(I am posting this material for those who are interested in the history of theology. The doctrine of the hypostatic union as articulated at the Council of Chalcedon (451 A.D.) is one of the "elemental forms" or basic constitutive concepts of T. F. Torrance's doctrine of the mediation of Jesus Christ.)
While the New Testament assertion of a two-fold order of being in Jesus Christ as both Son of God and Son of man is the "foundation datum" of all subsequent christological development, it also contains all the elements of the "christological problem" that would later emerge, particularly in the fourth century: that is, how to define the relation of the divine and human natures in Jesus Christ (Kelly, 1978:138). Despite aberrant forms of christology that had existed as far back as the second century (e.g., Ebionism and Docetism), during the fourth century, especially in the early years of the Arian controversy, issues related to the doctrine of the Trinity outweighed the importance of questions related to christology. Once the question of the divinity of Jesus Christ was considered settled, however, theologians inevitably turned their attention to the relationship between divinity and humanity in the incarnate Son of God (Gonzales, 1987:335, 336).
The Nicene fathers were not content to assert only the consubstantial unity between Jesus and God; they also understood the vital importance of asserting the consubstantial union between Jesus Christ and humanity (cf. Torrance, 1988a:3, 4). In asserting the consubstantial relation between the Father and the incarnate Son, the Nicene Fathers sought to secure "both ends" of the homoousion, that is, the divine and the human. As Torrance notes, "Everything would be emptied of evangelical and saving import if Jesus Christ were not fully, completely, entirely man, as well as God" (Torrance, 1988a:146). Clauses related to the humanity of the Son were added as vital components of the creed (e.g., "He came down from heaven: by the power of the Holy Spirit, He became incarnate from the Virgin Mary, and was made man. For our sake He was crucified under Pontius Pilate; He suffered death and was buried."). As Torrance notes, those creedal statements that refer to the humanity of Jesus Christ are dominated by a soteriological concern: "for us and for our salvation." The Nicene fathers sought to secure the truth that Jesus Christ is both God and Saviour. The mediation of Christ in reconciliation involved a "two-fold movement," from God to man and from man to God, so that both the divine and human activity of Jesus Christ must be regarded as issuing from one person. In regard to the significance of "both ends" of the Nicene homoousion, Torrance notes, "If Jesus Christ the incarnate Son is not true God from true God, then we are not saved, for it is only God who can save; but if Jesus Christ is not truly man, then salvation does not touch our human existence and condition" (Torrance, 1988a:146-149).
The message of the gospel is articulated in the basic Nicene principle that the human acts of Jesus Christ are the very acts of God. As Torrance (1988a:149) asserts:
In him God has really become man, become what we are, and so lives and acts, God though he is, 'as man for us'. . . . Only God can save, but he saves precisely as man ‒ Jesus Christ is God's act, God acting personally and immediately as man in and through him, and thus at once in a divine and in a human manner.
Notwithstanding the Nicene creedal assertion of the full divinity and full humanity of Jesus Christ, however, the question remained as to exactly "how" the divine and human natures of Jesus Christ are related. Inevitably, the question arose as to exactly "what kind" of human nature was assumed in the incarnation and to "what degree" was it assumed? In regard to this "constant problem of theology," Torrance (2008:182) asks:
[H]ow can we be faithful in our theological statements to the nature of the eternal being of the Son who became man and who yet remains God, and at the same time be faithful to the nature and person of the historical Jesus Christ?
The christological debates of the early church concerned the relation of divinity and humanity in the incarnate Son. These often heated debates took place primarily in the eastern Mediterranean world and were conducted in the Greek language under the ubiquitous influence of the metaphysical presuppositions of Greek philosophy (McGrath, 1998:32). The problem of the relation between the two natures of Christ can be better understood by a comparison of the rival christologies of ancient Alexandria (Egypt), with its Docetic tendencies, and that of Antioch (Syria), with its Ebionite tendencies (Torrance, 2008:198ff).
