The phrase ‘one incarnate nature of God the Word’, therefore, emphasizes three ideas:
(1) It was God the Word Himself who became incarnate, without undergoing any change.
(2) In becoming incarnate, He was not assuming a manhood which had already been formed in the womb of the Virgin. The manhood was formed only in the union.
(3) The incarnate Word is one Person. He who is eternally ‘simple’ took unto Himself concrete manhood and thus became ‘composite’.
Godhead creates and is not created, but manhood is created. In Jesus Christ the two have been converged into a unity, wherefore things divine and things human are present in Him in their respective reality and perfection. In fact, in our contemplation of the one Christ, we can discern them. But from this we should not proceed to assign to each nature a status independent of the other, for that would not enable us to affirm a genuine incarnation, in which manhood did not come into concrete existence by itself. The phrase ‘one nature’ then is not to be used with reference to Christ without the word ‘incarnate’. The ‘one’ in the phrase is not a simple one, or the ‘one single’ as John Meyendorff renders it; it is the one which includes the fullness of Godhead and manhood. Jesus Christ is not ‘single-natured’, but He is one ‘composite’ nature. This idea is stated in unmistakable terms in another passage:
It is not merely with reference to those that are simple by nature that the word ‘one’ is employed, but it is used also with reference to those that have come into being in composition, for which man is a good example.
The term ‘one’ in the phrase ‘one incarnate nature of God the Word’ cannot legitimately be rendered as the monoj of the monofusithj (monophysite). Severus never objected to the dynamic continuance of the two natures in the one Christ, and the ascription of the term ‘monophysite’ to his theological position is not accurate in this sense.
3.a. Objections to Chalcedon in the Light of Tradition.
Severus admits that it is possible to find evidence in the works of the earlier Fathers for the use of the ‘two natures’ formula adopted by the Council of Chalcedon, but he argues that those Fathers employed it before the outbreak of the Nestorian controversy. Since then the situation had changed, and the imprecise expressions of the past had been given up in favour of a theological tradition based on the Nicene Creed as confirmed by the Councils of Constantinople and Ephesus. In this context, Leo of Rome, without paying attention to the tradition established in the Church, insisted on the ‘in two natures’ in his Tome, and on this basis the Council of Chalcedon adopted it. This was, for Severus, a violation of the established tradition of the Church. He points out that Church Fathers, from Ignatius of Antioch and Irenaeus of Lyons to Cyril of Alexandria, all teach Christ is a unity. He is one Person, God the Word incarnate. The idea behind the phrase ‘two natures after the union’ or the ‘in two natures’ of Chalcedon, argues Severus, is opposed to the teachings of these Fathers. The real question at issue concerning Christ’s unity is for Severus the subject of the words and deeds recorded about Him in the Gospels. The Fathers, he insists, have ascribed them to one Person, and he writes:
To walk bodily on earth and to move from place to place is indeed human. But to enable those who are lame and cannot use their feet to walk […] is God-befitting. However, it is the same God the Word incarnate who works in both.
It is this principle embedded in the tradition set up by the Fathers, which is being violated by the ‘two natures after the union’ or the ‘in two natures’. What, then, can be made of the reunion formula of 433 between Cyril of Alexandria and John of Antioch, which contained the expression ‘two natures’? The Formula of Reunion, contends Severus, had been drawn up against the background of a split in the Church, which itself was the result of an inability on the part of the Antiochene tradition to understand the faith in a proper way. Cyril agreed to it only after seeing that all basic principles of the faith had been preserved. In other words, the Formula of Reunion can be cited as authority only after taking into account the terms of agreement which went with it. It is in this context that one should look into the meaning of the statement in which the phrase occurs. This statement reads:
And with regard to the evangelistic and apostolic sayings concerning the Lord, know that theologians make some common, as relating to one Person—prosopon—and distinguish others, as relating to two natures, interpreting the God-befitting ones to the Godhead of Christ, and the lowly ones of His humanity.
This statement affirms that theologians take some of the words and deeds of our Lord as referring to the one Person, and the others they divide between the two natures. The intention is not to divide the words and deeds ‘between the natures in such a way that some are ascribed to the divine nature alone, and some to the human nature exclusively; they are of the one incarnate nature of God the Word. We recognize the difference in the words and the deeds; some are God befitting, some are man befitting, and some befit Godhead and manhood together’. The fact about this statement is that it did not contradict the Cyrilline principle of seeing the difference between Godhead and manhood in the one Christ in contemplation. But the Council of Chalcedon, argues Severus, went beyond the Formula of Reunion in sanctioning the ‘two natures after the union’, which the fathers had excluded.