In Martin Luther’s Disputation concerning the Passage: “The Word Was Made Flesh” (1539) we find the following thesis (2):

In theologia verum est, verbum esse carnem factum, in philosophia simpliciter impossibile et absurdum.

In theology it is true that the Word was made flesh. In philosophy, it is simply impossible and absurd.

This may seem shocking at first–“See?!? I told you! Luther doesn’t believe in rrrrreason!”–but Luther is just channeling a basic Augustinian point, and the statement is no more scandalous than what Augustine says in Confessions 7 about the “books of the Platonists.” Here he is (punctuation slightly modified):

13. And You, willing first to show me how You “resist the proud, but give grace to the humble” and by how great art act of mercy You had pointed out to men the path of humility, in that Your “Word was made flesh” and dwelt among men — You procured for me, by the instrumentality of one inflated with most monstrous pride, certain books of the Platonists, translated from Greek into Latin. And therein I read, not indeed in the same words, but to the selfsame effect, enforced by many and various reasons, that, “In the beginning was the Word, and the Word was with God, and the Word was God. The same was in the beginning with God. All things were made by Him; and without Him was not anything made that was made.“ That which was made by Him is “life; and the life was the light of men. And the light shines in darkness; and the darkness comprehends it not.” And that the soul of man, though it “bears witness of the light,” yet itself “is not that light; but the Word of God, being God, is that true light that lights every man that comes into the world.” And that “He was in the world, and the world was made by Him, and the world knew Him not.” But that “He came unto His own, and His own received Him not. But as many as received Him, to them gave He power to become the sons of God, even to them that believe in His name,” this I did not read there.

14. In like manner, I read there that God the Word was born not of flesh, nor of blood, nor of the will of man, nor of the will of the flesh, but of God. But that “the Word was made flesh, and dwelt among us,” I read not there. For I discovered in those books that it was in many and various ways said, that the Son was in the form of the Father, and “thought it not robbery to be equal with God,” for that naturally He was the same substance. But that He emptied Himself, “and took upon Him the form of a servant, and was made in the likeness of men: and being found in fashion as a man, He humbled Himself, and became obedient unto death, even the death of the cross. Wherefore God also has highly exalted Him” from the dead, “and given Him a name above every name; that at the name of Jesus every knee should bow, of things in heaven, and things in earth, and things under the earth; and that every tongue should confess that Jesus Christ is Lord, to the glory of God the Father,” those books have not.

The same Augustinian-Lutheran tradition of reflection reappeared in the twentieth century in W.H. Auden’s Christmas oratorio For the Time Being, where we read:

We who must die demand a miracle.

How could the Eternal do a temporal act,

The Infinite become a finite fact?

Nothing can save us that is possible:

We who must die demand a miracle.

These are deep waters. Just as the Trinity isn’t math, the Incarnation isn’t philosophy. But it is a miracle, and worthy of our grateful contemplation.