Summa summae S. Thomae sive compendium theologiae

That the Holy Spirit proceeds from the Father is a common and certain matter of faith, which Scripture expressly hands down. John 15:26: When the Paraclete comes, whom I will send to you from the Father, the Spirit of truth, who proceeds from the Father; and this the First Council of Constantinople decisively defined against the Arians and the Macedonians — who, reducing the Son and the Holy Spirit to the order of creatures, said that the Son was made by the Father alone, and the Holy Spirit by the Son alone — by adding to the Nicene Creed these words concerning the Holy Spirit: "Who proceeds from the Father."

But the Greeks deny that he proceeds from the Son, though they do not deny every respect toward the Son in him. For they grant that the Holy Spirit is the Spirit of the Son, and that he is from the Father through the Son — indeed, that he is from the Son, that he flows forth, wells up, emanates, is breathed forth from the Son; but not that he proceeds from him, since they hold that this would imply two principles, and that the Father and the Son are not a single principle of that procession — because, in their usage, "to proceed" designates a procession from a principle which does not itself proceed from another. Whence the question appears to be almost one of terminology, born of ignorance or obstinacy.

I say: The Holy Spirit proceeds from the Son.¹

Proof, first, from the authority of Scripture. Scripture asserts three things which cannot stand if the Holy Spirit does not proceed from the Son: first, that the Holy Spirit receives from the Son; second, that the Son sends the Holy Spirit; third, that the Holy Spirit is the Spirit of the Son. Therefore:

First, the Holy Spirit receives from the Son. John 16:13-14:

He will not speak of himself; but whatever he shall hear, he shall speak, and the things that are to come he shall declare to you. He shall glorify me, because he shall receive of mine, and shall declare it to you. But in the divine, one person does not receive from another except because he proceeds from that other. Therefore. — Proof of the minor. What one receives from another is either something accidental or something substantial. But the Holy Spirit does not receive anything accidental from the Son, for both are devoid of accident. Therefore he receives something substantial, and indeed the very substance through a substantial action, which is to proceed in substance from the Son. Likewise, the Holy Spirit receives knowledge from the Son; for from him he hears whatever he will declare. But for him, to know is to be, as Augustine says, Tractate 99 on John, n. 4. And this is clear, since in God knowledge is not distinct from essence.

Second, the Son sends the Holy Spirit.² John 15:26: When the Paraclete comes, whom I will send you from the Father. And chapter 16:7: If I do not go, the Paraclete will not come to you; but if I go, I will send him to you. But for the Holy Spirit to be sent by the Son is for him to proceed from him. Therefore. — Proof of the minor. The sending of one by another occurs either as by a superior, through command; or as by one wiser, through counsel; or through procession or origin, as from a principle. But the Holy Spirit is not sent by the Son as by a superior, through command; nor as by one wiser, through counsel. Therefore as from a principle, through procession or origin.

Third, the Holy Spirit is called³ the Spirit of the Son. Acts 16:7: And when they had come into Mysia, they attempted to go into Bithynia, and the Spirit of Jesus did not allow them. Galatians 4:6: God sent the Spirit of his Son into your hearts; and elsewhere. From which I argue thus. The Holy Spirit is called the Spirit of the Son in the same way that he is called the Spirit of the Father, Matthew 10:20: The Spirit of your Father, who speaks in you. But he is called the Spirit of the Father precisely insofar as he proceeds from the Father. Therefore. — Likewise, the Holy Spirit is called the Spirit of the Son either because he proceeds from the Son, or because the Son proceeds from him. Not the second. Therefore the first. — Proof of the major. The Holy Spirit is not called the Spirit of the Son by reason of subjection or servitude, but as a coequal person. Therefore by reason of origin — namely, because he proceeds from the Son, or the Son from him; for nothing else can be assigned.

Proof, second, from the Greek Fathers who flourished before the schism, and from the general councils. Saint Athanasius, Oration 3 Against the Arians: "Whoever," he says, "has the Spirit, has this from the Word." And in the Creed inscribed under his name: "The Holy Spirit, from the Father and the Son, not made, nor begotten, but proceeding." Saint Basil, book 5 Against Eunomius, proves that the Holy Spirit is third in order in the Most Holy Trinity, and second from the Son, "in that he has his being from him." Saint Epiphanius, in the Ancoratus, n. 8: "The Spirit of the Father and the Spirit of the Son..., proceeding from the Father and the Son." Saint Cyril of Alexandria, with the Synod of Alexandria, in the Letter to Nestorius, n. 10: "Although the Spirit subsists in his own person, and is considered eternal in himself insofar as he is, and is not the Son, he is nevertheless not foreign to him, since he is named the Spirit of truth, and Christ is the truth; and accordingly he also proceeds from him and from God the Father."

Moreover, this letter of Saint Cyril was read and approved in five general councils — the third, fourth, fifth, sixth, and eighth. The same truth, with the Greeks present and consenting, was afterward defined by the Fourth Lateran Council, under Innocent III; the Second Council of Lyons, under Gregory X; and the Council of Florence, under Eugene IV.

