Appendix D

The Ecumenical Councils' Christological Definitions — A Quick Reference

Introduction

The seven ecumenical councils of the early church — spanning from the first gathering at Nicaea in 325 to the second gathering at Nicaea in 787 — represent the most authoritative and broadly received doctrinal achievements in Christian history. Catholics, Eastern Orthodox, and the vast majority of Protestants regard their Christological teachings as definitive statements of biblical truth. As Timothy Pawl observes, these seven councils are "held as binding by both Catholic and Orthodox Christians," and very many Protestants also "consider some subset of these councils as binding, in some sense."¹ Herbert Relton rightly notes that in these conciliar definitions "we find preserved the finest results attained by the most acute intellects of the past," results that are "not lightly to be estimated nor hastily to be set aside as outworn dogma."²

This appendix presents, in a single convenient reference, the key Christological definitions and anathemas from each of the seven ecumenical councils. For each council, we provide: (1) the date and location; (2) the heresy or controversy being addressed; (3) the key definition, creed, or anathema, including original Greek terminology where available with English translation; and (4) the significance of each conciliar statement for the central argument of this book — that orthodox Christology requires Christ to possess a complete human nature consisting of both a rational soul and a body, and that physicalism about human nature contradicts these definitions.

A note on sources: the conciliar texts referenced throughout this appendix are drawn primarily from Norman Tanner's authoritative collection, Decrees of the Ecumenical Councils, supplemented by the standard patristic collections (NPNF, Denzinger) and the analyses of major scholars including Aloys Grillmeier, J. N. D. Kelly, Timothy Pawl, and Oliver Crisp.³

I. The First Council of Nicaea (325)

Date and Location

The First Council of Nicaea convened in the summer of 325 in Nicaea (modern-day İznik, Turkey), in the province of Bithynia. It was summoned by the Emperor Constantine and attended by approximately 318 bishops, making it the first empire-wide gathering of Christian bishops in history. Though the exact number of attendees is debated, the figure of 318 became traditional in subsequent centuries, echoing the 318 servants of Abraham in Genesis 14:14.⁴

Heresy Addressed

The primary target of Nicaea was Arianism — the teaching of Arius of Alexandria (c. 256–336) that the Son of God is a created being, the first and greatest of all creatures, but not truly and eternally God. Arius taught that "there was a time when the Son was not" (ἦν ποτε ὅτε οὐκ ἦν, ēn pote hote ouk ēn). On this view, the Son is not homoousios (ὁμοούσιος, "of the same substance") with the Father but rather heteroousios (ἑτεροούσιος, "of a different substance") — a creature, however exalted, rather than the eternal Creator. The key figures in the controversy were Arius himself, his bishop Alexander of Alexandria, and Alexander's brilliant young deacon Athanasius, who would become the great champion of Nicene orthodoxy for decades after the council.⁵

The Key Definition: The Nicene Creed (325)

The council produced the original Nicene Creed, the first universally binding creedal statement of the Christian faith. The creed's Christological core reads as follows:

We believe in one Lord Jesus Christ, the Son of God, begotten from the Father, only-begotten (μονογενής, monogenēs), that is, from the substance of the Father (ἐκ τῆς οὐσίας τοῦ Πατρός, ek tēs ousias tou Patros), God from God, Light from Light, true God from true God, begotten not made, of one substance with the Father (ὁμοούσιον τῷ Πατρί, homoousion tō Patri), through whom all things came into being, things in heaven and things on earth, who because of us human beings and because of our salvation came down and became incarnate (σαρκωθέντα, sarkōthenta), became human (ἐνανθρωπήσαντα, enanthrōpēsanta), suffered and rose again on the third day, ascended to the heavens, and will come to judge the living and the dead.⁶

The creed then appended a series of anathemas directed against Arian slogans:

But as for those who say, "There was when he was not," and "Before being born he was not," and that "he came into existence out of nothing," or who assert that the Son of God is of a different substance (ἐξ ἑτέρας ὑποστάσεως ἢ οὐσίας, ex heteras hypostaseōs ē ousias) or is subject to alteration or change — these the catholic and apostolic church anathematizes.⁷

Two words in the creed deserve special attention. The term sarkōthenta (σαρκωθέντα, "became incarnate" or literally "was enfleshed") affirms that the Son took on human flesh — He entered into material, bodily existence. The term enanthrōpēsanta (ἐνανθρωπήσαντα, "became human") goes further: the Son did not merely take on a body; He became a full human being. The distinction between these two terms matters enormously. "Becoming incarnate" could theoretically refer to assuming a body alone, but "becoming human" implies assuming a complete human nature — everything that makes one genuinely human. As Grillmeier notes, the Nicene framework served as the deliberate starting point for the later Chalcedonian Definition, which would make the content of that complete human nature explicit.⁸

Significance for the Book's Argument

Nicaea's primary contribution is the definitive establishment of Christ's full deity. If the Son is truly homoousios with the Father — if He is not a creature but the eternal, uncreated God — then the Incarnation is the union of the infinite divine nature with a finite human nature. This raises the stakes for the question of what that human nature includes. If God Himself became human, then the human nature He assumed must be complete. If it were incomplete — if Christ lacked any essential component of humanity — then God did not truly become one of us. Nicaea does not yet specify the composition of Christ's human nature in detail (that will come at later councils), but by affirming Christ's full deity, it establishes the theological framework within which the question of His full humanity becomes both urgent and non-negotiable.

