The Significance of Constantinople II’s Alteration of Chalcedon’s Formula About Christ’s Natures ‘Coinciding In One Prosôpon ’

The Antiochene Understanding of Hypostasis and Prosôpon

Since the phrase ‘one prosôpon’ comes out of the Antiochene christological tradition, it is crucial to understand its meaning there. To grasp its nuances, however, one must be aware of how the leading Antiochene theologians considered the meaning of the words physis (nature) and hypostasis in a christological context. The Antiochenes agreed, in general, with the other Fathers over the meaning of ‘nature,’ regarding it as expressing what constitutes a reality to be what it is. It sums up what are considered to be its specific properties. The Antiochene Fathers, nevertheless, differed, radically so at times, over how ‘nature’ was related to the other major terms, especially hypostasis. For them, hypostasis was understood up to the Council of Chalcedon to be expressing an existing complete nature (physis), whether this be a ‘person’ or a thing such as a tree or even the sun when it is no longer visible at night. ² They simply could not conceive of a hypostasis apart from a complete nature in which the hypostasis inheres and thus provides its existence. For the term indicates that some nature is actually existing. Therefore, to preserve and defend Christ as really human as well as divine, the Antiochenes held that Christ’s natures each possessed its own hypostasis in the sense that both of his natures are real. So when Apollinaris (ca. 310–ca. 390) used the term hypostasis to denote the existing unity of the Word’s divine nature with a human nature that is lacking its rational soul, Theodore of Mopsuestia (ca. 350–428) viewed such an application to be novel, bizarre, and heretical. ³ For in Theodore’s mind, this meant Apollinaris was holding that Christ possessed only one complete nature, that of the divinity. The same outlook explains why Nestorius (ca. 380–ca. 451) understood the mia physis (one nature) statements of Cyril of Alexandria (ca. 370–444) as espousing in fact the heresy of Apollinaris. As will be seen, Theodoret (ca. 393–ca. 458) will at the time of Chalcedon accept its formula when he realized that the Fathers were taking hypostasis not in the sense of a complete existing nature (as Theodore did who regarded Christ’s divine and human natures existing as such) but that of the overall subject or ‘person’ who possessed two natures. ⁴ For Theodoret, this meant that ‘nature’ could be considered to be distinct from ‘hypostasis,’ which up to that point the Antiochene Fathers could not conceive of as a possible distinction.

As regards the meaning of prosôpon, the Antiochenes considered that each of Christ’s natures possessed its own prosôpon and that the union of the two took place in ‘one common prosôpon.’ The term is a Greek word whose wider meaning, as Theodore used it, is not well understood at present. It is generally taken as the outward appearance of a hypostasis. But it also has a wider meaning as attested to in the writings of Theodore, Nestorius, and Theodoret among the Antiochenes as well as in the writing of the Greek Patriarchs Proclus (434–46) and Flavian (447–ca. 451), and the Latin Tome of Pope Leo the Great (ca. 391 or 400–61). These are doubtless, each in his own separate way, the sources influencing the Council of Chalcedon’s decision to add the phrase ‘one prosôpon’ in its faith formulation. Since the christological use of prosôpon traces its origin back to Theodore, it is important to be aware of his meaning and his applications of the term. ⁵ He arrived, so it seems, at his full understanding of its christological meaning when he applied his literal, historical method to those Gospel texts, where Jesus speaks and acts as man and as God and specifically to the Pauline passage in Philippians 2: 5–11. ⁶ Since Theodore accepted all of these accounts as God’s revelation, he reasoned in an inductive way that each nature is acting according to its nature and, in this sense, both must be considered as acting as the sources and causes of these actions. He, therefore, considered prosôpon as denoting how a hypostasis (as an existing nature) reveals itself by particular activity peculiar to itself and known as such by these. Theodore then reasoned that, if each of Christ’s two natures has its own existing nature, then there must also be present in Christ two prosôpa as well as two hypostaseis. ⁷

Theodore was sensitive to the need to defend not only the two natures in Christ but also a true unity for his two prosôpa. He likely found his answer in Philippians 2: 5–11, where he read that the Lord Jesus Christ acted as one in divine and human ways. ⁸ Though he does not speak of each nature as possessing its own prosôpon—probably because the Pauline author has used the word ‘form’—he does refer to the unity as being one. ⁹ For it sums up how Christ Jesus acts in divine self-emptying and humble human ways. ¹⁰ However, Theodore did call the source of these disparate prosopic acts to be their prosôpon; that is, in his overall thought, their ‘one common prosôpon.’ This highlights a dilemma for Theodore. For while he can easily claim that the New Testament reveals in distinctive ways Christ’s human and divine activities, yet he is faced with serious problems as to whether or not and how he can rightly maintain a deeper personal unity on the basis of such evidence. For one may be misjudging the true source of the activity or not allowing for other factors or reasons to account for why one is acting in this way and, thus, end up reaching the wrong conclusion about this ‘person’ as an individual. But Theodore believed that the New Testament attests to this unity when it uses such concrete titles as the ‘Lord Jesus Christ’ and ‘Christ’ (as signifying that he is both God and man). Yet Theodore possessed no single abstract word for this purpose. He could not resort to hypostasis because the term had already been earlier preempted by Apollinaris, who affirmed the existence of only one complete nature in Christ, that of the Word.

