Summa Th. I EN Qu.40 a.2
Objection: 1. It would seem that the persons are not distinguished by the relations. For simple things are distinct by themselves. But the persons are supremely simple. Therefore they are distinguished by themselves, and not by the relation.
2. Further, a form is distinguished only in relation to its genus. For white is distinguished from black only by quality. But "hypostasis" signifies an individual in the genus of substance. Therefore the hypostases cannot be distinguished by relations.
3. Further, what is absolute comes before what is relative. But the distinction of the divine persons is the primary distinction. Therefore the divine persons are not distinguished by the relations.
4. Further, whatever presupposes distinction cannot be the first principle of distinction. But relation presupposes distinction, which comes into its definition; for a relation is essentially what is towards another. Therefore the first distinctive principle in God cannot be relation.
On the contrary Boethius says (De Trin.): "Relation alone multiplies the Trinity of the divine persons."
I answer that In whatever multitude of things is to be found something common to all, it is necessary to seek out the principle of distinction. So, as the three persons agree in the unity of essence, we must seek to know the principle of distinction whereby they are several. Now, there are two principles of difference between the divine persons, and these are "origin" and "relation." Although these do not really differ, yet they differ in the mode of signification; for "origin" is signified by way of act, as "generation"; and "relation" by way of the form, as "paternity."
Some, then, considering that relation follows upon act, have said that the divine hypostases are distinguished by origin, so that we may say that the Father is distinguished from the Son, inasmuch as the former begets and the latter is begotten. Further, that the relations, or the properties, make known the distinctions of the hypostases or persons as resulting therefrom; as also in creatures the properties manifest the distinctions of individuals, which distinctions are caused by the material principles.
This opinion, however, cannot stand---for two reasons. Firstly, because, in order that two things be understood as distinct, their distinction must be understood as resulting from something intrinsic to both; thus in things created it results from their matter or their form. Now origin of a thing does not designate anything intrinsic, but means the way from something, or to something; as generation signifies the way to a thing generated, and as proceeding from the generator. Hence it is not possible that what is generated and the generator should be distinguished by generation alone; but in the generator and in the thing generated we must presuppose whatever makes them to be distinguished from each other. In a divine person there is nothing to presuppose but essence, and relation or property. Whence, since the persons agree in essence, it only remains to be said that the persons are distinguished from each other by the relations. Secondly: because the distinction of the divine persons is not to be so understood as if what is common to them all is divided, because the common essence remains undivided; but the distinguishing principles themselves must constitute the things which are distinct. Now the relations or the properties distinguish or constitute the hypostases or persons, inasmuch as they are themselves the subsisting persons; as paternity is the Father, and filiation is the Son, because in God the abstract and the concrete do not differ. But it is against the nature of origin that it should constitute hypostasis or person. For origin taken in an active sense signifies proceeding from a subsisting person, so that it presupposes the latter; while in a passive sense origin, as "nativity," signifies the way to a subsisting person, and as not yet constituting the person.
It is therefore better to say that the persons or hypostases are distinguished rather by relations than by origin. For, although in both ways they are distinguished, nevertheless in our mode of understanding they are distinguished chiefly and firstly by relations; whence this name "Father" signifies not only a property, but also the hypostasis; whereas this term "Begetter" or "Begetting" signifies property only; forasmuch as this name "Father" signifies the relation which is distinctive and constitutive of the hypostasis; and this term "Begetter" or "Begotten" signifies the origin which is not distinctive and constitutive of the hypostasis.
Reply to Objection: 1. The persons are the subsisting relations themselves. Hence it is not against the simplicity of the divine persons for them to be distinguished by the relations.
2. The divine persons are not distinguished as regards being, in which they subsist, nor in anything absolute, but only as regards something relative. Hence relation suffices for their distinction.
3. The more prior a distinction is, the nearer it approaches to unity; and so it must be the least possible distinction. So the distinction of the persons must be by that which distinguishes the least possible; and this is by relation.
4. Relation presupposes the distinction of the subjects, when it is an accident; but when the relation is subsistent, it does not presuppose, but brings about distinction. For when it is said that relation is by nature to be towards another, the word "another" signifies the correlative which is not prior, but simultaneous in the order of nature.
