Objection 1: It would seem that the persons cannot be predicated of the concrete essential names; so that we can say for instance, "God is three persons"; or "God is the Trinity." For it is false to say, "man is every man," because it cannot be verified as regards any particular subject. For neither Socrates, nor Plato, nor anyone else is every man. In the same way this proposition, "God is the Trinity," cannot be verified of any one of the "supposita" of the divine nature. For the Father is not the Trinity; nor is the Son; nor is the Holy Ghost. So to say, "God is the Trinity," is false.
Objection 2: Further, the lower is not predicated of the higher except by accidental predication; as when I say, "animal is man"; for it is accidental to animal to be man. But this name "God" as regards the three persons is as a general term to inferior terms, as Damascene says (De Fide Orth. iii, 4). Therefore it seems that the names of the persons cannot be predicated of this name "God," except in an accidental sense.
On the contrary, Augustine says, in his sermon on Faith [*Serm. ii, in coena Domini], "We believe that one God is one divinely named Trinity."
I answer that, As above explained (A[5]), although adjectival terms, whether personal or notional, cannot be predicated of the essence, nevertheless substantive terms can be so predicated, owing to the real identity of essence and person. The divine essence is not only really the same as one person, but it is really the same as the three persons. Whence, one person, and two, and three, can be predicated of the essence as if we were to say, "The essence is the Father, and the Son, and the Holy Ghost." And because this word "God" can of itself stand for the essence, as above explained (A[4], ad 3), hence, as it is true to say, "The essence is the three persons"; so likewise it is true to say, "God is the three persons."
Reply to Objection 1: As above explained this term "man" can of itself stand for person, whereas an adjunct is required for it to stand for the universal human nature. So it is false to say, "Man is every man"; because it cannot be verified of any particular human subject. On the contrary, this word "God" can of itself be taken for the divine essence. So, although to say of any of the "supposita" of the divine nature, "God is the Trinity," is untrue, nevertheless it is true of the divine essence. This was denied by Porretanus because he did not take note of this distinction.
Reply to Objection 2: When we say, "God," or "the divine essence is the Father," the predication is one of identity, and not of the lower in regard to a higher species: because in God there is no universal and singular. Hence, as this proposition, "The Father is God" is of itself true, so this proposition "God is the Father" is true of itself, and by no means accidentally.
Whether the essential names should be appropriated to the persons?
Objection 1: It would seem that the essential names should not be appropriated to the persons. For whatever might verge on error in faith should be avoided in the treatment of divine things; for, as Jerome says, "careless words involve risk of heresy" [*In substance Ep. lvii.]. But to appropriate to any one person the names which are common to the three persons, may verge on error in faith; for it may be supposed either that such belong only to the person to whom they are appropriated or that they belong to Him in a fuller degree than to the others. Therefore the essential attributes should not be appropriated to the persons.
Objection 2: Further, the essential attributes expressed in the abstract signify by mode of form. But one person is not as a form to another; since a form is not distinguished in subject from that of which it is the form. Therefore the essential attributes, especially when expressed in the abstract, are not to be appropriated to the persons.
Objection 3: Further, property is prior to the appropriated, for property is included in the idea of the appropriated. But the essential attributes, in our way of understanding, are prior to the persons; as what is common is prior to what is proper. Therefore the essential attributes are not to be appropriated to the persons.
On the contrary, the Apostle says: "Christ the power of God and the wisdom of God" ( 1 Cor. 1:24 ).
I answer that, For the manifestation of our faith it is fitting that the essential attributes should be appropriated to the persons. For although the trinity of persons cannot be proved by demonstration, as was above expounded (Q[32], A[1]), nevertheless it is fitting that it be declared by things which are more known to us. Now the essential attributes of God are more clear to us from the standpoint of reason than the personal properties; because we can derive certain knowledge of the essential attributes from creatures which are sources of knowledge to us, such as we cannot obtain regarding the personal properties, as was above explained (Q[32], A[1]). As, therefore, we make use of the likeness of the trace or image found in creatures for the manifestation of the divine persons, so also in the same manner do we make use of the essential attributes. And such a manifestation of the divine persons by the use of the essential attributes is called "appropriation."
The divine person can be manifested in a twofold manner by the essential attributes; in one way by similitude, and thus the things which belong to the intellect are appropriated to the Son, Who proceeds by way of intellect, as Word. In another way by dissimilitude; as power is appropriated to the Father, as Augustine says, because fathers by reason of old age are sometimes feeble; lest anything of the kind be imagined of God.
Reply to Objection 1: The essential attributes are not appropriated to the persons as if they exclusively belonged to them; but in order to make the persons manifest by way of similitude, or dissimilitude, as above explained. So, no error in faith can arise, but rather manifestation of the truth.
Reply to Objection 2: If the essential attributes were appropriated to the persons as exclusively belonging to each of them, then it would follow that one person would be as a form as regards another; which Augustine altogether repudiates (De Trin. vi, 2), showing that the Father is wise, not by Wisdom begotten by Him, as though only the Son were Wisdom; so that the Father and the Son together only can be called wise, but not the Father without the Son. But the Son is called the Wisdom of the Father, because He is Wisdom from the Father Who is Wisdom. For each of them is of Himself Wisdom; and both together are one Wisdom. Whence the Father is not wise by the wisdom begotten by Him, but by the wisdom which is His own essence.