For the argument of this book, Nicaea establishes the first crucial premise: the Person who became incarnate is the eternal, divine Son — not a creature, not a lesser being, but God Himself. The Incarnation is therefore not the indwelling of a creature in a human body but the personal union of the divine nature with a human nature. What that human nature includes — whether it is merely a physical body or a body-soul composite — becomes the decisive question for the councils that follow.

II. The First Council of Constantinople (381)

Date and Location

The First Council of Constantinople met from May to July 381, in the imperial capital of Constantinople (modern Istanbul, Turkey). It was convened by Emperor Theodosius I and attended by approximately 150 bishops, all from the Eastern church. Though initially a regional council, its decisions were subsequently recognized as ecumenically authoritative, particularly by the Council of Chalcedon in 451.⁹

Heresies Addressed

Constantinople I addressed three heresies. First, it reaffirmed the Nicene condemnation of Arianism in all its forms, including the semi-Arian position that the Son is homoiousios (ὁμοιούσιος, "of similar substance") rather than homoousios ("of the same substance") with the Father. Second, it addressed the Pneumatomachians (also called Macedonians), who denied the full deity of the Holy Spirit, affirming instead that the Spirit is a creature or a subordinate being. Third, and most relevant for our purposes, Constantinople I formally condemned Apollinarianism — the teaching of Apollinarius of Laodicea (c. 310–390) that the divine Logos replaced the human rational soul (nous, νοῦς) in Christ, so that Christ possessed a human body but not a human mind or rational soul.¹⁰

The Key Definition: The Niceno-Constantinopolitan Creed

Constantinople I produced the expanded form of the Nicene Creed that is recited in churches to this day — what is commonly (if somewhat inaccurately) called "the Nicene Creed." Its Christological section reads:

We believe in one Lord Jesus Christ, the only-begotten Son of God, begotten of the Father before all ages, Light of Light, true God of true God, begotten not made, of one substance with the Father (ὁμοούσιον τῷ Πατρί, homoousion tō Patri), through whom all things were made; who for us human beings and for our salvation came down from heaven and was incarnate of the Holy Spirit and the Virgin Mary and became human (ἐνανθρωπήσαντα, enanthrōpēsanta), and was crucified for us under Pontius Pilate, and suffered and was buried, and rose on the third day according to the Scriptures, and ascended into heaven, and sits at the right hand of the Father, and will come again with glory to judge the living and the dead, whose kingdom shall have no end.¹²

The creed retains the critical term enanthrōpēsanta — "became human" — and adds important narrative detail about the circumstances of the Incarnation: "incarnate of the Holy Spirit and the Virgin Mary." This grounds the Incarnation in historical reality. The Son did not appear as a phantom or take on the mere appearance of humanity. He was conceived in the womb of a real woman by the power of the Holy Spirit. He became genuinely, fully, completely human.

The Condemnation of Apollinarianism

The council's canons include the condemnation of various heresies. Canon 1 anathematizes "every heresy," and the council's synodical letter explicitly names and condemns the "Apollinarians" among the heretical groups. The Code of Theodosius (16.1.2 and 16.5.6.2), issued in connection with the council, gave civil enforcement to these condemnations, including the condemnation of Apollinarianism.¹³ The condemnation had been building through earlier synods — the Synod of Alexandria (362) under Athanasius's leadership, Pope Damasus's condemnation in 377, and the Roman Council of the same year — but Constantinople I gave it the fullest ecumenical authority.

Significance for the Book's Argument

Constantinople I is the council that formally and ecumenically condemned the denial of Christ's human rational soul. Apollinarius denied that Christ has a human nous — a human rational mind or soul. The council said this view is heresy. This is of enormous significance for our argument because physicalism about human nature produces the same Christological result. Whether one denies the rational soul in Christ specifically (as Apollinarius did) or in all human beings universally (as physicalists do), the outcome is identical: Christ lacks an immaterial rational soul. The councils condemned the first position. The second position falls under the same condemnation — not because physicalists intend to be Apollinarian (they do not), but because the Christological consequence is structurally the same.¹⁴

As Michael Wilkinson argues, the Apollinarian Christ has "only a divine life" — a being whose inner rational capacities are entirely divine, not genuinely human. Such a Christ "can neither feel nor meet the deepest and distinctly human need of salvation."¹⁵ The church recognized this and acted decisively. Constantinople I draws a line in the theological sand: any Christology that eliminates Christ's human rational soul stands outside the bounds of orthodoxy.

