thus He is known in
the same way as the Father is known, by "common spiration." The Holy
Ghost can be known by the fact that He is from another, or from
others; thus He is known by "procession"; but not by the fact that
another is from Him, as no divine person proceeds from Him.

Therefore, there are Five notions in God: "innascibility,"
"paternity," "filiation," "common spiration," and "procession." Of
these only four are relations, for "innascibility" is not a relation,
except by reduction, as will appear later (Q. 33, A. 4, ad 3).
Four only are properties. For "common spiration" is not a property;
because it belongs to two persons. Three are personal notions--i.e.
constituting persons, "paternity," "filiation," and "procession."
"Common spiration" and "innascibility" are called notions of Persons,
but not personal notions, as we shall explain further on (Q. 40, A. 1,
ad 1).

Reply Obj. 1: Besides the four relations, another notion must be
admitted, as above explained.

Reply Obj. 2: The divine essence is signified as a reality; and
likewise the persons are signified as realities; whereas the notions
are signified as ideas notifying the persons. Therefore, although God
is one by unity of essence, and trine by trinity of persons,
nevertheless He is not quinary by the five notions.

Reply Obj. 3: Since the real plurality in God is founded only on
relative opposition, the several properties of one Person, as they
are not relatively opposed to each other, do not really differ. Nor
again are they predicated of each other, because they are different
ideas of the persons; as we do not say that the attribute of power is
the attribute of knowledge, although we do say that knowledge is
power.

Reply Obj. 4: Since Person implies dignity, as stated above (Q. 19,
A. 3), we cannot derive a notion of the Holy Spirit from the fact
that no person is from Him. For this does not belong to His dignity,
as it belongs to the authority of the Father that He is from no one.

Reply Obj. 5: The Son and the Holy Ghost do not agree in one special
mode of existence derived from the Father; as the Father and the Son
agree in one special mode of producing the Holy Ghost. But the
principle on which a notion is based must be something special; thus
no parity of reasoning exists.
_______________________

FOURTH ARTICLE [I, Q. 32, Art. 4]

Whether It Is Lawful to Have Various Contrary Opinions of Notions?

Objection 1: It would seem that i