Article 4 — Whether the Holy Spirit proceeds from the Son

The fourth point of inquiry is whether the Holy Spirit proceeds from the Son. (Parallel texts: ST I.36.2; SCG IV.24, 26; In I Sent. 11.1; Contra errores Graecorum, part 2, cc. 27–32; Compendium theologiae, ch. 49; De rationibus fidei, ch. 4; Commentary on the Gospel of John, ch. 14, lect. 6; ch. 16, lect. 4.)

Obj. 1: And it would seem that he does not. For Dionysius says that the Son and the Holy Spirit are, as it were, flowers of the God-bearing divinity. (Pseudo-Dionysius, The Divine Names 2.7 (PG 3:645–46).) Now, a flower is not from a flower. Therefore, the Holy Spirit is not from the Son.

Obj. 2: If the Son is the principle of the Holy Spirit, he has this either from himself or from another. He has it not from himself, since it belongs to the Son as Son to be from a principle rather than to be a principle. And if he has this from the Father, he must be a principle in the same way as the Father. But the Father is a principle by generation. Therefore, the Son must be the principle of the Holy Spirit by generation, and thus, the Holy Spirit will be the Son of the Son.

Obj. 3: Whatsoever is common to the Father and the Son belongs to each in the same way. If, then, it is common to the Father and Son to be a principle, the Son will be a principle in the same way as the Father. Now, since the Father is a principle by generation, the Son will be so also; and thus, the same conclusion follows as above.

Obj. 4: The Son is Son because he proceeds from the Father and is his Word. Now, the Holy Spirit is the word of the Son, according to Basil, (Basil the Great, Against Eunomius 5, in the chapter that begins with propterea (PL 29:731).) who gathers this from the statement of the Apostle that the Son upholds all things by the word of his power (Heb 1:3). Therefore, if the Holy Spirit proceeds from the Son, he must be the Son of the Son.

Obj. 5: Although in reality paternity and filiation are in God with priority, compared to their being in us, according to the saying of the Apostle: of whom, namely, God the Father, all paternity in heaven and earth is named (Eph 3:15), yet as regards the imposition of the name, these names have been transferred from human things to divine. But among human beings, the one proceeding from a son is called a “grandson.” So if the Holy Spirit proceeds from the Son, he will be the Father’s grandson, which is absurd.

Obj. 6: The property of the Son consists in his receiving; for he is called “Son” because he receives the Father’s nature by generation. If, then, the Son sends forth the Holy Spirit from himself, there will be two contrary properties in the Son, which is inadmissible.

Obj. 7: Whatsoever is in God is either common or proper. Now, to send forth the Holy Spirit is not common to all the Trinity, since it does not apply to the Holy Spirit. Therefore, it is proper to the Father, and in this way it does not apply to the Son.

Obj. 8: Augustine proves, in On the Trinity, that the Holy Spirit is love. (Augustine, On the Trinity 6.5 (PL 42:927–28).) Now, the Father’s love of the Son is gratuitous; for he loves the Son not as though he received something from him but only as giving him something. But the Son’s love of the Father is a love that is due; for he loves the Father as receiving something from him. Now, the love which is due is distinct from the love that is gratuitous. Hence, if the Holy Spirit is love proceeding from the Father and Son, it follows that he is distinct from his very self.

Obj. 9: The Holy Spirit is gratuitous love. Hence, from him flow the diversities of graces, according to 1 Cor 12:4: there are diversities of graces but the same Spirit. If, then, the Son’s love of the Father is not gratuitous, the Holy Spirit will not be the Son’s love, and thus he does not proceed from the Son.

Obj. 10: If the Holy Spirit proceeds from the Son as love, since the Son loves the Father as the Father loves the Son, it will follow that the Holy Spirit proceeds from the Son to the Father just as he proceeds from the Father to the Son. But this is apparently impossible, for it would follow that the Father receives from the Son, which is utterly inadmissible.

Obj. 11: As the Father and Son love each other, so also do the Son and the Holy Spirit, or the Father and the Holy Spirit. If, then, the Holy Spirit proceeds from Father and Son because Father and Son love each other, in like manner, because Father and Holy Spirit love each other, the Holy Spirit proceeds from his very self, which is impossible.

Obj. 12: Dionysius says: we must not dare to say or even think anything concerning the supersubstantial and hidden divine nature except what has been divinely revealed to us by the sacred oracles. (Pseudo-Dionysius, The Divine Names 1.2 (PG 3:587–88).) Now, Scripture does not assert that the Holy Spirit proceeds from the Son, but only that he proceeds from the Father, according to John 15:26; when the Paraclete comes whom I will send you from the Father, the Spirit of truth, who proceeds from the Father. Therefore, we must neither say nor think that the Holy Spirit proceeds from the Son.

