Article 31

In the thirty-first article, (For related articles, See S.Th. III, q. 77 a. 2 and q. 76 a. 5.) the question is raised whether after the miraculous transubstantiation of the substance of bread into the substance of the body of Christ, the substance of the body of Christ is naturally and without miracle in the sacrament of the altar under the dimensions of the host which remain because a substance, by the very fact that it is a substance, is not prevented from being in a large or small dimension.

I believe the first point (Namely, that substance of the body of Christ is naturally and without miracle in the sacrament of the altar under the dimensions of the host.) to be false because just as the substance of the bread is not naturally but miraculously turned into the substance of the body of Christ, so also it is preserved miraculously under certain dimensions and not naturally. For as Augustine says in the eighth book of On the Litteral Interpretation of Genesis, God preserves things in the same manner by which he brings them about. Indeed, he is not like a builder who only works to build a house and then no longer cares for it, but God exerts a continual action on his work by preserving it in being in accordance with the words of John 5:17, my Father is at work until now. Now as to the idea that a substance inasmuch as it is a substance is not prevented from being in a large or small dimension, one should not understand this as meaning that it is proper to any substance to be able to be in a large or small dimension. On the contrary, this ability does not belong to a substance inasmuch as it is a substance just as it does not pertain to an animal inasmuch as it is an animal to be rational—even though it is not necessary for it to be irrational either. If, then, it belonged to the notion of a substance [as substance] that it would not be prohibited from being in a large or a small dimension, it would follow that the substance of the body of Christ would naturally have to be equal under a large or small dimension. But the fact that it does not belong to the notion of a substance [as substance] that it be able to be in a large or small dimension and that it is not, however, contrary to the notion of a substance for it to be so, makes it clear that to posit that the substance of the body of Christ is in a large or small dimension does not imply a contradiction because a contradiction occurs when something is attributed to another that is repugnant to the other's nature. The introduction of that idea [that substance is not prevented from being in a large or a small dimension], then, excludes the possibility of a contradiction [when it is said that the substance of the body of Christ is in the sacrament under the dimensions of the host] although it is not demonstrated to be natural on account of it.