I recently started and finished Tertullian’s Against Praxeas after I had written two recent posts on Christ in the Old Testament: one on whether anyone has seen God’s “form,” and another on whether anyone has heard God’s voice. He’s not the only witness in early Christianity for this way of reasoning about Christ. Though to my surprise, Tertullian is a witness to what I considered a speculation about the fulfillment of Numbers 12:8 on the Mount of Transfiguration in one of those posts.
I have decided to provide sections 14 and 15 of this text for consideration, especially as they relate my prior posts. The text comes from the 1920 translation by A. Souter, pages 61-69. Bold and italic emphases are my own. Scripture references provided by the translator. Footnotes also by the translator.
Against Praxeas 14-15
14. Further, there comes to our support in claiming two, Father and Son, the rule that defined God as invisible. For when Moses in Egypt had longed for a sight of the Lord, saying: “If therefore I have found grace in thine eyes, reveal Thyself unto me, that I may see Thee and know Thee [Exod 33:13],” He said: “Thou canst not see my face; for no one will see my face and live [Exod 33:20],” that is: he who sees it will die. But we find that God was seen by many, and yet none of those who had seen Him, died: He had, of course, been seen as far as men’s powers served, not in the fullness of His divinity [cf. Genesis 12:7]. The patriarchs are related to have seen God [cf Gen. 28:13; 32:30], for example Abraham and Jacob, and the prophets, as Isaiah and Ezekiel, and yet they did not die [cf. Isa. 6:1]. Therefore, either they must have died if they had seen Him—“for no one will see [cf. Ezek. 1:1]” God “and live”—or, if they saw God and did not die [Exod. 33:20 Ibid], Scripture is false in stating that God said: “If a man see my face, he shall not live.” Or if Scripture does not lie [cf. John. 1:18, etc.], either in declaring God to be invisible, or in stating that He has been seen, it must therefore be some one else who was seen, because he who was seen, the same cannot be defined as invisible, and it will follow that we must understand the Father as invisible in virtue of the fullness of His majesty, while we recognise the Son as visible in accordance with the measure of a secondary nature; just as we may not view the sun, so far as the sum-total of its matter in the sky is concerned, but we can bear a ray of it with our eyes, as that is only a portion toned down, projected from it on to the earth. Here some one from the opposite side will seek to maintain that even the Son is invisible, like a word, like breath, and in claiming one state for Father and Son, to establish that Father and Son are rather one and the same. But we have said above that Scripture supports a difference by its distinction between the visible and the invisible. They will then add this point to their reasoning, that if it was the Son who then spoke to Moses [cf. Exod. 33:20], He Himself declared His face to be visible to no one, because, of course, the invisible Father Himself was (present) under the Son’s name. By this means they will have the same being regarded as both visible and invisible, even as the same is both Father and Son, since a little earlier also, before He refuses to show His face to Moses, it is written that “the Lord spoke to Moses face to face, as if one were speaking to his friend [Exod. 33:11],” and in like manner Jacob also says: “I have seen God face to face [Gen. 32:30].” “Therefore [Praxeas says] the same being is visible and invisible; and because he is both, therefore also the Father Himself is invisible, but being also the Son, He is visible.” As if, indeed, the explanation of the Scripture passage we are now giving were suited to a Son separated from the Father in His visibility! For we say that even the Son in His own name is invisible to the same extent as the Word and Spirit of God are, in virtue of the state of His being, even now also because He is God and Word and Spirit of God, but that He was visible before He took flesh, in the way to which He refers in speaking to Aaron and Miriam: “And if there be a prophet among you, I shall be known of him in a vision, and in a dream shall I speak to him, not in the way” he described to “Moses: I will speak to him mouth to mouth, in my visible form,” that is, in reality, “and not in a riddle [Numb. 12:6–8],” that is, not in a phantom; even as also the Apostle says: “Now we see as if by means of a mirror in a riddle, but then face to face [1 Cor. 13:12].” Therefore, when in Moses’ case He keeps the sight of Himself and face to face converse for a future date—for this was afterwards fulfilled in the retirement “on the mountain,” [cf. Matt. 17:1] since we read in the Gospel that “Moses was seen conversing with Him”—it is clear that previously God—that is, the Son of God—had always been seen “in a mirror” and “riddle” and “vision” and “dream,” as much by prophets and patriarchs as also till that time by Moses himself, and the Lord Himself indeed perchance spoke face to face, yet not in such a way that a man might see his face, except perhaps “in a mirror, in a riddle.” For if the Lord had spoken to Moses in such a way that even Moses knew his face at close quarters, how does he immediately and on the very spot long to see His face, which he would not long to see, because he had seen it [cf. Exod. 33:20]? How is it that the Lord also equally declares that His face cannot be seen, which He had already shown, if He really had shown it? But what is that “face” of God, the “sight” of which is refused? If it was that which was seen—“I saw God,” says Jacob, “face to face, and my soul was saved”—that “face” must be different which, if seen, slays. Or was the Son indeed seen—although “face to face,” yet this very sight occurred “in vision” and “dream” and “mirror and riddle,” because Word and Spirit cannot be seen except in an imaginary form—and does he mean by his “face” the invisible Father? Who is the Father? Will not the Son’s face be His by virtue of the authority which He obtains as begotten by the Father? Is it not fitting to use the expression about some greater being: “That man is my face,” and: “he countenances me”? “The Father,” He says, “is greater than I [John 14:28].” Therefore the Son’s face will be the Father. For, besides, what is it the Scripture says? “The spirit of His face (lit. mask), Christ the Lord [Lam. 4:20].” Therefore, if “Christ is the spirit of the Father’s face,” it follows that He proclaimed His own face (as the result of their unity, of course), to be that of the Spirit whose face He was, namely that of the Father. It is matter for wonder whether the Son’s face can be taken as the Father, who is “His head.” For “God is Christ’s head [1 Cor 11:3; my addition].”