Obj. 13: In the Acts of the Council of Ephesus, it is stated that, after the reading of the Creed of the Council of Nicaea, the holy synod decreed that no one might profess, write, or devise any faith other than that which was defined by the holy fathers assembled at Nicaea together with the Holy Spirit, and whosoever shall either presume to devise or teach or suggest another faith to such pagans, Jews, or heretics as are desirous of being converted to a knowledge of the truth, let them be deprived of their bishopric, if they be bishops, and banished from the clergy if they be clerics: if they be laymen let them be excommunicated. (Council of Ephesus, Definition of Faith at Nicaea (6th session, July 22, 431 AD); see Clavis Patrum Graecorum [CPG] 8721.) In like terms, the Council of Chalcedon, after setting forth the decisions of other councils, continues: whosoever shall dare to devise another faith, or pronounce, teach, or deliver another Creed to pagans, Jews, or heretics wishing to be converted, such, if they be bishops or clerics, shall be deprived of their sees in the case of bishops, and unfrocked if they be clerics; and if they be monks or laymen they shall be excommunicated. (Council of Chalcedon, Definition of Faith; see Acta Conciliorum Oecumenicorum [ACO], ed. Edward Schwartz (Berlin: Walter de Gruyter & Co, 1936), 2.2.2, 14.)

Now, in the definitions of the foregoing councils it is not stated that the Holy Spirit proceeds from the Son, but only that he proceeds from the Father. Moreover, we read in the profession of faith of the Council of Constantinople: we believe in the Holy Spirit, Lord and lifegiver, who proceeds from the Father; with the Father and the Son to be adored and glorified. (Council of Constantinople, Nicene Creed (CPG 8599).) Therefore, by no means should it have been added in the Creed that the Holy Spirit proceeds from the Son.

Obj. 14: If it be asserted that the Holy Spirit proceeds from the Son, this statement is made either on the authority of Scripture or on account of some proof. But seemingly Scripture nowhere affords sufficient authority for this statement. It is true that Holy Scripture speaks of the Holy Spirit as being of the Son; thus, it is said: God sent the spirit of his Son into your hearts (Gal 4:6), and: if any man have not the spirit of Christ, he is none of his (Rom 8:9). Again, we read that the Holy Spirit was sent by the Son; thus, Christ said: for if I go not, the Paraclete will not come to you, but if I go, I will send him to you (John 16:7). But it does not follow that the Holy Spirit proceeds from the Son because he is the Spirit of the Son, for according to the Philosopher the genitive case has many senses. Likewise, neither does it follow because the Holy Spirit is stated to be sent by the Son, since although the Son does not proceed from the Holy Spirit, he is said to be sent by the Holy Spirit, according to the words spoken in Christ’s person: and now the Lord God and his Spirit has sent me (Isa 48:16), and: the spirit of the Lord is upon me . . . he has sent me to preach to the meek (Isa 61:1), which words Christ declared to have been fulfilled in himself. Furthermore, the statement cannot be proved through any satisfactory argument. For allowing that the Holy Spirit is not from the Son, it seems that they would still remain distinct from each other; for they differ by their personal properties. Nothing, therefore, compels us to say that the Holy Spirit proceeds from the Son.

Obj. 15: Whatsoever proceeds from something has something from it. If, then, the Holy Spirit proceeds from two, namely, the Father and the Son, it follows that he receives from two, and thus, it seems to follow that he is composite.

Obj. 16: It is of the account of a principle that it is not from another, according to the Philosopher. (Aristotle, Physics 1.6, 189a17–33.) Now, the Son is from another, namely, the Father. Therefore, the Son is not a principle of the Holy Spirit.

Obj. 17: The will moves the intellect to its activity, since a man understands when he wills to do so. But the Holy Spirit proceeds through the mode of will as Love, and the Son through the mode of intellect as a Word. Therefore, it seems that the Holy Spirit does not proceed from the Son but contrariwise.

Obj. 18: Nothing proceeds from that wherein it abides. Now, the Holy Spirit proceeds from the Father and abides in the Son, as is written in the Acts of the blessed Andrew. (Acts of Saint Andrew, Introduction.) Therefore, the Holy Spirit does not proceed from the Son.

Obj. 19: A simple thing cannot proceed from two, since then the effect would be simpler than and prior to the cause. But the Holy Spirit is simple. Therefore, he does not proceed from two, namely, the Father and the Son.

Obj. 20: If a thing proceeds perfectly from one, it is superfluous for it to proceed from two. Now, the Holy Spirit proceeds perfectly from the Father. Therefore, it would be superfluous for him to proceed from the Father and Son together.

