Novatian, On the Trinity 23
At this point I am allowed to collect arguments even from the side of other heretics. A proof drawn from an opponent is especially solid, because then the truth is established even by the enemies of truth themselves. Scripture makes it so clear that God exists that many heretics, overwhelmed by the magnitude and truth of his divinity, have carried their honors for him beyond all measure and have dared to proclaim or imagine not the Son but God the Father himself. That view contradicts the truth of Scripture, yet it stands as a great and principal argument for the divinity of Christ. He is so truly God, yet precisely as the Son of God born from God, that many heretics (as I said) have accepted him as God in such a way that they thought he ought to be called not the Son but the Father. Let them consider, then, whether this is the God whose authority has so moved certain people that they thought him, as I said above, to be God the Father himself, confessing the divinity in Christ without restraint and with such fullness that the manifest divinity of Christ compelled them to regard the One they read of as the Son — because they perceived him as God — as the Father. Other heretics have likewise embraced the manifest divinity of Christ so completely that they said he was without flesh, and they stripped away the whole man assumed by him, lest they diminish the power of the divine name in him by associating a human birth with him, as they supposed. We do not approve of that; but we offer the argument that Christ is so much God that some have thought him to be only God, with the man removed, while others have believed him to be God the Father himself. For the reason and balance of the heavenly scriptures show Christ to be God, but as the Son of God, and with the man also assumed by God the Son, he is to be believed to be a man as well. Since he came to human beings in order to be the mediator of God and men, it was necessary for him to be with them, and for the Word to become flesh, so that in himself he might establish harmony between earthly and heavenly things, while joining the pledges of both sides in himself and linking God to men and men to God; so that the Son of God, by the assumption of flesh, may become the Son of men, and the Son of men, by the reception of the Word of God, may become the Son of God. The salvation of the human race, destined before the ages, is found fulfilled in the Lord Jesus Christ, who is both God and man, and by that condition the human race may be brought to the fruit of eternal salvation.
Latin
Hoc in loco licebit mihi argumenta etiam ex aliorum haereticorum parte conquirere. firmum est genus probationis, quod etiam ab aduersario sumitur, ut ueritas etiam ab ipsis inimicis ueritatis probetur. nam usque adeo hunc manifestum est in scripturis esse et deum tradi, ut plerique haereticorum, diuinitatis ipsius magnitudine et ueritate commoti, ultra modum extendentes honores eius, ausi sint non filium sed ipsum deum patrem promere uel putare. quod, etsi contra scripturarum ueritatem est, tamen diuinitatis Christi argumentum grande atque praecipuum est; qui usque adeo deus, sed qua filius dei natus ex deo, ut plerique illum (ut diximus) haeretici ita deum acceperint, ut non filium sed patrem pronuntiandum putarint. aestiment ergo an hic sit deus, cuius auctoritas tantum mouit quosdam, ut putarent illum, ut diximus superius, iam ipsum patrem deum, effrenatius et -effusius in Christo diuinitatem confitentes, ad hoc illos manifesta Christi diuinitate cogente, ut, quem filium legerent, quia deum animaduerterent, patrem putarent. alii quoque haeretici usque adeo Christi manifestam amplexati sunt diuinitatem, ut dixerint illum fuisse sine carne, et totum illi susceptum detraxerint hominem, ne decoquerent in illo diuini nominis potestatem, si humanam illi sociassent, ut arbitrabantur, natiuitatem. quod tamen nos non probamus; sed argumentum afferimus usque adeo Christum esse deum, ut quidam illum, subtracto homine, tantummodo putarint deum, quidam autem ipsum crediderint patrem deum: cum ratio et temperamentum scripturarum caelestium Christum ostendant deum, sed qua filium dei, et, assumpto a deo etiam filio hominis, credendum et hominem. quoniam si ad hominem ueniebat, ut mediator dei et hominum esse deberet, oportuit illum cum eo esse, et uerbum carnem fieri, ut in semetipso concordiam confibularet terrenorum pariter atque caelestium, dum utriusque partis in se conectens pignora et deum homini et hominem deo copularet; ut merito filius dei per assumptionem carnis filius hominis, et filius hominis per receptionem dei uerbi filius dei effici possit. salutem generis humani ante saecula destinatum, in domino Iesu Christo deo et homine inuenitur impleri, quo condicio generis humani ad fructum aeternae salutis posset adduci.