In a remarkable passage, Theodore expresses what he means by his ‘one prosôpon’ uniting Christ’s two prosôpa. He finds an apt analogy in Paul’s comments on Romans 7: 15–20 as to why one can do good and yet also sin. ¹¹ He is speaking of the ability that an individual’s ‘ego’ has to act in response to physical and spiritual promptings. This analogy, of course, cannot be applied in every detail. But Theodore’s point is clear. For just as the human ‘ego’ can act in a physical as well as a spiritual way, something similar—if one can speak about God in this way—can be asserted of how Christ’s one common prosôpon can act in divine and human ways and still be one. He, therefore, looks upon Christ’s ‘ego’ or common prosôpon as operating as one in a functional sense. He is careful, however, to indicate that when the ‘ego’ is acting in one way, the other nature is also present because they are wholly united as one common prosôpon. This is further exemplified in those passages where Theodore has Christ speaking at one moment as the Word and then as a man. ¹² He does, however, insist that when Christ as God acts, it is always with, in, and through Christ’s humanity. On such occasions, his humanity is revealing to others the presence of the Word’s divine nature within himself.

The question then becomes: does this functional unity of Christ’s two prosôpa acting together as one ‘ego’ constitute a substantial unity, presuming once again that one can speak of ‘levels’ in Christ? To support his claim that his functional approach suffices for establishing a true unity in Christ, Theodore would appeal to the numerous New Testament passages where Christ is portrayed as speaking as one in divine and human ways. His authenticating source is, therefore, primarily the New Testament, which for him is the revealed word of God. But he addresses this question directly when he believes that John himself answers how the Word became flesh (1: 14) in the second half of this verse: ‘Then to explain “he became,” John said: “He made his tabernacle among us,” that is, He was made flesh in the sense that He dwelt in our nature. For (the words) “He made his tabernacle with us” clearly means that “He has dwelt in us.”’ ¹³ But what does he mean by this ‘indwelling,’ which he later calls ‘an indwelling of good pleasure?’ ¹⁴ Theodore accepts this indwelling as a revealed verification that the triune God is the subject freely dwelling in Christ’s humanity. His addition ‘of good pleasure’ at least suggests that the Word becomes one with Jesus by means of a unique, unparalleled gift of love, where he is one with Jesus and, as indicated in other places, that the Spirit wholly fills his human nature with all grace and bonds it to the Son and, through the Son, to the Father. ¹⁵

Theodore further explains this unity by means of two analogies. The first occurs when he is commenting on how the Father and Christ as man are one. ¹⁶ Theodore likens the way the splendour of the sun is one with the sun and shares in its grandeur and power to the way that Christ’s humanity is one with the Father and shares in his majesty. In this way, the Father and Christ as man can be said to be both one and distinct at the same time, but, yet, with Christ as man fully sharing in the Father’s grandeur and power, even to the point that he can be rightly said to have participated in the creation of the world. But he is unlike the Father in their unity because his humanity is not uncaused as is the Father’s nature. ¹⁷ This also enables him in upholding the mystery of the Incarnation to safeguard Christ’s human freedom in his essential role in salvation by his freely dying on the cross for others.

Theodore offers another analogy to suggest how Christ’s two prosôpa interact within a union of good pleasure, when he compares this unity to that between a husband and wife who are two in one flesh (I Cor 6: 16). He points out: ‘For just as (the husband and wife) can be said to be one flesh without contradicting the fact that they are numerically two—of course, this is clearly dependent on how they are said to be one—so also in the present case the union in [one] prosôpon does not undermine the distinction between the natures.’ ¹⁸ While this analogy limps as it deals with the functional way that a husband and wife interact in love with one another, it insinuates that the Word and Christ as man have so totally given themselves to each other in love that the two are indeed truly one. This unity between the Word and Christ as man, is, of course, sui generis. In such a relationship of bonded love, Christ as the Word and as man would love each other as a husband and wife would ideally do, while at the same time respecting each other’s freedom in their desire to please the other. Theodore’s thought is well expressed by the Greek text of Colossians 2: 9: ‘The whole fullness of the divinity dwells in him in a bodily way.’ These two analogies, therefore, taken from the New Testament, offer insight into how to interpret Theodore’s understanding of the phrase ‘an indwelling of good pleasure’ as a bonded relationship of love existing between Christ’s two prosôpa acting as one common prosôpon.

One last point needs to be made to clarify the meaning of Theodore’s ‘one common prosôpon.’ While Theodore’s understanding of an indwelling union of love can be conceived as happening on a much deeper ‘level,’ where Christ is the whole ‘person,’ that of his common ‘ego’ ought to be viewed as being where the two natures function as one. It is at that level that Christ acts as one in dual ways as the common source of his individual human and divine actions. So when Christ acts in a divine way, he must still act with and through his human nature. For the transcendent divine will has determined to reveal itself through its human co-prosôpon. So too when Christ acts in a human way, the Word is still involved in this act as the humanity’s co-prosôpon. Theodore expresses this clearly in those incidents where one must ascertain from the context which nature is actually the one speaking and acting at this particular moment. It is also apparent in those passages where Christ as the ‘person’ who is now acting can switch instantaneously from operating as one of the natures to that of the other, as exemplified in the following:

In both cases, whether in regard to his divinity or humanity, (John) employs the pronoun ‘I,’ so that the meaning of what is being said will be known from the context, with the natures being recognized by the different words [being used]. Because he speaks of himself in both instances as one subject, he manifests his prosopic union. ¹⁹