Obj. 21: As the Father and the Son are one in substance and nature, so also are the Father and the Holy Spirit. Now, the Holy Spirit does not belong with the Father in the generation of the Son. Neither, therefore, does the Son belong with the Father in sending forth the Holy Spirit.

Obj. 22: As Dionysius expresses it, the Son is the ray of the Father. (Pseudo-Dionysius, The Celestial Hierarchy 1.2 (PG 3:121–22).) Now, the Holy Spirit is brightness; and brightness does not issue from the ray. Therefore, neither does the Holy Spirit proceed from the Son.

Obj. 23: The Son is a certain light of the Father, since he is his Word, whereas the Holy Spirit is like heat, for he is a certain love; wherefore also he appeared over the Apostles in the form of fire (Acts 2:3). But heat does not come from light. Neither, then, does the Holy Spirit proceed from the Son.

Obj. 24: Damascene says that the Holy Spirit is said to be of the Son but not from the Son. (John Damascene, On the Orthodox Faith 1.8 (PG 94:831–34).)

On the contrary (1), Athanasius says: the Holy Spirit is from the Father and the Son; not made, nor created, nor begotten, but proceeding. (Athanasius, Athanasian Creed (PG 28:1582–83).)

Furthermore (2), the Holy Spirit is called the third person in the Trinity, the Son the second, the Father the first. Now, the number three proceeds from unity by the mediation of the number two. Therefore, the Holy Spirit proceeds from the Father by the mediation of the Son.

Furthermore (3), since there is supreme agreement between the divine persons, each of them is immediately akin with the others. But this would not be the case if the Holy Spirit were not from the Son, for then the Son and the Holy Spirit would not be immediately akin with each other, but only through the Father, inasmuch as both are from one. Therefore, the Holy Spirit is from the Son.

Furthermore (4), the divine persons are not distinct from one another otherwise than according to origin. Therefore if the Holy Spirit were not from the Son, he would not be distinguished from him; which is inadmissible.

I answer that, according to what has already been concluded, it is necessary that the Holy Spirit proceed from the Son. For if the Son and the Holy Spirit are two persons, the procession of one must be distinct from the procession of the other. Now, it has been shown above that there cannot be two processions in God except according to the order of the processions, namely, that there be a second procession from one who proceeds. (Q. 10, a. 2.) It follows, then, of necessity that the Holy Spirit must be from the Son.

Besides this argument, however, there are other reasons that prove that the Holy Spirit is from the Son. For every difference of things must arise from the original root of their distinction (except perhaps in the case of an accidental difference, as that between one who walks and one who sits), and this is because whatsoever is in a thing through itself is either of its essence or results from its essential principles, and from these is the original root of distinction between things. In God, however, nothing can be accidental. For whatsoever is in a thing accidentally, since it is outside the nature of that thing, must come to it from some external cause, and this cannot be said of God.

Accordingly, any difference between the divine persons must follow from the original root of their distinction. Now, the original root of the distinction between the Father and the Son is paternity and filiation. Wherefore, any difference between the Father and the Son must follow from the fact that this one is the Father and that one the Son. But it does not belong to the Father as Father by reason of paternity to be the principle of the Holy Spirit, since in this way he is related only to the Son, and it would follow that the Holy Spirit is a Son.

In like manner, this is not repugnant to the account of filiation, since filiation implies relation to none but the Father. Consequently, the difference between the Father and the Son cannot arise from the fact that the Father is the principle of the Holy Spirit and the Son is not.

Again, as stated in On Synods, it is proper to the creature that God produced it by his will. And Hilary proves this from the fact that the creature is not the sort of thing God is, but the sort of thing that God wills it to be. (Hilary of Poitiers, On Synods 24.58 (PL 10:520).) Now, because the Son is as the sort of thing the Father is, it is said that the Father has begotten the Son naturally. However, for the same reason the Holy Spirit is from the Father naturally, because he is like and equal to the Father; for nature produces its like. Now, the creature, which is from the Father according to his will, must also be from the Son; for the Father and the Son have the same will. Likewise, they both have the same nature.

Consequently, just as the Holy Spirit is from the Father, so also must he be from the Son. And yet it does not follow that the Son or the Holy Spirit is from the Holy Spirit, although he also has a nature that is one with the Father (whereas it does follow that the creature is from him inasmuch as he also has a will that is one with the Father); for an absurdity would follow if one were to say that the Holy Spirit proceeds from his very self, or that the Son, who is his principle, proceeds from him.

