ow although "God" is
really the same as "Godhead," nevertheless the mode of signification
is not in each case the same. For since this word "God" signifies the
divine essence in Him that possesses it, from its mode of
signification it can of its own nature stand for person. Thus the
things which properly belong to the persons, can be predicated of
this word, "God," as, for instance, we can say "God is begotten" or
is "Begetter," as above explained (A. 4). The word "essence,"
however, in its mode of signification, cannot stand for Person,
because it signifies the essence as an abstract form. Consequently,
what properly belongs to the persons whereby they are distinguished
from each other, cannot be attributed to the essence. For that would
imply distinction in the divine essence, in the same way as there
exists distinction in the _supposita._

Reply Obj. 1: To express unity of essence and of person, the holy
Doctors have sometimes expressed themselves with greater emphasis
than the strict propriety of terms allows. Whence instead of
enlarging upon such expressions we should rather explain them: thus,
for instance, abstract names should be explained by concrete names,
or even by personal names; as when we find "essence from essence"; or
"wisdom from wisdom"; we should take the sense to be, _the Son_ who
is essence and wisdom, is from the Father who is essence and wisdom.
Nevertheless, as regards these abstract names a certain order should
be observed, forasmuch as what belongs to action is more nearly
allied to the persons because actions belong to _supposita._ So
"nature from nature," and "wisdom from wisdom" are less inexact than
"essence from essence."

Reply Obj. 2: In creatures the one generated has not the same nature
numerically as the generator, but another nature, numerically
distinct, which commences to exist in it anew by generation, and
ceases to exist by corruption, and so it is generated and corrupted
accidentally; whereas God begotten has the same nature numerically as
the begetter. So the divine nature in the Son is not begotten either
directly or accidentally.

Reply Obj. 3: Although God and the divine essence are really the
same, nevertheless, on account of their different mode of
signification, we must speak in a different way about each of them.

Reply Obj. 4: The divine essence is predicated of the Father by mode
of identity by reason of the divine simplicity; yet it does not
follow that it can