Alexandrian Christology and Apollinarianism
The christology of the Alexandrian school was strongly soteriological in character. Redemption was equated with "divinization" or "deification," that is, "being taken up into the life of God." For divinization to occur, human nature must be united with the divine nature; that is, God must be united with human nature in such a way that the latter is enabled to share in the divine life of God. This is precisely what happened in the incarnation: the divine Logos assumed human nature, thereby assuring its divinization. In short, God became human so that humanity may become divine. In regard to the relation between divinity and humanity in the incarnation, Alexandrians emphasised the unity of divine and human natures in Jesus Christ. In addition, they argued that, in the incarnation, there is only one "nature," in that the Logos united human nature to itself. This emphasis on one nature in the incarnation distinguishes the Alexandrian school from the Antiochene school, with its emphasis on the two natures of the incarnate Word (McGrath, 1998:51, 52).
Hinting of Docetism, the Alexandrians regarded the humanity of Christ as a passive, impersonal vehicle for use by the divine Logos, asserting that the humanity did not have a mind and will distinct from that of the eternal Word. By the fourth century, they had developed a "Logos-flesh" christology; that is, an assertion that human flesh, not humanity in its entirety, was assumed in the incarnation. Their assertion of only one nature in the incarnation allowed the Alexandrians to assert the important doctrine of communicatio idiomatum; that is, what is attributed to Christ's humanity may also be predicated of the divine Logos. Unfortunately, they applied this principle in such a way that the human nature of Jesus Christ was severely compromised (Gonzales, 1987:340, 343, 344; McGrath, 1998:52; Olson, 1999:204-206).
Alexandrian christology reached its climax and natural conclusion with Apollinaris of Laodicea (c. 310-c. 390). Because he regarded the human mind as the source of sin, Apollinaris was concerned that the assumption of a complete human nature would compromise the sinlessness of Jesus Christ; thus, he argued that the Logos did not assume a rational human mind in the incarnation; rather, the human mind was replaced by the divine mind of the Logos. Basing his argument on the trichotomist position that humans are composed of body, soul, and spirit (cf. 1Thes 5:23), Apollinaris argued that the soul is the impersonal, unconscious, but vital principle that gives life to the body; the spirit is the seat of personality, that is, the centre of the rational faculties or reason. In the incarnation, the Logos occupies the place of the spirit, so that in Jesus Christ, a human body and soul are joined to a divine reason or mind. In this way, Apollinaris preserved the immutability of the Logos, while solving the problem of how divine and human natures could unite without creating a new nature. Christ is human because he possesses a human body and soul; he is divine because his mind or reason is that of the eternal Logos. Moreover, in harmony with the "Logos-flesh" christology of Alexandria, Apollinaris argued that if a complete human being with its own personality and reason had been united to the Logos, then the incarnation would result in "two persons," one divine and one human. Since the existence of two centres of consciousness, each with an independent mind and will, would undermine the union of divinity and humanity in the incarnation, Apollinaris preserved the unity of the Saviour by asserting the "one nature" of the incarnate Word. Yet, in so doing, he mutilated the human nature of Jesus Christ by taking away its rational faculties and substituting the divine Logos in their place (Gonzales, 1987:346-348; McGrath, 1998:52; Olson, 1999:207, 208).
Opponents of Apollinaris' position, represented by Gregory Nazianzus (329-389), stressed the redemptive importance of the assumption of human nature in its entirety in the incarnation. Because God has assumed human flesh, we are enabled to obtain deification. Accordingly, Nazianzus argued that "what has not been assumed has not been healed"; that is, only those aspects of human nature that are united to the Logos in the incarnation have been redeemed. According to Nazianzus, if we are to be saved in the totality of our humanity, then humanity in its totality must be brought into union with the divine (Gonzales, 1987:349-352; McGrath, 1998:53-55; Olson, 1999:208).
Apollinarianism was officially condemned at the Council of Constantinople (381 A.D.), not because it asserted the one nature of the God-man in the incarnation, but because it denied the full, complete humanity of Jesus Christ. Against Apollinaris, the council asserted that Jesus Christ is "fully human" (Gonzales, 1987:352; Olson, 1999:208; Torrance, 2008:196, 197).
