Prima Pars, Question 43 — Summa Theologiae
Article 1. Whether a divine person can be properly sent?
Objection 1. It would seem that a divine person cannot be properly sent. For one who is sent is less than the sender. But one divine person is not less than another. Therefore one person is not sent by another.
Objection 2. Further, what is sent is separated from the sender; hence Jerome says, commenting on Ezekiel 16:53: “What is joined and tied in one body cannot be sent.” But in the divine persons there is nothing that is separable, as Hilary says (De Trin. vii). Therefore one person is not sent by another.
Objection 3. Further, whoever is sent, departs from one place and comes anew into another. But this does not apply to a divine person, Who is everywhere. Therefore it is not suitable for a divine person to be sent.
On the contrary, It is said (John 8:16): “I am not alone, but I and the Father that sent Me.”
I answer that, the notion of mission includes two things: the habitude of the one sent to the sender; and that of the one sent to the end whereto he is sent. Anyone being sent implies a certain kind of procession of the one sent from the sender: either according to command, as the master sends the servant; or according to counsel, as an adviser may be said to send the king to battle; or according to origin, as a tree sends forth its flowers. The habitude to the term to which he is sent is also shown, so that in some way he begins to be present there: either because in no way was he present before in the place whereto he is sent, or because he begins to be there in some way in which he was not there hitherto. Thus the mission of a divine person is a fitting thing, as meaning in one way the procession of origin from the sender, and as meaning a new way of existing in another; thus the Son is said to be sent by the Father into the world, inasmuch as He began to exist visibly in the world by taking our nature; whereas “He was” previously “in the world” (John 1:1).
Reply to Objection 1. Mission implies inferiority in the one sent, when it means procession from the sender as principle, by command or counsel; forasmuch as the one commanding is the greater, and the counsellor is the wiser. In God, however, it means only procession of origin, which is according to equality, as explained above (I:42:6).
Reply to Objection 2. What is so sent as to begin to exist where previously it did not exist, is locally moved by being sent; hence it is necessarily separated locally from the sender. This, however, has no place in the mission of a divine person; for the divine person sent neither begins to exist where he did not previously exist, nor ceases to exist where He was. Hence such a mission takes place without a separation, having only distinction of origin.
Reply to Objection 3. This objection rests on the idea of mission according to local motion, which is not in God.
Article 2. Whether mission is eternal, or only temporal?
Objection 1. It would seem that mission can be eternal. For Gregory says (Hom. xxvi, in Ev.), “The Son is sent as He is begotten.” But the Son’s generation is eternal. Therefore mission is eternal.
Objection 2. Further, a thing is changed if it becomes something temporally. But a divine person is not changed. Therefore the mission of a divine person is not temporal, but eternal.
Objection 3. Further, mission implies procession. But the procession of the divine persons is eternal. Therefore mission is also eternal.
On the contrary, It is said (Galatians 4:4): “When the fullness of the time was come, God sent His Son.”
I answer that, A certain difference is to be observed in all the words that express the origin of the divine persons. For some express only relation to the principle, as “procession” and “going forth.” Others express the term of procession together with the relation to the principle. Of these some express the eternal term, as “generation” and “spiration”; for generation is the procession of the divine person into the divine nature, and passive spiration is the procession of the subsisting love. Others express the temporal term with the relation to the principle, as “mission” and “giving.” For a thing is sent that it may be in something else, and is given that it may be possessed; but that a divine person be possessed by any creature, or exist in it in a new mode, is temporal.
Hence “mission” and “giving” have only a temporal significance in God; but “generation” and “spiration” are exclusively eternal; whereas “procession” and “giving,” in God, have both an eternal and a temporal signification: for the Son may proceed eternally as God; but temporally, by becoming man, according to His visible mission, or likewise by dwelling in man according to His invisible mission.
Reply to Objection 1. Gregory speaks of the temporal generation of the Son, not from the Father, but from His mother; or it may be taken to mean that He could be sent because eternally begotten.
Reply to Objection 2. That a divine person may newly exist in anyone, or be possessed by anyone in time, does not come from change of the divine person, but from change in the creature; as God Himself is called Lord temporally by change of the creature.
Reply to Objection 3. Mission signifies not only procession from the principle, but also determines the temporal term of the procession. Hence mission is only temporal. Or we may say that it includes the eternal procession, with the addition of a temporal effect. For the relation of a divine person to His principle must be eternal. Hence the procession may be called a twin procession, eternal and temporal, not that there is a double relation to the principle, but a double term, temporal and eternal.