The term φύσις has always had strong connections with ἀρχή and with ούσία in Ancient Greek metaphysics and is commonly linked with τῷ ὀν (the being). Therefore, when it was introduced into theology, firstly, in scripture itself starting in the Greek Old Testament, and into the Apostolic fathers through the fathers of the ancient church, these three terms were incorporated into the understanding of the reality of God’s own Being and of the Incarnation. Just as meticulous care was taken to interpret the word homoousios into Greek theology, other words mentioned above were also given careful theological application. A clear understanding of φύσιν and its application in the ancient church can also give a clearer understanding of the hypostatic union, which we believe adequately describes the Incarnation and the subsequent soteriological implications to the degree that the Divinity actually touches us and heals us in His own humanity. Opposition to such terms means there are hidden speculations and dualisms built into their antitheses.
A proper understanding of union of the divine and human natures in the Incarnation requires the humility to accept there is mystery in this aspect of the atonement. To question hypostatic union requires reading into what constitutes Divine nature and what constitutes human nature in the Person of Jesus Christ and how they are brought together in the Incarnation using speculative, unverifiable viewpoints to maintain their argument. Who can truly know how the two are made one; who can truly know how the Word enfleshed Himself with humanity; who can truly know how the Being, the existence, the Person, the Spirit, the soul and the nature of the Divinity operated within the humanity of Jesus Christ? All we know is the Word was made flesh and dwelt in us (John 1.14). No one can ever truly know precisely how the Incarnation, that is, how the divine and human nature came together without falling into logical causal processes resulting in endless debates that never come to any definitive solutions to this question.
There is much controversy with the term μία φύσις which should not be the case. I believe φύσις incorporated οὐσία and ὑπόστασις and the humanity of Jesus Christ all into “one nature.” My mentor, T. F. Torrance, frequently coined the term κατά φύσιν (according to nature) which he drew from the works of Athanasius and Cyril of Alexandria. This is a real test to see whether or not we are following his line of thinking without speculation or taking a dualist’s approach to the manner of the Incarnation. The question in this debate is the nature of the humanity of God in Jesus Christ and the nature of the divinity of the Word in the Person and work of Jesus Christ and how they came to be together in His Incarnation. Torrance followed the Hebraic unitary approach to defining what entails our humanity. That is the body of the spirit/soul and the soul/spirit of the body make up the one whole human being. No one can precisely define how they are incorporated together as a unitary whole. No one can scientifically establish through observation of the human body what constitutes the spirit and the soul and empirically verify the factor that animates it. We know the spirit/soul animate the body. However, on the one hand, when the body fails us “something happens” to the spirit/soul. On the other hand, when a baby is brought to life, we know it is something like the spirit/soul that brings it about and animates it. But we do not know what it is. To try and work out what happens in either case requires us to go beyond what we are capable of knowing.
How did people see Jesus when He walked the earth? With our 20/20 hindsight, we know this is the Divine Word who was made flesh. But if we were to be face to face with Him, how would we see Him? Many in the establishment were astonished regarding the claim of Jesus stating He had equality with God. “How can you a mere man claim equality with God?” as Athanasius pointed out. He rightly said this is the wrong question, which should be, “Why have you being God, become man?” Thus, the disciples did not see Jesus Christ except as a whole person with real existence like any other form of existence. Nicodemus, a Jewish teacher of his time and a highly educated member of the Sanhedrin was confused when confronted with Jesus and the things He said. Jesus Christ was God, and He together with the whole Trinity, are the ground of all existence, and Jesus Christ, the Word made flesh, truly existed “as man.”
The decades and centuries that followed Jesus Christ’s ministry on earth were confronted by numerous questions regarding how that which was divine by nature related to His human nature, particularly how the two were united in His one Person. From the very beginning this was shrouded in mystery and the reality of it was considered, with fear and trembling, beyond the comprehension of our minds. What happened was utterly astonishing, but we know it happened. This was not helped by the constant interference of the world-view understanding of the divine/spiritual. According to them the uncreated was considered to be “good,” and all created matter was considered to be evil. It was the world view’s constant belief that the spiritual (good) and the created (evil) had to be held apart. When they were confronted by the assertions of the gospel that the Uncreated Divine had made Himself a creature and dwelt in the creaturely conditions of this world, they could only conclude this was insanity. How can the Uncreated ever allow Himself to be one of His creatures and touch evil matter? There had to be some other explanation for it that would serve their own ends.