Our Lord and Savior, Jesus Christ, being God and man, shows by the trustworthy word of God that the Jews could charge him appropriately qua man for having violated the Sabbath. But he (really) did not do so. For everything he wants to do [as man] is allowed him, because all that belongs to God (the Word) by reason of His nature has been bestowed also on him as ‘man’ because of his union with Him. He is, therefore, speaking here by way of the majestic nature that is present in him, in order to take the occasion when the Jews censured him, to reveal, as far as possible, what is his Other nature. For this reason, he switched over in a controlled way from (his divine way of acting and speaking) to his human one, for what he has said is very much contrary to his visible (nature). ²⁰

In other words, Theodore has opted to stress the functional unity of Christ’s two natures, but he is, of course, presuming a deeper unique unity, where these two natures are distinct but truly one ‘person.’ He does not explain exactly how this is so, being a mysterious unity of love, but he believes this union is indeed a true unity that differs from a substantial union, where two natures become one of the natures or a hybrid. Needless to say, the Word enjoys pre-eminence in this unity whose will is in no way dependent on Christ’s will. Nevertheless, Christ’s human will is free to play its mediating role in God’s plan for salvation. Today theologians determine which nature is speaking or working by distinguishing Christ qua God and Christ qua man as the one who is primarily acting. ²¹

The Later Antiochene Views of Prosôpon

Since Theodore has established the full range of meanings for prosôpon, time has been spent to clarify in some detail his nuances of this term. Some discussion, however, is also needed to consider whether or not later Antiochenes have had some influence on the Fathers at Chalcedon, when they introduced the phrase ‘one prosôpon’ into their faith formula. Among the Antiochenes, two are important. Because the Fathers at Chalcedon explicitly condemned Nestorius (ca. 380–451), his influence would have been minimal. Nevertheless, it is helpful to be aware of how Nestorius viewed prosôpon. Since few of his early writings have survived, his view of prosôpon has to be drawn from his Liber Heracleides (a collection, so it seems, of three writings). ²² It is admittedly difficult to grasp what Nestorius wants to say in his Heracleides about the unity in Christ, for he lacked a philosophical or abstract term to express a true personal union. He, like Theodore, viewed hypostasis as a term denoting an existing nature. But he appears to have taken prosôpon to be a collective term connoting all the essential properties that belong to the human and divine natures of Christ (as revealed in the New Testament) and used to distinguish one nature from the other. As regards the phrase ‘one prosôpon,’ he seems to consider the phrase to be expressing the union and unity of Christ’s natures in a functional sense. This is seen when he elaborates on how the Word assumed Christ’s humanity, describing this as a mutual active interpenetration of the natures (in what Grillmeier calls a perichoresis). ²³ Nestorius regarded this mutual interplay as being the way that the Word functions together with Christ’s humanity in their unity. As such, he would be talking about how Christ’s two natures function as one common prosôpon. He believed that by stressing the dynamic interplay of the natures, he could in this way avoid the charge that he was proposing a purely moral, accidental union of the natures. Cyril, however, attacked this functional approach for failing to express the true substantial unity that occurred in Christ when the Word became man. Cyril rejected Nestorius’s dynamic interplay of natures because it could be interpreted as being two separate, cooperating individuals. If Nestorius, however, is judged in the context of Theodore’s thought, he can be defended as trying to distinguish the activities of two natures in the same unity and, therefore, not of ‘persons.’ In this question, neither Cyril nor Nestorius seems to have had any inkling of both the linguistic and theological framework out of which the other was operating.

The Antiochene theologian who seems to have had at least an indirect influence on the framing of the Council of Chalcedon’s faith statement about Christ’s two natures ‘coinciding in one prosôpon’ is Theodoret of Cyr. At the beginning of the controversy with Cyril, he initially wrote works opposing Cyril—which were later condemned at Constantinople II. He is also recognized as the chief author of the ‘Formula of Reunion’ in 433 that served as a mutually acceptable faith statement between the moderate Antiochenes and Cyril. ²⁴ This agreement later showed the Fathers at Chalcedon that the Antiochenes and Cyril could agree on a faith formula despite their bitter controversy over the condemnation of Nestorius at the Council of Ephesus in 431. In this formula, Theodoret regarded the title the ‘Lord Jesus Christ’ as the prime subject of the faith statement. For this is how both the New Testament and the Nicene-Constantinople Creed in its second strophe refer to Christ. Cyril accepted this wording because the formula then proceeds to state that this ‘Lord Jesus Christ’ is in an unconfused way ‘both perfect God and perfect man, begotten homoousios (of the same nature) with the Father as to his divinity and homoousios with Mary as to his humanity.’ For their part, the Antiochenes willingly conceded that Mary can be rightly designated as the theotokos (the Mother of God) once they became convinced that Cyril did not understand his mia physis formula in a strict Apollinarian sense and that he accepted the title of ‘Mary as the Mother of God’ as referring to the Lord Jesus Christ as the subject of unity. This agreement is important, for as Grillmeier has observed: ‘Here, then, we can see quite clearly the basic framework of two christologies, which can be alike in substance, but quite different in their tendencies.’ ²⁵ The Fathers at Chalcedon, therefore, wanted to acknowledge, in a positive sense, Cyril’s basic intuition about the true unity of Christ as a ‘person’ and, by adding the phrase ‘in one prosôpon’ into their faith formula, their awareness of what was authentic in the Antiochene defense of Christ’s human nature. While the sources make no mention of what was the personal role that Theodoret played in the inclusion of the phrase ‘in one prosôpon’ into the Chalcedonian formula, he did have an impact because of the ‘Formula of Reunion’ that he composed. For as will be seen, his wording is evident in Chalcedon’s faith document.