III. The Council of Ephesus (431)

Date and Location

The Council of Ephesus convened on June 22, 431, in the Church of the Virgin Mary in Ephesus (in modern western Turkey). It was called by Emperor Theodosius II in response to the bitter dispute between Nestorius, Patriarch of Constantinople, and Cyril, Patriarch of Alexandria. The council was marked by intense ecclesiastical politics — Cyril opened proceedings before the arrival of the Antiochene delegation sympathetic to Nestorius, leading to rival sessions and mutual excommunications. Nevertheless, the council's theological decisions were ultimately received as ecumenically authoritative.¹⁶

Heresy Addressed

The council addressed what was perceived as Nestorianism — the view attributed to Nestorius that Christ is not one person but effectively two persons, a divine person and a human person, loosely joined together in a moral or relational union (a synapheia, συνάφεια, or "conjunction") rather than a genuine personal or hypostatic union. Whether Nestorius himself actually held this view in its most extreme form is debated by modern scholars, but the view as the council understood and condemned it involved the division of Christ into "two sons" — the divine Son of God and a separate human son of Mary.¹⁷

The practical test case was the title Theotokos (Θεοτόκος, "God-bearer" or "Mother of God") for the Virgin Mary. Nestorius objected to this title, preferring Christotokos (Χριστοτόκος, "Christ-bearer"), on the grounds that Mary bore the human nature of Christ, not His divine nature. But the council judged that refusing the title Theotokos implied a division in Christ's person: if Mary is not the "God-bearer," then the one she bore is not God — or at least, the one she bore is not the same person as the divine Son. The title Theotokos is not a statement about the origin of the divine nature (no one claims Mary created God) but about the unity of Christ's person: the person Mary bore is the divine Son, and therefore Mary is rightly called the Mother of God.¹⁸

The Key Definition

The council's primary doctrinal achievement was the formal endorsement of Cyril of Alexandria's Second Letter to Nestorius, which became the authoritative statement of the council's Christological teaching. Cyril wrote:

We do not say that the nature of the Word was changed and became flesh, or that it was converted into a whole man consisting of soul and body (ὅλον ἄνθρωπον ἐκ ψυχῆς καὶ σώματος, holon anthrōpon ek psychēs kai sōmatos); but rather that the Word, having personally united to Himself flesh animated by a rational soul (σάρκα ἐψυχωμένην ψυχῇ λογικῇ, sarka epsychōmenēn psychē logikē), became man in an ineffable and incomprehensible way and was called the Son of Man.¹⁹

Notice the precision of Cyril's language. He explicitly identifies what the Word assumed: "flesh animated by a rational soul" (sarka epsychōmenēn psychē logikē). This is not a casual phrase. It is a deliberate anti-Apollinarian affirmation that the human nature Christ assumed is not mere flesh but flesh enlivened by a rational soul. The Word did not simply take on a body. He united to Himself a complete human nature — body and rational soul together.

Cyril's letter also makes clear that the union is personal, not merely moral or relational:

The union is not as though the Word merely dwelt in a man born of the holy Virgin... Rather, the natures which are brought together in a true union are different, but from both is one Christ and one Son — not as though the difference of the natures is eliminated by the union, but rather the divinity and the humanity, by their ineffable and inexpressible coming together into unity, have produced for us the one Lord and Christ and Son.²⁰

The council also approved Cyril's Twelve Anathemas against Nestorius, though the exact status of these anathemas at Ephesus itself is debated by scholars. Richard Price notes that by the middle of the sixth century, Cyril's Third Letter (which contained the anathemas) "was presumed to be one of the 'conciliar' letters connected to Ephesus I and acclaimed by Chalcedon."²¹ Emperor Justinian, writing in his defense of the Second Council of Constantinople, explicitly cited Cyril's Twelve Anathemas as endorsed by both Ephesus and Chalcedon.²²

Significance for the Book's Argument

Ephesus contributes two vital elements to our case. First, it reinforces the affirmation that Christ's human nature includes a rational soul — Cyril's formula "flesh animated by a rational soul" is explicit and unambiguous. Second, by affirming the personal unity of Christ against Nestorian division, Ephesus establishes that the one Person of the Son genuinely possesses both natures. He does not merely dwell in a human being; He is a human being — fully, completely, with a rational soul as well as a body. On physicalism, a "complete human nature" is just a physical body with a functioning brain. But Cyril defines it as body plus rational soul, and the council endorsed his definition. Physicalism contradicts the Christological understanding that Ephesus formally endorsed.

IV. The Council of Chalcedon (451)

Date and Location

The Council of Chalcedon met from October 8 to November 1, 451, in the Church of St. Euphemia in Chalcedon (modern Kadıköy, a district of Istanbul, Turkey), directly across the Bosporus from Constantinople. It was convened by Emperor Marcian and Empress Pulcheria. According to various reports, somewhere between 520 and 630 bishops attended, making it the largest gathering of bishops in the ancient church up to that time.²³ As Aloys Grillmeier observes, "Here, as in almost no other formula from the early councils, all the important centres of church life and all the trends of contemporary theology, Rome, Alexandria, Constantinople and Antioch, have contributed towards the framing of a common expression of faith."²⁴

Heresy Addressed

Chalcedon addressed the opposite extreme from Nestorianism: Eutychianism, or extreme Monophysitism. Eutyches, an elderly monk in Constantinople, taught that after the Incarnation, Christ has only one nature (mia physis, μία φύσις) — a hybrid or blend of divinity and humanity in which the human nature is effectively absorbed into or swallowed up by the divine. Where Nestorius was perceived as dividing Christ into two persons, Eutyches was seen as collapsing Christ's two natures into one, destroying the genuine humanity of Christ in a different way. The council needed to chart a middle course: one person, but two distinct and unconfused natures.²⁵