Objection: 1. It would seem that the hypostases remain if the properties or relations are mentally abstracted from the persons. For that to which something is added, may be understood when the addition is taken away; as man is something added to animal which can be understood if rational be taken away. But person is something added to hypostasis; for person is "a hypostasis distinguished by a property of dignity." Therefore, if a personal property be taken away from a person, the hypostasis remains.
2. Further, that the Father is Father, and that He is someone, are not due to the same reason. For as He is the Father by paternity, supposing He is some one by paternity, it would follow that the Son, in Whom there is not paternity, would not be "someone." So when paternity is mentally abstracted from the Father, He still remains "someone"---that is, a hypostasis. Therefore, if property be removed from person, the hypostasis remains.
3. Further, Augustine says (De Trin. v, 6): "Unbegotten is not the same as Father; for if the Father had not begotten the Son, nothing would prevent Him being called unbegotten." But if He had not begotten the Son, there would be no paternity in Him. Therefore, if paternity be removed, there still remains the hypostasis of the Father as unbegotten.
On the contrary Hilary says (De Trin. iv): "The Son has nothing else than birth." But He is Son by "birth." Therefore, if filiation be removed, the Son's hypostasis no more remains; and the same holds as regards the other persons.
I answer that Abstraction by the intellect is twofold---when the universal is abstracted from the particular, as animal abstracted from man; and when the form is abstracted from the matter, as the form of a circle is abstracted by the intellect from any sensible matter. The difference between these two abstractions consists in the fact that in the abstraction of the universal from the particular, that from which the abstraction is made does not remain; for when the difference of rationality is removed from man, the man no longer remains in the intellect, but animal alone remains. But in the abstraction of the form from the matter, both the form and the matter remain in the intellect; as, for instance, if we abstract the form of a circle from brass, there remains in our intellect separately the understanding both of a circle, and of brass. Now, although there is no universal nor particular in God, nor form and matter, in reality; nevertheless, as regards the mode of signification there is a certain likeness of these things in God; and thus Damascene says (De Fide Orth. iii, 6) that "substance is common and hypostasis is particular." So, if we speak of the abstraction of the universal from the particular, the common universal essence remains in the intellect if the properties are removed; but not the hypostasis of the Father, which is, as it were, a particular.
But as regards the abstraction of the form from the matter, if the non-personal properties are removed, then the idea of the hypostases and persons remains; as, for instance, if the fact of the Father's being unbegotten or spirating be mentally abstracted from the Father, the Father's hypostasis or person remains.
If, however, the personal property be mentally abstracted, the idea of the hypostasis no longer remains. For the personal properties are not to be understood as added to the divine hypostases, as a form is added to a pre-existing subject: but they carry with them their own "supposita," inasmuch as they are themselves subsisting persons; thus paternity is the Father Himself. For hypostasis signifies something distinct in God, since hypostasis means an individual substance. So, as relation distinguishes and constitutes the hypostases, as above explained (Article ), it follows that if the personal relations are mentally abstracted, the hypostases no longer remain. Some, however, think, as above noted, that the divine hypostases are not distinguished by the relations, but only by origin; so that the Father is a hypostasis as not from another, and the Son is a hypostasis as from another by generation. And that the consequent relations which are to be regarded as properties of dignity, constitute the notion of a person, and are thus called "personal properties." Hence, if these relations are mentally abstracted, the hypostasis, but not the persons, remain.
But this is impossible, for two reasons: first, because the relations distinguish and constitute the hypostases, as shown above (Article ); secondly, because every hypostasis of a rational nature is a person, as appears from the definition of Boethius (De Duab. Nat.) that, "person is the individual substance of a rational nature." Hence, to have hypostasis and not person, it would be necessary to abstract the rationality from the nature, but not the property from the person.
Reply to Objection: 1. Person does not add to hypostasis a distinguishing property absolutely, but a distinguishing property of dignity, all of which must be taken as the difference. Now, this distinguishing property is one of dignity precisely because it is understood as subsisting in a rational nature. Hence, if the distinguishing property be removed from the person, the hypostasis no longer remains; whereas it would remain were the rationality of the nature removed; for both person and hypostasis are individual substances. Consequently, in God the distinguishing relation belongs essentially to both.
2. By paternity the Father is not only Father, but is a person, and is "someone," or a hypostasis. It does not follow, however, that the Son is not "someone" or a hypostasis; just as it does not follow that He is not a person.
