, Q. 90, Art. 1]

Whether the Soul Was Made or Was of God's Substance?

Objection 1: It would seem that the soul was not made, but was God's
substance. For it is written (Gen. 2:7): "God formed man of the slime
of the earth, and breathed into his face the breath of life, and man
was made a living soul." But he who breathes sends forth something of
himself. Therefore the soul, whereby man lives, is of the Divine
substance.

Obj. 2: Further, as above explained (Q. 75, A. 5), the soul is a
simple form. But a form is an act. Therefore the soul is a pure act;
which applies to God alone. Therefore the soul is of God's substance.

Obj. 3: Further, things that exist and do [not] differ are the same.
But God and the mind exist, and in no way differ, for they could only
be differentiated by certain differences, and thus would be
composite. Therefore God and the human mind are the same.

_On the contrary,_ Augustine (De Orig. Animae iii, 15) mentions
certain opinions which he calls "exceedingly and evidently perverse,
and contrary to the Catholic Faith," among which the first is the
opinion that "God made the soul not out of nothing, but from Himself."

_I answer that,_ To say that the soul is of the Divine substance
involves a manifest improbability. For, as is clear from what has
been said (Q. 77, A. 2; Q. 79, A. 2; Q. 84, A. 6), the human soul
is sometimes in a state of potentiality to the act of intelligence
--acquires its knowledge somehow from things--and thus has various
powers; all of which are incompatible with the Divine Nature, Which
is a pure act--receives nothing from any other--and admits of no
variety in itself, as we have proved (Q. 3, AA. 1, 7; Q. 9, A. 1).

This error seems to have originated from two statements of the
ancients. For those who first began to observe the nature of things,
being unable to rise above their imagination, supposed that nothing
but bodies existed. Therefore they said that God was a body, which
they considered to be the principle of other bodies. And since they
held that the soul was of the same nature as that body which they
regarded as the first principle, as is stated _De Anima_ i, 2, it
followed that the soul was of the nature of God Himself. According
to this supposition, also, the Manichaeans, thinking that God was
corporeal light, held that the soul was part of that light bound up
with the body.

Then a further step in advance was made, and some surmised the
existence of