Tertullian, Against Marcion 3.11

Marcion took up all these tricks of putative bulk in Christ with this aim: that from the witness of human substance his nativity too should not be defended, and so Christ should be claimed as the Creator’s — as one announced birth-able and therefore fleshy. Most stupidly here too the Pontic: as if flesh not born would not be believed in God more easily than false flesh, while the Creator’s angels who lived in true flesh yet were not born prepare that faith most of all. For that Philumene more persuaded Apelles and the other deserters of Marcion that Christ did indeed carry flesh in faith, yet of no nativity, borrowing it from the elements. But if Marcion feared that faith in flesh would also bring in faith in nativity, without doubt the one who seemed man was believed born. For a certain woman had also cried out: Blessed the womb that bore you, and the breasts you drank. And how were his mother and brothers said to stand outside? Certainly, when he himself also preached himself Son of man, he was confessing that he was born.

We will look at these chapters in their time; now, though I have put all this off to examination of the gospel, still what I set above: if the one who seemed man had to be believed born in every way, he thought vainly that faith in nativity was to be stormed by a plan of imaginary flesh. For what did it profit that what was held for true was not truly so — flesh as much as nativity? Or if you say, Let human opinion see to itself — already you honor your god with the title of deceit, if he knew himself to be other than what he had made men think; already you could have fitted even a putative nativity to him, so as not to strike on this question too. For little women sometimes seem pregnant to themselves, swollen by a tribute of blood or by some illness. And surely a phantasm ought to have run through the stage-play, lest he who played the role of the substance itself should not have danced out the origin of flesh. Clearly you refused the lie of nativity: for you put forth the flesh itself as true. Most shameful, of course, even a true nativity of God. Come then, speechify against those most holy and reverend works of nature; inveigh against the whole of what you are; destroy the origin of flesh and soul; call the womb a sewer, the workshop of producing so great an animal — that is, man; chase the unclean and shameful torments of birth and then the foul, anxious, laughable exits of the lying-in itself: yet when you have destroyed all that to confirm them unworthy of God, nativity will not be more unworthy than death, infancy than the cross, nature than punishment, flesh than damnation.

If Christ truly suffered these things, it was less to be born; if he suffered by a lie, as a phantasm, he could also be born by a lie. These are Marcion’s chief arguments by which he makes another Christ; we have shown, I think, that they do not stand at all, while we teach that truth of that habit in which he exhibited his Christ fits God more than a lie. If it was truth, it was flesh; if it was flesh, he was born. For what this heresy storms are confirmed when what it storms with are destroyed. Therefore if he will be held fleshy because born, and born because fleshy, because he was not a phantasm, he himself must be recognized who was announced by the Creator’s prophets as about to come in flesh and from nativity — as the Creator’s Christ.