Proof by arguments. First: If the Holy Spirit did not proceed from the Son, he would not be distinguished from him; for the persons are distinguished solely by relation of origin.⁴ Therefore. The Council of Florence employed this argument against the Greeks, although the Scotists do not admit it.

Second: All things in the divine are common, where the opposition of relation does not stand in the way, as the commonly received axiom holds. But between the Father and the Son there is no relative opposition by reason of active spiration. Therefore this is common to both.

Third: If the Holy Spirit did not proceed from the Son, the Son would not have the whole essence of the Father, and accordingly would not be the Son, nor coequal with the Father. Therefore. — Proof of the antecedent. He would not have the same will as the Father; for if he had it, he would produce the Holy Spirit through it, just as the Father produces him. Therefore. Suppose you say: The Son has the same intellect as the Father, and yet does not produce a Word as the Father does; likewise, the Holy Spirit has the same will as the Father, yet does not produce another Holy Spirit, as the Father does.

Response: the disparity is that the Son, proceeding through the intellect, by his very procession exhausts the whole fecundity of the divine intellect, since he is its adequate term; and thus there remains no other Word to be produced. Likewise the Holy Spirit, proceeding through the will, equally exhausts the whole fecundity of the divine will, as being its adequate term; whence there remains no other term to be produced. But when the Word, through his generation, receives the will from the Father, this will is not yet conceived as exhausted, nor as having its adequate term through the procession of the Holy Spirit, since the Word is conceived as proceeding prior to the Holy Spirit. And therefore the will is no less fecund in the Son for the production of the Holy Spirit than it is in the Father.

Fourth: Whatever is not against the nature of something is not impossible. But to be a principle of the Holy Spirit is not against the nature of the Son — not insofar as he is God, since the Father, who is God, is a principle of the Holy Spirit; nor insofar as he is Son, since the procession of the Holy Spirit is one thing, that of the Son another. Nor is it repugnant that what is from a principle according to one procession should itself be the principle of another procession, just as the Son is from the Father as from a principle, and the Son himself is the principle of another. It remains, then, that it is not impossible for the Son to be a principle of the Holy Spirit. But in the divine, to be and to be able are not different. Therefore the Son is a principle of the Holy Spirit.⁵

You will ask, first, whether it is rightly said that the Holy Spirit proceeds from the Father through the Son.

I answer affirmatively.⁶ For thus spoke the Greek Fathers, and among the Latins, Saint Hilary, book 12 On the Trinity. The reason is that the Son has from the Father that the Holy Spirit proceeds from him. Therefore it can be said that the Father, through the Son, breathes forth the Holy Spirit; or, what is the same, that the Holy Spirit proceeds from the Father through the Son — in the same sense in which this is also said of the operations ad extra, John 1:3: All things were made through him.

You will ask, second, whether the Father and the Son are one principle of the Holy Spirit.

I answer affirmatively.⁷

Proof, first, from the Fathers. Augustine, book 5 On the Trinity, ch. 14, n. 15: "It must be confessed," he says, "that the Father and the Son are one principle of the Holy Spirit, not two principles." The same is held by Basil, book 2 Against Eunomius; and Anselm, in the book On the Procession of the Holy Spirit.

Proof, second, from the councils. The Second Council of Lyons: "We condemn," it says, "those who have presumed with rash daring to assert that the Holy Spirit proceeds from the Father and the Son as from two principles, and not as from one." This is reported in the chapter Fideli, On the Supreme Trinity, in the Liber Sextus of the Decretals, and the Council of Florence, in the letter of union: "We define that the Holy Spirit proceeds eternally from the Father and the Son... as from one principle and a single spiration."

Proof, third, by arguments. First: The Father and the Son are one in all things in which the opposition of relation does not distinguish them. But in this — namely, in being a principle of the Holy Spirit — they are not relatively opposed. Therefore. Second: Because in the Father and the Son there is one spirative power. Whence, just as, because there is one deity in the three persons, they are not called three gods; so, because there is one spirative power in the Father and the Son, they are not two principles, but one principle of the Holy Spirit.

You will ask, third, whether this word Filioque was rightly added to the Nicene-Constantinopolitan Creed.

I answer affirmatively: because this addition was made by legitimate authority, namely that of the Church, and for a necessary cause, namely, that the error then spreading rather widely among the Greeks against the procession of the Holy Spirit from the Son might be effectively suppressed. Whence the Greeks themselves, at the Second Council of Lyons, approved this addition and the Creed, and, repeating this addition three times, sang it together with the Latins during the solemnities of the Mass. And the Council of Florence, after the matter had been most diligently discussed, in the definition of faith to which all the Greeks subscribed together with the Latins, except Mark of Ephesus, says thus: "We define, moreover, that the explanation of those words Filioque, for the sake of declaring the truth, and under a pressing necessity at that time, was licitly and reasonably inserted into the Creed." Therefore.