And therefore others have said that the substance of the bread and wine returns during the corruption of the species, and so from the returning substance of the bread and wine, ashes or worms or something of the kind are generated. But this explanation seems an impossible one. First of all, because if the substance of the bread and wine be converted into the body and blood of Christ, as was shown above (Q. 75, AA. 2, 4), the substance of the bread and wine cannot return, except the body and blood of Christ be again changed back into the substance of bread and wine, which is impossible: thus if air be turned into fire, the air cannot return without the fire being again changed into air. But if the substance of bread or wine be annihilated, it cannot return again, because what lapses into nothing does not return numerically the same. Unless perchance it be said that the said substance returns, because God creates anew another new substance to replace the first. Secondly, this seems to be impossible, because no time can be assigned when the substance of the bread returns. For, from what was said above (A. 4; Q. 76, A. 6, ad 3), it is evident that while the species of the bread and wine remain, there remain also the body and blood of Christ, which are not present together with the substance of the bread and wine in this sacrament, according to what was stated above (Q. 75, A. 2). Hence the substance of the bread and wine cannot return while the sacramental species remain; nor, again, when these species pass away; because then the substance of the bread and wine would be without their proper accidents, which is impossible. Unless perchance it be said that in the last instant of the corruption of the species there returns (not, indeed, the substance of bread and wine, because it is in that very instant that they have the being of the substance generated from the species, but) the matter of the bread and wine; which, matter, properly speaking, would be more correctly described as created anew, than as returning. And in this sense the aforesaid position might be held.
However, since it does not seem reasonable to say that anything takes place miraculously in this sacrament, except in virtue of the consecration itself, which does not imply either creation or return of matter, it seems better to say that in the actual consecration it is miraculously bestowed on the dimensive quantity of the bread and wine to be the subject of subsequent forms. Now this is proper to matter; and therefore as a consequence everything which goes with matter is bestowed on dimensive quantity; and therefore everything which could be generated from the matter of bread or wine, if it were present, can be generated from the aforesaid dimensive quantity of the bread or wine, not, indeed, by a new miracle, but by virtue of the miracle which has already taken place.
Reply Obj. 1: Although no matter is there out of which a thing may be generated, nevertheless dimensive quantity supplies the place of matter, as stated above.
Reply Obj. 2: Those sacramental species are indeed accidents, yet they have the act and power of substance, as stated above (A. 3).
Reply Obj. 3: The dimensive quantity of the bread and wine retains its own nature, and receives miraculously the power and property of substance; and therefore it can pass to both, that is, into substance and dimension. _______________________
SIXTH ARTICLE [III, Q. 77, Art. 6]
Whether the Sacramental Species Can Nourish?
Objection 1: It seems that the sacramental species cannot nourish, because, as Ambrose says (De Sacram. v), "it is not this bread that enters into our body, but the bread of everlasting life, which supports the substance of our soul." But whatever nourishes enters into the body. Therefore this bread does not nourish: and the same reason holds good of the wine.
Obj. 2: Further, as is said in De Gener. ii, "We are nourished by the very things of which we are made." But the sacramental species are accidents, whereas man is not made of accidents, because accident is not a part of substance. Therefore it seems that the sacramental species cannot nourish.
Obj. 3: Further, the Philosopher says (De Anima ii) that "food nourishes according as it is a substance, but it gives increase by reason of its quantity." But the sacramental species are not a substance. Consequently they cannot nourish.