but by the
masculine and feminine is expressed the determined subject in the
common nature. Hence also in human affairs, if we ask, Who is this
man? we answer, Socrates, which is the name of the _suppositum_;
whereas, if we ask, What is he? we reply, A rational and mortal
animal. So, because in God distinction is by the persons, and not by
the essence, we say that the Father is other than the Son, but not
something else; while conversely we say that they are one thing, but
not one person.
_______________________

THIRD ARTICLE [I, Q. 31, Art. 3]

Whether the Exclusive Word "Alone" Should Be Added to the Essential
Term in God?

Objection 1: It would seem that the exclusive word "alone" [solus] is
not to be added to an essential term in God. For, according to the
Philosopher (Elench. ii, 3), "He is alone who is not with another."
But God is with the angels and the souls of the saints. Therefore we
cannot say that God is alone.

Obj. 2: Further, whatever is joined to the essential term in God can
be predicated of every person _per se,_ and of all the persons
together; for, as we can properly say that God is wise, we can say
the Father is a wise God; and the Trinity is a wise God. But
Augustine says (De Trin. vi, 9): "We must consider the opinion that
the Father is not true God alone." Therefore God cannot be said to be
alone.

Obj. 3: Further if this expression "alone" is joined to an essential
term, it would be so joined as regards either the personal predicate
or the essential predicate. But it cannot be the former, as it is
false to say, "God alone is Father," since man also is a father; nor,
again, can it be applied as regards the latter, for, if this saying
were true, "God alone creates," it would follow that the "Father
alone creates," as whatever is said of God can be said of the Father;
and it would be false, as the Son also creates. Therefore this
expression "alone" cannot be joined to an essential term in God.

_On the contrary,_ It is said, "To the King of ages, immortal,
invisible, the only God" (1 Tim. 1:17).

_I answer that,_ This term "alone" can be taken as a categorematical
term, or as a syncategorematical term. A categorematical term is one
which ascribes absolutely its meaning to a given _suppositum_; as, for
instance, "white" to man, as when we say a "white man." If the term
"alone" is taken in this sense, it cannot in any way be joined to any
term in God; for it would mean solitude in the t