3. Augustine does not mean to say that the hypostasis of the Father would remain as unbegotten, if His paternity were removed, as if innascibility constituted and distinguished the hypostasis of the Father; for this would be impossible, since "being unbegotten" says nothing positive and is only a negation, as he himself says. But he speaks in a general sense, forasmuch as not every unbegotten being is the Father. So, if paternity be removed, the hypostasis of the Father does not remain in God, as distinguished from the other persons, but only as distinguished from creatures; as the Jews understand it.
Objection: 1. It would seem that the notional acts are understood before the properties. For the Master of the Sentences says (Sent. i, D, xxvii) that "the Father always is, because He is ever begetting the Son." So it seems that generation precedes paternity in the order of intelligence.
2. Further, in the order of intelligence every relation presupposes that on which it is founded; as equality presupposes quantity. But paternity is a relation founded on the action of generation. Therefore paternity presupposes generation.
3. Further, active generation is to paternity as nativity is to filiation. But filiation presupposes nativity; for the Son is so called because He is born. Therefore paternity also presupposes generation.
On the contrary Generation is the operation of the person of the Father. But paternity constitutes the person of the Father. Therefore in the order of intelligence, paternity is prior to generation.
I answer that According to the opinion that the properties do not distinguish and constitute the hypostases in God, but only manifest them as already distinct and constituted, we must absolutely say that the relations in our mode of understanding follow upon the notional acts, so that we can say, without qualifying the phrase, that "because He begets, He is the Father." A distinction, however, is needed if we suppose that the relations distinguish and constitute the divine hypostases. For origin has in God an active and passive signification---active, as generation is attributed to the Father, and spiration, taken for the notional act, is attributed to the Father and the Son; passive, as nativity is attributed to the Son, and procession to the Holy Ghost. For, in the order of intelligence, origin, in the passive sense, simply precedes the personal properties of the person proceeding; because origin, as passively understood, signifies the way to a person constituted by the property. Likewise, origin signified actively is prior in the order of intelligence to the non-personal relation of the person originating; as the notional act of spiration precedes, in the order of intelligence, the unnamed relative property common to the Father and the Son. The personal property of the Father can be considered in a twofold sense: firstly, as a relation; and thus again in the order of intelligence it presupposes the notional act, for relation, as such, is founded upon an act: secondly, according as it constitutes the person; and thus the notional act presupposes the relation, as an action presupposes a person acting.
Reply to Objection: 1. When the Master says that "because He begets, He is Father," the term "Father" is taken as meaning relation only, but not as signifying the subsisting person; for then it would be necessary to say conversely that because He is Father He begets.
2. This objection avails of paternity as a relation, but not as constituting a person.
3. Nativity is the way to the person of the Son; and so, in the order of intelligence, it precedes filiation, even as constituting the person of the Son. But active generation signifies a proceeding from the person of the Father; wherefore it presupposes the personal property of the Father.
We now consider the persons in reference to the notional acts, concerning which six points of inquiry arise:
(1) Whether the notional acts are to be attributed to the persons?
(2) Whether these acts are necessary, or voluntary?
(3) Whether as regards these acts, a person proceeds from nothing or from something?
(4) Whether in God there exists a power as regards the notional acts?
(5) What this power means?
(6) Whether several persons can be the term of one notional act?
Objection: 1. It would seem that the notional acts are not to be attributed to the persons. For Boethius says (De Trin.): "Whatever is predicated of God, of whatever genus it be, becomes the divine substance, except what pertains to the relation." But action is one of the ten "genera." Therefore any action attributed to God belongs to His essence, and not to a notion.
2. Further, Augustine says (De Trin. v, 4,5) that, "everything which is said of God, is said of Him as regards either His substance, or relation." But whatever belongs to the substance is signified by the essential attributes; and whatever belongs to the relations, by the names of the persons, or by the names of the properties. Therefore, in addition to these, notional acts are not to be attributed to the persons.
3. Further, the nature of action is of itself to cause passion. But we do not place passions in God. Therefore neither are notional acts to be placed in God.
On the contrary Augustine (Fulgentius, De Fide ad Petrum ii) says: "It is a property of the Father to beget the Son." Therefore notional acts are to be placed in God.
I answer that In the divine persons distinction is founded on origin. But origin can be properly designated only by certain acts. Wherefore, to signify the order of origin in the divine persons, we must attribute notional acts to the persons.
