Commentaria in Summam contra Gentiles, Liber IV

To the fifth difficulty¹, St. Thomas says first that, according to the aforesaid, we can posit the per se subsisting dimensions as the subject of the breaking. He says secondly that, when dimensions of this kind are broken, the substance of the body of Christ is not broken, because the whole body of Christ remains under each portion; since it is in this sacrament through its substance by the power of the sacrament, while its dimensions are there by natural concomitance—contrary to the way in which a body is naturally in a place, because a natural body is in a place by means of its dimensions, by which it is commensurated with the place. He says thirdly, for the clarification of the aforesaid, that something substantial is related to that in which it is in one way, and something quantified in another way. For a quantified thing is whole in a whole in such a way that the whole is not in a part, but part is in part, just as the whole is in the whole. And in like manner it is in a place, because it is in a place by means of dimensions. But if something substantial as a whole is in a whole, it is also whole in each part of it. This is explained in the species of water, and in the soul. Because therefore the body of Christ is in the sacrament by reason of its substance, into which the substance of the bread has been converted while its dimensions remain; just as the whole species of bread was under each part of the dimensions, so also is the whole body of Christ. And consequently that breaking does not reach the body of Christ; rather, its subject is the dimensions of the bread and wine, just as we have said² that they are the subject of the other accidents. II. Concerning the first statement, it should be noted that in the breaking of the sacrament there seems to be a twofold change: namely, the local motion of the parts, and the corruption of the total quantity. Now it is clear that local motion is in that which is moved locally. Likewise, that the corruption of the form of the whole is nothing other than the form itself tending from being into non-being. When therefore it is said that such a breaking is subjectively in the dimensions themselves, this is understood as regards the local motion itself of the parts. For the corruption of the total quantity is not, properly speaking, in the quantity itself, nor in its parts, as in a subject, but is the quantity itself. And therefore, just as the quantity itself is without a subject, so also is such a corruption. Concerning the second statement, it should be noted that from the fact that the dimensions of the body of Christ are in the sacrament by concomitance with the substance, the body itself is said to be contrary to the way in which a body is naturally in a place, because a natural body is in a place by means of dimensions, by which it is commensurated with the place, namely because the dimensions themselves are the reason for its existing in a place; but the body of Christ is not in the sacrament by means of its dimensions, since they are not there by the power of the sacrament, but on the contrary the dimensions themselves are in the sacrament by reason of the substance of the body of Christ, so that the very substance of the body is the reason for their being in the sacrament. Concerning the third statement, it should be noted, when the soul is said to be whole in each part, that this is not understood of every totality of the soul, but only of the totality of essence and perfection. For the intellective soul, according to the totality of power, is not in each part of the body, but according to diverse powers is in diverse parts. If, however, there are any souls extended per accidens to the extension of the body, as is thought of the souls of imperfect animals and of the souls of plants, these are whole in each part neither according to the totality of power nor according to the totality of dimensive quantity belonging to them per accidens, but diverse parts are in diverse parts. III. But concerning this third statement a doubt arises. For St. Thomas does not seem to show sufficiently that the body of Christ is not divided upon the division of the subsisting dimensions because it is there by reason of its substance, while substance is whole in each part. For it could be said that, although the substance of the body of Christ is whole in each part according to the totality of essence, it is not nonetheless whole in each part according to the dimensive totality which it also has existing in the sacrament: just as extended whiteness is indeed whole according to essence in each part of a white thing, but not according to quantitative totality. And therefore the body of Christ could be divided upon the division of those dimensions, just as whiteness is divided upon the division of a white thing. He answers that St. Thomas proceeds very well, if it be examined carefully. For as was said above³, although the quantity of the body of Christ gives to the substance existing in the sacrament to be divisible and partible intrinsically, it does not nonetheless give to it partibility in relation to an extrinsic thing, because the substance itself does not have that it is present to the dimensions of the bread by reason of its own dimensions, but on the contrary the dimensions are there by reason of the substance. And because it belongs to substance, inasmuch as it is substance, to be indivisibly in that in which it is, and to be whole in each part, therefore quantity also has the same mode of being in the sacrament. Hence it cannot be said that the substance of the body of Christ is there whole indivisibly according to essence, but divisibly according to extensive quantity, as whiteness is; for whiteness is divisible in the very subject in which it is, because it has extension itself and divisibility from the very quantity of the subject.