The council drew on four principal source documents: the Creed of Nicaea (325), the Niceno-Constantinopolitan Creed (381), Cyril of Alexandria's Second Letter to Nestorius (endorsed at Ephesus), and Pope Leo the Great's Tome (the letter to Flavian of Constantinople). As Bronwen Neil writes, Leo's Tome "became the touchstone of Chalcedonian Orthodoxy."²⁶ J. N. D. Kelly notes that these documents together formed the basis on which the council's defining formula was constructed.²⁷

The Key Definition: The Chalcedonian Definition (451)

The Chalcedonian Definition is the single most important Christological statement in the history of the church. It reads in its central portion:

Following, then, the holy Fathers, we all with one voice teach that it is to be confessed that our Lord Jesus Christ is one and the same Son, the same perfect in Godhead and the same perfect in manhood (τέλειον τὸν αὐτὸν ἐν θεότητι καὶ τέλειον τὸν αὐτὸν ἐν ἀνθρωπότητι, teleion ton auton en theotēti kai teleion ton auton en anthrōpotēti), truly God and truly man (alēthōs theon kai alēthōs anthrōpon), the same of a rational soul and a body (ἐκ ψυχῆς λογικῆς καὶ σώματος, ek psychēs logikēs kai sōmatos), of one substance with the Father as regards his Godhead (ὁμοούσιον τῷ Πατρί κατὰ τὴν θεότητα, homoousion tō Patri kata tēn theotēta), and the same of one substance with us as regards his manhood (ὁμοούσιον ἡμῖν κατὰ τὴν ἀνθρωπότητα, homoousion hēmin kata tēn anthrōpotēta), like us in all things apart from sin.²⁸

The Definition continues with the four famous negative adverbs that define the boundaries of the union:

...acknowledged in two natures, without confusion (ἀσυγχύτως, asynchytōs), without change (ἀτρέπτως, atreptōs), without division (ἀδιαιρέτως, adiairetōs), without separation (ἀχωρίστως, achōristōs); the distinction of the natures being in no way abolished by the union, but rather the characteristic property of each nature being preserved and coming together into one person (πρόσωπον, prosōpon) and one subsistence (ὑπόστασιν, hypostasin), not parted or divided into two persons, but one and the same Son, Only-begotten, God, Word, Lord Jesus Christ.²⁹

Let us examine the four negative adverbs in turn, as each has implications for our argument:

Without confusion (asynchytōs, ἀσυγχύτως): The two natures do not blend into a hybrid "third thing." The divine nature remains fully divine; the human nature remains fully human. This means the human nature retains all its essential properties — and if a rational soul is an essential component of human nature (as the Definition itself says), then Christ's human nature retains its rational soul. It is not absorbed, replaced, or overridden by the divine nature.

Without change (atreptōs, ἀτρέπτως): Neither nature is altered or transformed by the union. The divine nature does not cease to be divine, and the human nature does not cease to be human. The human nature is not elevated into something other than human nature. It remains genuinely, fully, recognizably human — with a rational soul.

Without division (adiairetōs, ἀδιαιρέτως): The two natures are not separated into two persons. There is one Christ, not two. This guards against Nestorianism. The natures are distinct but not divided.

Without separation (achōristōs, ἀχωρίστως): The natures cannot be pulled apart — they are permanently, inseparably united in the one person of the Son. This is critical for the triduum mortis argument developed in Chapters 21–22 of this book. If the natures cannot be separated, then even at death, the hypostatic union must persist in some form. On dualism, the Son remains united to both the body (in the tomb) and the soul (in the realm of the dead) during the three days between death and resurrection. On physicalism, with no soul to sustain the union, the hypostatic union appears to dissolve entirely at the cross — a devastating problem.³¹

The Definition also affirms a double homoousios — Christ is "of one substance with the Father as regards his Godhead" and "of one substance with us as regards his manhood." This dual consubstantiality means that whatever belongs to the essence of human nature belongs to Christ's human nature. If a rational soul is essential to being human (as the Definition explicitly states), then Christ is consubstantial with us in having a rational soul. Gerald Bray notes that the Definition uses prosōpon "not as the conjunction (synapheia) of two natures but as 'person' in the Roman way. This made the word equivalent to hypostasis," which was used in the East to distinguish the divine persons from each other.³²

Significance for the Book's Argument

Chalcedon is the keystone of the entire argument of this book. Its Definition explicitly identifies the components of Christ's human nature — a rational soul and a body — and insists that this complete human nature is preserved without confusion, change, division, or separation in union with the divine nature in the one Person of the Son. Every element of this Definition creates problems for physicalism. The explicit mention of the "rational soul" contradicts physicalism's denial of the soul. The "without separation" clause creates the triduum mortis problem that physicalism cannot solve. The double homoousios means Christ shares our human nature — and if our human nature essentially includes a rational soul, so does His. As Oliver Crisp argues forcefully, "any view that holds there to be no soul there, or holds the soul to be the Second Person is a view inconsistent with Conciliar Christology."³³

V. The Second Council of Constantinople (553)

Date and Location

The Second Council of Constantinople (the Fifth Ecumenical Council) met from May 5 to June 2, 553, in Constantinople. It was convened by Emperor Justinian I, who played an unusually active and direct role in theological matters. The council was attended by approximately 165 bishops, predominantly from the East. Pope Vigilius, though present in Constantinople at the time, initially refused to participate, though he later accepted the council's decisions.³⁴