By signing the ‘Formula of Reunion,’ the Antiochenes and Cyril found that they could mutually agree on an overall faith framework about Christ’s unity of two natures. But this compromise papered over their different views as to how the human nature relates to the Word as the subject of the unity, and whether there are one or two operations in Christ. This compromise, moreover, did not treat these underlying questions, perhaps because they regarded them as of secondary importance to establishing their faith reconciliation. Still the signing of the ‘Formula of Reunion’ underscores Theodoret’s conviction at Chalcedon that the Antiochene and Cyrillian faith outlooks could be merged, if the major authentic points of each are included in a balanced formula of faith.

The Cyrillian Influence

In this section we will discuss first the language and evolving faith formulas of Cyril and then the modifications introduced by the Patriarchs Proclus and Flavian. For while Cyril’s view on the meaning of hypostasis is not exactly what the Fathers at the Councils of Chalcedon and Constantinople II meant by the term, his stress on the Word as the subject of unity and the almost universal esteem shown him by his followers played a profound role. Nevertheless, one must be sensitive to the fact that his language and faith formulas were initially ambiguous. His approach, however, did evolve as he became aware of the need to express clearly and accurately how his faith formula conformed to the New Testament and the Nicene-Constantinople Creed. This lack of clarity was due in no small measure to the fact that the basic christological terms were in flux. In fact, much of the controversy during that period was to determine in a commonly acceptable way the meanings of physis, hypostasis, and prosôpon and their relationships to one another.

Cyril initially espoused what is called today a Logos-sarx (Word-flesh) Christology that was promoted by his mentor, Athanasius of Alexandria (ca. 296–373). He expressed the unity of Christ’s two natures as one of mia physis (one nature), mistakenly thinking that this formula had come from Athanasius and was the accepted teaching of others of his day. In reality, however, it had originated with Apollinaris. Cyril expresses his thought in his often quoted statement ‘mia physis tou Theou Logou sesarkōmenē (the one incarnate nature of God the Word).’ His intent was to indicate that it is the Word who is the subject to whom Christ’s sarx (flesh in the sense of a human being) is existentially united at the Incarnation. Cyril, nevertheless, was aware that this sentence had to be rightly understood. He meant it to express the dynamic unity of Christ’s complete natures in a concrete, historical sense and not nature in an abstract sense. ²⁶ Rather he understood mia physis to be signifying that the Word’s life-giving power is acting in a vital way in and through his human nature. When this formula was attacked as being Apollinarian, Cyril became conscious of the need to explicitly state that Christ possessed a complete nature with a rational soul. He then granted that, while Christ’s two natures were undivided, they could be conceived of as separate in an intellectual way: ‘(Christ) is thus indivisible after the union and is not separated into two persons (prosôpa), even though we conceive of the Word of God as being other than the flesh in which He dwelt.’ ²⁷

To address the concern of those who found his use of mia physis ambiguous, Cyril turned to the term hypostasis to express the unity. But he had once again to deal with the charge that he was appropriating Apollinaris’s term that equated hypostasis with the notion of one complete nature in Christ, that of the divinity. Cyril, however, regarded physis to be a nature in a dynamic sense and hypostasis to be the living reality in whom the two natures were united in a symbiotic way. He, thus, regarded both terms to be complementing each other as constitutive ‘elements’ of the same reality. In other words, Cyril understood Christ’s sarx as connoting, if not denoting, Christ’s humanity as so totally grounded in a perfect synthesis with the Word’s nature that they comprise one hypostasis, that of the Word. Grillmeier sums this up when he asserts: ‘It is clear that Cyril in fact transfers the unity in Christ into the “personal” realm while ascribing a duality to the natures.’ ²⁸ Grillmeier believes that Cyril is anticipating here what the Fathers at Chalcedon intend to convey when they chose the phrase ‘one hypostasis.’ For them, it signified Christ’s ‘personal’ unity that is centered in the Word in whom a divine and a human nature coincide and subsist.

Cyril drew his insight into what constitutes the dynamic unity of the incarnate Christ from John 1: 14, where the Word is said, not to have come to, but to have become, flesh. While Cyril did distinguish the Word as such and Christ as a title that signifies the union of the Word and Christ’s flesh, he, nevertheless, regarded the Word as being the subject of the union. ²⁹ He then concluded that there exists only one operating power that is active in the union: ‘(Christ) took the hand (of the ruler’s daughter) and, as it is written, he gave her life as God by means of his all-powerful command and, by the touch of his holy flesh, he shows that there was one kindred operation on the part of both.’ ³⁰ By emphasizing that the Word became man and, therefore, the subject of the union’s activity, he concluded to the existence of only one operation in Christ. ³¹ This is a different view from what the Antiochenes held. While they admitted one prosôpon or ‘ego’ as the common source of all of Christ’s actions, they insisted that this common activity must work through his human nature and, therefore, would act in a truly human way, though one could say that the divine was also present. So while the Antiochenes taught the presence of two operations in Christ, this must be nuanced in light of their view on ‘one prosôpon.’ This is why Nestorius wanted to state clearly that Mary is the mother of the Christ in whom the Word dwells. Nestorius may appear to be affirming two separate individuals operating in the Incarnation—as Cyril believed—but he always presumed that the Word was also playing a role in Christ’s human activity by reason of the unity existing between his natures. ³² While it is difficult to state exactly how Cyril’s understanding of the symbiotic relationship existing between Christ’s two natures and the Word’s hypostasis can relate to the Antiochenes’ analogy of Christ’s humanity being similar to the splendor emanating from the sun, Cyril does not appear to have developed what is the specific role played by Christ’s human nature. Cyril, however, does at least mention without elaboration the roles the New Testament assigns to Christ’s humanity as the head of the Body the Church, and the mediator of salvation, but he places the primary emphasis upon the Word being the operating agent at work.

