Q: Whether to Create Is Proper to Any Person?

A: 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.

Nevertheless the divine Persons, according to the nature of their procession, have a causality respecting the creation of things. For as was said above (Q. 14, A. 8; Q. 19, A. 4), when treating of the knowledge and will of God, God is the cause of things by His intellect and will, just as the craftsman is cause of the things made by his craft. Now the craftsman works through the word conceived in his mind, and through the love of his will regarding some object. Hence also God the Father made the creature through His Word, which is His Son; and through His Love, which is the Holy Ghost. And so the processions of the Persons are the type of the productions of creatures inasmuch as they include the essential attributes, knowledge and will.

Reply Obj. 1: The processions of the divine Persons are the cause of creation, as above explained.

Reply Obj. 2: As the divine nature, although common to the three Persons, still belongs to them in a kind of order, inasmuch as the Son receives the divine nature from the Father, and the Holy Ghost from both: so also likewise the power of creation, whilst common to the three Persons, belongs to them in a kind of order. For the Son receives it from the Father, and the Holy Ghost from both. Hence to be the Creator is attributed to the Father as to Him Who does not receive the power of creation from another. And of the Son it is said (John 1:3), "Through Him all things were made," inasmuch as He has the same power, but from another; for this preposition "through" usually denotes a mediate cause, or "a principle from a principle." But to the Holy Ghost, Who has the same power from both, is attributed that by His sway He governs, and quickens what is created by the Father through the Son. Again, the reason for this particular appropriation may be taken from the common notion of the appropriation of the essential attributes. For, as above stated (Q. 39, A. 8, ad 3), to the Father is appropriated power which is chiefly shown in creation, and therefore it is attributed to Him to be the Creator. To the Son is appropriated wisdom, through which the intellectual agent acts; and therefore it is said: "Through Whom all things were made." And to the Holy Ghost is appropriated goodness, to which belong both government, which brings things to their proper end, and the giving of life--for life consists in a certain interior movement; and the first mover is the end, and goodness.

Reply Obj. 3: Although every effect of God proceeds from each attribute, each effect is reduced to that attribute with which it is naturally connected; thus the order of things is reduced to "wisdom," and the justification of the sinner to "mercy" and "goodness" poured out super-abundantly. But creation, which is the production of the very substance of a thing, is reduced to "power."