, it remains to be said, as stated above (A. 4),
that this sentence possesses the power of effecting the conversion of
the bread into the body of Christ. And therefore it is compared to
other sentences, which have power only of signifying and not of
producing, as the concept of the practical intellect, which is
productive of the thing, is compared to the concept of our
speculative intellect which is drawn from things, because "words are
signs of concepts," as the Philosopher says (Peri Herm. i). And
therefore as the concept of the practical intellect does not
presuppose the thing understood, but makes it, so the truth of this
expression does not presuppose the thing signified, but makes it; for
such is the relation of God's word to the things made by the Word.
Now this change takes place not successively, but in an instant, as
stated above (Q. 77, A. 7). Consequently one must understand the
aforesaid expression with reference to the last instant of the words
being spoken, yet not so that the subject may be understood to have
stood for that which is the term of the conversion; viz. that the
body of Christ is the body of Christ; nor again that the subject be
understood to stand for that which it was before the conversion,
namely, the bread, but for that which is commonly related to both,
i.e. that which is contained in general under those species. For
these words do not make the body of Christ to be the body of Christ,
nor do they make the bread to be the body of Christ; but what was
contained under those species, and was formerly bread, they make to
be the body of Christ. And therefore expressly our Lord did not say:
"This bread is My body," which would be the meaning of the second
opinion; nor "This My body is My body," which would be the meaning of
the third opinion: but in general: "This is My body," assigning no
noun on the part of the subject, but only a pronoun, which signifies
substance in common, without quality, that is, without a determinate
form.

Reply Obj. 1: The term "this" points to a substance, yet without
determining its proper nature, as stated above.

Reply Obj. 2: The pronoun "this" does not indicate the accidents, but
the substance underlying the accidents, which at first was bread, and
is afterwards the body of Christ, which body, although not informed
by those accidents, is yet contained under them.

Reply Obj. 3: The meaning of this expression is, in the order of
nature, understood before the