Therefore it follows that the accidents continue in this sacrament without a subject. This can be done by Divine power: for since an effect depends more upon the first cause than on the second, God Who is the first cause both of substance and accident, can by His unlimited power preserve an accident in existence when the substance is withdrawn whereby it was preserved in existence as by its proper cause, just as without natural causes He can produce other effects of natural causes, even as He formed a human body in the Virgin's womb, "without the seed of man" (Hymn for Christmas, First Vespers).
Reply Obj. 1: There is nothing to hinder the common law of nature from ordaining a thing, the contrary of which is nevertheless ordained by a special privilege of grace, as is evident in the raising of the dead, and in the restoring of sight to the blind: even thus in human affairs, to some individuals some things are granted by special privilege which are outside the common law. And so, even though it be according to the common law of nature for an accident to be in a subject, still for a special reason, according to the order of grace, the accidents exist in this sacrament without a subject, on account of the reasons given above (Q. 75, A. 5).
Reply Obj. 2: Since being is not a genus, then being cannot be of itself the essence of either substance or accident. Consequently, the definition of substance is not—"a being of itself without a subject," nor is the definition of accident—"a being in a subject"; but it belongs to the quiddity or essence of substance "to have existence not in a subject"; while it belongs to the quiddity or essence of accident "to have existence in a subject." But in this sacrament it is not in virtue of their essence that accidents are not in a subject, but through the Divine power sustaining them; and consequently they do not cease to be accidents, because neither is the definition of accident withdrawn from them, nor does the definition of substance apply to them.
Reply Obj. 3: These accidents acquired individual being in the substance of the bread and wine; and when this substance is changed into the body and blood of Christ, they remain in that individuated being which they possessed before, hence they are individual and sensible.
Reply Obj. 4: These accidents had no being of their own nor other accidents, so long as the substance of the bread and wine remained; but their subjects had such being through them, just as snow is white through whiteness. But after the consecration the accidents which remain have being; hence they are compounded of existence and essence, as was said of the angels, in the First Part (Q. 50, A. 2, ad 3); and besides they have composition of quantitative parts. _______________________
SECOND ARTICLE [III, Q. 77, Art. 2]
Whether in This Sacrament the Dimensive Quantity of the Bread or Wine
Is the Subject of the Other Accidents?
Objection 1: It seems that in this sacrament the dimensive quantity of the bread or wine is not the subject of the other accidents. For accident is not the subject of accident; because no form can be a subject, since to be a subject is a property of matter. But dimensive quantity is an accident. Therefore dimensive quantity cannot be the subject of the other accidents.
Obj. 2: Further, just as quantity is individuated by substance, so also are the other accidents. If, then, the dimensive quantity of the bread or wine remains individuated according to the being it had before, in which it is preserved, for like reason the other accidents remain individuated according to the existence which they had before in the substance. Therefore they are not in dimensive quantity as in a subject, since every accident is individuated by its own subject.
Obj. 3: Further, among the other accidents that remain, of the bread and wine, the senses perceive also rarity and density, which cannot be in dimensive quantity existing outside matter; because a thing is rare which has little matter under great dimensions, while a thing is dense which has much matter under small dimensions, as is said in Phys. iv. It does not seem, then, that dimensive quantity can be the subject of the accidents which remain in this sacrament.