No real attention was paid to the question of the two natures of Christ until towards the end of the fourth century and into the fifth century. Following the Apollinarian controversy more attention was paid to the kind of humanity the Divine Word assumed and the significance of His human soul. Apollinarius proposed the seat of sin lies in the mind, therefore the Word could not have assumed the human mind and it must have been replaced by the Divine mind. Gregory Nazianzus coined the term, “What is not assumed is not healed,” as a direct antithesis of Apollinarianism. The Antiochene model suggested a distinction of natures which acts as one “Person.” To them the Incarnation was real where the Word assumes our nature, clothed Himself in it and dwells in it, uniting it to Himself and He presented Himself to us as “one Person.” However, the detail of the inner workings of the Incarnation led to speculative ideas on how the human nature and the divine nature interacted in the Person of Jesus Christ.
The divine nature and the human nature were understood to be distinctions rather than two concrete realities that existed side by side. Cyril of Alexandria in his response to the Nestorian controversy would say that before the Incarnation of the Word He was considered ἄσαρκος or “outside flesh” and in the Incarnation is now ἐνσώματος (embodied) and likewise “enfleshed,” σεσαρκωμένη. Therefore, all the peculiar characteristics of the Divine and all the characteristics of the human has a “coming together” (σύνοδος). In contrast to this Nestorius would say the Divine Word dwelt in a man while Cyril asserted the divine came and dwelt with us “as man.” Nestorius would treat nature as if it represented the reality of the substance while Cyril and Athanasius would say the nature was a characteristic of the reality but not the reality itself. For us to see the reality of God, God must disclose Himself to us in a way that we are able to apprehend. The actual reality of God is presented to us in His own Incarnation in the Person and work of Jesus Christ. In direct contrast to Apollinarianism our rational minds are able to engage with the mind of God in Jesus Christ as He outwardly engages with us in His Person and work.
Nestorius was enthroned as Patriarch of Constantinople in 428 and was a student of Theodore Mopsuestia. It would be unfair to judge the whole of Antiochene Christology on the work of Nestorius alone, or even Theodore. Rather it was the product of a clumsy exegesis of Nestorius’ position. Nestorius questioned the suitability of the title θεοτόκος (God-bearer) as the title for Mary, the Blessed Virgin, and he felt it needed qualification with terms like “man-bearing” (ἀνθρωποτόκος) and even introduced a term “Christ-bearer” (χριστοτόκος). The manner in which he put across his argument were less than conciliatory. He was impatient and temperamental with those who disagreed with him which only inflamed his opponents. It was here that dualities began to appear in his explanation. This was the beginning of not just theological debates but also political struggles and the often the immoral behaviour that goes with it. There were many accusations levelled at Nestorius which did not truly reflect his own beliefs. Yet, there were many things he said that appeared to wander from the faith of the ancient church.
The term, “nature,” (φύσις) was often used interchangeably with “hypostasis” (ὑπόστασις) and ousia (οὐσία). While “nature” (φύσις) was defined as “a concrete character of a thing,” hypostasis” (ὑπόστασις) was defined as “having concrete existence” and ousia (οὐσία) was defined as “to be” or “being.” So, there was a debate regarding the nature, hypostasis and being of the Divine Word and the nature, hypostasis and being of the Incarnate Word. The corresponding Latin words for hypostasis and ousia were essentia and substantia respectively. While it was granted in Greek theology these terms were more or less synonyms, Latin theology was never really able to fully grasp this relationship in their language. Their word for nature tended to lean towards the Antiochene definition bringing with it the speculations and the dualisms. There has been the tendency for this dualism between the words to carry over into English theology.
Now the substance (or being) of a thing, including its existence was thought to exhibit its own attributes or characteristics which is precisely what the Latin natura tried to express. The Greek word used for “nature” was φύσιν. So, a particular substance might be recognised “according to its nature (κατά φύσιν),” and might either distinguish it from other substances (or being) or show its commonalities. There was a connection between “substance” (or “being”) and “nature” but it did not mean the same thing. The nature of a thing helped us to distinguish one substance from another, but nature was not the substance itself. One might consider nature was the approximation of both substance and hypostasis. However, substance and hypostasis were considered the technical terms while nature was more than satisfactory to generally say all that was needed to be said about substance and hypostasis. It is important to remember that ousia/hypostasis was the reality while nature was the characteristics of the reality. Nature is never the reality itself.