The same conclusion becomes apparent in yet another way. For no distinction is possible between the divine persons except according to the relations, since in God whatsoever things are ascribed absolutely signify the essence and are common, such as goodness, wisdom, and so forth. But diverse relations cannot make a distinction except by reason of their opposition, for one and the same thing can have diverse relations to the same thing. Thus, A may stand to B in the relation of son, disciple, equal, or any other relation that does not imply opposition.

Now, it is plain that the Son is distinguished from the Father in that he stands in a certain relation to him, and likewise the Holy Spirit is distinguished from the Father by reason of a relation. Wherefore, their relations, however diverse they may appear to be, can in no way distinguish the Holy Spirit from the Son unless they be opposed to each other. But there can be no opposition in God other than that which is by reason of origin, in that one person is from another. Therefore, the Son and the Holy Spirit can by no means be distinguished from each other simply because each is differently related to the Father, unless one of them be related to the other as existing from him.

Now, it is certain that the Son does not proceed from the Holy Spirit, since the account of a son consists in being related to a father by existing from him. It remains, then, of necessity that the Holy Spirit is from the Son.

Since, however, someone might say that articles of faith should be confirmed not only by reasons but also by authorities, it remains for us to show by the authority of Holy Scripture that the Holy Spirit proceeds from the Son. In several passages of Scripture the Holy Spirit is mentioned as being of the Son. Thus: he that has not the Spirit of Christ is none of his (Rom 8:9); God has sent the Spirit of his Son into your hearts (Gal 4:6); and they attempted to go into Bithynia, and the Spirit of Jesus suffered them not (Acts 16:7). For we cannot take this as meaning that the Holy Spirit is the Spirit of Christ in reference to his humanity, filling him, as it were, because the Holy Spirit is the Spirit of a man as of its possessor and not as of its giver; whereas the Holy Spirit is the Spirit of the Son as of his giver, according to 1 John 4:13, in this we know that we abide in him and he in us, because he has given us of his Spirit: and it is said that God has given the Holy Spirit to them that obey him (Acts 5:32).

Accordingly, the Holy Spirit must be called the Spirit of the Son inasmuch as he is a divine person. Either, then, he is said to be his absolutely, or his as his Spirit. If absolutely, then the Son must have authority over the Holy Spirit. For with us one may be said to be another’s in a qualified way, one who does not have authority over him, for example, when one says, “Peter is John’s companion”; but we cannot say that “Peter is John’s” absolutely, unless he be some possession of him, like a slave; as to all that he is he is said to be his master’s. Now, in God there is no slavery or subjection, and authority in him is only in respect of origin. Consequently, the Holy Spirit must originate from the Son.

The same conclusion follows if it be said that the Holy Spirit is the Son’s as his Spirit; because “Spirit” as a personal name implies the relation of origin to the spirator, as does “Son” to the begetter.

Moreover, we find it stated in the Scriptures that the Son sends the Holy Spirit, as stated above. For a sender seems always to have authority over the one sent. Now, as already stated, authority in God is only in respect of origin. Hence, it follows that the Holy Spirit originates from the Son.

Now, we have it from Holy Scripture that by the Holy Spirit we are conformed to the Son, according to Romans 8:15, you have received the Spirit of adoption of sons; and Galatians 4:6, because you are sons God has sent the Spirit of his Son into your hearts. But nothing is conformed to a thing except through its proper characteristic.

And even in created natures, that which conforms A to B is from B; thus, the seed of man becomes like not to a horse but to a man whence it is. Now, the Holy Spirit is from the Son as his proper characteristic; wherefore, it is said of Christ: who has sealed us and given the pledge of the Spirit in our hearts (2 Cor 1:22). More explicit still are the words spoken by Christ of the Holy Spirit: he shall glorify me because he shall receive of mine (John 16:4). Now, it is plain that the Holy Spirit does not receive from the Son as one not possessing before, since thus he would be of a changeable and needy nature. It is evident, then, that he received from the Son from eternity; nor could he receive anything that was not his essence from eternity. Therefore, the Holy Spirit received the essence from the Son.

The reason why the Holy Spirit received from the Son is stated by the Son himself when he says: all things whatsoever the Father has are mine: therefore, I said that he shall receive of mine (John 16:15), as though to say, “since mine and the Father’s is the same essence, the Holy Spirit cannot be of the same essence as the Father unless he be of my essence.”

Holy Scripture also states that the Son works through the Spirit, as for instance: which (that is, miracles and other blessings) Christ works by me, says the Apostle, in . . . the Holy Spirit (that is, through the Holy Spirit) (Rom 15:18); and it is stated that Christ offered himself by the Holy Spirit (Heb 9:14). Now, whenever one person is said to work through another, either it is he who gives active power to the one through whom he works, as a king is said to work through a provost or bailiff, or contrariwise, as when the bailiff is said to work by virtue of the king.

