Of What Belongs to the Unity or Plurality in God
Of What Belongs to the Unity or Plurality in God — St. Thomas Aquinas asks: Whether there is trinity in God?; Whether the Son is other than the Father?; Whether the exclusive word "alone" should be added to the essential term in God?; Whether an exclusive diction can be joined to the personal term?.
We now consider what belongs to the unity or plurality in God; which gives rise to four points of inquiry:
Article 1: Whether there is trinity in God?
Athanasius says: "Unity in Trinity; and Trinity in Unity is to be revered."
The name "Trinity" in God signifies the determinate number of persons. And so the plurality of persons in God requires that we should use the word trinity; because what is indeterminately signified by plurality, is signified by trinity in a determinate manner.
Article 2: Whether the Son is other than the Father?
Augustine [*Fulgentius, De Fide ad Petrum i.] says: "There is one essence of the Father and Son and Holy Ghost, in which the Father is not one thing, the Son another, and the Holy Ghost another; although the Father is one person, the Son another, and the Holy Ghost another."
Since as Jerome remarks [*In substance, Ep. lvii.], a heresy arises from words wrongly used, when we speak of the Trinity we must proceed with care and with befitting modesty; because, as Augustine says (De Trin. i, 3), "nowhere is error more harmful, the quest more toilsome, the finding more fruitful." Now, in treating of the Trinity, we must beware of two opposite errors, and proceed cautiously between them---namely, the error of Arius, who placed a Trinity of substance with the Trinity of persons; and the error of Sabellius, who placed unity of person with the unity of essence.
Thus, to avoid the error of Arius we must shun the use of the terms diversity and difference in God, lest we take away the unity of essence: we may, however, use the term "distinction" on account of the relative opposition. Hence whenever we find terms of "diversity" or "difference" of Persons used in an authentic work, these terms of "diversity" or "difference" are taken to mean "distinction." But lest the simplicity and singleness of the divine essence be taken away, the terms "separation" and "division," which belong to the parts of a whole, are to be avoided: and lest quality be taken away, we avoid the use of the term "disparity": and lest we remove similitude, we avoid the terms "alien" and "discrepant." For Ambrose says (De Fide i) that "in the Father and the Son there is no discrepancy, but one Godhead": and according to Hilary, as quoted above, "in God there is nothing alien, nothing separable."
To avoid the heresy of Sabellius, we must shun the term "singularity," lest we take away the communicability of the divine essence. Hence Hilary says (De Trin. vii): "It is sacrilege to assert that the Father and the Son are separate in Godhead." We must avoid the adjective "only" [unici] lest we take away the number of persons. Hence Hilary says in the same book: "We exclude from God the idea of singularity or uniqueness." Nevertheless, we say "the only Son," for in God there is no plurality of Sons. Yet, we do not say "the only God," for the Deity is common to several. We avoid the word "confused," lest we take away from the Persons the order of their nature. Hence Ambrose says (De Fide i): "What is one is not confused; and there is no multiplicity where there is no difference." The word "solitary" is also to be avoided, lest we take away the society of the three persons; for, as Hilary says (De Trin. iv), "We confess neither a solitary nor a diverse God."
This word "other" [alius], however, in the masculine sense, means only a distinction of "suppositum"; and hence we can properly say that "the Son is other than the Father," because He is another "suppositum" of the divine nature, as He is another person and another hypostasis.
Article 3: Whether the exclusive word "alone" should be added to the essential term in God?
It is said, "To the King of ages, immortal, invisible, the only God" (1 Tim. 1:17).
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 term to which it is joined; and it would follow that God was solitary, against what is above stated (). A syncategorematical term imports the order of the predicate to the subject; as this expression "every one" or "no one"; and likewise the term "alone," as excluding every other "suppositum" from the predicate. Thus, when we say, "Socrates alone writes," we do not mean that Socrates is solitary, but that he has no companion in writing, though many others may be with him. In this way nothing prevents the term "alone" being joined to any essential term in God, as excluding the predicate from all things but God; as if we said "God alone is eternal," because nothing but God is eternal.
Article 4: Whether an exclusive diction can be joined to the personal term?
This proposition "The Father alone is God" includes two assertions---namely, that the Father is God, and that no other besides the Father is God. But this second proposition is false, for the Son is another from the Father, and He is God. Therefore this is false, The Father alone is God; and the same of the like sayings.
When we say, "The Father alone is God," such a proposition can be taken in several senses. If "alone" means solitude in the Father, it is false in a categorematical sense; but if taken in a syncategorematical sense it can again be understood in several ways. For if it exclude (all others) from the form of the subject, it is true, the sense being "the Father alone is God"---that is, "He who with no other is the Father, is God." In this way Augustine expounds when he says (De Trin. vi, 6): "We say the Father alone, not because He is separate from the Son, or from the Holy Ghost, but because they are not the Father together with Him." This, however, is not the usual way of speaking, unless we understand another implication, as though we said "He who alone is called the Father is God." But in the strict sense the exclusion affects the predicate. And thus the proposition is false if it excludes another in the masculine sense; but true if it excludes it in the neuter sense; because the Son is another person than the Father, but not another thing; and the same applies to the Holy Ghost. But because this diction "alone," properly speaking, refers to the subject, it tends to exclude another Person rather than other things. Hence such a way of speaking is not to be taken too literally, but it should be piously expounded, whenever we find it in an authentic work.