Continued in: Next
number of persons related to each other; and hence it is that the word in itself does not express regard to another.
Reply Obj. 2: Two things are implied in a collective term, plurality of the _supposita,_ and a unity of some kind of order. For "people" is a multitude of men comprehended under a certain order. In the first sense, this word "trinity" is like other collective words; but in the second sense it differs from them, because in the divine Trinity not only is there unity of order, but also with this there is unity of essence.
Reply Obj. 3: "Trinity" is taken in an absolute sense; for it signifies the threefold number of persons. "Triplicity" signifies a proportion of inequality; for it is a species of unequal proportion, according to Boethius (Arithm. i, 23). Therefore in God there is not triplicity, but Trinity.
Reply Obj. 4: In the divine Trinity is to be understood both number and the persons numbered. So when we say, "Trinity in Unity," we do not place number in the unity of the essence, as if we meant three times one; but we place the Persons numbered in the unity of nature; as the _supposita_ of a nature are said to exist in that nature. On the other hand, we say "Unity in Trinity"; meaning that the nature is in its _supposita._
Reply Obj. 5: When we say, "Trinity is trine," by reason of the number implied, we signify the multiplication of that number by itself; since the word trine imports a distinction in the _supposita_ of which it is spoken. Therefore it cannot be said that the Trinity is trine; otherwise it follows that, if the Trinity be trine, there would be three _supposita_ of the Trinity; as when we say, "God is trine," it follows that there are three _supposita_ of the Godhead.
SECOND ARTICLE [I, Q. 31, Art. 2]
Whether the Son Is Other Than the Father?