Whether Any Procession in God Can Be Called Generation?

Objection 1: It would seem that no procession in God can be called
generation. For generation is change from non-existence to existence,
and is opposed to corruption; while matter is the subject of both.
Nothing of all this belongs to God. Therefore generation cannot exist
in God.

Obj. 2: Further, procession exists in God, according to an
intelligible mode, as above explained (A. 1). But such a process is
not called generation in us; therefore neither is it to be so called
in God.

Obj. 3: Further, anything that is generated derives existence from
its generator. Therefore such existence is a derived existence. But
no derived existence can be a self-subsistence. Therefore, since the
divine existence is self-subsisting (Q. 3, A. 4), it follows that no
generated existence can be the divine existence. Therefore there is
no generation in God.

_On the contrary,_ It is said (Ps. 2:7): "This day have I begotten
Thee."

_I answer that,_ The procession of the Word in God is called
generation. In proof whereof we must observe that generation has a
twofold meaning: one common to everything subject to generation and
corruption; in which sense generation is nothing but change from
non-existence to existence. In another sense it is proper and belongs
to living things; in which sense it signifies the origin of a living
being from a conjoined living principle; and this is properly called
birth. Not everything of that kind, however, is called begotten; but,
strictly speaking, only what proceeds by way of similitude. Hence a
hair has not the aspect of generation and sonship, but only that has
which proceeds by way of a similitude. Nor will any likeness suffice;
for a worm which is generated from animals has not the aspect of
generation and sonship, although it has a generic similitude; for
this kind of generation requires that there should be a procession by
way of similitude in the same specific nature; as a man proceeds from
a man, and a horse from a horse. So in living things, which proceed
from potential to actual life, such as men and animals, generation
includes both these kinds of generation. But if there is a being
whose life does not proceed from potentiality to act, procession (if
found in such a being) excludes entirely the first kind of
generation; whereas it may have that kind of generation which belongs
to living things. So in this manner the procession of