The Cyrillian Tradition Concerning Prosôpon

The term prosôpon played a minimal role in Cyril’s writings. For he was preoccupied by the dilemma of how to express the Word as the subject of unity for Christ’s natures in terms of physis and hypostasis. Since prosôpon was not a central concern, Cyril uses it in his writings as signifying the visible, outward manifestation of the Word or as a vague synonym for hypostasis. This general view of prosôpon is reflected in how the Fathers at Constantinople II understood it. The Fathers at Chalcedon, however, regarded the phrase ‘one prosôpon’ as having more meaning in light of their dispute with the Eutychians. This is seen in the writings of the Patriarchs Proclus and Flavian and the Letter of Pope Leo to Flavian. In his Tome to the Armenians, written in response to the questions that some Armenians had concerning several excerpts of Theodore, Proclus, though negative toward Theodore, sought to reconcile Cyrillian and Antiochene terms by broadening the understanding of ‘hypostasis.’ ³³ Proclus sought to refine Cyril’s faith statement by altering his statement concerning ‘one incarnate physis of God the Word’ to that of ‘the one hypostasis of the incarnating Word of God.’ ³⁴ The latter denotes that the Word is the personal subject of the union, while the former stresses the unity of the natures. When Proclus tried to have the Antiochenes both accept his letter to the Armenians and condemn those extracts of Theodore that he had appended to his letter, they agreed to the first section but refused the latter. Since the Antiochenes were ready to accept his christological formula as a balanced statement of orthodox faith, this helped to lay the ground for the future compromise ‘of one prosôpon’ that was proposed at Chalcedon.

Proclus’s successor to the patriarchate was Flavian, who struggled throughout his short reign with the Eutychians. In a trial against Eutyches (ca. 380–ca. 456), Flavian affirmed his faith in the one Christ who is ‘from two natures in one hypostasis and one prosôpon.’ ³⁵ This phrasing was likely received from Proclus. Eutyches, however, cleverly twisted Flavian’s phrase ‘from two natures’ to mean that, while two natures may have existed before Christ’s Incarnation, only one has existed afterwards. To reject this interpretation as wrong, the Fathers at Chalcedon intentionally changed the phrase ‘from two natures’ to explicitly read ‘in two natures.’ Also, by revising Flavian’s formula the Fathers wanted to assert what they deemed acceptable in the Antiochian as well as Cyrillian traditions by introducing Flavian’s formula into their own. Their intent seems to have been a desire, like Proclus’s, to offer a synthesis that both sides could accept in the spirit of the ‘Formula of Reunion.’

The next major influence upon Chalcedon’s statement of faith was the Tome of Pope Leo the Great. ³⁶ At Ephesus II, his attempt to have his Tome to Flavian read was denied. The Fathers at Chalcedon, however, recognized it as offering the balanced language that they desired to express accurately the unity and the integrity of Christ’s two natures. Leo achieved this by alternating in a balanced, rhythmic way how Christ’s two natures act in different ways but are flowing from one and the same personal centre. As regards the meaning of his term for the subject of the union, the Latin persona, Leo used it as referring to Christ as the ‘person’ of unity functioning in two different ways. In this sense, persona is more exactly equivalent to Theodore’s ‘one common prosôpon’ than it is to Cyril’s hypostasis. This suggests that Leo upheld the coexistence of two complete, perfect natures subsisting in Christ, with each having its own peculiar characteristics and mode of operation. Grillmeier offers here an insightful distinction by pointing out that Pope Leo regarded the ‘person’ of Christ in a twofold way: as a principium quod (the ultimate subject of an operation) and the principium quo (the act whereby Christ as a ‘person’ is working with, in, and through his two natures). This distinction is based on the fact that, while the ‘person’ of Christ is the source that is ultimately responsible for an action, he still had to operate through or by means of his human nature. So while both the Cyrillians and the Antiochenes maintain with different emphases that Christ as God and man is the operative agent, the Cyrillians are focused on the Word as the ultimate principle of all operations. The Antiochenes, however, believed that, when Christ is acting as a man in a clearly defined way, he is operating in and through his human nature, with his divine nature, nevertheless, being present and active in the background. Such a distinction helps not merely to explain those New Testament passages, where Christ is clearly portrayed as acting in a human way, but also to indicate how Christ can have a truly operating free will. In other words, while Cyril conceived of Christ’s human nature as being hypostatically united with the Word, he regards the Word as the one who is directly and immediately acting as the principle of operation. But it is not clear how his human nature operates in this union other than in a vague way as a co-operator. In summary, the approaches of Proclus, Flavian, and Leo provided a language that attempted to effect a balance between the Cyrillian emphasis on the personal unity of Christ and the Antiochene concern to defend the full role of Christ’s humanity within this unity. These are clearly the ones that had a major impact on those at Chalcedon who agreed upon a consensus formula similar to what the ‘Formula of Reunion’ had previously achieved.

