So, too, no one will hesitate to
affirm that the Holy Spirit is also a substance. But when, on the other
hand, I take together all three, Father, Son, and Holy Spirit, the
result is not three substances but one substance. The one substance of
the Three, then, cannot be separated or divided, nor is it made up of
various parts, combined into one: it is simply one. Everything,
therefore, that is affirmed of the divine substance must be common to
the Three, and we can recognize what predicates may be affirmed of the
substance of the godhead by this sign, that all those which are affirmed
of it may also be affirmed severally of each of the Three combined into
one. For instance if we say "the Father is God, the Son is God, and the
Holy Spirit is God," then Father, Son, and Holy Spirit are one God. If
then their one godhead is one substance, the name of God may with right
be predicated substantially of the Divinity.

Similarly the Father is truth, the Son is truth, and the Holy Spirit is
truth; Father, Son, and Holy Spirit are not three truths, but one truth.
If, then, they are one substance and one truth, truth must of necessity
be a substantial predicate. So Goodness, Immutability, Justice,
Omnipotence and all the other predicates which we apply to the Persons
singly and collectively are plainly substantial predicates. Hence it
appears that what may be predicated of each single One but not of all
Three is not a substantial predicate, but of another kind--of what kind
I will examine presently. For He who is Father does not transmit this
name to the Son nor to the Holy Spirit. Hence it follows that this name
is not attached to Him as something substantial; for if it were a
substantial predicate, as God, truth, justice, or substance itself, it
would be affirmed of the other Persons.

Similarly the Son alone receives this name; nor does He associate it
with the other Persons, as in the case of the titles God, truth, and the
other predicates which I have already mentioned. The Spirit too is not
the same as the Father and the Son. Hence we gather that Father, Son,
and Holy Spirit are not predicated of the Divinity in a substantial
manner, but otherwise.[27] For if each term were predicated
substantially it would be affirmed of the three Persons both separately
and collectively. It is evident that these terms are relative, for the
Father is some one's Father, th