Reply to Objection: 1. Every origin is designated by an act. In God there is a twofold order of origin: one, inasmuch as the creature proceeds from Him, and this is common to the three persons; and so those actions which are attributed to God to designate the proceeding of creatures from Him, belong to His essence. Another order of origin in God regards the procession of person from person; wherefore the acts which designate the order of this origin are called notional; because the notions of the persons are the mutual relations of the persons, as is clear from what was above explained (Question , Article ).
2. The notional acts differ from the relations of the persons only in their mode of signification; and in reality are altogether the same. Whence the Master says that "generation and nativity in other words are paternity and filiation" (Sent. i, D, xxvi). To see this, we must consider that the origin of one thing from another is firstly inferred from movement: for that anything be changed from its disposition by movement evidently arises from some cause. Hence action, in its primary sense, means origin of movement; for, as movement derived from another into a mobile object, is called "passion," so the origin of movement itself as beginning from another and terminating in what is moved, is called "action." Hence, if we take away movement, action implies nothing more than order of origin, in so far as action proceeds from some cause or principle to what is from that principle. Consequently, since in God no movement exists, the personal action of the one producing a person is only the habitude of the principle to the person who is from the principle; which habitudes are the relations, or the notions. Nevertheless we cannot speak of divine and intelligible things except after the manner of sensible things, whence we derive our knowledge, and wherein actions and passions, so far as these imply movement, differ from the relations which result from action and passion, and therefore it was necessary to signify the habitudes of the persons separately after the manner of act, and separately after the manner of relations. Thus it is evident that they are really the same, differing only in their mode of signification.
3. Action, so far as it means origin of movement, naturally involves passion; but action in that sense is not attributed to God. Whence, passions are attributed to Him only from a grammatical standpoint, and in accordance with our manner of speaking, as we attribute "to beget" with the Father, and to the Son "to be begotten."
Objection: 1. It would seem that the notional acts are voluntary. For Hilary says (De Synod.): "Not by natural necessity was the Father led to beget the Son."
2. Further, the Apostle says, "He transferred us to the kingdom of the Son of His love" (Col 1,13). But love belongs to the will. Therefore the Son was begotten of the Father by will.
3. Further, nothing is more voluntary than love. But the Holy Ghost proceeds as Love from the Father and the Son. Therefore He proceeds voluntarily.
4. Further, the Son proceeds by mode of the intellect, as the Word. But every word proceeds by the will from a speaker. Therefore the Son proceeds from the Father by will, and not by nature.
5. Further, what is not voluntary is necessary. Therefore if the Father begot the Son, not by the will, it seems to follow that He begot Him by necessity; and this is against what Augustine says (Ad Orosium qu. vii).
On the contrary Augustine says, in the same book, that, "the Father begot the Son neither by will, nor by necessity."
I answer that When anything is said to be, or to be made by the will, this can be understood in two senses. In one sense, the ablative designates only concomitance, as I can say that I am a man by my will---that is, I will to be a man; and in this way it can be said that the Father begot the Son by will; as also He is God by will, because He wills to be God, and wills to beget the Son. In the other sense, the ablative imports the habitude of a principle as it is said that the workman works by his will, as the will is the principle of his work; and thus in that sense it must be said the God the Father begot the Son, not by His will; but that He produced the creature by His will. Whence in the book De Synod, it is said: "If anyone say that the Son was made by the Will of God, as a creature is said to be made, let him be anathema." The reason of this is that will and nature differ in their manner of causation, in such a way that nature is determined to one, while the will is not determined to one; and this because the effect is assimilated to the form of the agent, whereby the latter acts. Now it is manifest that of one thing there is only one natural form whereby it exists; and hence such as it is itself, such also is its work. But the form whereby the will acts is not only one, but many, according to the number of ideas understood. Hence the quality of the will's action does not depend on the quality of the agent, but on the agent's will and understanding. So the will is the principle of those things which may be this way or that way; whereas of those things which can be only in one way, the principle is nature. What, however, can exist in different ways is far from the divine nature, whereas it belongs to the nature of a created being; because God is of Himself necessary being, whereas a creature is made from nothing. Thus, the Arians, wishing to prove the Son to be a creature, said that the Father begot the Son by will, taking will in the sense of principle. But we, on the contrary, must assert that the Father begot the Son, not by will, but by nature. Wherefore Hilary says (De Synod.): "The will of God gave to all creatures their substance: but perfect birth gave the Son a nature derived from a substance impassible and unborn. All things created are such as God willed them to be; but the Son, born of God, subsists in the perfect likeness of God."