15. If I do not succeed in explaining this part of my subject by investigations of the Old Scripture, I will take from the New Testament the confirmation of my interpretation, lest whatever I attribute to the Son, you should in like manner claim for the Father. For observe, both in the Gospels and in the Apostles I find that God is visible and invisible, with a clear and personal difference between the two states. John, as it were, shouts aloud: “No one hath seen God at any time,” [John 1:18] and therefore, of course, not in the past; for he has removed all question as to time by saying that “God has never been seen.” And the Apostle also confirms this as regards God: “whom no human being hath seen, nor indeed can see,” [1 Tim. 6:16] assuredly because he who does see Him will die. These very same Apostles testify that they “have both seen and handled” Christ. But if Christ Himself is both Father and Son, how was He both seen and invisible? Some opponent of ours will now argue, with the view of combining this distinction of visible and invisible in a unity, that both statements are correct, that He was visible indeed in the flesh, but invisible before He became flesh, with the result that the Father, invisible before He became flesh, is the same as the Son who is visible in the flesh. But if the same was invisible before becoming flesh, how is He found to have been seen even in the past before He became flesh? Likewise, if the same was visible after becoming flesh, how is He even now declared invisible by the Apostles, except because it was one who even in the past was seen “in a riddle” and was made more fully visible by flesh, namely, “the Word,” who “was” also “made flesh,” [John 1:14] and it was another whom “no one ever saw,” the Father, of course, whose the Word is? For let us examine who it was the Apostles saw. “What we have seen,” says John, “what we have heard, what we with our eyes have seen, and our hands have handled of the Word of life.” [1 John 1:1] For “the Word” “of life” “was made flesh”—was heard and seen and handled, because flesh—who before the Incarnation was merely “the Word in the beginning with God” [John 1:1] the Father, not the Father with Himself. For although “the Word was God,” yet, because God springs from God, it was “with God,” because in company with the Father means “with” the Father. “And we saw His glory, as of the only begotten of the Father,” [John 1:14] assuredly the Son, of course visible, “glorified” by the invisible Father [cf. John 17:4, etc.]. And it was for that reason (since he had called “the Word” of God “God”), lest he should encourage the assumption of his enemies, that he claimed to have seen the Father Himself, that in order to distinguish between the invisible Father and the visible Son he adds over and above: “God no one hath seen at any time.” [John 1:18] Which God? The Word? Nay: “we have seen and heard and handled of the Word of life” preceded. But what God? The Father, of course, “with whom was God the Word, “the only begotten Son, who Himself declared the Father’s bosom.” [John 1:18] He Himself was “both heard and seen,” and lest He should be believed to be an apparition, was even “handled.” Him also Paul saw, but yet he did not see the Father. “Have I not,” he said, “seen Jesus?” [1 Cor. 9:1] But he also surnamed “Christ” “God”: “Of whom were the fathers and from whom was Christ according to the flesh, who is over all things, God blessed for ever.” [Rom 9:5] He also showed that God the Son was visible, that is, “the Word” of God, because he “who was made flesh” was called Christ. But about the Father he says to Timothy: “Whom no one of men hath seen, nor indeed can see,” amplifying further: “Who alone hath immortality and inhabiteth unapproachable light,” [1 Tim. 6:16] concerning whom he had also said earlier: “And to the King of the ages, immortal, invisible, the only God,” [1 Tim. 1:17] that we might also ascribe the contrary qualities to the Son Himself, mortality, accessibility, who, he testifies, “died according to the Scriptures [1 Cor. 15:3]” and “was last seen by himself [1 Cor. 15:8],” by means of “approachable” “light,” of course—and yet even it neither he himself could experience without danger to his sight nor could Peter, John and James, without having to reckon the chance of loss of reason, who, if they had seen, not the glory of the Son that was to suffer, but the Father, would, I believe, have straightway died. For “no one shall see God and live [Exod. 33:20].” If these things are so, it is certain that He who was seen at the end, was always seen from the beginning, and that He was not seen at the end who was not seen from the beginning, and that thus the seen and the unseen are two. Therefore the Son was always seen and the Son always moved about and the Son always “worked,” by the authority and will of the Father, because “the Son can do nothing of Himself [John 5:19], unless He see the Father doing it,” that is, of course, doing it in thought. For the Father acts by thought, the Son, who is in the Father’s thought, sees and accomplishes. Thus “all things were done by” the Son “and without Him nothing was done [John 1:3].”
 “secondary,” i.e. not inferior, but derived, deduced from the other, as an irrigation canal is “deduced” from a river. But Tertullian seems here (cf. c. 26) to come perilously near to subordinationism, cf. d’Alès, p. 101. On p. 102 he gives parallels to the general argument of the chapter.