Chapter 20

The Problem Stated: Why Physicalism Cannot Account for the Incarnation

Introduction: The Equation That Changes Everything

We have arrived at the heart of this book. Everything we have built so far — the biblical case for substance dualism, the philosophical arguments for the soul, the empirical evidence from near-death experiences, the biblical witness to Christ's two natures, the councils' careful definitions, and the models of the Incarnation — all of it has been leading to this moment. In this chapter, and in the nine chapters that follow, we are going to see why physicalism about human nature is not just philosophically inadequate, not just biblically unsupported, but Christologically devastating. Physicalism, when applied consistently to the person of Jesus Christ, produces a cascade of theological disasters that would have horrified the church fathers, contradicted the ecumenical councils, and undermined the very salvation that the Incarnation was designed to accomplish.

Let me be as clear as I can about what I mean. The claim I am making is strong, and I want readers to feel the full weight of it: physicalism about human nature is fundamentally incompatible with orthodox Christology. It cannot be patched. It cannot be adjusted with clever workarounds. It cannot be rescued by appeals to mystery. When you follow physicalism's own logic consistently — when you apply its claims about human nature to the human nature of Christ — the result is a Christology that the ecumenical councils explicitly condemned.

I realize that is a startling statement. Many Christian physicalists are sincere believers who love Jesus, affirm the creeds, and would never intentionally deny any element of orthodox Christology. I respect them. I do not question their faith or their motives. But I am convinced — and I believe the evidence will show — that physicalism's denial of the immaterial soul produces consequences for Christology that these believers have not fully thought through. This chapter is an invitation to think them through together.

Here is the simple equation that changes everything. It is easy to state, and once you see it, you cannot unsee it:

That equation looks innocent enough. But as we will see, it is a theological time bomb. Once you accept it, a chain of unavoidable consequences follows — consequences that touch every major element of orthodox Christology: the hypostatic union, the death of Christ, the descent to the dead, the resurrection, the virgin birth, the ascension, Christ's sinlessness, and the doctrine of the Trinity itself.

Defining Our Terms

Before we walk through the problems, let me make sure we are all on the same page about the key terms. Some readers may be jumping into this chapter without having read the earlier parts of the book, so a brief review will help.

Physicalism (sometimes called "materialism") is the view that a human being is entirely physical — a biological organism with no immaterial component. There is no soul. There is no spirit that exists as a separate substance from the body. What we call the "mind" or "consciousness" is simply what the brain does. When the brain stops working, the person ceases to exist. There are several varieties of physicalism — reductive physicalism, nonreductive physicalism, constitution views, and others (as we surveyed in Chapter 2) — but they all share this core commitment: there is no immaterial soul that can exist apart from the body.¹

Substance dualism, by contrast, is the view that a human being is composed of two distinct substances: a material body and an immaterial soul (or spirit). The soul is not merely a function of the brain. It is a genuine, distinct entity — an immaterial substance — that can exist and function apart from the body. At death, the body and soul separate: the body goes into the ground, and the soul continues to exist in a conscious state. As we argued in Chapters 3 through 5, this is the view taught in Scripture, supported by philosophy, and confirmed by the empirical evidence of veridical near-death experiences.²

The hypostatic union is the technical term for the way Christ's two natures — His divine nature and His human nature — are united in one Person (the Greek word is hypostasis, ὑπόστασις, meaning "person" or "subsistence"). The Council of Chalcedon in 451 AD defined this union using four famous adverbs: the two natures are united "without confusion" (asynchytōs, ἀσυγχύτως), "without change" (atreptōs, ἀτρέπτως), "without division" (adiairetōs, ἀδιαιρέτως), and "without separation" (achōristōs, ἀχωρίστως).³ That last adverb — "without separation" — is going to be especially important for our argument. It means the two natures are never pulled apart. The Incarnation, once it happens, is permanent. The Son does not stop being united to His human nature — not at death, not during the three days in the tomb, not ever.

The triduum mortis (a Latin phrase meaning "the three days of death") refers to the period between Christ's death on Good Friday and His resurrection on Easter Sunday — roughly thirty-six to forty hours. This period is theologically crucial, and it is where physicalism's problems become most visible. What happened during those hours? Was Christ still incarnate? Was the Son still united to a human nature? As we shall see, how you answer those questions depends entirely on what you think a human nature is.

