e whatever presupposed. So, were the Son to proceed from the
Father as out of nothing, then the Son would be to the Father what
the thing made is to the maker, whereto, as is evident, the name of
filiation would not apply except by a kind of similitude. Thus, if
the Son of God proceeds from the Father out of nothing, He could not
be properly and truly called the Son, whereas the contrary is stated
(1 John 5:20): "That we may be in His true Son Jesus Christ."
Therefore the true Son of God is not from nothing; nor is He made,
but begotten.

That certain creatures made by God out of nothing are called sons of
God is to be taken in a metaphorical sense, according to a certain
likeness of assimilation to Him Who is the true Son. Whence, as He is
the only true and natural Son of God, He is called the "only
begotten," according to John 1:18, "The only begotten Son, Who is in
the bosom of the Father, He hath declared Him"; and so as others are
entitled sons of adoption by their similitude to Him, He is called the
"first begotten," according to Rom. 8:29: "Whom He foreknew He also
predestinated to be made conformable to the image of His Son, that He
might be the first born of many brethren." Therefore the Son of God is
begotten of the substance of the Father, but not in the same way as
man is born of man; for a part of the human substance in generation
passes into the substance of the one begotten, whereas the divine
nature cannot be parted; whence it necessarily follows that the Father
in begetting the Son does not transmit any part of His nature, but
communicates His whole nature to Him, the distinction only of origin
remaining as explained above (Q. 40, A. 2).

Reply Obj. 1: When we say that the Son was born of the Father, the
preposition "of" designates a consubstantial generating principle,
but not a material principle. For that which is produced from matter,
is made by a change of form in that whence it is produced. But the
divine essence is unchangeable, and is not susceptive of another form.

Reply Obj. 2: When we say the Son is begotten of the essence of the
Father, as the Master of the Sentences explains (Sent. i, D, v), this
denotes the habitude of a kind of active principle, and as he
expounds, "the Son is begotten of the essence of the Father"--that
is, of the Father Who is essence; and so Augustine says (De Trin. xv,
13): "When I say of the Father Who is essence, it is the same as if I
said more explicitly, of t