Now Nestorius created a dualism between nature and hypostasis (and likewise being) but tried to show that Jesus Christ was a “unified person” but with two existences or two beings, one divine and one human and, in some respects, they did not actually touch each other. He was always at pains to show the Father and the Son shared the same Being but his detractors refused to listen. In the Greek community having two substances or existences presented quite a problem because of their relationship to the term nature. Suddenly, there is the question of having two beings which leads to the question of, “what are the natures of each?” What is the nature of the Divine and what is the nature of His humanity? According to Nestorius, he insists again and again that “He who was born of Mary, our Lord, the Christ, was one Son, the Son of God, but twofold in His Godhead and in His Manhood.” He also said, “For the same person was both babe and Lord of the babe.”
This is what he says of the Incarnation: When the divine Scripture is about to speak of the birth of Christ from the Virgin, or of the death, it is nowhere found that it puts ‘God’, but either ‘Christ,’ or ‘the Son’ or ‘the Lord,’ for all three of these titles are indications of the two natures: sometimes of this, sometimes of that and sometimes of this and that. For example, when the Scripture relates to us the birth from the Virgin, what does it say? ‘God sent His Son.” It does not say God sent God the ‘Word,’ but it takes the word that declares the two natures. Because the Son is God and man, it says “God sent His Son, and He was made from a woman.” And when thou seest the name given, which declares both natures thou wilt call the Child of the Blessed Virgin ‘Son’; for the Virgin mother of Christ bore the Son of God. But because the Son of God is twofold in natures, she did not bear the Son of God, but the manhood, which is Son on account of the Son who is united thereto.”
The concern for Nestorius and many in the Antiochene community was a moral one while the concern for much of the West including the Alexandrian community was soteriological. Nestorius was concerned with the Western idea that the Godhead would limit Himself to human birth or allow Himself to undergo human death. In his own mind the impassibility of the Divine must be preserved. Internally, there must have been a co-existence of the Divine and human natures while, externally, a single “person” was portrayed. The Divine being and the human being came together in a form of merger. The impassable, indefectible, unchangeable and unalterable nature could not have touched the passions, soul, intelligence and defects of the body asserting the impossibility of a hypostatic union. The outward function of Christ presented to us the giving and taking of these two beings or natures. In the Incarnation, the human nature was born but not the divine nature. In Christ’s ministry there were acts that were attributed to His human nature and acts that were attributed to His divine nature. When He died it was human nature that died and not His Divine nature.
When the Creed says, “was made man, and was crucified for us under Pontius Pilate. He suffered and was buried . . .” this was attributed to His human nature and had no bearing on His divine nature. According to the Antiochenes through Nestorius, there was no true kenosis of the Word. The Word only condescended part of the way into His humanity, just so far as to not really experience human passions because the hypostasis, and likewise the ousia, in Jesus Christ were each divided into two parts.
Entirely contrary to this Cyril of Alexandria argues the mediation of God as man where neither the humanity nor the Godhead is lost from each other in their unity. In the Incarnation, God truly became what we are so that He in no way diminishes His Being as God. In becoming incarnate, God is not shy in holding to Himself the likeness of our humanity making no part of our human nature prohibitive to Him; meaning He assumed the depths, the breadths and the heights of our human existence. The full majesty of His Godhead was disclosed in His humanity while in His humanity, He truly was God with us, the Immanuel. Cyril says: though the unity is absolute, the distinction of natures was always there to be perceived. But it is a distinction that involves no separation, and which can only be apprehended “with they eyes of the mind,” that is, by an act of intellectual insight or analysis (Kelly, J. N. D., Early Christian Doctrines, Adams and Charles Black, London, 1968, p 321).
Nestorius would say that “neither the Godhead was changed into human nature, nor was the manhood deified.” Jesus was unified in His person but had a two-fold nature. The connection between God and humanity in the Person of Jesus Christ was not of any concrete union but merely a psychological one where the two natures had some sort of work-in-progress truce. More telling is Nestorius understanding of the Passion where He believed the death of Jesus Christ did not touch His divinity. Thus, the incarnation and the atonement became somewhat of an illusion and almost Docetic in its definition.