The Syllogism: Stating the Problem with Precision

Now let me state the core argument as precisely as I can. I am going to present it as a syllogism — a logical argument where, if the premises are true, the conclusion follows necessarily. Here it is:

Every one of these premises is either a core commitment of physicalism or a core commitment of Christian orthodoxy. The physicalist cannot deny Premise 1 without ceasing to be a physicalist. The Christian cannot deny Premises 2 or 4 without ceasing to be a Christian. And Premise 3 is simply a biological fact that no one disputes. The conclusion, therefore, follows with iron logic: on physicalism, nothing of Christ's human nature survived His death.

Now, why is that conclusion so devastating? Because orthodox Christology requires that the Incarnation be permanent — that the Son never ceases to be united to His human nature. As we saw in Chapter 11, the Chalcedonian Definition explicitly states that the two natures are united "without separation." As we explored in Chapters 17 and 18, both Andrew Loke's Kryptic Model and Timothy Pawl's Conciliar Christology require the continuous union of the two natures in the one Person of the Son.⁴ If Christ's human nature ceased to exist at death — even temporarily — then the Incarnation was interrupted. The Son was no longer "true God and true man." The Chalcedonian "without separation" was violated. And the consequences ripple outward in every direction.

Let me walk you through each of these consequences, one at a time. Each of them will receive its own chapter in the chapters that follow (Chapters 21 through 29), but here I want to give you the full picture — a bird's-eye view of the entire landscape of problems that physicalism creates for the Incarnation.

Problem One: The Triduum Mortis — The Incarnation Interrupted

This is the most devastating single problem, and it is the subject of Chapters 21 and 22. Let me preview it here.

On Good Friday, Jesus of Nazareth hung on a Roman cross. He suffered. He cried out. He breathed His last. He died. His body was taken down, wrapped in linen, and placed in a borrowed tomb. For approximately thirty-six to forty hours — from late Friday afternoon to early Sunday morning — His body lay in that tomb. Then, on the third day, He rose from the dead.

What happened during those hours in between? That question is the most critical test of any Christological framework. And it is where physicalism collapses.

On substance dualism, here is what happened: Christ's human soul separated from His body at death, just as happens with every human being who dies. But the Son of God — the second Person of the Trinity — remained united to both the human soul and the human body. The hypostatic union was not dissolved. The soul went to paradise (Luke 23:43 — "Today you will be with me in paradise") and descended to the dead (1 Peter 3:18–20). The body lay in the tomb. Both the soul and the body remained the Son's — still united to His divine Person, even though they were temporarily separated from each other. The Incarnation continued without interruption.⁵

This is exactly how Thomas Aquinas understood the situation. During the triduum, Aquinas argued, the Son remained united to both the separated soul (which was in the limbus patrum, the "limbo of the fathers") and the body in the tomb. Both remained hypostatically united to the divine Person. The union was strained — the human nature was in a state of separation — but it was not dissolved. The soul provided the continuity that kept the entire arrangement intact.⁶

Now consider what happens on physicalism. Christ's human nature just is His physical body — there is no soul. When that body died, it ceased to function. There was no consciousness, no brain activity, no heartbeat, no life. The "human nature" was now a corpse — dead biological matter lying in a stone tomb. And there was nothing else. No soul departed. No spirit went to paradise. No immaterial aspect of Christ's humanity survived.

So what was the Son of God united to during those thirty-six to forty hours? A corpse? But a corpse is not a human nature. Dead biological matter is not a person. A lifeless body is not a living human being. The hypostatic union is supposed to be the union of the divine nature with a human nature — and dead matter simply is not a human nature in any theologically meaningful sense.

If the Son was not united to a living human nature during the triduum, then several devastating consequences follow:

First, the Incarnation was temporary, not permanent. For roughly a day and a half, the second Person of the Trinity was not incarnate. He was not "true God and true man." He was simply God — as He had been before the Incarnation began. The Incarnation had a gap.

Second, Chalcedon's "without separation" (achōristōs) was violated. The two natures were separated — the divine nature continued to exist (God does not die), but the human nature ceased to exist. The union was broken.

Third, the creedal language — "was crucified, died, and was buried" — becomes problematic. These things are said of the Person of the Son, through His human nature. But on physicalism, the human nature no longer existed after death. The Son existed (He is God, and God cannot cease to exist), but He was no longer incarnate. To whom, exactly, do the creedal statements about burial and rest in the tomb refer?