Antiochene Christology and Nestorianism
Against the more metaphysical soteriology of the Alexandrians, the Antiochene theologians viewed salvation as a wonderful moral-ethical accomplishment wrought by a human being on behalf of all by uniting his will to that of the divine Logos. Given its moral concerns, Antiochene christology emphasized the humanity of Christ, producing a "Logos-man" christology in which the human nature of Christ was not regarded in a passive, instrumental way, but as actively able to obey God. In their concern to preserve the genuineness of the humanity of the incarnate Son, while, at the same time, guarding the transcendent divinity of the Logos against the creaturely contamination of human nature, the Antiochenes emphasized the "distinction" of the two natures of Jesus Christ. In contrast to the "one nature" christology of Alexandria, the Antiochenes defended the "two natures" of the incarnate Son by arguing that Jesus Christ is both God and a human being, possessing both a perfect divine nature and a perfect human nature in "perfect conjunction." Against the Alexandrian insistence on the assumption of a "general" human nature, the Antiochenes argued that the Logos united to a specific human being in the incarnation; that is, the human nature of Christ is a whole and complete person, having an active mind and will. Convinced that the Alexandrian position led to the "mingling" or "confusion" of the divine and human natures, the Antiochenes emphasized their distinct identities, viewing the two natures of Jesus Christ much like water-tight compartments, neither interacting nor mingling with one another, yet held together by the good pleasure of God. Antiochene christology reached a crisis point in the thought of Nestorius (died c.451), who, his critics argued, expressed a doctrine of "two sons," that is, that Jesus Christ was not a single individual but "two persons," one human and the other divine (McGrath, 1998:55-57; Olson, 1999: 205, 206).
Controversy erupted when Nestorius, bishop of Constantinople, forbade the use of the popular term, Theotokos ("God-bearer"), to refer to Mary, the mother of Jesus. Against the Alexandrians, who favoured the term as a logical outcome of their doctrine of communicatio idiomatum, Nestorius, regarding the nature of divinity in the Greek philosophical terms of immutability and impassibility, argued that divine nature could neither be born nor die. Because he believed so strongly in the divinity of the Son, Nestorius resisted any attribution of creatureliness to the incarnate Word, believing that it would confuse the divine and human natures. The humanity is merely the "vehicle" or "instrument" for the use of the divinity and is not the divinity itself. Moreover, Nestorius viewed Theotokos as "crypto-Apollinarian," regarding the title, "God-bearer," as an implication that Jesus Christ was not fully human. In common with Antiochene christology, Nestorius regarded divinity and humanity as mutually exclusive categories; that is, one cannot be both fully human and fully divine. For Nestorius, to say that Mary gave birth to God is to deny the full humanity of Jesus Christ; therefore, he denied the Alexandrian doctrine of communicatio idiomatum as the basis of his rejection of Theotokos (Gonzales, 1987:354, 363, 364; Olson, 1999:211-214).
Nestorius' thinking on the relation between the divine and human natures of Jesus Christ can be viewed as the logical conclusion of Antiochene christology, which emphasized the humanity of Jesus while trying to do justice to his divinity. Nestorius tried to explain the humanity and divinity of the incarnate Son in such a way as to preserve the integrity of both natures. For Nestorius, real humanity cannot exist apart from a specific individual who is the conscious centre of that nature; thus, prosopon ("person") and physis ("nature") go together in both divinity and humanity. In an attempt to avoid the assertion of adoptionism, Nestorius posited a special kind of union between the divine and human natures of Christ, one he referred to as synapheia (L., conjunctio): Jesus Christ is a "conjunction" of "divine nature-person" and "human nature-person," the eternal Logos and the human Jesus in intimate union. Arguing that each nature retains its own predicates, which may not be confused, Nestorius denied the Alexandrian doctrine of the communicatio idiomatum. Thus, he was compelled to assert that the incarnation results in two persons: the Son of God and the Son of Mary. To this union of two persons, we assign the name Jesus Christ (Gonzales, 1987:363; Olson, 1999:215, 216).
Nestorius was opposed by Cyril, bishop of Alexandria (died 444), who considered the former's christology a sophisticated form of the "adoptionism" associated with the Antiochene heretic, Paul of Samosata. The similarity between adoptionism and Nestorianism lay in the fact that, in both, the Son of God never truly enters human existence; rather, the person of the divine Logos remains both distinct to, and different from, the human person of Jesus. Cyril dismissed the "non-interactive" Antiochene model as a mere "conjunction" of natures rather than a genuine union, arguing that it was ineffective in safeguarding the vital soteriological principles at stake in the doctrine of the incarnation (i.e., divinization) (Gonzales, 1987:366, 367; Olson, 1999:216, 217; cf. McGrath, 1998:57-61).