Reply to Objection: 1. This saying is directed against those who did not admit even the concomitance of the Father's will in the generation of the Son, for they said that the Father begot the Son in such a manner by nature that the will to beget was wanting; just as we ourselves suffer many things against our will from natural necessity---as, for instance, death, old age, and like ills. This appears from what precedes and from what follows as regards the words quoted, for thus we read: "Not against His will, nor as it were, forced, nor as if He were led by natural necessity did the Father beget the Son."
2. The Apostle calls Christ the Son of the love of God, inasmuch as He is superabundantly loved by God; not, however, as if love were the principle of the Son's generation.
3. The will, as a natural faculty, wills something naturally, as man's will naturally tends to happiness; and likewise God naturally wills and loves Himself; whereas in regard to things other than Himself, the will of God is in a way, undetermined in itself, as above explained (Question , Article ). Now, the Holy Ghost proceeds as Love, inasmuch as God loves Himself, and hence He proceeds naturally, although He proceeds by mode of will.
4. Even as regards the intellectual conceptions of the mind, a return is made to those first principles which are naturally understood. But God naturally understands Himself, and thus the conception of the divine Word is natural.
5. A thing is said to be necessary "of itself," and "by reason of another." Taken in the latter sense, it has a twofold meaning: firstly, as an efficient and compelling cause, and thus necessary means what is violent; secondly, it means a final cause, when a thing is said to be necessary as the means to an end, so far as without it the end could not be attained, or, at least, so well attained. In neither of these ways is the divine generation necessary; because God is not the means to an end, nor is He subject to compulsion. But a thing is said to be necessary "of itself" which cannot but be: in this sense it is necessary for God to be; and in the same sense it is necessary that the Father beget the Son.
Objection: 1. It would seem that the notional acts do not proceed from anything. For if the Father begets the Son from something, this will be either from Himself or from something else. If from something else, since that whence a thing is generated exists in what is generated, it follows that something different from the Father exists in the Son, and this contradicts what is laid down by Hilary (De Trin. vii) that, "In them nothing diverse or different exists." If the Father begets the Son from Himself, since again that whence a thing is generated, if it be something permanent, receives as predicate the thing generated therefrom just as we say, "The man is white," since the man remains, when not from white he is made white---it follows that either the Father does not remain after the Son is begotten, or that the Father is the Son, which is false. Therefore the Father does not beget the Son from something, but from nothing.
2. Further, that whence anything is generated is the principle regarding what is generated. So if the Father generate the Son from His own essence or nature, it follows that the essence or nature of the Father is the principle of the Son. But it is not a material principle, because in God nothing material exists; and therefore it is, as it were, an active principle, as the begetter is the principle of the one begotten. Thus it follows that the essence generates, which was disproved above (Question , Article ).
3. Further, Augustine says (De Trin. vii, 6) that the three persons are not from the same essence; because the essence is not another thing from person. But the person of the Son is not another thing from the Father's essence. Therefore the Son is not from the Father's essence.
4. Further, every creature is from nothing. But in Scripture the Son is called a creature; for it is said (Si 24,5), in the person of the Wisdom begotten,"I came out of the mouth of the Most High, the first-born before all creatures": and further on (Si 24,14) it is said as uttered by the same Wisdom, "From the beginning, and before the world was I created." Therefore the Son was not begotten from something, but from nothing. Likewise we can object concerning the Holy Ghost, by reason of what is said (Zach. 12:1): "Thus saith the Lord Who stretcheth forth the heavens, and layeth the foundations of the earth, and formeth the spirit of man within him"; and (Amos 4:13) according to another version [*The Septuagint]: "I Who form the earth, and create the spirit."
On the contrary Augustine (Fulgentius, De Fide ad Petrum i, 1) says: "God the Father, of His nature, without beginning, begot the Son equal to Himself."
