Obj. 3: Further, the New Testament seems to be an internal inspiration, as is evident from the Apostle quoting the words of Jeremias (31:31): "I will perfect unto the house of Israel a New Testament . . . I will give My laws into their mind" (Heb. 8:8). But a sacrament is an outward visible act. Therefore, in the form of the sacrament the words "of the New Testament" are improperly added.
Obj. 4: Further, a thing is said to be new which is near the beginning of its existence. But what is eternal has no beginning of its existence. Therefore it is incorrect to say "of the New and Eternal," because it seems to savor of a contradiction.
Obj. 5: Further, occasions of error ought to be withheld from men, according to Isa. 57:14: "Take away the stumbling blocks out of the way of My people." But some have fallen into error in thinking that Christ's body and blood are only mystically present in this sacrament. Therefore it is out of place to add "the mystery of faith."
Obj. 6: Further, it was said above (Q. 73, A. 3, ad 3), that as Baptism is the sacrament of faith, so is the Eucharist the sacrament of charity. Consequently, in this form the word "charity" ought rather to be used than "faith."
Obj. 7: Further, the whole of this sacrament, both as to body and blood, is a memorial of our Lord's Passion, according to 1 Cor. 11:26: "As often as you shall eat this bread and drink the chalice, you shall show the death of the Lord." Consequently, mention ought to be made of Christ's Passion and its fruit rather in the form of the consecration of the blood, than in the form of the consecration of the body, especially since our Lord said: "This is My body, which shall be delivered up for you" (Luke 22:19).
Obj. 8: Further, as was already observed (Q. 48, A. 2; Q. 49, A. 3), Christ's Passion sufficed for all; while as to its efficacy it was profitable for many. Therefore it ought to be said: "Which shall be shed for all," or else "for many," without adding, "for you."
Objection 9: Further, the words whereby this sacrament is consecrated draw their efficacy from Christ's institution. But no Evangelist narrates that Christ spoke all these words. Therefore this is not an appropriate form for the consecration of the wine.
On the contrary, The Church, instructed by the apostles, uses this form.
I answer that, There is a twofold opinion regarding this form. Some have maintained that the words "This is the chalice of My blood" alone belong to the substance of this form, but not those words which follow. Now this seems incorrect, because the words which follow them are determinations of the predicate, that is, of Christ's blood. consequently they belong to the integrity of the expression.
And on this account others say more accurately that all the words which follow are of the substance of the form down to the words, "As often as ye shall do this," which belong to the use of this sacrament, and consequently do not belong to the substance of the form. Hence it is that the priest pronounces all these words, under the same rite and manner, namely, holding the chalice in his hands. Moreover, in Luke 22:20, the words that follow are interposed with the preceding words: "This is the chalice, the new testament in My blood."