While on the one hand, the Antiochenes defined φύσις as a combination of concrete characteristics or attributes, the Alexandrians took on the more widely held belief that there was a relationship between φύσις and ὑπόστασις (and likewise ούσία) and were roughly connected without meaning exactly the same thing with terms like “concrete individual” or “independent existence.” Cyril qualified the Antiochene term of φύσις (nature) with phrases ἡ ἰδιότης ἡ κατὰ φύσιν or “according to the peculiarities of His nature” and ὁ τοῦ πῶς εἶναι λόγος “the manner of being of the Word and ἡ ποιότης φυσική “natural qualities.”
It is with these qualified definitions of nature (φύσιν) that we can begin to explore the divinity and humanity of Jesus Christ. What is primary in this discussion is the Being or hypostasis of Jesus Christ while nature is the secondary. It is only through the secondary (φύσιν) that we are able to receive any clues to the primary (οὐσία/ὑπόστασις). I believe that even though we are trying to grasp the Divine and human nature of Jesus Christ, they are secondary and can only give us an indication of His true existence and Being.
Though He was by nature divine, He took on human nature where out of the two the One Jesus Christ came about. Thus everything that characterises what it is to be human including the body and the soul and everything that characterises what it is to be Divine were all brought together and acted as one. Internally, we understand the two natures of Divine and human but not in a way that shows us what part is God and what part is human. Rather, He is all God and all human. Externally, Jesus Christ presents Himself as having one nature, i.e. the God-man. The Word was still Divine and the Incarnate Word was still human but the two acted as one: His being and His hypostasis spirit/soul etc., Cyril says – The one nature after the union was this nature enfleshed (μία φύσις μετὰ τὴν ἔνωσιν ἡ αὐτου τοῦ λόγου σεσαρκωμεν). This was the main thrust of Cyril’s argument.
The Cyrilian approach tried to take on a less speculative and dualistic definition of the Incarnation maintaining its mystery. That is, the Hebraic unitary spirit/soul/body approach. All we know is the Being/Hypostasis, what was considered collectively as nature, was united with and animated the flesh and body of Jesus Christ. How this happened was considered a mystery. The rumblings of this debate began as early as Apollinarius but came to a head in Nestorius. Through the likes of Basil the Great the emphasis on defining οὐσία and ὑπόστασις as synonyms came under enormous pressure and began to break apart. It was never his intention for this to happen, However, this opened the door for more speculation to creep in in regard to the soul of the body and the body of the soul concept so rooted in Alexandrine theology. Cyril of Alexandria and the Greek speaking community tried to maintain the mystery of the Incarnation and close the door to the speculative ideas proposed by Nestorius and the growing support he received from the Antiochene community.
It is obvious the dualistic and speculative modes of ancient thinking had crept in to the Antiochene Church through the likes of Nestorius, perhaps beginning in Theodore of Mopsuestia. By trying to peer into the manner of the Word uniting Himself to flesh, they had resorted to the speculations and dualisms characteristic of the widespread ancient pagan world views that had hounded the church for centuries. If one was to examine closely the main points of contention between Cyril of Alexandria and with those of Nestorius and the Antiochenes one might consider them to be mere semantics (and sometimes that it precisely what happened!). Often their terminologies appear to run side by side as amounting to the same thing. However, Nestorius had the tendency to stress far too much on the nature of God and the nature of the man in Jesus Christ as if he was privy to new and fresh insights on how the Incarnation actually worked. Nestorius acted as if he could peer into the mystery of the hypostatic union and could claim to see more than anyone else. Therefore, he was not so cautious in defining his understanding of the “two natures” in the One Person of Jesus Christ.
