XII.

Argument:  "Man" and "humanity" have the same meaning.  Therefore it is

rightly said that Christ is humanity.

Response:  This is not conceded, but rather that Christ is man, because this

is a concrete term with personal signification, whereas an abstract signifies

the mode of nature, or naturally, so that therefore it is false that Christ

is human nature, that is, humanity, or that Christ is humanity.  Aristotle

says that abstract terms refer to nature, and concrete terms to a person.

XII [a].

Argument:  Whatever belongs [inest] to something, can be predicated of it. 

Humanity belongs to Christ.  Therefore Christ is humanity.

Response:  To "belong" is to inhere to a subject.  Whiteness inheres to John. 

Therefore John is whiteness.  But this does not follow in the abstract.  But

I concede it in the concrete:  Whiteness inheres to John, therefore he is

white.  Humanity belongs to Christ, therefore he is a man.