Controversy Addressed: The Three Chapters

The council addressed the so-called "Three Chapters" controversy — a complex dispute involving the posthumous condemnation of three theologians and their writings: Theodore of Mopsuestia, certain writings of Theodoret of Cyrrhus, and a letter of Ibas of Edessa. All three were perceived as tending toward Nestorian sympathies. The condemnation was motivated by Justinian's desire to reconcile the non-Chalcedonian churches (the Monophysites), who viewed Chalcedon as too sympathetic to Nestorianism. By condemning these suspected Nestorian-leaning figures, Justinian hoped to demonstrate that Chalcedon could be understood in a way compatible with Cyril's Christology.³⁵

But Constantinople II did far more than just condemn the Three Chapters. It produced fourteen detailed anathemas that provide the most philosophically precise Christological statements of any ecumenical council. These anathemas clarify the relationship between Chalcedon and Cyril, reinforce the personal unity of Christ, and — critically for our purposes — contain the most explicit conciliar statement about Christ's human rational soul.

The Key Definitions: The Fourteen Anathemas

Several of the fourteen anathemas are directly relevant to our argument. The most important is the fourth anathema:

Anathema 4: If anyone does not confess that the union of the Word of God with human flesh which is possessed by a rational and intellectual soul (σαρκὶ ἐμψύχῳ ψυχῇ λογικῇ τε καὶ νοερᾷ, sarki empsychō psychē logikē te kai noera) took place by way of composition, or, what is the same thing, by way of hypostasis [personal union] — and therefore that there is only one hypostasis, which is our Lord Jesus Christ, one of the Trinity — let him be anathema.³⁶

This anathema is remarkably precise. It specifies that the flesh the Word assumed is not mere physical matter but flesh "possessed by a rational and intellectual soul" (psychē logikē te kai noera). The use of both logikē (rational) and noera (intellectual) is deliberate — it emphasizes that the soul in question is not merely an animating life-principle (the lower psychē that even animals possess) but a rational, thinking, intellectual soul — precisely the component that Apollinarius denied in Christ. And the anathema pronounces the curse of excommunication on anyone who refuses to confess this.

As Pawl notes, this fourth anathema of Constantinople II makes it "difficult to see how, given the teachings of Conciliar Christology, one could make sense of the Word playing the role of Christ's soul, as some people contend." The view that the Word replaces the soul — the Apollinarian view — "is condemned multiple times over in the seven councils."³⁷

Other relevant anathemas include:

Anathema 3: If anyone says that the wonder-working Word of God is one and the Christ who suffered is another, or says that God the Word was together with the Christ who was born of a woman, or was in him as one in another, and does not confess that our Lord Jesus Christ is one and the same — the Word of God incarnate and made man, and that the wonders and the suffering which he voluntarily endured in the flesh belong to the same person — let him be anathema.³⁸

Anathema 5: If anyone understands the one subsistence (hypostasis) of our Lord Jesus Christ in such a way that it means the conjunction of several subsistences, and if he thus attempts to introduce into the mystery of Christ two subsistences or two persons, and if, having introduced two persons, he speaks of one person only in respect of dignity, honor, or adoration, as Theodore and Nestorius have insanely written — let him be anathema.³⁹

Significance for the Book's Argument

Constantinople II provides the strongest single conciliar text for the argument of this book. Its fourth anathema leaves no room for ambiguity: Christ's human nature includes a "rational and intellectual soul," and anyone who denies this is anathematized. This is not directed at physicalism specifically — the council was dealing with lingering Nestorian and Apollinarian tendencies — but the principle it establishes is devastating for physicalism. If a rational soul is a formally defined, anathema-protected component of Christ's human nature, then any anthropology that denies the existence of rational souls contradicts the conciliar definition. Physicalism does precisely this. The fact that physicalists deny the soul universally rather than in Christ specifically does not help — the result is the same: Christ has no rational soul. And that result is what the council condemned.⁴⁰

VI. The Third Council of Constantinople (680–681)

Date and Location

The Third Council of Constantinople (the Sixth Ecumenical Council) met in eighteen sessions from November 7, 680, to September 16, 681, in the domed hall (trullus) of the imperial palace in Constantinople. It was convened by Emperor Constantine IV. The council referenced approximately 630 bishops at Chalcedon and was itself attended by a significant number of bishops from both East and West, including papal legates who played a prominent role in the proceedings.⁴¹

Heresy Addressed: Monothelitism

The council addressed monothelitism — the teaching that Christ has only one will (μόνον θέλημα, monon thelēma), namely the divine will. Monothelitism arose in the early seventh century as a political compromise designed to reconcile Chalcedonian Christians with the Monophysites. If Christ has only one nature (as the Monophysites claimed), He presumably has only one will. Emperor Heraclius and Patriarch Sergius of Constantinople proposed that even if Christ has two natures (as Chalcedon taught), He operates with a single "theandric" (divine-human) energy and a single will. This formula was intended to be conciliatory but was theologically devastating. If Christ has no genuinely human will, He has no genuinely human moral agency — He cannot freely choose to obey the Father, cannot genuinely be tempted, and cannot serve as our representative before God.⁴²

The great champion of dyothelitism (the view that Christ has two wills — one divine, one human) was Maximus the Confessor (c. 580–662), who suffered imprisonment, the cutting off of his tongue and right hand, and eventual death in exile for his refusal to accept the monothelite compromise. Maximus argued that the will is a property of nature, not of person. Since Christ has two complete natures, He must have two complete wills — one belonging to each nature. A human nature without a human will is an incomplete human nature, just as a human nature without a human soul is incomplete.⁴³