Accordingly, if the Son works through the Holy Spirit, either the Holy Spirit gives active power to the Son, or the Son to the Holy Spirit; and consequently, one gives the essence to the other, since the active power in each is not distinct from his essence. Now, it is plain that the Holy Spirit does not give the essence to the Son, since the Son is Son of none but the Father. It follows, therefore, that the Holy Spirit is from the Son.

Yet another argument in support of the same conclusion may be taken from the points acknowledged by the Greeks. For they believe that the Holy Spirit is from the Father through the Son, and that the Father spirates the Holy Spirit through the Son. Now, that through which a thing is produced is always a principle of what is produced. Wherefore, it follows that the Son is a principle of the Holy Spirit. If, however, they refuse to acknowledge that the Holy Spirit is from the Son because the Son is from another and consequently is not the first root of the Holy Spirit’s origin, it is plain that this motive is empty, since no one declines to allow that the stone is moved by the stick, even though the stick is moved by the hand; or that Jacob was from Isaac although Isaac was from Abraham. In fact, in the point at issue still less reason is there for this refusal; for Father and Son have one and the same productive power, which is not the case in created movements and agents.

Therefore, just as we must acknowledge that creatures are from the Son, though the Son is from the Father, even so must we acknowledge that the Holy Spirit is from the Son, though the Son is from the Father. It is evident, then, that those who assert that the Holy Spirit is from the Father through the Son but not from the Son, do not know their own speech, as Aristotle said of Anaxagoras; (Aristotle, Metaphysics 1.4, 985a10–21.) [and it is written]: desiring to be teachers of the law, understanding neither the things they say nor whereof they affirm (1 Tim 1:7).

Reply Obj. 1: The Son and the Holy Spirit are said to be flowers of the God-bearing, that is, paternal, divinity, inasmuch as both are from the Father. (Pseudo-Dionysius, The Divine Names 2.7 (PG 3:645–46).) But inasmuch as the Holy Spirit is from the Son, the Son may be called the root and the Holy Spirit the flower; for likenesses with corporeal realities need not be extended to all things in God.

Reply Obj. 2: The Son has it from the Father that he sends forth the Holy Spirit from himself. Wherefore, it belongs to him in the same way as it does to the Father. Now, the Father is the principle of a divine person not in one way only but in two, namely, by generation and spiration. Wherefore, we cannot conclude that the Son is the principle of the Holy Spirit by generation: this is a fallacy of the consequent, and so much the more so, seeing that the Father is not the principle of the Holy Spirit by generation.

Reply Obj. 3: The same answer applies to the third objection.

Reply Obj. 4: The Holy Spirit cannot be called a “Word” properly speaking, but in a common sense, inasmuch as anything that makes a thing known is called a “word” of that thing. For the Holy Spirit makes the Son known, as stated by this same Son concerning the Holy Spirit: he shall glorify me because he will receive of mine (John 16:14). But the Son is called the “Word” properly speaking because he is the concept of the divine intellect.

Reply Obj. 5: In a human genealogy, a grandson is one who proceeds from the son in the same way as the son from his father, whereas in God the Holy Spirit does not proceed from the Son in the same way as the Son from the Father; hence, the objection fails.

Reply Obj. 6: There is no opposition between being a principle and being from a principle unless this is understood to be in respect of the same thing. Thus, a thing cannot be a principle of what it is from as from a principle. Hence, it does not follow that there are contrary properties in the Son if he proceeds from the Father as from a principle and is himself the principle of the Holy Spirit.

Reply Obj. 7: Whatsoever is in God is indeed either proper or common. The proper, however, is spoken of in two ways: it is said simply and absolutely of a thing to which it applies exclusively, for example, risibility is proper to man; or it is said of a thing not simply but as regards something, for instance, one might say that rationality is proper to a man as compared to a horse, although it applies to another, like an angel. Accordingly, in God there is something common that belongs to the three persons, for instance, “to be God” and so forth; something that is proper simply and belongs to one person only; and something that is proper as regards something, for instance, to spirate the Holy Spirit is proper to the Father and the Son with respect to the Holy Spirit. For we must acknowledge this kind of property in God even if the Holy Spirit were not from the Son; for “to be from another” still remains proper to the Son and Holy Spirit as compared to the Father.

Reply Obj. 8: If we are to come to a right decision on this point, it seems hardly correct to speak of anything being due in the divine persons, since this word “due” implies subjection and obligation of a kind, and such things cannot be in God. Richard of St. Victor, however, distinguishes between due love and gratuitous love, but by “gratuitous love” he means love that is not from another, and by “due love,” that which is from another. (Richard of St. Victor, On the Trinity 3.3; 5.17–18 (PL 196:917–18; 961–62).) In this sense, there is nothing to hinder the same love from being gratuitous as the Father’s and due as the Son’s, since it is the same love whereby the Father loves and whereby the Son loves; yet this love the Son has from the Father, but the Father from no one.

