50. Trin. 15.7.11 (CCL 50A:475); trans. McKenna, FOTC 45:465. (continued)
On the Trinity 311 tually unchangeable and always equal. There never was a time when it was not, nor when it was otherwise; neither will there ever be a time when it will not be what it is, nor when it will be otherwise. These three, however, which are in the unequal [human] image, are now separated from one another in this life, not in place since they are not bodies, but in terms of their magnitudes. For though no bulk is present there, we do not, therefore, fail to see that the memory is greater in one person than the understanding, while in another person it is just the opposite; in another person, these two [dynamics] are surpassed by a greatness of love, whether the two themselves are equal to each other or not. And so each two are surpassed by each one, and each one by each two, and each one by each one, and the lesser by the greater. And when these [three inner dynamics] are cured of every weakness and shall be mutually equal, even then that human being, which through grace will not be changed, will not be made equal to the reality [of God] who is unchangeable in nature, because the creature cannot be equal to the Creator and will have to undergo a change when it is cured of every weakness.
(23.44) But when the "face-to-face" vision shall come that is promised to us, we shall see the Trinity—the Trinity that is not only incorporeal, but in the highest degree inseparable and truly unchangeable—much more clearly and with much more certainty than we now see its image in who we are. But those who see "through this mirror" and "in this enigma" (1 Cor 13:12), as it is permitted to see in this life, are not those who see those things which we have explained and commended in their minds, but those who look upon their mind as an image so that they are able, in some way or another, to refer what they see to Him, whose image they are, and also to see by conjecturing that which they now see through the image by beholding, since they cannot yet see face-to-face, for the Apostle did not say that "We now see a mirror," but that "We now see through a mirror" (1 Cor 13:12).
(24.44) Therefore, those who now see the mind as it can be seen, and that trinity in it that I have explained in as many different ways as I could and yet do not believe or understand it to be an image of God, they see a mirror indeed, but see so little of Him through a mirror, who is to be seen now through a mirror, that they do not even know the mirror itself, which they see, to be a mirror, that is, an image. If they did know this and cleansed their hearts by an unfeigned faith (1 Tm 1:5), then they would perhaps perceive that He, whom their mind is this mirror of, is to be sought through this, and in the meantime seen through this, in whatever way He can be seen, and in order that He may be able to be seen "face-to-face" who is now seen "through a mirror" (1 Cor 13:12).51
51. Trin. 15.22.42–24.44 (CCL 50A:519–22); my trans., based on McKenna, FOTC 45:509–12.
Filioque
In seventh-century Spain, a key phrase was inserted into the Creed: that the Holy Spirit "proceeds from the Father and the Son." This added phrase, "and the Son" (Filioque), eventually became standard in the Latin West and made its way officially into the Roman rite. After the great schism of Rome and Constantinople in the eleventh century, it became a serious point of doctrinal controversy and remains a source of tension between Orthodox and Catholics to this day. Augustine is often blamed for this. In fact, this teaching on the double procession of the Spirit had been a commonplace in the Latin West and appears in Marius Victorinus, Hilary of Poitiers, and others. But Augustine gave the teaching its classic exposition. It appears in many places in Augustine's works, but the passage below is one that Augustine himself thought was his best version. It comes from Tractates on the Gospel of John 99. Augustine dictated that this passage be added word-for-word into Book 15 of On the Trinity:
(7) Why should we not believe that the Holy Spirit proceeds from the Son as well since He is also the Spirit of the Son? For if He did not proceed from Him, [Jesus], showing Himself anew to His disciples after the Resurrection, would not have breathed upon them, saying, "Receive the Holy Spirit" (Jn 20:22). For what else did that "breathing upon" signify except that the Holy Spirit also proceeds from Him? . . .
(8) If the Holy Spirit proceeds, therefore, both from the Father and from the Son, why did the Son say: "The Spirit proceeds from the Father" (Jn 15:26)? Why do you think, except that He usually refers even what belongs to Himself to the Father, whom He Himself also is from? For this reason, He says: "My teaching is not my own, but is from the One who sent me" (Jn 7:16). If, therefore, the teaching here is understood as His, which He nonetheless said was not His, but the Father's, how much more must it be understood there that the Holy Spirit proceeds from Him of whom He said, "He proceeds from the Father," in such a way that He did not say: "He does not proceed from me"! But He, from whom the Son has that He is God (for He is God from God), has it also that the Holy Spirit also proceeds from Him. And because of this, the Holy Spirit has it from the Father Himself that He proceeds also from the Son, just as He proceeds from the Father.
(9) Here, too, to some extent, it is understood (as far as it can be understood by those such as us) why the Holy Spirit is not said to have been "born," but rather to "proceed." For if He were also called "son," then, of course, he would be called the "son" of both—and this is utterly absurd. For, indeed, no one is the son of two except of a father and a mother. But far be it from us to suspect some such thing between God the Father and God the Son. For neither does the son of human beings proceed at the same time both from the