The Council of Chalcedon’s Dogmatic Statement

When the Fathers at Chalcedon gathered to express their faith conviction about Christ, they were resolved not to formulate a new declaration of faith beyond what the Councils of Nicaea and Constantinople I had already established. Their intent was to end the theological controversies over how best to express a personal unity in Christ while safeguarding the integrity of his natures. To facilitate this, they entrusted this task to a special commission of 23 bishops and special commissioners appointed by the emperor. Despite minor disputes over the meanings of a few words, the council Fathers accepted the formula that there exists ‘one and the same Christ, Son, Lord, the Only-Begotten One, to be acknowledged in two natures without confusion, without change, without division, without separation, with the difference of the natures in no way having been taken away by reason of the union, but rather with the property of each being preserved intact and [both] concurring into one prosôpon and one hypostasis and not separated or divided into two prosôpa, but one and the same Only-Begotten Son, God the Word, the Lord Jesus Christ.’ ³⁷ It is clear from the wording that the Fathers have taken their faith statement almost literally from the ‘Formula of Reunion’ and from the writings of the Patriarchs Proclus and Flavian and Pope Leo. The Fathers did alter Flavian’s ‘from two natures’ to ‘in two natures,’ in order to exclude Eutyches’s attempt to interpret ‘from’ in a strict Monophysite sense. When they included ‘one prosôpon,’ they appear to have been influenced by Flavian’s formula and especially by Pope Leo’s Tome. As indicated above, Leo emphasized a functional unity in Christ, his Latin word persona being equivalent to the Greek prosôpon. Though he may not have been aware of it, Leo was in fact presenting what this study holds to be the Antiochene understanding of the term as referring to the essential, active role Christ’s divinity and humanity play in the union. So when the Fathers add the phrase ‘in one prosôpon,’ this at least suggests a functional meaning. When they reject in their formula the possibility of two prosôpa in Christ’s hypostasis, they are insisting that Christ does not have two separate centers of operation: that is, Christ was merely a title designating two separate, independent persons. In point of fact, the Antiochenes hold for only one common prosôpon that can act in two different ways but always as a unity.

The Fathers at Chalcedon believed that their formula conformed to the New Testament and the ecclesiastical tradition about the Word’s incarnation. When they gave their blessing to ‘in one prosôpon’ in their formula, they meant this as a response to Eutyches’s understanding of hypostasis as expressing Christ’s one ‘nature’ after the Incarnation. They added, therefore, ‘in one prosôpon’ to bring out clearly that Christ’s individualized natures were actively present after the Incarnation. They were not asserting this explicitly in the sense that Theodore explained the phrase in his writings, but as proposed by Proclus, Flavian, and Leo, who recognized what was authentic in the Antiochene tradition. But it is important to note that the Fathers at Chalcedon made no concerted effort to define their major terms in a strict way. Nor did they analyze their relationship to one another other than that they distinguished physis, hypostasis, and prosôpon as being somehow different from each other. Nor did they enter into the question of whether there exist one or two operations in Christ. The significant point, however, is that they spoke about the unity of Christ’s natures occurring ‘in one prosôpon and one hypostasis’ as complementary to one another.

The Period Between Chalcedon and Constantinople

After the Council of Chalcedon, many opponents, broadly included under the title ‘non-Chalcedonians,’ began to attack the Chalcedon’s formula of faith. They believed that it reflected the council’s infiltration by Nestorian influences, especially when it refers to the union of Christ’s natures as taking place ‘in one prosôpon’ as well as ‘in one hypostasis.’ For them, prosôpon characterized Theodore’s and Nestorius’s Christology. To defend Chalcedon as a true ecumenical council, the emperor Justinian (483–565) followed the advice of Theodore Askidas (bishop 536–ca. 558) and condemned Theodore, Theodoret, and the ‘so-called letter of Ibas’ by an imperial edict and letter. ³⁸ He was convinced that he could thereby win over the moderate Monophysite Patriarch Severus (512–18) to a reconciliation by showing that the Chalcedonians did not favor these ‘heretics.’ His efforts ultimately failed.

Before the faith formula of Constantinople II is discussed, there is a need to consider an effort to clarify and expand upon the meaning of the term hypostasis. For the Chalcedonian faith formula raised a serious theological issue. For if each of Christ’s two natures is distinct and real in Chalcedon’s formula, this implies that each has its own hypostasis. This would mean that there are two hypostaseis in Christ and, therefore, two ‘persons.’ To respond to this dilemma, the monks Leontius of Byzantium (ca. 485–ca. 543) and Leontius of Jerusalem proposed an intimate connection between hypostasis and enhypostasis (subsisting in the hypostasis; insubstantia in Latin). ³⁹ In this view, the word hypostasis is understood as signifying both the Word as the subject of unity in Christ, and also his act of giving existence to Christ’s human nature. Enhypostasis then expresses this life-giving act. According to this view, the Word’s hypostasis creates a spiritually ensouled human nature for himself for the purpose of being its hypostasis and to exist humanly in it as its hypostasis. In other words, hypostasis denotes the ‘person’ of the Word as the life-giving subject of unity who provides the existence needed for the human nature of Christ to exist and to act. So conceived, the assumed human nature of Christ can be said to exist only by its ‘inexisting’ or subsisting in the Word’s own hypostasis. So conceived, the assumed human nature of Christ can be said to exist only by its ‘inexisting’ or subsisting in the Word’s own hypostasis. The adherents of this view believe that this distinction explains how the human as well as the divine nature can be real, complete, and individualized physeis within the one hypostasis of the Word.

