OF THE PERSON OF THE FATHER (FOUR ARTICLES)
We now consider the persons singly; and first, the Person of the Father, concerning Whom there are four points of inquiry:
(1) Whether the Father is the Principle?
(2) Whether the person of the Father is properly signified by this name "Father"?
(3) Whether "Father" in God is said personally before it is said essentially?
(4) Whether it belongs to the Father alone to be unbegotten?
Whether it belongs to the Father to be the principle?
Objection 1: It would seem that the Father cannot be called the principle of the Son, or of the Holy Ghost. For principle and cause are the same, according to the Philosopher (Metaph. iv). But we do not say that the Father is the cause of the Son. Therefore we must not say that He is the principle of the Son.
Objection 2: Further, a principle is so called in relation to the thing principled. So if the Father is the principle of the Son, it follows that the Son is a person principled, and is therefore created; which appears false.
Objection 3: Further, the word principle is taken from priority. But in God there is no "before" and "after," as Athanasius says. Therefore in speaking of God we ought not to used the term principle.
On the contrary, Augustine says (De Trin. iv, 20), "The Father is the Principle of the whole Deity."
I answer that, The word "principle" signifies only that whence another proceeds: since anything whence something proceeds in any way we call a principle; and conversely. As the Father then is the one whence another proceeds, it follows that the Father is a principle.
Reply to Objection 1: The Greeks use the words "cause" and "principle" indifferently, when speaking of God; whereas the Latin Doctors do not use the word "cause," but only "principle." The reason is because "principle" is a wider term than "cause"; as "cause" is more common than "element." For the first term of a thing, as also the first part, is called the principle, but not the cause. Now the wider a term is, the more suitable it is to use as regards God (Q[13], A[11]), because the more special terms are, the more they determine the mode adapted to the creature. Hence this term "cause" seems to mean diversity of substance, and dependence of one from another; which is not implied in the word "principle." For in all kinds of causes there is always to be found between the cause and the effect a distance of perfection or of power: whereas we use the term "principle" even in things which have no such difference, but have only a certain order to each other; as when we say that a point is the principle of a line; or also when we say that the first part of a line is the principle of a line.
Reply to Objection 2: It is the custom with the Greeks to say that the Son and the Holy Ghost are principled. This is not, however, the custom with our Doctors; because, although we attribute to the Father something of authority by reason of His being the principle, still we do not attribute any kind of subjection or inferiority to the Son, or to the Holy Ghost, to avoid any occasion of error. In this way, Hilary says (De Trin. ix): "By authority of the Giver, the Father is the greater; nevertheless the Son is not less to Whom oneness of nature is give."
Reply to Objection 3: Although this word principle, as regards its derivation, seems to be taken from priority, still it does not signify priority, but origin. For what a term signifies, and the reason why it was imposed, are not the same thing, as stated above (Q[13], A[8]).
Whether this name "Father" is properly the name of a divine person?
Objection 1: It would seem that this name "Father" is not properly the name of a divine person. For the name "Father" signifies relation. Moreover "person" is an individual substance. Therefore this name "Father" is not properly a name signifying a Person.
Objection 2: Further, a begetter is more common than father; for every father begets; but it is not so conversely. But a more common term is more properly applied to God, as stated above (Q[13], A[11]). Therefore the more proper name of the divine person is begetter and genitor than Father.
Objection 3: Further, a metaphorical term cannot be the proper name of anyone. But the word is by us metaphorically called begotten, or offspring; and consequently, he of whom is the word, is metaphorically called father. Therefore the principle of the Word in God is not properly called Father.
Objection 4: Further, everything which is said properly of God, is said of God first before creatures. But generation appears to apply to creatures before God; because generation seems to be truer when the one who proceeds is distinct from the one whence it proceeds, not only by relation but also by essence. Therefore the name "Father" taken from generation does not seem to be the proper name of any divine person.
On the contrary, It is said ( Ps. 88:27 ): "He shall cry out to me: Thou art my Father."
I answer that, The proper name of any person signifies that whereby the person is distinguished from all other persons. For as body and soul belong to the nature of man, so to the concept of this particular man belong this particular soul and this particular body; and by these is this particular man distinguished from all other men. Now it is paternity which distinguishes the person of the Father from all other persons. Hence this name "Father," whereby paternity is signified, is the proper name of the person of the Father.
Reply to Objection 1: Among us relation is not a subsisting person. So this name "father" among us does not signify a person, but the relation of a person. In God, however, it is not so, as some wrongly thought; for in God the relation signified by the name "Father" is a subsisting person. Hence, as above explained (Q[29], A[4]), this name "person" in God signifies a relation subsisting in the divine nature.
Reply to Objection 2: According to the Philosopher (De Anima ii, text 49), a thing is denominated chiefly by its perfection, and by its end. Now generation signifies something in process of being made, whereas paternity signifies the complement of generation; and therefore the name "Father" is more expressive as regards the divine person than genitor or begettor.
Reply to Objection 3: In human nature the word is not a subsistence, and hence is not properly called begotten or son. But the divine Word is something subsistent in the divine nature; and hence He is properly and not metaphorically called Son, and His principle is called Father.