I answer that The Son was not begotten from nothing, but from the Father's substance. For it was explained above (Question , Article ; Question , Articles ,3) that paternity, filiation and nativity really and truly exist in God. Now, this is the difference between true "generation," whereby one proceeds from another as a son, and "making," that the maker makes something out of external matter, as a carpenter makes a bench out of wood, whereas a man begets a son from himself. Now, as a created workman makes a thing out of matter, so God makes things out of nothing, as will be shown later on (Question , Article ), not as if this nothing were a part of the substance of the thing made, but because the whole substance of a thing is produced by Him without anything else whatever presupposed. So, were the Son to proceed from the Father as out of nothing, then the Son would be to the Father what the thing made is to the maker, whereto, as is evident, the name of filiation would not apply except by a kind of similitude. Thus, if the Son of God proceeds from the Father out of nothing, He could not be properly and truly called the Son, whereas the contrary is stated (1Jn 5,20): "That we may be in His true Son Jesus Christ." Therefore the true Son of God is not from nothing; nor is He made, but begotten.
That certain creatures made by God out of nothing are called sons of God is to be taken in a metaphorical sense, according to a certain likeness of assimilation to Him Who is the true Son. Whence, as He is the only true and natural Son of God, He is called the "only begotten," according to Jn 1,18, "The only begotten Son, Who is in the bosom of the Father, He hath declared Him"; and so as others are entitled sons of adoption by their similitude to Him, He is called the "first begotten," according to Rm 8,29: "Whom He foreknew He also predestinated to be made conformable to the image of His Son, that He might be the first born of many brethren." Therefore the Son of God is begotten of the substance of the Father, but not in the same way as man is born of man; for a part of the human substance in generation passes into the substance of the one begotten, whereas the divine nature cannot be parted; whence it necessarily follows that the Father in begetting the Son does not transmit any part of His nature, but communicates His whole nature to Him, the distinction only of origin remaining as explained above (Question , Article ).
Reply to Objection: 1. When we say that the Son was born of the Father, the preposition "of" designates a consubstantial generating principle, but not a material principle. For that which is produced from matter, is made by a change of form in that whence it is produced. But the divine essence is unchangeable, and is not susceptive of another form.
2. When we say the Son is begotten of the essence of the Father, as the Master of the Sentences explains (Sent. i, D, v), this denotes the habitude of a kind of active principle, and as he expounds, "the Son is begotten of the essence of the Father"---that is, of the Father Who is essence; and so Augustine says (De Trin. xv, 13): "When I say of the Father Who is essence, it is the same as if I said more explicitly, of the essence of the Father."
This, however, is not enough to explain the real meaning of the words. For we can say that the creature is from God Who is essence; but not that it is from the essence of God. So we may explain them otherwise, by observing that the preposition "of" [de] always denotes consubstantiality. We do not say that a house is "of" [de] the builder, since he is not the consubstantial cause. We can say, however, that something is "of" another, if this is its consubstantial principle, no matter in what way it is so, whether it be an active principle, as the son is said to be "of" the father, or a material principle, as a knife is "of" iron; or a formal principle, but in those things only in which the forms are subsisting, and not accidental to another, for we can say that an angel is "of" an intellectual nature. In this way, then, we say that the Son is begotten 'of' the essence of the Father, inasmuch as the essence of the Father, communicated by generation, subsists in the Son.
3. When we say that the Son is begotten of the essence of the Father, a term is added which saves the distinction. But when we say that the three persons are 'of' the divine essence, there is nothing expressed to warrant the distinction signified by the preposition, so there is no parity of argument.
4. When we say "Wisdom was created," this may be understood not of Wisdom which is the Son of God, but of created wisdom given by God to creatures: for it is said, "He created her [namely, Wisdom] in the Holy Ghost, and He poured her out over all His works" (Si 1,9-10). Nor is it inconsistent for Scripture in one text to speak of the Wisdom begotten and wisdom created, for wisdom created is a kind of participation of the uncreated Wisdom. The saying may also be referred to the created nature assumed by the Son, so that the sense be, "From the beginning and before the world was I made"---that is, I was foreseen as united to the creature. Or the mention of wisdom as both created and begotten insinuates into our minds the mode of the divine generation; for in generation what is generated receives the nature of the generator and this pertains to perfection; whereas in creation the Creator is not changed, but the creature does not receive the Creator's nature. Thus the Son is called both created and begotten, in order that from the idea of creation the immutability of the Father may be understood, and from generation the unity of nature in the Father and the Son. In this way Hilary expounds the sense of this text of Scripture (De Synod.). The other passages quoted do not refer to the Holy Ghost, but to the created spirit, sometimes called wind, sometimes air, sometimes the breath of man, sometimes also the soul, or any other invisible substance.
Summa Th. I EN Qu.40 a.2