Nestorianism was officially condemned at the Council of Ephesus in 431 A.D. Against Nestorius, the council affirmed the unity of the divine and human natures in affirming that Jesus Christ is "one person," not two. Perhaps unfairly, Nestorius is regarded as one of the great heresiarchs of church history, while Cyril is regarded as one of the great defenders of orthodox christology (Gonzales, 1987:367; Olson, 1999:217, 218, 220; Torrance, 2008:197, 200).
Cyril, the staunch opponent of Nestorius, is credited with articulating the basic outlines of the doctrine of the "hypostatic union," the doctrine that became foundational to the orthodox articulation of the mystery of the incarnation of God in Jesus Christ. In brief, the doctrine asserts that the subject of the life of Jesus Christ is the divine Logos, the eternal Son of God, who assumed a human nature while remaining fully divine. Cyril rejected a Nestorian conjunction of natures and replaced it with "hypostatic" union: the union of two realities in the one hypostasis, or "personal subject," of the divine Logos. According to Cyril, there is no human personal subject in the incarnation. While the human nature of Jesus Christ includes every aspect of humanity, that is, body, soul, spirit, mind, will, it lacks an "independent" or "autonomous" personal being over against the Logos. The humanity appears anhypostasia, that is, "impersonal." The hypostasis, or "personal subsistence," of Jesus Christ is the eternal Son of God, who condescended to take on human flesh through Mary. As Cyril argued, Mary gave birth to God in the flesh. Hence, the doctrine of the hypostatic union is the foundation of the communicatio idiomatum. For Cyril, the one personal subject of the eternal Son is both divine and human; thus, because they are one and the same person in two modes of being, it is correct to say that the Son of God was born, suffered, and died, and it is also correct to say that the human Jesus worked miracles and forgave sin (Olson, 1999:218, 219; cf. Gonzales, 1987:366, 367, 378).
The Chalcedonian Definition
Notwithstanding the condemnation of Apollinarianism at Constantinople and Nestorianism at Ephesus, the christological disputes between Alexandria and Antioch continued, with both schools convinced that the christology of the other compromised the doctrine of the incarnation in ways that undermined or destroyed Jesus Christ's ability to save. Antiochene christology continued to emphasize the two natures in such a way as to functionally separate the human from the divine, so that Jesus Christ accomplished salvation as a godly man who fully cooperated with the divine Logos that assumed him. Alexandrian christology, on the other hand, emphasized the role of the divine Logos, who assumes humanity unto himself and, thereby, heals the wounds of sin and death for all who participate in him by faith. Alexandrian christology, with its emphasis on the divine nature of the Logos, reached an extreme point in the monophysite ("one nature") christology of Eutyches. A staunch opponent of Nestorius, Eutyches rejected any assertion of "two natures" after the incarnation and subsequently undermined the humanity of Jesus Christ to such a degree that it seemed to vanish like a drop of wine in the ocean of his divinity. Eutyches' main error consisted in denying the consubstantiality of the Saviour with humanity. In asserting the humanity of Jesus made no difference to the divine Logos, Eutychianism was hardly more than a new form of Docetism (Olson, 1999:222, 223; cf. Gonzales, 1987:370-372).
The differences between Alexandrian and Antiochene christology were finally resolved at the Council of Chalcedon (451 A.D.). Seeking to preserve the truth of both positions, while avoiding the extremes of either, particularly Eutychianism and Nestorianism respectively, the Council reached what is essentially a compromise between the rival positions by affirming that Jesus Christ is "one person" in "two natures." In harmony with the Antiochene position, the council affirmed the real humanity of Jesus Christ and his two natures; in harmony with Alexandrian christology, it asserted that the two natures cannot be separated or divided, but must be held together in one person. Antioch was declared right in its affirmation of two natures, but wrong in its Nestorian denial of the unity of those natures. Alexandria was declared right in its affirmation of "one person" of Jesus Christ, but wrong in the Eutychian denial of the completeness and integrity of the distinct natures of humanity and divinity in their union in Jesus Christ (Olson, 1999:231-233; cf. Gonzales, 1987:380).
