There was, it is true, a difference between western and Antiochian thinking, for, while all Antiochians, Nestorius included, even when starting with the Logos endeavoured to make intelligible the oneness of the person of Christ, that is, to use Melanchthon's[1] words, to explain the modus incarnationis, the Westerners did not trouble themselves with this difficulty. The oneness of the person of the Jesus of history—"persona" being here more than the πρόσωπον of the Antiochians and nearer to what we understand by "person"—was with the western theologians an indisputable fact, which was presupposed in all their christological explanations. About this one person they asserted, that it was the filius dei incarnatus and also that two distinct substances or natures were clearly to be seen in it[2]. The speculative question as to how this was to be conceived did not occupy the western church; the doctrine of two natures meant here nothing more than that only afterwards one discerned in this one person the two natures; and the presupposition of the oneness of the person of him who was God and man together was here regarded without any efforts of thought as so certain, that because of this oneness of the person the phrases deus natus est and crucifixus est were used in early times[3].
