Reply Obj. 2: The determinate distance of parts in an organic body is based upon its dimensive quantity; but the nature of substance precedes even dimensive quantity. And since the conversion of the substance of the bread is terminated at the substance of the body of Christ, and since according to the manner of substance the body of Christ is properly and directly in this sacrament; such distance of parts is indeed in Christ's true body, which, however, is not compared to this sacrament according to such distance, but according to the manner of its substance, as stated above (A. 1, ad 3).
Reply Obj. 3: This argument is based on the nature of a body, arising from dimensive quantity. But it was said above (ad 2) that Christ's body is compared with this sacrament not by reason of dimensive quantity, but by reason of its substance, as already stated. _______________________
FOURTH ARTICLE [III, Q. 76, Art. 4]
Whether the Whole Dimensive Quantity of Christ's Body Is in This
Sacrament?
Objection 1: It seems that the whole dimensive quantity of Christ's body is not in this sacrament. For it was said (A. 3) that Christ's entire body is contained under every part of the consecrated host. But no dimensive quantity is contained entirely in any whole, and in its every part. Therefore it is impossible for the entire dimensive quantity of Christ's body to be there.
Obj. 2: Further, it is impossible for two dimensive quantities to be together, even though one be separate from its subject, and the other in a natural body, as is clear from the Philosopher (Metaph. iii). But the dimensive quantity of the bread remains in this sacrament, as is evident to our senses. Consequently, the dimensive quantity of Christ's body is not there.
Obj. 3: Further, if two unequal dimensive quantities be set side by side, the greater will overlap the lesser. But the dimensive quantity of Christ's body is considerably larger than the dimensive quantity of the consecrated host according to every dimension. Therefore, if the dimensive quantity of Christ's body be in this sacrament together with the dimensive quantity of the host, the dimensive quantity of Christ's body is extended beyond the quantity of the host, which nevertheless is not without the substance of Christ's body. Therefore, the substance of Christ's body will be in this sacrament even outside the species of the bread, which is unreasonable, since the substance of Christ's body is in this sacrament, only by the consecration of the bread, as stated above (A. 2). Consequently, it is impossible for the whole dimensive quantity of Christ's body to be in this sacrament.
On the contrary, The existence of the dimensive quantity of any body cannot be separated from the existence of its substance. But in this sacrament the entire substance of Christ's body is present, as stated above (AA. 1, 3). Therefore the entire dimensive quantity of Christ's body is in this sacrament.
I answer that, As stated above (A. 1), any part of Christ is in this sacrament in two ways: in one way, by the power of the sacrament; in another, from real concomitance. By the power of the sacrament the dimensive quantity of Christ's body is not in this sacrament; for, by the power of the sacrament that is present in this sacrament, whereat the conversion is terminated. But the conversion which takes place in this sacrament is terminated directly at the substance of Christ's body, and not at its dimensions; which is evident from the fact that the dimensive quantity of the bread remains after the consecration, while only the substance of the bread passes away.
Nevertheless, since the substance of Christ's body is not really deprived of its dimensive quantity and its other accidents, hence it comes that by reason of real concomitance the whole dimensive quantity of Christ's body and all its other accidents are in this sacrament.