is generated is the principle
regarding what is generated. So if the Father generate the Son from
His own essence or nature, it follows that the essence or nature of
the Father is the principle of the Son. But it is not a material
principle, because in God nothing material exists; and therefore it
is, as it were, an active principle, as the begetter is the principle
of the one begotten. Thus it follows that the essence generates,
which was disproved above (Q. 39, A. 5).

Obj. 3: Further, Augustine says (De Trin. vii, 6) that the three
persons are not from the same essence; because the essence is not
another thing from person. But the person of the Son is not another
thing from the Father's essence. Therefore the Son is not from the
Father's essence.

Obj. 4: Further, every creature is from nothing. But in Scripture
the Son is called a creature; for it is said (Ecclus. 24:5), in the
person of the Wisdom begotten,"I came out of the mouth of the Most
High, the first-born before all creatures": and further on (Ecclus.
24:14) it is said as uttered by the same Wisdom, "From the beginning,
and before the world was I created." Therefore the Son was not
begotten from something, but from nothing. Likewise we can object
concerning the Holy Ghost, by reason of what is said (Zech. 12:1):
"Thus saith the Lord Who stretcheth forth the heavens, and layeth the
foundations of the earth, and formeth the spirit of man within him";
and (Amos 4:13) according to another version [*The Septuagint]: "I
Who form the earth, and create the spirit."

_On the contrary,_ Augustine (Fulgentius, De Fide ad Petrum i, 1) says:
"God the Father, of His nature, without beginning, begot the Son equal
to Himself."

_I answer that,_ The Son was not begotten from nothing, but from the
Father's substance. For it was explained above (Q. 27, A. 2; Q. 33,
AA. 2 ,3) that paternity, filiation and nativity really and truly
exist in God. Now, this is the difference between true "generation,"
whereby one proceeds from another as a son, and "making," that the
maker makes something out of external matter, as a carpenter makes a
bench out of wood, whereas a man begets a son from himself. Now, as a
created workman makes a thing out of matter, so God makes things out
of nothing, as will be shown later on (Q. 45, A. 1), not as if this
nothing were a part of the substance of the thing made, but because
the whole substance of a thing is produced by Him without anything
els