The Key Definition

The council's definition affirms dyothelitism — two wills and two natural operations in Christ — in explicit and detailed terms:

We also proclaim two natural wills (δύο φυσικὰ θελήματα, dyo physika thelēmata) in Him, and two natural operations (δύο φυσικὰς ἐνεργείας, dyo physikas energeias), without division, without change, without separation, without confusion, according to the teaching of the holy Fathers; and two natural wills not contrary to each other — God forbid — as the impious heretics have asserted, but His human will following and not resisting or opposing but rather submitting to His divine and omnipotent will.⁴⁴

The council goes on to clarify that the two wills belong to the two natures, not to two persons:

For as His most holy and immaculate animated flesh (σάρκα ἔμψυχον, sarka empsychon) was not destroyed by being deified but continued in its own proper state and sphere, so also His human will, though deified, was not destroyed but rather preserved, as Gregory the Theologian says: "For His will, the will of the one who was considered a Savior, is not opposed to God, being wholly deified."⁴⁵

The council also formally condemned Patriarch Sergius, Patriarch Pyrrhus, Pope Honorius I (who had appeared to endorse a form of monothelitism in a letter to Sergius), and several other proponents of the monothelite position.

Significance for the Book's Argument

Constantinople III completes the conciliar Christological framework by adding the affirmation of two wills and two operations to the existing affirmations of two natures in one person. This is significant for our argument in at least three ways. First, the human will is a capacity of the human rational soul — affirming the will implies affirming the soul. Second, the council's definition of Christ's human will as a natural property (belonging to the nature) means that the will is not an emergent property of brain complexity but an intrinsic feature of human nature. Third, the council's description of Christ's flesh as "animated" (empsychon, ἔμψυχον, literally "ensouled") directly uses soul-language: Christ's flesh is not merely alive in a biological sense but is enlivened by a soul. Physicalism cannot account for any of this: there is no soul to be the seat of the will, no intrinsic natural property of will apart from brain processes, and no literal "ensoulment" of flesh. As Crisp argues, "it is difficult to see how Christ could be said to be fully human without having a human will that is distinct from the divine will" — and a human will requires a human soul.⁴⁷

VII. The Second Council of Nicaea (787)

Date and Location

The Second Council of Nicaea (the Seventh Ecumenical Council) convened on September 24, 787, in Nicaea — the same city where the first ecumenical council had met over four and a half centuries earlier. It was called by Empress Irene as regent for her young son, Emperor Constantine VI. Approximately 350 bishops attended.⁴⁸

Controversy Addressed: Iconoclasm

The primary issue at Nicaea II was not Christology per se but iconoclasm — the controversy over whether the veneration of icons (images of Christ, the saints, and biblical scenes) is permissible or constitutes idolatry. The iconoclasts, supported by Emperor Leo III and his successors, argued that images of Christ are impossible or idolatrous: either the image depicts only Christ's human nature (which divides the Person, a Nestorian error) or it attempts to depict the divine nature (which is impossible and blasphemous) or it depicts the union of both (which confuses the natures, a Eutychian error).⁴⁹

The iconodules (defenders of icons) responded with a Christological argument rooted in the Incarnation: because the Son of God truly became human — taking on a visible, material, bodily human nature — He can legitimately be depicted in visible, material form. An icon of Christ does not depict the divine nature (which is invisible and uncircumscribable) but the human nature of the incarnate Word — the flesh He actually wore, the face He actually had, the body in which He actually lived and died and rose again. The possibility of depicting Christ depends on the reality of the Incarnation: He really did have a visible, tangible, material human body.

The Key Definition

The council's decree affirms the veneration (not worship) of icons and grounds this practice explicitly in the Incarnation:

We define with all precision and care that the venerable and holy icons are to be set up just like the image of the precious and life-giving cross... For the more frequently they are seen in their representational form, the more those who behold them are led to the remembrance and desire of the originals... For the honor given to the icon passes to the original (ἡ τῆς εἰκόνος τιμὴ ἐπὶ τὸ πρωτότυπον διαβαίνει, hē tēs eikonos timē epi to prōtotypon diabainei), and he who venerates the icon venerates the person (hypostasis) of the one depicted in it.⁵⁰

The theological reasoning behind this decree draws on the full Chalcedonian framework: Christ is one Person in two natures, and His human nature is real, visible, and material. Because the Son truly became incarnate — truly took on human flesh, truly had a human body and a human face — He can be depicted in art. Icons are a testimony to the reality of the Incarnation against all forms of Docetism (the view that Christ only appeared to be human). The council's judgment is that denying the possibility of depicting Christ effectively denies the reality of the Incarnation itself.

