Reply Obj. 1: The man who baptizes offers but his outward ministration; whereas Christ it is Who baptizes inwardly, Who can use all men to whatever purpose He wills. Consequently, the unbaptized can baptize: because, as Pope Nicolas I says, "the Baptism is not theirs," i.e. the baptizers', "but His," i.e. Christ's.
Reply Obj. 2: He who is not baptized, though he belongs not to the Church either in reality or sacramentally, can nevertheless belong to her in intention and by similarity of action, namely, in so far as he intends to do what the Church does, and in baptizing observes the Church's form, and thus acts as the minister of Christ, Who did not confine His power to those that are baptized, as neither did He to the sacraments.
Reply Obj. 3: The other sacraments are not so necessary as Baptism. And therefore it is allowable that an unbaptized person should baptize rather than that he should receive other sacraments. _______________________
SIXTH ARTICLE [III, Q. 67, Art. 6]
Whether Several Can Baptize at the Same Time?
Objection 1: It seems that several can baptize at the same time. For unity is contained in multitude, but not vice versa. Wherefore it seems that many can do whatever one can but not vice versa: thus many draw a ship which one could draw. But one man can baptize. Therefore several, too, can baptize one at the same time.
Obj. 2: Further, it is more difficult for one agent to act on many things, than for many to act at the same time on one. But one man can baptize several at the same time. Much more, therefore, can many baptize one at the same time.
Obj. 3: Further, Baptism is a sacrament of the greatest necessity. Now in certain cases it seems necessary for several to baptize one at the same time; for instance, suppose a child to be in danger of death, and two persons present, one of whom is dumb, and the other without hands or arms; for then the mutilated person would have to pronounce the words, and the dumb person would have to perform the act of baptizing. Therefore it seems that several can baptize one at the same time.
On the contrary, Where there is one agent there is one action. If, therefore, several were to baptize one, it seems to follow that there would be several baptisms: and this is contrary to Eph. 4:5: "one Faith, one Baptism."
I answer that, The Sacrament of Baptism derives its power principally from its form, which the Apostle calls "the word of life" (Eph. 5:26). Consequently, if several were to baptize one at the same time, we must consider what form they would use. For were they to say: "We baptize thee in the name of the Father and of the Son and of the Holy Ghost," some maintain that the sacrament of Baptism would not be conferred, because the form of the Church would not be observed, i.e. "I baptize thee in the name of the Father and of the Son and of the Holy Ghost." But this reasoning is disproved by the form observed in the Greek Church. For they might say: "The servant of God, N . . ., is baptized in the name of the Father and of the Son and of the Holy Ghost," under which form the Greeks receive the sacrament of Baptism: and yet this form differs far more from the form that we use, than does this: "We baptize thee."