One must note that Cyril of Alexandria was as hot-headed as Nestorius and with as big an ego. The two never actually confronted each other face-to-face. However, Cyril tried to maintain the mystery of the Incarnation as much as possible. Cyril was concerned more for the unity of the Word of God who was made flesh so that out of the two we have the One Lord Jesus Christ: not God “in a man” but God “as man.” That is the οὐσια (being), ὑπόστασις (existence/person), φύσιν (nature), πνευμά (spirit), ψύχε (soul) of the Word and the humanity somehow mysteriously became “one.” Just as in Genesis, God breathed into Adam animating and bringing life to his body, the life of God, in the whole manner of His Being, existence, Person, nature, spirit, soul, and upon whose image we are created, animated the flesh and body He assumed. The incorporeal and the corporeal became one. That is whole God and whole Man. What we see in Jesus Christ is the nature of God exhibited in His one Person. The Seraphim and the Cherubim covered their eyes at such an event. These distinctions were clearly understood but the inner workings were clearly not. In addition to this, we have the mystery of our sinful humanity He assumed. Sin in itself is inexplicable. Thus, the Word of God’s assumption of our sinful human flesh is also inexplicable in itself. In addition to His entire nature, this mystery of our sin and darkness is included in the inner workings of His Being and existence of which we have no clue as to how this all worked in the humanity of God, the Person of Jesus Christ.
The hypostatic union understood in this way brings about enormous assurance of what this means for us and for our salvation. The Word hypostatically united Himself to our human nature in such a way that is beyond our intellect to fully grasp but we are able to miraculously comprehend it somehow. Yet, what it means is the work of Jesus Christ is as universal and throughout as we could ever imagine. Whether one knows it or not, the reality of the Incarnation unites us all to the Father in the Person of Jesus Christ. The humanity of God is as important to our salvation as His divinity. We cannot pull the two apart for any reason. Once we start to pull it apart, we are left with a vacuum that can only be filled with speculative explanations of ordinary blind human beings who are as blind as all human beings. How can anyone claim they can see into places the Seraphim and the Cherubim are not privy to see? Within this vacuum, people are at risk of the wolves in sheep clothing entering into this and leading them astray. Instead, what we discover when the light shines in our hearts and we see Jesus Christ the way we ought to see Him, it is an unveiling of the reality of the way we truly are in our complete unity to Him. The hypostatic union is the reality even when we were not aware of it. When we became aware of our union in Jesus Christ, this hypostatic union is actualised and we see it internally through the eyes of our heart. On that day you will realise that I am in my Father, and you in Me, and I in you (Jn. 14.20). We can have this knowledge with utterly staggering confidence and certainty, that when Jesus Christ was born, God united Himself (or hypostatically united Himself) with every single human being. This is regardless of whether we know it or not. If any do not know it, we can be confident on imparting this knowledge, this is the Light that will shine in our darkness. We can confidently declare from the rooftops, The One who is behind all things, who is the Creator of all things, has come as the Man Jesus Christ. When He was born, God united Himself to you!
The term κατά φύσιν (according to nature) has to be taken in context within the crisis Cyril and the Western Church found themselves in when confronted with the dubious ideas of Nestorius. “According to nature” is the outward expression of the ousia and the hypostasis of the Word made flesh, which we see in the Person and work of Jesus Christ. We see God in this outward form. In this outward form we see the characteristics that give us clues to His actual existence into His Being. It was clearly understood there was the Divine nature and the human nature. It was not in the way the ousia of the Divinity was co-existing with the ousia of the humanity. The divinity and humanity were mysterious distinctions where somehow out the two there came “one.” The expression or nature of the ousia and hypostasis was expressed through the Word embodied and enfleshed in the Person of Jesus Christ. Therefore, there is unity in Being and act in His Person. There is unity in the imminence and economy of God. On the one hand, we cannot go the way of the Monophysites’ who believe that the humanity of Jesus was totally absorbed by His divinity, on the other hand, we cannot push to far into two natures without falling into the trap of speculative and dualistic thinking.
Needless to say, those who might object to the term κατά φύσιν (according to nature) misunderstand the context for which it was used. The only other choice we have is to speculate and divide which is the habit of pagans. The things Jesus Christ said and the acts He carried out were uniquely peculiar to Him. He singled Himself out as the One who was sent from God, declaring He was one with Him. The signs and wonders associated with His acts endeavoured to show the Hebrew community that He indeed was the One. Though it is granted there were distinctions between His divinity and His humanity, in some mysterious way they became united and one in His Person. The characteristics He portrayed point to something extraordinary within His own Being and existence. This nature tells us something of His Being (οὐσία) and the manner of His existence (ὑπόστασις) or more precisely He is the ground, origin and source of existence (ὑπάρξις). Yet, it is not exhaustive to us because only God knows His own self. The interplay between His divinity and His humanity is hidden from us. To try and definitively describe how they interacted takes us on the course of speculation rather than remaining within what is disclosed in the Person and work of Jesus Christ.