it is manifest from the foregoing ( Question [27], Article [2]; Question [28], Article [4]), that the perfect idea of paternity and filiation is to be found in God the Father, and in God the Son, because one is the nature and glory of the Father and the Son. But in the creature, filiation is found in relation to God, not in a perfect manner, since the Creator and the creature have not the same nature; but by way of a certain likeness, which is the more perfect the nearer we approach to the true idea of filiation. For God is called the Father of some creatures, by reason only of a trace, for instance of irrational creatures, according to Job 38:28: "Who is the father of the rain? or who begot the drops of dew?" Of some, namely, the rational creature (He is the Father), by reason of the likeness of His image, according to Dt. 32:6: "Is He not thy Father, who possessed, and made, and created thee?" And of others He is the Father by similitude of grace, and these are also called adoptive sons, as ordained to the heritage of eternal glory by the gift of grace which they have received, according to Rm. 8:16,17: "The Spirit Himself gives testimony to our spirit that we are the sons of God; and if sons, heirs also." Lastly, He is the Father of others by similitude of glory, forasmuch as they have obtained possession of the heritage of glory, according to Rm. 5:2: "We glory in the hope of the glory of the sons of God." Therefore it is plain that "paternity" is applied to God first, as importing regard of one Person to another Person, before it imports the regard of God to creatures.
Reply to Objection 1: Common terms taken absolutely, in the order of our intelligence, come before proper terms; because they are included in the understanding of proper terms; but not conversely. For in the concept of the person of the Father, God is understood; but not conversely. But common terms which import relation to the creature come after proper terms which import personal relations; because the person proceeding in God proceeds as the principle of the production of creatures. For as the word conceived in the mind of the artist is first understood to proceed from the artist before the thing designed, which is produced in likeness to the word conceived in the artist's mind; so the Son proceeds from the Father before the creature, to which the name of filiation is applied as it participates in the likeness of the Son, as is clear from the words of Rm. 8:29: "Whom He foreknew and predestined to be made conformable to the image of His Son."
Reply to Objection 2: To "receive" is said to be common to the creature and to the Son not in a univocal sense, but according to a certain remote similitude whereby He is called the First Born of creatures. Hence the authority quoted subjoins: "That He may be the First Born among many brethren," after saying that some were conformed to the image of the Son of God. But the Son of God possesses a position of singularity above others, in having by nature what He receives, as Basil also declares (Hom. xv De Fide); hence He is called the only begotten (Jn. 1:18): "The only begotten Who is in the bosom of the Father, He hath declared unto us."
From this appears the Reply to the Third Objection.
Whether it is proper to the Father to be unbegotten?
Objection 1: It would seem that it is not proper to the Father to be unbegotten. For every property supposes something in that of which it is the property. But "unbegotten" supposes nothing in the Father; it only removes something. Therefore it does not signify a property of the Father.
Objection 2: Further, Unbegotten is taken either in a privative, or in a negative sense. If in a negative sense, then whatever is not begotten can be called unbegotten. But the Holy Ghost is not begotten; neither is the divine essence. Therefore to be unbegotten belongs also to the essence; thus it is not proper to the Father. But if it be taken in a privative sense, as every privation signifies imperfection in the thing which is the subject of privation, it follows that the Person of the Father is imperfect; which cannot be.
Objection 3: Further, in God, "unbegotten" does not signify relation, for it is not used relatively. Therefore it signifies substance; therefore unbegotten and begotten differ in substance. But the Son, Who is begotten, does not differ from the Father in substance. Therefore the Father ought not to be called unbegotten.
Objection 4: Further, property means what belongs to one alone. Since, then, there are more than one in God proceeding from another, there is nothing to prevent several not receiving their being from another. Therefore the Father is not alone unbegotten.
Objection 5: Further, as the Father is the principle of the person begotten, so is He of the person proceeding. So if by reason of his opposition to the person begotten, it is proper to the Father to be unbegotten it follows that it is proper to Him also to be unproceeding.
On the contrary, Hilary says (De Trin. iv): "One is from one ---that is, the Begotten is from the Unbegotten---namely, by the property in each one respectively of innascibility and origin."
I answer that, As in creatures there exist a first and a secondary principle, so also in the divine Persons, in Whom there is no before or after, is formed the principle not from a principle, Who is the Father; and the principle from a principle, Who is the Son.
Now in things created a first principle is known in two ways; in one way as the first "principle," by reason of its having a relation to what proceeds from itself; in another way, inasmuch as it is a "first" principle by reason of its not being from another. Thus therefore the Father is known both by paternity and by common spiration, as regards the persons proceeding from Himself. But as the principle, not from a principle He is known by the fact that He is not from another; and this belongs to the property of innascibility, signified by this word "begotten."
Reply to Objection 1: Some there are who say that innascibility, signified by the word "unbegotten," as a property of the Father, is not a negative term only, but either that it means both these things together---namely, that the Father is from no one, and that He is the principle of others; or that it imports universal authority, or also His plenitude as the source of all. This, however, does not seem true, because thus innascibility would not be a property distinct from paternity and spiration; but would include them as the proper is included in the common. For source and authority signify in God nothing but the principle of origin. We must therefore say with Augustine (De Trin. v, 7) that "unbegotten" imports the negation of passive generation. For he says that "unbegotten" has the same meaning as "not a son." Nor does it follow that "unbegotten" is not the proper notion of the Father; for primary and simple things are notified by negations; as, for instance, a point is defined as what has no part.
Reply to Objection 2: "Unbegotten" is taken sometimes in a negative sense only, and in that sense Jerome says that "the Holy Ghost is unbegotten," that is, He is not begotten. Otherwise "unbegotten" may be taken in a kind of privation sense, but not as implying any imperfection. For privation can be taken in many ways; in one way when a thing has not what is naturally belongs to another, even though it is not of its own nature to have it; as, for instance, if a stone be called a dead thing, as wanting life, which naturally belongs to some other things. In another sense, privation is so called when something has not what naturally belongs to some members of its genus; as for instance when a mole is called blind. In a third sense privation means the absence of what something ought to have; in which sense, privation imports an imperfection. In this sense, "unbegotten" is not attributed to the Father as a privation, but it may be so attributed in the second sense, meaning that a certain person of the divine nature is not begotten, while some person of the same nature is begotten. In this sense the term "unbegotten" can be applied also to the Holy Ghost. Hence to consider it as a term proper to the Father alone, it must be further understood that the name "unbegotten" belongs to a divine person as the principle of another person; so that it be understood to imply negation