Christological Reaffirmation

Though iconoclasm was the presenting issue, the council reaffirmed the entire preceding Christological tradition. In its doctrinal statement, the council recited the Niceno-Constantinopolitan Creed and explicitly endorsed the Christological definitions of all six preceding ecumenical councils. The council thus functions as a capstone, binding together the accumulated Christological teaching of the first seven centuries into a single, coherent, authoritative body of doctrine. The Christological framework it presupposes is the full Chalcedonian framework: one Person, two complete and unconfused natures, two wills, two operations — and a human nature that consists of a rational soul and a body.⁵¹

Significance for the Book's Argument

Nicaea II makes its contribution to our argument primarily by implication. The iconodule defense of images depends on the reality of the Incarnation — and the reality of the Incarnation depends on the completeness of Christ's human nature. If Christ is truly God made truly human, and if "truly human" means having a body and a rational soul (as Chalcedon and Constantinople II define it), then the Incarnation is a genuine entrance of God into the full range of human existence — physical, psychological, intellectual, volitional, spiritual. Icons testify to the visible, material dimension of this complete Incarnation. On physicalism, the Incarnation is the union of a divine Person with a physical organism. But on the conciliar understanding, it is the union of a divine Person with a complete human nature — body and rational soul together. Nicaea II, by presupposing this entire framework, implicitly confirms it.

Furthermore, the iconodule argument has an interesting implication for anthropology. If Christ can be depicted precisely because He has a real human body, this confirms the importance of embodiment — but not at the expense of the soul. The Chalcedonian framework affirmed at Nicaea II insists on both body and soul as essential to human nature. The icon depicts the body; the body is animated and made human by the rational soul. Neither alone constitutes human nature. Both together do.

Summary: The Conciliar Consensus

Taken together, the seven ecumenical councils present a remarkably consistent and detailed Christological framework. We can summarize the key elements as follows:

From Nicaea (325): Christ is fully God — homoousios with the Father. The Person who became incarnate is the eternal divine Son.

From Constantinople I (381): Apollinarianism is formally condemned. Christ's humanity must include a rational soul, not merely a body.

From Ephesus (431): Christ is one Person, not two. He assumed "flesh animated by a rational soul" (Cyril's formula). Theotokos is affirmed.

From Chalcedon (451): Christ is one Person in two natures, "of a rational soul and a body" — without confusion, without change, without division, without separation. He is consubstantial with us in His humanity.

From Constantinople II (553): The union is with "flesh possessed by a rational and intellectual soul." Anyone who denies this is anathematized.

From Constantinople III (681): Christ has two natural wills and two natural operations. The human will belongs to the human nature and presupposes a rational soul as its seat.

From Nicaea II (787): The entire preceding Christological framework is reaffirmed. Icons are legitimate because the Incarnation is real — Christ truly took on a complete human nature.

Implications for Physicalism

The implications of this conciliar consensus for physicalism about human nature are stark and unavoidable. Consider the logical structure:

Premise 1: The ecumenical councils define Christ's human nature as consisting of a rational soul and a body (Chalcedon, Constantinople II, confirmed by all subsequent councils).

Premise 2: The councils condemn any view that eliminates the rational soul from Christ's human nature (Constantinople I's condemnation of Apollinarianism, Constantinople II's fourth anathema).

Premise 3: Physicalism denies the existence of rational souls in all human beings, including Christ.

Conclusion: Physicalism, as applied to Christology, falls under the conciliar condemnation.

Now, it is important to acknowledge — as we have throughout this book — that physicalists do not intend to be Apollinarian. They are not motivated by the same concerns as Apollinarius. They do not deny the soul in Christ specifically while affirming it in other humans. They deny the soul universally, on philosophical and scientific grounds, and then apply this universal denial to Christ as one instance. Their intentions are sincere and their reasoning is internally consistent within their philosophical framework.⁵²

But the councils did not define orthodoxy by intention. They defined it by content. The question is not what a theologian intends to affirm but what their position logically entails for the person and work of Christ. And what physicalism logically entails is a Christ without a rational soul — precisely the view the councils condemned. As discussed extensively in Chapter 31, the historical context may differ (Apollinarius denied the soul in Christ for Christological reasons; physicalists deny it in everyone for philosophical reasons), but the Christological result is structurally identical: an incomplete human nature in which the body stands alone without an immaterial rational soul.⁵³

The burden of proof, therefore, lies on the physicalist to show either (a) that the councils did not mean what they said when they defined Christ's human nature as consisting of a "rational soul and a body," or (b) that the councils' language can be reinterpreted in physicalist terms without loss of meaning, or (c) that the authority of the councils can be overridden by modern philosophical or scientific considerations. Each of these options faces severe difficulties, as argued in Chapters 31, 33, and 35 of this book.

What we can say with confidence is this: the ecumenical councils of the undivided church, received as authoritative by Catholic, Orthodox, and Protestant Christians, consistently and explicitly affirm that Christ possesses a complete human nature including a rational soul — and they condemn any view that denies it. This is not a matter of ambiguous language or uncertain interpretation. It is stated clearly, defined precisely, and enforced with anathemas. Physicalism contradicts it. The defender of physicalism owes the church an explanation.