While the enhypostasis approach provides a reasonable explanation of why Christ can be said to have only one hypostasis and a human will that is free, it is vague as to how there is a unity of wills and operations in Christ. Specifically how do Christ’s natures relate to each other in regard to how his humanity shares in the Word’s knowledge and is able to avoid temptations? Moreover, if the Word’s life-giving power vivifies Christ’s human nature and enables all of Christ’s individual human properties to be actualized and participate in the exercise of divine power, is the Word’s life-giving power the same as his operating power? If they are different, how so? There is also a further dilemma: while one may argue that the Word’s life-giving power can sustain Jesus’ spiritual rational soul, since it is eternal by its very nature, how does it activate Christ’s mortal and passable body? It would seem to make Christ’s body immortal, as those espousing the doctrine of aphtharsia (the incorruptibility of Christ’s human body) assert. ⁴⁰ It does seem logical to conclude that Christ’s body should be completely incorruptible. This is, of course, difficult, if not impossible, to reconcile with the Gospel witnesses.

Constantinople II’s Interpretation of ‘One Prosôpon’ and ‘One Hypostasis’

One can gain insight into how the Fathers at Constantinople II understood the terms physis, hypostasis, and prosôpon by examining the wording of their faith formula and their canonical condemnations of Theodore of Mopsuestia. While holding Cyril in great esteem and upholding his stress on the unity in Christ, they followed Chalcedon’s lead in distinguishing the concepts of hypostasis and physis. They regarded physis in its generic sense as what constitutes a reality to be itself and not another, with perhaps a suggestion of Cyril’s dynamic sense of how Christ’s two natures are united symbiotically. But in regard to the term hypostasis, the Fathers at Chalcedon viewed it in practice as signifying the existing subject of unity or ‘person’ and, thus, as asserting something more than a nature. The Fathers at Constantinople, however, took the term in its enriched sense as being the existing ‘person’ of the Word, whose life-giving power enables his human nature to subsist in his own hypostasis, as expressed in the Latin saying ‘synthesis in hypostasi et secundum hypostasim (a synthesis achieved in the person and according to the person).’ In regard to hypostasis’s relationship to prosôpon, the Fathers at Constantinople considered these terms to be synonymous when they declare that Chalcedon’s clause that Christ’s two natures are ‘coinciding in one prosôpon and in one hypostasis’ means: ‘the Word of God is truly united to His flesh hypostatically—it is in this sense that the one hypostasis or the one prosôpon is one. For this is how the holy Synod at Chalcedon has professed the one hypostasis of our Lord Jesus Christ.’ ⁴¹

The Fathers at Constantinople, therefore, understood hypostasis in a concrete, historical sense as the personal union in which Christ’s two natures are subsisting by means of the Word’s hypostasis. They regarded prosôpon as simply denoting the outward manifestation of this hypostatic unity. As regards the relationship existing between Christ’s human nature and his hypostasis/prosôpon, they considered it to be truly symbiotically united to his ‘person,’ but distinguishable in thought. So understood, they believed that it was unnecessary to cite explicitly the functional unity of the natures in their formula of faith as Proclus, Flavian, Leo, and the Fathers at Chalcedon did by adding ‘in one prosôpon.’ Because of their desire to win over the moderate non-Chalcedonians, the Fathers at Constantinople could not have included a phrase that could be easily misinterpreted as an acceptance of the Antiochene way of affirming the unity in Christ. As the Chalcedonians did earlier, the Fathers at Constantinople left open the question of whether or not there exist one or two operations in Christ, and how he can know and freely act as a man, so as to fulfill his role in God’s plan of salvation.

One can obtain further insight into how the Fathers at Constantinople understood nature, hypostasis, and prosôpon from their canonical rejections of all Theodore’s works and person. Grillmeier highlights the critical problem involved in these condemnations when he observes: ‘One will immediately recognize that … the critical examination and judgment of these documents still demand an extraordinarily great expenditure of time and energy.’ ⁴² In other words, the Fathers at Constantinople made no real effort to understand what Theodore meant by his terms or to situate his comments in their historical context and theological framework. This is evident by the fact that they condemned Theodore almost immediately after hearing 71 excerpts taken from his works. ⁴³ This reading was interrupted at least twice by loud outbursts, denouncing the passages as impious. ⁴⁴ Nor did Justinian permit those favorable to Theodore the opportunity to defend his statements. Instead under pressure from Justinian, the Fathers evaluated Theodore’s writings in light of their own christological understanding of the terms hypostasis, physis, and prosôpon. They accepted the term hypostasis in its enhypostasis sense; that is, as expressing the ‘person’ of the unity who supplied subsistence to Christ’s human nature, so that Christ had but one hypostasis. Because they recognized a real distinction between hypostasis and nature, they were able to attack Theodore for holding two hypostaseis in Christ, which for them meant he was asserting two separate ‘persons.’ Theodore, however, understood ‘two hypostaseis in Christ’ to mean that each of Christ’s two natures was actually existing.

