linguistic:translation, quality:corruption
Nature of Jesus Christ

In the Summa Theologica, Thomas begins his discussion of Jesus Christ by recounting the biblical story of Adam and Eve and by describing the negative effects of original sin. The purpose of Christ's Incarnation was to restore human nature by removing the contamination of sin, which humans cannot do by themselves. "Divine Wisdom judged it fitting that God should become man, so that thus one and the same person would be able both to restore man and to offer satisfaction." Thomas argued in favour of the satisfaction view of atonement; that is, that Jesus Christ died "to satisfy for the whole human race, which was sentenced to die on account of sin."

Thomas argued against several specific contemporary and historical theologians who held differing views about Christ. In response to Photinus, Thomas stated that Jesus was truly divine and not simply a human being. Against Nestorius, who suggested that the Son of God was merely conjoined to the man Christ, Thomas argued that the fullness of God was an integral part of Christ's existence. However, countering Apollinaris ' views, Thomas held that Christ had a truly human (rational) soul, as well. This produced a duality of nature in Christ. Thomas argued against Eutyches that this duality persisted after the Incarnation. Thomas stated that these two natures existed simultaneously yet distinguishably in one real human body, unlike the teachings of Manichaeus and Valentinus.

With respect to Paul 's assertion that Christ, "though he was in the form of God... emptied himself" (Philippians 2:6–7) in becoming human, Thomas offered an articulation of divine kenosis that has informed much subsequent Catholic Christology. Following the Council of Nicaea, Augustine of Hippo, as well as the assertions of Scripture, Thomas held the doctrine of divine immutability. Hence, in becoming human, there could be no change in the divine person of Christ. For Thomas, "the mystery of Incarnation was not completed through God being changed in any way from the state in which He had been from eternity, but through His having united Himself to the creature in a new way, or rather through having united it to Himself."

Similarly, Thomas explained that Christ "emptied Himself, not by putting off His divine nature, but by assuming a human nature." For Thomas, "the divine nature is sufficiently full, because every perfection of goodness is there. But human nature and the soul are not full, but capable of fulness, because it was made as a slate not written upon. Therefore, human nature is empty." Thus, when Paul indicates that Christ "emptied himself" this is to be understood in light of his assumption of a human nature.

In short, "Christ had a real body of the same nature of ours, a true rational soul, and, together with these, perfect Deity ". Thus, there is both unity (in his one hypostasis) and composition (in his two natures, human and Divine) in Christ.

I answer that, The Person or hypostasis of Christ may be viewed in two ways. First as it is in itself, and thus it is altogether simple, even as the Nature of the Word. Secondly, in the aspect of person or hypostasis to which it belongs to subsist in a nature; and thus the Person of Christ subsists in two natures. Hence though there is one subsisting being in Him, yet there are different aspects of subsistence, and hence He is said to be a composite person, insomuch as one being subsists in two.

Echoing Athanasius of Alexandria, he said that "The only begotten Son of God... assumed our nature, so that he, made man, might make men gods."