Quick Reference Table

Key Greek Terms Referenced in the Conciliar Definitions

For the reader's convenience, here is a glossary of the principal Greek terms used in the conciliar Christological definitions, arranged alphabetically by transliteration:

achōristōs (ἀχωρίστως) — "without separation." One of Chalcedon's four negative adverbs. The two natures of Christ cannot be pulled apart or separated from one another.

adiairetōs (ἀδιαιρέτως) — "without division." One of Chalcedon's four negative adverbs. The two natures are not divided into two persons.

asynchytōs (ἀσυγχύτως) — "without confusion." One of Chalcedon's four negative adverbs. The two natures do not blend into a hybrid or third thing.

atreptōs (ἀτρέπτως) — "without change." One of Chalcedon's four negative adverbs. Neither nature is altered or transformed by the union.

dyo physika thelēmata (δύο φυσικὰ θελήματα) — "two natural wills." The affirmation of Constantinople III that Christ possesses both a divine will and a human will.

dyo physikas energeias (δύο φυσικὰς ἐνεργείας) — "two natural operations" or "two natural energies." Alongside the two wills, Constantinople III affirmed two natural operations or activities in Christ.

ek psychēs logikēs kai sōmatos (ἐκ ψυχῆς λογικῆς καὶ σώματος) — "of a rational soul and a body." The Chalcedonian Definition's explicit statement of the composition of Christ's human nature.

empsychon (ἔμψυχον) — "ensouled" or "animated." Used at Constantinople III to describe Christ's flesh as "animated" — alive with a soul, not merely biologically functioning.

enanthrōpēsanta (ἐνανθρωπήσαντα) — "became human." Used in both the Nicene Creed (325) and the Niceno-Constantinopolitan Creed (381) to affirm that the Son did not merely take on flesh but became a complete human being.

homoousios / homoousion (ὁμοούσιος / ὁμοούσιον) — "of the same substance" or "consubstantial." Affirmed at Nicaea (325) to describe the Son's relationship to the Father. Used at Chalcedon (451) in a double formula: Christ is consubstantial with the Father in divinity and consubstantial with us in humanity.

hypostasis (ὑπόστασις) — "subsistence" or "person." In its developed theological usage, hypostasis refers to the particular, concrete individual — the "who" as distinct from the "what" (ousia/physis). Christ is one hypostasis (one person) subsisting in two natures.⁵⁴

logikē (λογική) — "rational" or "logical." Used to modify psychē (soul) — the soul in question is not merely a life-principle or animal soul but a rational, thinking, intellectual soul.

monogenēs (μονογενής) — "only-begotten" or "unique." Used in the Nicene Creed to describe the Son's unique relationship to the Father.

noera (νοερά) — "intellectual" or "noetic." Used at Constantinople II alongside logikē to emphasize that Christ's human soul is a thinking, reasoning, intellectual soul — not merely an animating life-force.

nous (νοῦς) — "mind," "intellect," or "rational soul." The specific component of the human soul that Apollinarius denied in Christ. The nous is the seat of reason, intellect, and will.

ousia (οὐσία) — "substance," "essence," or "being." The "what" of a thing — what it is, as distinct from who it is (hypostasis). The Son shares the same ousia as the Father.

physis (φύσις) — "nature." Often used interchangeably with ousia in Christological discussions, though the precise relationship between the terms was debated. Christ has two physeis — a divine nature and a human nature.

prosōpon (πρόσωπον) — "person" or "face." In the Chalcedonian Definition, prosōpon is used alongside hypostasis to refer to the one person of Christ.⁵⁵

psychē (ψυχή) — "soul." The immaterial component of human nature. When modified by logikē ("rational"), it refers specifically to the human rational soul — the seat of reason, will, and intellect.

sarkōthenta (σαρκωθέντα) — "was incarnate" or "became flesh." Used in the Nicene Creed to affirm that the Son took on human flesh — entered into material, bodily existence.

Theotokos (Θεοτόκος) — "God-bearer" or "Mother of God." Affirmed at Ephesus (431) as a proper title for the Virgin Mary, because the person she bore is the divine Son — not merely a human being in whom God dwells.

Conclusion

The seven ecumenical councils represent the most widely received doctrinal authority in Christian history. Their Christological definitions — developed over the course of more than four centuries, in response to a succession of carefully analyzed heresies, by hundreds of bishops drawing on the best theological minds of their age — constitute a comprehensive and detailed account of who Jesus Christ is: one divine Person subsisting in two complete, unconfused natures, each with its own will and operation, forever united without division or separation.

At the heart of this framework stands the insistence that Christ's human nature is complete — not merely a physical body, but a body united to a rational, intellectual soul. This insistence is not incidental or decorative. It was forged in the fire of the Apollinarian controversy, defended at great cost by theologians like Gregory of Nazianzus and Maximus the Confessor, defined at Chalcedon, reinforced with anathemas at Constantinople II, and presupposed by the dyothelitism of Constantinople III. It is woven into the very fabric of conciliar Christology.

Physicalism about human nature — the view that human beings are purely physical organisms with no immaterial soul — stands in direct contradiction to this conciliar framework. It produces a Christ without a rational soul, which is precisely the Christological error the councils identified, condemned, and excluded from orthodoxy. The church has spoken on this matter with remarkable clarity and consistency. Those who wish to affirm physicalism while remaining within the bounds of conciliar orthodoxy face a challenge that, in the judgment of this author, has not been — and perhaps cannot be — successfully met.

As Gregory of Nazianzus wrote in the fourth century, in words that echo through the ages: "What is not assumed is not healed" (τὸ γὰρ ἀπρόσληπτον ἀθεράπευτον). If Christ did not assume a human rational soul, the human rational soul remains unredeemed. The councils understood this. They insisted on the rational soul. And their insistence remains binding on all who confess that Jesus Christ is truly God and truly man — the Word made flesh, body and soul, for our salvation.⁵⁶