d eye from ear. But this could not be so, if
Christ were entire under every part of the species; for every part
would have to be under every other part, and so where one part would
be, there another part would be. It cannot be then that the entire
Christ is under every part of the host or of the wine contained in
the chalice.

Obj. 3: Further, Christ's body always retains the true nature of a
body, nor is it ever changed into a spirit. Now it is the nature of a
body for it to be "quantity having position" (Predic. iv). But it
belongs to the nature of this quantity that the various parts exist
in various parts of place. Therefore, apparently it is impossible for
the entire Christ to be under every part of the species.

_On the contrary,_ Augustine says in a sermon (Gregory,
Sacramentarium): "Each receives Christ the Lord, Who is entire under
every morsel, nor is He less in each portion, but bestows Himself
entire under each."

_I answer that,_ As was observed above (A. 1, ad 3), because the
substance of Christ's body is in this sacrament by the power of the
sacrament, while dimensive quantity is there by reason of real
concomitance, consequently Christ's body is in this sacrament
substantively, that is, in the way in which substance is under
dimensions, but not after the manner of dimensions, which means, not
in the way in which the dimensive quantity of a body is under the
dimensive quantity of place.

Now it is evident that the whole nature of a substance is under every
part of the dimensions under which it is contained; just as the
entire nature of air is under every part of air, and the entire
nature of bread under every part of bread; and this indifferently,
whether the dimensions be actually divided (as when the air is
divided or the bread cut), or whether they be actually undivided, but
potentially divisible. And therefore it is manifest that the entire
Christ is under every part of the species of the bread, even while
the host remains entire, and not merely when it is broken, as some
say, giving the example of an image which appears in a mirror, which
appears as one in the unbroken mirror, whereas when the mirror is
broken, there is an image in each part of the broken mirror: for the
comparison is not perfect, because the multiplying of such images
results in the broken mirror on account of the various reflections in
the various parts of the mirror; but here there is only one
consecration, whereby Christ's