In summary, it seems that the Fathers at Chalcedon in their opposition to the Eutychians also wanted to fashion a faith formula, as the ‘Formula of Reunion’ did earlier, that would win over the Antiochenes, while rejecting Eutychianism. The Fathers at Constantinople, however, sought to win over the moderate Monophysites, who believed that the Fathers at Chalcedon had gone too far in accommodating the Antiochenes. While the faith statements of both councils can be reconciled with each other, at least as regards there being a significant difference in meaning between nature and hypostasis, they notably differ over how much to stress the functional unity of Christ’s natures. They especially part company over the role that the word prosôpon ought to play in their faith formulas. For Chalcedon, it signifies a functional unity in which each of Christ’s two natures act in accordance with its own nature. For the other, the term prosôpon was simply a revelatory term used to express the visible ways that an individual hypostasis or ‘person’ manifests oneself. Therefore, when the Fathers at the Council of Constantinople learned that Theodore of Mopsuestia taught that Christ had two prosôpa, they took this to mean that he understood his ‘Christ’ to be a moral unity of two separate independent ‘persons.’ The Fathers at Constantinople were evidently interpreting Theodore’s language within their own framework and do not seem to have had an inkling as to what he really meant when he spoke of Christ having two prosôpa united in one common prosôpon.

Ramifications

The Fathers at Chalcedon and Constantinople composed their faith statements in different historical settings from each other. These differences exerted a significant impact upon what the Fathers sought to convey in their formulas. The Fathers at Chalcedon were primarily interested in rejecting Eutychianism and, to an extent, in reconciling the Antiochenes by adding the phrase ‘one prosôpon’ to their formula. The Fathers at Constantinople, however, strongly pressured by the emperor Justinian, were seeking to forge a faith reconciliation with moderate Monophysites by defining the term hypostasis in such a well-crafted way that Christ’s human nature is being sustained in its existence by the Word’s hypostasis. While Justinian’s efforts to win over the Monophysites ended in complete failure, Constantinople’s Christological stress on Christ’s divinity became prevalent among the orthodox churches. For church officials and theologians have over the past centuries promoted this formula as the true approved one. Karl Rahner, while affirming this formula as orthodox, pointed out in his article ‘Current Problems in Christology’ that it is not the last word ‘but also our beginning.’ ⁴⁵ He believed that the present articulation of the formula does not specifically address the fundamental issue of how Christ as man freely acts as the redeeming mediator for all creation. Rahner also recognized the present-day desire of many to reunite christological Dogma with ‘a theological phenomenology of an “incarnational” piety, valid now and always, [that] would … have significance for the doctrine of the spiritual life.’ ⁴⁶ This was, in fact, the outlook practised in the first centuries. The early church showed herself open to different approaches and to the need to provoke lived experiences of the risen Christ. For instance, they insisted against those seeking to fashion one Gospel that there exist four valid accounts of Christ’s life, each orthodox in its own way. The Synoptics portray Jesus Christ as acting as one in human and divine ways, with the emphasis on Christ as a man. John, on the other hand, complements this approach by stressing the divinity of Jesus. Similarly different approaches are highlighted in the Antiochenes and the Cyrillian emphases upon Christ as man and God. The attempts, however, to successfully balance these in an orthodox synthesis, proved elusive because of the varied understanding of basic christological terms. The Fathers at the Council of Chalcedon sought to attain this balance by including in their formula what they believed to be authentic in both of these antagonistic approaches. Something similar can be said as to how the Second and Third Councils of Constantinople complement one another. Because Constantinople II’s formula did not address how Christ’s human nature fully functions in its unity within the Word’s hypostasis, this led over time to the development of the theory of Monotheletism (Christ had but one will). The Third Council of Constantinople (680–81) answered this by defining that Christ really possesses two wills and two operations. ⁴⁷ This was deemed necessary to preserve the essential mediating role that Christ’s free human will serves in God’s redemptive plan for salvation.

Admittedly the Fathers at Chalcedon did not enter into the question of what they were actually intending by introducing the phrase ‘in one prosôpon’ into their formula. They seem to be insisting that there does exist a functional unity operating between Christ’s two natures. They were concerned to counteract a tendency to overstress the Word’s divinity to the detriment of the valid role that Christ’s humanity plays in salvation. For the New Testament witnesses to how Christ as man has a unique, necessary, central task in this endeavor by his life and death. Without denying the multiple efforts and achievements of the traditional dogmatic Christology, a return to Chalcedon’s emphasis upon balancing a substantial Christology with a functional one may be a helpful and needed way today to reunite dogmatic Christology with its Spirituality counterpart. This could be obtained by putting greater stress upon developing the central mediating roles that Christ’s humanity plays in salvation: as the true image of God; as the head of his Body, the Church; as really present in the sacraments; as the preacher of God’s Kingdom; and as the Lord of History. Teresa of Avila came to a realization of the importance of Christ’s humanity in knowing God from her own mystical prayer experiences. I see no better way to end this article than to cite Teresa’s own words: ‘I can see clearly, and since that time have always seen, that it is God’s will, if we are to please Him, and He is to grant us great favors, that this should be done through His most sacred Humanity in whom His majesty said, He is well pleased.’ ⁴⁸