Reply Obj. 9: The Holy Spirit is so gratuitous a love inasmuch as it is opposed to the mercenary love whereby a thing is loved not for its very self but for the sake of some benefit extrinsic to it. But if by gratuitous love we understand the love that originates from another, it is not against the account of the Holy Spirit that he be gratuitous love; for the love whereby we love God through the Holy Spirit originates in God’s benefits bestowed on us. And thus, nothing prevents even the love of the Son, who derives this love from another, from being the Holy Spirit.

Reply Obj. 10: The Holy Spirit proceeds both from the Father to the Son, and from the Son to the Father, not as recipients but as objects of love. For the Holy Spirit is said to proceed from the Father to the Son inasmuch as he is the love whereby the Father loves the Son; and in the same way it may be said that the Holy Spirit proceeds from the Son to the Father inasmuch as he is the love whereby the Son loves the Father. He may be understood, however, to proceed from the Father to the Son inasmuch as the Son receives from the Father the power to spirate the Holy Spirit, and in this sense he cannot be said to proceed from the Son to the Father, seeing that the Father receives nothing from the Son.

Reply Obj. 11: This word “love” signifies not only the outpouring of love but also a certain affection or disposition according to love. Now, in God, whatever things signify a sending forth must be taken as referring to the person only, for instance, begetting, spirating, and so forth; on the other hand, terms that do not denote a sending forth, but pertain more to the formation of that whereof they are predicated, must be taken as referring to the essence, for instance, being good, intelligent, and the like. For this reason the Holy Spirit is said to love not as sending forth love—for thus it belongs only to the Father and the Son—but insofar as “to love” is being taken as an essential property in God.

Reply Obj. 12: In Holy Scripture, it must be regarded as a constant rule that what is said of the Father must be understood as applicable to the Son, and what is said of both or either of them must be understood as applicable to the Holy Spirit, even if the expression should contain an exclusive term, except when reference is made to the distinction between the divine persons. Take, for instance, the following: this is eternal life, that they know you the only true God, and Jesus Christ whom you have sent (John 17:3); for it cannot be denied that the Son is true God, although the Son himself affirms this of the Father alone, because since the Father and Son are one thing, though not one person, it follows that what is said of the Father must be understood of the Son also. Nor again may we deny (seeing that no mention is made there of the Holy Spirit) that eternal life is in knowing the Holy Spirit, since there is but one knowledge of the three. In like manner, we are not to deny that the Holy Spirit knows the Father and the Son, although it is said: no one knows the Son but the Father, neither does anyone know the Father but the Son (Matt 11:27). Wherefore, since to have the Holy Spirit proceeding from oneself does not enter into the account of paternity or filiation whereby the Father and the Son are distinguished from each other, it follows that, from the very fact that it is said in the Gospel that the Holy Spirit proceeds from the Father, we must understand that he proceeds from the Son.

Reply Obj. 13: The doctrine of the Catholic faith was sufficiently laid down by the Council of Nicaea; wherefore, in the subsequent councils the holy fathers had no mind to make any additions. Yet on account of the heresies that arose they were at pains to declare explicitly what had already been implicitly asserted. Thus, in the definition of the Council of Chalcedon, it is said: this holy, great, and universal synod teaches this doctrine which has been constantly held from the beginning, the same which 318 holy fathers assembled at Nicaea defined to be the unalterable faith. On account of those who contend against the Holy Spirit, we confirm the doctrine delivered afterwards by the 150 fathers assembled at Constantinople concerning the substance of the Holy Spirit, which doctrine they made known to all, not indeed as though something were lacking in previous definitions, but by appealing to the authority of the Scriptures to explain what had already been defined against those who endeavored to belittle the Holy Spirit. (Council of Chalcedon, Definition of Faith; see Acta conciliorum oecumenicorum (ACO), series 1, bk. 2, vol. 2, part 2, n. 5, pp. 12–13.)

Accordingly, we must acknowledge that the procession of the Holy Spirit from the Son was contained implicitly in the Creed of the Council of Constantinople, inasmuch as it is declared there that he proceeds from the Father; for what is said of the Father must be understood to be true of the Son since they differ in nothing except in that this one is the Son and that one the Father. However, on account of errors arising of those who denied that the Holy Spirit proceeds from the Son, it was becoming that in the Creed should be made an insertion, not by way of addition but by way of explicit interpretation of what it already contained implicitly. Thus, were a heresy to arise denying that the Holy Spirit is the maker of heaven and earth, it would be necessary to mention this explicitly, since in the Creed this is attested explicitly of the Father only. Now, just as a subsequent council has the power to interpret the Creed of a previous council and to insert an explanation of what that Creed contains (as is clear from what has been said above), so too the Roman pontiff can do this of his own authority, since by his authority alone can a council be convoked and by him are its decisions confirmed, and since from the council appeals can be made to him. All of this is clear from the Acts of the Council of Chalcedon.