At the heart of the "Chalcedonian Definition" (cf. Kelly, 1978:339, 340; Gonzales, 1987:379; Olson, 1999:231, 232) is the "four fences" of Chalcedon: "without confusion, without change, without division, without separation." These phrases serve as boundaries surrounding the mystery of the hypostatic union. "Without confusion, without change" guards the mystery against the monophysite attempt to preserve the one person of Jesus Christ by creating a mixed or hybrid nature from divinity and humanity. "Without division, without separation" protects the mystery from a Nestorian over-emphasis on the distinction of natures, with its tendency to separate them and make two persons of the incarnate Son. In addition, the "Definition" asserts that Jesus Christ is "homoousios with the Father as to his Godhead" and "homoousios with us as to his manhood." Thus, Jesus Christ is both fully divine and fully human. The Definition further asserts that the two natures of Jesus Christ concur "in" one person (prosopon) and one hypostasis, with the properties of each nature preserved. Moreover, despite the omission of Cyril's phrase, "hypostatic union," it is clear that the divine Logos is regarded as the unique subject of the incarnation, as evidenced by the sanction given to the controversial term, Theotokos. Thus, orthodox, catholic belief is that Jesus Christ is God with a human nature, not merely a man elevated into a special relationship with God (Kelly, 1978:341; Olson, 1999:233, 234).
Torrance (2008:83-86) makes the three important points regarding the doctrine of the person of Jesus Christ as articulated at Chalcedon: First, the doctrine of Jesus Christ is the "mystery of true divine nature and true human nature in one person." This is the "heart" of the Christian faith. This mystery cannot be categorized in terms of what we already know; rather, it can be known only out of itself and can only be acknowledged with wonder and thanksgiving; hence, doxology is the "first step" in the doctrine of Christ.
In acknowledging that the mystery can be known only out of itself, Torrance remains true to his scientific methodology, wherein a reality is known only in accordance with its nature and not in terms of antecedent presuppositions or a priori conceptual categories. In assigning primacy to doxology, Torrance maintains his assertion that faith and worship are integral to the epistemological process.
Second, the mystery of Jesus Christ is that true God and true man are united in one person; that is the doctrine of the hypostatic union. Yet, the mystery of Christ can only be stated in negative terms; that is, we can only say what it is "not." The Chalcedonian doctrine of Christ states that divinity and humanity are united in Jesus Christ in such a way that there is no impairing or diminishing of either the divinity or the humanity, and there is neither separation of the natures or confusion between them. This is expressed in the four great negative terms inconfuse ("without confusion"), immutabiliter ("without change"), indivise ("without division"), and inseparabiliter ("without separation").
In noting that the mystery of the hypostatic union can only be stated in negative terms, Torrance is not retreating to a form of apophatic mysticism, wherein descriptions of God can only be stated negatively (i.e., God is "not this"). Rather, notwithstanding the definitive self-disclosure of God in Jesus Christ, wherein God may be known positively according to his nature, we are not given to understand, let alone articulate, exactly "how" divinity and humanity are united in one person; we are given only to know, by faith, that such mystery has occurred in Jesus Christ.
Third, the union of divine and human natures in the incarnation is entirely the result of the transcendent act of the eternal Son in assuming human flesh. As a result of that act, the eternal Son of God, without ceasing to be God, now exists as the man Jesus, who is fully and truly human with his own individual life. On the other hand, apart from the act of God in the incarnation, there would have been no Jesus of Nazareth, so that the humanity of Jesus is grounded in the act of the eternal Word becoming flesh. The doctrine of anhypostasia asserts that the human nature of Jesus exists only in union with God. It has no independent existence; hence, an-hypostasis ("not person", i.e., no separate person). The human nature of Jesus is given existence in the existence of God. It co-exists in the divine mode of being; hence, en-hypostasis ("person in," i.e., real human person in the person of the eternal Son). This means that Jesus has a fully human mind, will, and body, and is in complete possession of all human faculties.
Torrance's assertion of the doctrine of anhypostasia, that is, that there would be no such person as Jesus of Nazareth apart from the incarnation of the eternal Word, rules out adoptionist christologies. Jesus is not merely a man upon whom came the Holy Spirit at his baptism; rather, apart from the incarnation of the Word, he would never have existed. At the same time, Torrance's assertion of the doctrine of the enhpostasia means that Jesus was fully human and, therefore, rules out Docetic, Apollinarian, and monothelist christologies.
As will be shown, Torrance's understanding of the hypostatic union is clearly in line with the Definition of Chalcedon. He adds nothing new to the orthodox understanding of the relation of divinity and humanity in the one person of Jesus Christ; rather, he goes to great length to articulate the epistemological and evangelical significance of the doctrine.
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