Reply Obj. 3: As Augustine says (Contra Faust. xix), the sacraments of things present should be different from sacraments of things to come. Now the sacraments of the Old Law foretold the coming of Christ. Consequently they did not signify Christ so clearly as the sacraments of the New Law, which flow from Christ Himself, and have a certain likeness to Him, as stated above. Nevertheless in the Old Law, certain words were used in things pertaining to the worship of God, both by the priests, who were the ministers of those sacraments, according to Num. 6:23, 24: "Thus shall you bless the children of Israel, and you shall say to them: The Lord bless thee," etc.; and by those who made use of those sacraments, according to Deut. 26:3: "I profess this day before the Lord thy God," etc. _______________________
SEVENTH ARTICLE [III, Q. 60, Art. 7]
Whether Determinate Words Are Required in the Sacraments?
Objection 1: It seems that determinate words are not required in the sacraments. For as the Philosopher says (Peri Herm. i), "words are not the same for all." But salvation, which is sought through the sacraments, is the same for all. Therefore determinate words are not required in the sacraments.
Obj. 2: Further, words are required in the sacraments forasmuch as they are the principal means of signification, as stated above (A. 6). But it happens that various words mean the same. Therefore determinate words are not required in the sacraments.
Obj. 3: Further, corruption of anything changes its species. But some corrupt the pronunciation of words, and yet it is not credible that the sacramental effect is hindered thereby; else unlettered men and stammerers, in conferring sacraments, would frequently do so invalidly. Therefore it seems that determinate words are not required in the sacraments.
On the contrary, our Lord used determinate words in consecrating the sacrament of the Eucharist, when He said (Matt. 26:26): "This is My Body." Likewise He commanded His disciples to baptize under a form of determinate words, saying (Matt. 28:19): "Go ye and teach all nations, baptizing them in the name of the Father, and of the Son, and of the Holy Ghost."
I answer that, As stated above (A. 6, ad 2), in the sacraments the words are as the form, and sensible things are as the matter. Now in all things composed of matter and form, the determining principle is on the part of the form, which is as it were the end and terminus of the matter. Consequently for the being of a thing the need of a determinate form is prior to the need of determinate matter: for determinate matter is needed that it may be adapted to the determinate form. Since, therefore, in the sacraments determinate sensible things are required, which are as the sacramental matter, much more is there need in them of a determinate form of words.
Reply Obj. 1: As Augustine says (Tract. lxxx super Joan.), the word operates in the sacraments "not because it is spoken," i.e. not by the outward sound of the voice, "but because it is believed" in accordance with the sense of the words which is held by faith. And this sense is indeed the same for all, though the same words as to their sound be not used by all. Consequently no matter in what language this sense is expressed, the sacrament is complete.
Reply Obj. 2: Although it happens in every language that various words signify the same thing, yet one of those words is that which those who speak that language use principally and more commonly to signify that particular thing: and this is the word which should be used for the sacramental signification. So also among sensible things, that one is used for the sacramental signification which is most commonly employed for the action by which the sacramental effect is signified: thus water is most commonly used by men for bodily cleansing, by which the spiritual cleansing is signified: and therefore water is employed as the matter of baptism.