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.
Obj. 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.
Obj. 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" (Luke 6:19). Therefore power should not be appropriated to the Father.
Obj. 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."
Obj. 5: Likewise, Truth is appropriated to the Son, according to John 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 Isaias, "Behold I go to the Gentiles" (65:1), 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.
The second agrees with the Son's property, inasmuch as He is the express Image of the Father. Hence we see that an image is said to be beautiful, if it perfectly represents even an ugly thing. This is indicated by Augustine when he says (De Trin. vi, 10), "Where there exists wondrous proportion and primal equality," etc.
The third agrees with the property of the Son, as the Word, which is the light and splendor of the intellect, as Damascene says (De Fide Orth. iii, 3). Augustine alludes to the same when he says (De Trin. vi, 10): "As the perfect Word, not wanting in anything, and, so to speak, the art of the omnipotent God," etc.