Nor does such an explanation require the assembling of an ecumenical council, since sometimes this is impossible on account of war. Thus, we read of the sixth Council that the Emperor Constantine found that he was prevented by the imminence of a war from summoning all the bishops together; and yet those who met decided certain doubtful points of faith in accordance with the mind of Pope Agatho, (Agatho, pope from 678–681 AD, who summoned to Constantinople the Third Council of Constantinople (6th Ecumenical Council), 680–681 AD, in which the heresy of the monothelites was overthrown.) namely, that in Christ there are two wills and two actions. In like manner, the fathers assembled in the Council of Chalcedon adopted the view of Pope Leo, who defined that after the Incarnation there were two natures in Christ. (Leo the Great, pope from 440–461 AD, who called the Council of Chalcedon (451 AD), which condemned the errors of Eutyches (see PL 54).)

We must observe, however, that we may gather from the definitions of the principal councils that the Holy Spirit proceeds from the Son. Thus, as stated in its decree, the Council of Chalcedon received the synodal letters of the blessed Cyril, bishop of Alexandria, (Cyril of Alexandria (ca. 370–444 AD). He presided over the Council of Ephesus (431 AD) and fought valiantly against the heresy of Nestorius (see PG 68–77).) addressed to Nestorius and others in the East. In one of these, we read: seeing that Christ in proof of his divine nature used his Spirit to perform great works, asserted that he was glorified by him, even as a man might say of his own strength, knowledge, or any other gift that they glorify him: even so this is true of the subsistent Spirit considered as a distinct person from the Son; although he is not of a different nature, for he is called and is the Spirit of truth and flows from him, as also from God the Father. (Cyril of Alexandria, Third Letter of Cyril to Nestorius [Letter 17, Cyril to Nestorius on Excommunication] (PG 77:118).) It is not a problem that it says that he “flows” and not “proceeds,” because (as we have already clearly stated) this word “proceed” is the most common of all the terms denoting origin. Wherefore, anything that is sent forth or flows forth or in any way originates may be said for this very reason to proceed. Again, in the definition of the fifth Council held at Constantinople it is said: in all things we follow the holy doctors of the Church, Athanasius, Hilary, Basil, Gregory the Theologian, Gregory of Nyssa, Ambrose, Augustine, Theophilus, John of Constantinople, William [Cyril], Leo, Proclus, and we receive all that they have taught in the true faith for the refutation of heretics. (Second Council of Constantinople (5th Ecumenical Council), 553 AD; Acts of the Council, Session 1; ACO 4.1, 13.) Now, it is plain that many of these taught that the Holy Spirit proceeds from the Son, and that this has not been denied by any one of them. Wherefore, it is not contrary to but in harmony with the Councils to say that the Holy Spirit proceeds from the Son.

Reply Obj. 14: Although “of this” has many significations, in God it nonetheless cannot be understood except according to an orientation of origin. As regards “sending,” it must be observed that all doctors are agreed that no person is sent who is not from another. Hence, it is altogether inappropriate to the Father to be sent, since he is not from anyone. But as regards the person from whom the sending arises, doctors are divided in opinion. Athanasius and others say that no person is sent temporally save by the person from whom he proceeds eternally. Thus, the Son is sent temporally by the Father, from whom he proceeds eternally: (Athanasius, Letter to Serapion 1.15–26 (PG 26:565–94).) and in accordance with this view it may be inferred without fear of error that if the Holy Spirit is sent by the Son, he proceeds from him eternally. And if the Son is said to be sent by the Holy Spirit, this must be understood in reference to the Son in his human nature being sent to preach by the Holy Spirit. Wherefore, it is said explicitly: he has sent me to preach to the meek (Isa 61:1). This is the interpretation given by Ambrose; (Ambrose, On the Holy Spirit 3.1, para. 1 (PL 16:777).) but Hilary expounds the words such that “Spirit” is understood as the Father, inasmuch as “Spirit” is taken eternally in the divine. (Hilary of Poitiers, On the Trinity 8.23–29 (PL 10:253–57).) On the other hand, Augustine holds that a person who proceeds may be sent temporally even by one from whom he does not proceed eternally. (Augustine, On the Trinity and the Unity of God 5 (PL 42:1198–1200); cf. On the Trinity 2.5–7, 5.15–16, 15.26–27 (PL 42:848–53, 921–24, 1092–97).) For since the sending of a divine person is understood in reference to some effect in creatures, who proceed from the whole Trinity, the person sent is sent by the whole Trinity; thus, “sending” does not imply an authority of the sender over the person sent, but rather causality in reference to the effect, and with regard to this effect the person is said to be sent.

