Thomas Aquinas - Summa Theologica, Part III (Tertia Pars)

Reply Obj. 2: Whatever accrues after the completion of the being comes accidentally, unless it be taken into communion with the complete being, just as in the resurrection the body comes to the soul which pre-exists, yet not accidentally, because it is assumed unto the same being, so that the body has vital being through the soul; but it is not so with whiteness, for the being of whiteness is other than the being of man to which whiteness comes. But the Word of God from all eternity had complete being in hypostasis or person; while in time the human nature accrued to it, not as if it were assumed unto one being inasmuch as this is of the nature (even as the body is assumed to the being of the soul), but to one being inasmuch as this is of the hypostasis or person. Hence the human nature is not accidentally united to the Son of God.

Reply Obj. 3: Accident is divided against substance. Now substance, as is plain from Metaph. v, 25, is taken in two ways: first, for essence or nature; secondly, for suppositum or hypostasis—hence the union having taken place in the hypostasis, is enough to show that it is not an accidental union, although the union did not take place in the nature.

Reply Obj. 4: Not everything that is assumed as an instrument pertains to the hypostasis of the one who assumes, as is plain in the case of a saw or a sword; yet nothing prevents what is assumed into the unity of the hypostasis from being as an instrument, even as the body of man or his members. Hence Nestorius held that the human nature was assumed by the Word merely as an instrument, and not into the unity of the hypostasis. And therefore he did not concede that the man was really the Son of God, but His instrument. Hence Cyril says (Epist. ad Monach. Aegyptii): "The Scripture does not affirm that this Emmanuel," i.e. Christ, "was assumed for the office of an instrument, but as God truly humanized," i.e. made man. But Damascene held that the human nature in Christ is an instrument belonging to the unity of the hypostasis. _______________________

SEVENTH ARTICLE [III, Q. 2, Art. 7]

Whether the Union of the Divine Nature and the Human Is Anything

Created?

Objection 1: It would seem that the union of the Divine and human natures is not anything created. For there can be nothing created in God, because whatever is in God is God. But the union is in God, for God Himself is united to human nature. Therefore it seems that the union is not anything created.

Obj. 2: Further, the end holds first place in everything. But the end of the union is the Divine hypostasis or Person in which the union is terminated. Therefore it seems that this union ought chiefly to be judged with reference to the dignity of the Divine hypostasis, which is not anything created. Therefore the union is nothing created.

Obj. 3: Further, "That which is the cause of a thing being such is still more so" (Poster. i). But man is said to be the Creator on account of the union. Therefore much more is the union itself nothing created, but the Creator.

On the contrary, Whatever has a beginning in time is created. Now this union was not from eternity, but began in time. Therefore the union is something created.

I answer that, The union of which we are speaking is a relation which we consider between the Divine and the human nature, inasmuch as they come together in one Person of the Son of God. Now, as was said above (I, Q. 13, A. 7), every relation which we consider between God and the creature is really in the creature, by whose change the relation is brought into being; whereas it is not really in God, but only in our way of thinking, since it does not arise from any change in God. And hence we must say that the union of which we are speaking is not really in God, except only in our way of thinking; but in the human nature, which is a creature, it is really. Therefore we must say it is something created.

Reply Obj. 1: This union is not really in God, but only in our way of thinking, for God is said to be united to a creature inasmuch as the creature is really united to God without any change in Him.

Reply Obj. 2: The specific nature of a relation, as of motion, depends on the subject. And since this union has its being nowhere save in a created nature, as was said above, it follows that it has a created being.

Reply Obj. 3: A man is called Creator and is God because of the union, inasmuch as it is terminated in the Divine hypostasis; yet it does not follow that the union itself is the Creator or God, because that a thing is said to be created regards its being rather than its relation. _______________________

EIGHTH ARTICLE [III, Q. 2, Art. 8]

Whether Union Is the Same As Assumption?

Objection 1: It would seem that union is the same as assumption. For relations, as motions, are specified by their termini. Now the term of assumption and union is one and the same, viz. the Divine hypostasis. Therefore it seems that union and assumption are not different.

Obj. 2: Further, in the mystery of the Incarnation the same thing seems to be what unites and what assumes, and what is united and what is assumed. But union and assumption seem to follow the action and passion of the thing uniting and the united, of the thing assuming and the assumed. Therefore union seems to be the same as assumption.

Obj. 3: Further, Damascene says (De Fide Orth. iii, 11): "Union is one thing, incarnation is another; for union demands mere copulation, and leaves unsaid the end of the copulation; but incarnation and humanation determine the end of copulation." But likewise assumption does not determine the end of copulation. Therefore it seems that union is the same as assumption.

On the contrary, The Divine Nature is said to be united, not assumed.

I answer that, As was stated above (A. 7), union implies a certain relation of the Divine Nature and the human, according as they come together in one Person. Now all relations which begin in time are brought about by some change; and change consists in action and passion. Hence the first and principal difference between assumption and union must be said to be that union implies the relation: whereas assumption implies the action, whereby someone is said to assume, or the passion, whereby something is said to be assumed. Now from this difference another second difference arises, for assumption implies becoming, whereas union implies having become, and therefore the thing uniting is said to be united, but the thing assuming is not said to be assumed. For the human nature is taken to be in the terminus of assumption unto the Divine hypostasis when man is spoken of; and hence we can truly say that the Son of God, Who assumes human nature unto Himself, is man. But human nature, considered in itself, i.e. in the abstract, is viewed as assumed; and we do not say the Son of God is human nature. From this same follows a third difference, which is that a relation, especially one of equiparance, is no more to one extreme than to the other, whereas action and passion bear themselves differently to the agent and the patient, and to different termini. And hence assumption determines the term whence and the term whither; for assumption means a taking to oneself from another. But union determines none of these things. Hence it may be said indifferently that the human nature is united with the Divine, or conversely. But the Divine Nature is not said to be assumed by the human, but conversely, because the human nature is joined to the Divine personality, so that the Divine Person subsists in human nature.

Reply Obj. 1: Union and assumption have not the same relation to the term, but a different relation, as was said above.

Reply Obj. 2: What unites and what assumes are not the same. For whatsoever Person assumes unites, and not conversely. For the Person of the Father united the human nature to the Son, but not to Himself; and hence He is said to unite and not to assume. So likewise the united and the assumed are not identical, for the Divine Nature is said to be united, but not assumed.