E.L. Mascall, Whatever Happened to the Human Mind, "Chalcedon in a Wider Context"

. . . the supreme theological truth about Mary is that she is Theotokos, the Mother of God, whose son is of the very same substance as us in his manhood, that has rescued Mariology from the apparently uncontrollable hypertrophy of the preconciliar years. The notion that the redemptive activity of God (Heilsgeschichte) was, with many divagations and setbacks, gradually focused down through the history of the Jewish people to its climactic convergence and concentration in the twofold figure Of Mary and her Son, and then spread out from that focal point into the whole world under the form of Christ's Spirit-endowed body the Catholic Church—this noble and inspiring notion has been part of the equipment of Christian tradition from the beginning. It is implicit in the Pauline epistles and was splendidly developed by St Irenaeus, though it has sometimes fallen into the background, especially in the West.  It has maintained itself far more strongly in the Christian East, where it has been set in an even larger context and given even wider implications. Very prominent in the Orthodox liturgy is the sense that the assumption of human nature by the person of the divine Word has had repercussions throughout the human race and indeed, beyond the human race, throughout the material universe. The whole of the material order is seen as in principle transfigured and transformed by the taking of a material body by the Son of God, and the Feast of the Transfiguration of Christ is seen as the feast of the transfiguration of the whole of the physical world.