Reply to Objection 3: Although the essential attribute is in its proper concept prior to person, according to our way of understanding; nevertheless, so far as it is appropriated, there is nothing to prevent the personal property from being prior to that which is appropriated. Thus color is posterior to body considered as body, but is naturally prior to "white body," considered as white.
Whether the essential attributes are appropriated to the persons in a fitting manner by the holy doctors?
Objection 1: It would seem that the essential attributes are appropriated to the persons unfittingly by the holy doctors. For Hilary says (De Trin. ii): "Eternity is in the Father, the species in the Image; and use is in the Gift." In which words he designates three names proper to the persons: the name of the "Father," the name "Image" proper to the Son (Q[35], A[2]), and the name "Bounty" or "Gift," which is proper to the Holy Ghost (Q[38], A[2]). He also designates three appropriated terms. For he appropriates "eternity" to the Father, "species" to the Son, and "use" to the Holy Ghost. This he does apparently without reason. For "eternity" imports duration of existence; "species," the principle of existence; and 'use' belongs to the operation. But essence and operation are not found to be appropriated to any person. Therefore the above terms are not fittingly appropriated to the persons.
Objection 2: Further, Augustine says (De Doctr. Christ. i, 5): "Unity is in the Father, equality in the Son, and in the Holy Ghost is the concord of equality and unity." This does not, however, seem fitting; because one person does not receive formal denomination from what is appropriated to another. For the Father is not wise by the wisdom begotten, as above explained (Q[37], A[2], ad 1). But, as he subjoins, "All these three are one by the Father; all are equal by the Son, and all united by the Holy Ghost." The above, therefore, are not fittingly appropriated to the Persons.
Objection 3: Further, according to Augustine, to the Father is attributed "power," to the Son "wisdom," to the Holy Ghost "goodness." Nor does this seem fitting; for "strength" is part of power, whereas strength is found to be appropriated to the Son, according to the text, "Christ the strength [*Douay: power] of God" ( 1 Cor. 1:24 ). So it is likewise appropriated to the Holy Ghost, according to the words, "strength [*Douay: virtue] came out from Him and healed all" ( Lk. 6:19 ). Therefore power should not be appropriated to the Father.
Objection 4: Likewise Augustine says (De Trin. vi, 10): "What the Apostle says, "From Him, and by Him, and in Him," is not to be taken in a confused sense." And (Contra Maxim. ii) "'from Him' refers to the Father, 'by Him' to the Son, 'in Him' to the Holy Ghost.'" This, however, seems to be incorrectly said; for the words "in Him" seem to imply the relation of final cause, which is first among the causes. Therefore this relation of cause should be appropriated to the Father, Who is "the principle from no principle."
Objection 5: Likewise, Truth is appropriated to the Son, according to Jn. 14:6 , "I am the Way, the Truth, and the Life"; and likewise "the book of life," according to Ps. 39:9, "In the beginning of the book it is written of Me," where a gloss observes, "that is, with the Father Who is My head," also this word "Who is"; because on the text of Is. 65:1, "Behold I go to the Gentiles," a gloss adds, "The Son speaks Who said to Moses, I am Who am." These appear to belong to the Son, and are not appropriated. For "truth," according to Augustine (De Vera Relig. 36), "is the supreme similitude of the principle without any dissimilitude." So it seems that it properly belongs to the Son, Who has a principle. Also the "book of life" seems proper to the Son, as signifying "a thing from another"; for every book is written by someone. This also, "Who is," appears to be proper to the Son; because if when it was said to Moses, "I am Who am," the Trinity spoke, then Moses could have said, "He Who is Father, Son, and Holy Ghost, and the Holy Ghost sent me to you," so also he could have said further, "He Who is the Father, and the Son, and the Holy Ghost sent me to you," pointing out a certain person. This, however, is false; because no person is Father, Son and Holy Ghost. Therefore it cannot be common to the Trinity, but is proper to the Son.
I answer that, Our intellect, which is led to the knowledge of God from creatures, must consider God according to the mode derived from creatures. In considering any creature four points present themselves to us in due order. Firstly, the thing itself taken absolutely is considered as a being. Secondly, it is considered as one. Thirdly, its intrinsic power of operation and causality is considered. The fourth point of consideration embraces its relation to its effects. Hence this fourfold consideration comes to our mind in reference to God.
According to the first point of consideration, whereby we consider God absolutely in His being, the appropriation mentioned by Hilary applies, according to which "eternity" is appropriated to the Father, "species" to the Son, "use" to the Holy Ghost. For "eternity" as meaning a "being" without a principle, has a likeness to the property of the Father, Who is "a principle without a principle." Species or beauty has a likeness to the property of the Son. For beauty includes three conditions, "integrity" or "perfection," since those things which are impaired are by the very fact ugly; due "proportion" or "harmony"; and lastly, "brightness" or "clarity," whence things are called beautiful which have a bright color.
The first of these has a likeness to the property of the Son, inasmuch as He as Son has in Himself truly and perfectly the nature of the Father. To insinuate this, Augustine says in his explanation (De Trin. vi, 10): "Where---that is, in the Son---there is supreme and primal life," etc.