I answer that, As stated above (Article 1, Reply to Objection 3; Article 3), Christ’s body is in this sacrament not after the proper manner of dimensive quantity, but rather after the manner of substance. But every body occupying a place is in the place according to the manner of dimensive quantity, namely, inasmuch as it is commensurate with the place according to its dimensive quantity. Hence it remains that Christ’s body is not in this sacrament as in a place, but after the manner of substance, that is to say, in that way in which substance is contained by dimensions; because the substance of Christ’s body succeeds the substance of bread in this sacrament: hence as the substance of bread was not locally under its dimensions, but after the manner of substance, so neither is the substance of Christ’s body. Nevertheless the substance of Christ’s body is not the subject of those dimensions, as was the substance of the bread: and therefore the substance of the bread was there locally by reason of its dimensions, because it was compared with that place through the medium of its own dimensions; but the substance of Christ’s body is compared with that place through the medium of foreign dimensions, so that, on the contrary, the proper dimensions of Christ’s body are compared with that place through the medium of substance; which is contrary to the notion of a located body.
Hence in no way is Christ’s body locally in this sacrament.