The argument proving that the Holy Spirit proceeds from the Son because they are distinct from each other is not refuted by saying that they are distinct by their properties; for these properties are relative and cannot cause distinction unless they be mutually opposed, as already stated. (Q. 8, aa. 3–4.)

Reply Obj. 15: Although the Holy Spirit proceeds from two, he is not composite; for those two, namely, the Father and the Son, are one in essence.

Reply Obj. 16: The Philosopher says that principles, insofar as they are first, are not from another; (Aristotle, Physics 1.6, 189a17–33.) and the first principle is a principle proceeding from no principle, and that is the Father.

Reply Obj. 17: Although the will moves the intellect to understand something, it cannot will something unless it has understood it previously. Wherefore, since it is impossible to go to infinity, one must come at length to an act whereby the intellect understands something naturally and not at the will’s command. Now, the Son proceeds from the Father naturally; whence although he proceeds through the mode of intellect, it does not follow that he proceeds from the Holy Spirit, but vice versa.

Reply Obj. 18: The Holy Spirit may be said to be at rest in the Son in three ways.

In one way, in respect of the human nature, according to Isaiah 11:1: there shall come forth a rod out of the root of Jesse, and a flower shall rise up out of his root, and the Spirit of the Lord shall rest upon him.

In another way, the Holy Spirit is said to rest in the Son because the spirative power is given to the Son by the Father and extends no further.

Third, according as love is said to rest in the beloved, thereby bringing to rest the affection of the lover.

In none of these ways is the procession of the Holy Spirit excluded from the Son.

Reply Obj. 19: It is not incompatible with the simplicity of the Holy Spirit that he proceeds from two, namely, the Father and the Son, inasmuch they are of one essence.

Reply Obj. 20: The same perfection is that of Father and Son. Wherefore, the fact that the Holy Spirit proceeds from the Father perfectly does not exclude his proceeding from the Son; otherwise it would follow that the creature is not created by the Son, since it is created perfectly by the Father.

Reply Obj. 21: Unity of essence does not involve confusion of persons. Wherefore, from unity of essence we cannot draw conclusions that are incompatible with the relative distinction. Thus, from the fact that Father and Holy Spirit are one, we cannot infer that the Son is from the Holy Spirit (although the Son is from the Father) because the Holy Spirit is from him; and again because it would follow that the Holy Spirit is the Father, seeing that to be the Father is nothing but to have a Son proceeding from him.

Reply Obj. 22: Brightness comes from the ray, since it is nothing else than the ray’s reflection upon a clear body. Moreover, brightness is attributed to the Son, who being the brightness of glory (Heb 1:3).

Reply Obj. 23: Heat is from brightness; for the heavenly bodies by their rays cause heat in the lower world.

Reply Obj. 24: It was the contention of the Nestorians that the Holy Spirit is not from the Son. Hence, in one of their synods, condemned by the Council of Ephesus, it is said thus: we hold that the Holy Spirit neither is the Son nor receives his essence from the Son. (Cf. Cyril of Alexandria, Anathema 9 (PG 77:122); Third Letter of Cyril to Nestorius [Letter 17, Cyril to Nestorius on Excommunication] (PG 77:118).) For this reason Cyril, in the epistle already quoted, affirmed against Nestorius that the Holy Spirit proceeds from the Son. (Cyril of Alexandria, Third Letter of Cyril to Nestorius [Letter 17, Cyril to Nestorius on Excommunication] (PG 77:118).) Again, Theodore in an epistle to John of Antioch expresses himself as follows: the Holy Spirit does not come from the Son nor has he his substance from the Son, but he proceeds from the Father: he is called the Spirit of the Son because he is consubstantial with him. Now, the above words were attributed by this Theodore to Cyril as though he had written them in a letter which he wrote to John of Antioch, and yet they are not to be found there; rather, he expresses himself thus: the Spirit of God the Father proceeds indeed from him, but he proceeds also from the Son, being one with him in essence. (Cyril of Alexandria, Letter of Cyril to John of Antioch about Peace [Letter 39] (PG 77:182).) Later on, Damascene followed this opinion of Theodore, although the latter theologian’s teaching was condemned in the Fifth Council. Wherefore, in this we must not agree with Damascene. (Cf. ST I.36.2, ad 3.)