven and on earth is named." From which evidently appears that no created being can cause anything, unless something is presupposed; which is against the very idea of creation.
Reply Obj. 2: A thing is made from its contrary indirectly (Phys. i, text 43), but directly from the subject which is in potentiality. And so the contrary resists the agent, inasmuch as it impedes the potentiality from the act which the agent intends to induce, as fire intends to reduce the matter of water to an act like to itself, but is impeded by the form and contrary dispositions, whereby the potentiality (of the water) is restrained from being reduced to act; and the more the potentiality is restrained, the more power is required in the agent to reduce the matter to act. Hence a much greater power is required in the agent when no potentiality pre-exists. Thus therefore it appears that it is an act of much greater power to make a thing from nothing, than from its contrary.
Reply Obj. 3: The power of the maker is reckoned not only from the substance of the thing made, but also from the mode of its being made; for a greater heat heats not only more, but quicker. Therefore although to create a finite effect does not show an infinite power, yet to create it from nothing does show an infinite power: which appears from what has been said (ad 2). For if a greater power is required in the agent in proportion to the distance of the potentiality from the act, it follows that the power of that which produces something from no presupposed potentiality is infinite, because there is no proportion between "no potentiality" and the potentiality presupposed by the power of a natural agent, as there is no proportion between "not being" and "being." And because no creature has simply an infinite power, any more than it has an infinite being, as was proved above (Q. 7, A. 2), it follows that no creature can create. _______________________
SIXTH ARTICLE [I, Q. 45, Art. 6]
Whether to Create Is Proper to Any Person?
Objection 1: It would seem that to create is proper to some Person. For what comes first is the cause of what is after; and what is perfect is the cause of what is imperfect. But the procession of the divine Person is prior to the procession of the creature: and is more perfect, because the divine Person proceeds in perfect similitude of its principle; whereas the creature proceeds in imperfect similitude. Therefore the processions of the divine Persons are the cause of the processions of things, and so to create belongs to a Person.
Obj. 2: Further, the divine Persons are distinguished from each other only by their processions and relations. Therefore whatever difference is attributed to the divine Persons belongs to them according to the processions and relations of the Persons. But the causation of creatures is diversely attributed to the divine Persons; for in the Creed, to the Father is attributed that "He is the Creator of all things visible and invisible"; to the Son is attributed that by Him "all things were made"; and to the Holy Ghost is attributed that He is "Lord and Life-giver." Therefore the causation of creatures belongs to the Persons according to processions and relations.
Obj. 3: Further, if it be said that the causation of the creature flows from some essential attribute appropriated to some one Person, this does not appear to be sufficient; because every divine effect is caused by every essential attribute—viz. by power, goodness and wisdom—and thus does not belong to one more than to another. Therefore any determinate mode of causation ought not to be attributed to one Person more than to another, unless they are distinguished in creating according to relations and processions.
On the contrary, Dionysius says (Div. Nom. ii) that all things caused are the common work of the whole Godhead.
I answer that, To create is, properly speaking, to cause or produce the being of things. And as every agent produces its like, the principle of action can be considered from the effect of the action; for it must be fire that generates fire. And therefore to create belongs to God according to His being, that is, His essence, which is common to the three Persons. Hence to create is not proper to any one Person, but is common to the whole Trinity.