Father Staniloae states that the Church has made two fundamental affirmations concerning Christology with reference to our salvation: first, that Christ is fully God and fully man; second, that Christ is one single being. The Church has used person or hypostasis to refer to this unity, and natures to refer to the godhead and manhood united in Christ.
In the Formula of Union of 433, it was stated that there was a “union of two natures,” “one Christ, one Son, one Lord,” a “union without confusion,” and that the Blessed Virgin is the Mother of God. In the Council of Chalcedon in 451, the first draft of the Definition had the words ἐκ δύο φύσεων, whereas the final draft had the words ἐν δύο φύσεσιν.
The Old Eastern Churches did not accept the formula “in two natures” (ἐν δύο φύσεσιν); therefore, subsequently the Church sought to explain such expression. One explanation equated ἐν δύο φύσεσιν with ἐκ δύο φύσεων as equivalent. The final text says that ἕνα και τον αὐτον Χριστόν, Υἱόν, Κύριον, Μονογενῆ, ἐν δύο φύσεσιν ἀσυγχύτως, ἀτρέπτως, ἀδιαιρέτως, ἀχωρίστως γνωριζόμενον· – that is to say, γνωριζόμενον refers to Christ, Son, Lord, Only Begotten. Christ is known/recognized in two natures, not the two natures themselves known/recognized as existing in themselves.
The oneness of the Person is recognized. Consequently, Christ is a Person in two natures and of two natures, while the natures do not lose their distinction. Similarly, the Council of 553 (5th), in its 13th anathema, states that if anyone uses ἐκ δύο φύσεων to mean a confusion of natures and one ousia, and not according to the original understanding of the Fathers, i.e., as referring to the hypostatic union, let him be anathema.
Similarly, Leontius of Byzantium’s doctrine of enhypostasis stated that it is the divine hypostasis of the Logos who gives existence to the human nature, which He takes from the Blessed Virgin. This emphasizes the oneness of the Person as the ontological basis of the humanhood. Justinian adopted this and agreed with Severus of Antioch in affirming that in Christ’s single hypostasis the two natures are not two realities but exist only in word and thought, i.e., thought alone conceives one nature separate from the other or from the oneness of the Person.
In reality, the two natures form one hypostatic whole – and yet the godhead and the manhood persist without confusion in Christ. Non-Chalcedonians (NC) objected to using numbers as it implies division; but the NC affirmed one nature, confusing the two natures. They answer that they speak of a “composite nature,” which the Orthodox rejected because this would imply two mutually dependent natures to form the unity; the NC also deny this, affirming three distinct oneness: of the godhead, of the manhood, and of the unit formed. Fr. Staniloae affirms that this ultimate puts the Orthodox and the NC in converging Christologies.
The 6th Ecumenical Council affirmed that the human nature continues in its human ontological status, and that it is the vehicle for manifesting the divine hypostasis. It affirmed two wills and two activities in Christ’s two natures, as they are dynamic. The human activities are penetrated by the godhead of his hypostasis, and the divine activities have a subject with a human nature. Thus God moves manhood to act and it reveals the godhead; Christ suffered voluntarily as God, and worked miracles humanly. This is done in one hypostasis.
The implication, as the 6th Ecumenical Council stated, is that there are two natural wills and activities and two unopposed wills (the human following the divine) and the body is the Word’s as the body’s nature will is the Words – i.e., the whole man, body, soul, will, activities, is deified by being united in One Person, one divine hypostasis, the Logos, with the divine essence. Christ is fully God and fully man, and one single being. Deified human will (and the whole human being) is not abolished but preserved, each sharing each other’s activities.
Fr Staniloae argues that the 5th, 6th, and 7th Ecumenical Councils brought the Orthodox and the NC nearer, in a common witness, moving in converging lines.
From the Journal ΕΚΚΛΗΣΙΑΣΤΙΚΟΣ ΦΑΡΟΣ (ALEXANDRIA) N. 58 (1976)