As Marc Cortez has argued in his important essay on physicalism and Holy Saturday, if human persons consist entirely of physical entities and processes, and if the life of the human person comes to an end at biological death, then the human life of Jesus terminated on the cross. Even if we maintain that this human life resumed when Jesus rose from the grave, we still must wrestle with the status of His humanity in the interim. As Cortez puts it, physicalism seems to suggest that the Son appears to divest Himself of humanity at one point and then incarnate Himself again shortly thereafter — creating a kind of reincarnation rather than a continuous Incarnation.⁷

I want to stress something here: this is not a minor theological quibble. This is not an obscure problem that only professional theologians would care about. This goes to the very heart of what the Incarnation is. If the Incarnation was interrupted — even for a single moment — then the Son did not permanently assume human nature. And if the assumption was not permanent, then the entire Christian understanding of who Jesus is, what happened on the cross, and what salvation means is fundamentally compromised.

We will develop this argument fully in Chapter 21 ("Holy Saturday and the Triduum Mortis") and Chapter 22 ("The Death of Christ and the Dissolution of the Hypostatic Union").

Problem Two: The Descent to the Dead — Where Was Christ?

The second major problem concerns what Christ was doing during the triduum. Scripture and the creedal tradition do not picture Jesus as simply lying inert in a tomb for three days. On the contrary, they tell us He was active — descending to the dead, proclaiming to imprisoned spirits, and bringing the gospel to those who had died.

Consider the key texts. In 1 Peter 3:18–20, we read that Christ was "put to death in the flesh but made alive in the spirit, in which he went and proclaimed to the spirits in prison" (ESV). The contrast here between "flesh" (sarx, σάρξ) and "spirit" (pneuma, πνεῦμα) presupposes a body-spirit distinction. Christ was "put to death" in the realm of the flesh — His body died — but He was "made alive" in the realm of the spirit. In this spiritual state, He "went and proclaimed." He was mobile. He was active. He was communicating.⁸

In 1 Peter 4:6, we learn that "the gospel was preached even to those who are dead" (euēngelisthē, εὐηγγελίσθη — "was proclaimed as good news"). The dead received the gospel. That requires a living subject to preach and conscious subjects to receive. On physicalism, the dead do not exist and cannot receive anything — and Christ Himself was dead and therefore (on physicalism) did not exist either.

In Luke 23:43, Jesus tells the thief on the cross, "Truly, I say to you, today you will be with me in paradise." Jesus promises the thief that he will be consciously present with Jesus on that very day — the day of their death. Their bodies would be on crosses and in tombs. But Jesus and the thief would be together in paradise. On physicalism, this promise is empty. There is no "you" (the thief) and no "me" (Jesus) to be anywhere, since both have ceased to exist.

In Acts 2:27 and 31, Peter at Pentecost quotes Psalm 16:10: God "did not abandon his soul (psychē, ψυχή) to Hades, nor did his Holy One see corruption." Peter explicitly states that Christ's psychē was in Hades during the triduum — and that God did not leave it there. On physicalism, Christ has no psychē to be in Hades. Peter's entire argument falls apart.

The Apostles' Creed affirms: "He descended into hell" (or "to the dead" — descendit ad inferos). On physicalism, there was no Christ to descend anywhere. His body was in the tomb. His "soul" does not exist. There is simply nothing left to go to the realm of the dead.

On substance dualism, by contrast, all of this makes perfect sense. Christ's human soul separated from His body at death. His soul — alive, conscious, active — descended to the realm of the dead, proclaimed the gospel to the spirits there, and promised the thief they would be together that very day in paradise. The body lay in the tomb. The soul was active. Both remained united to the Person of the Son. The descent is not only possible on dualism — it is expected.

This problem will be fully developed in Chapter 23 ("The Descent to the Dead — Christ's Activity Between Death and Resurrection").

Problem Three: The Resurrection and Personal Identity — Is the Risen Jesus the Same Person?

The third major problem concerns personal identity at the resurrection. Is the risen Jesus the same person as the crucified Jesus? This question might seem strange — of course He is the same person! — but on physicalism, the answer is far from obvious.

Here is the problem. On physicalism, what makes you you is your physical body — specifically, the particular arrangement and functioning of your physical matter. There is no soul to provide personal identity across time. Your identity is constituted entirely by your body.

Now, what happened at the resurrection? Jesus' body was transformed. The glorified body has properties that the pre-resurrection body did not have. It can pass through locked doors (John 20:19). It can appear and disappear (Luke 24:31). It is somehow different enough that people who knew Jesus well did not immediately recognize Him (Luke 24:16; John 20:14–15; 21:4). And yet it is continuous enough that it still bears the wounds of the crucifixion (John 20:27).

On substance dualism, there is no identity crisis. The same soul — the same immaterial person — that was united to the pre-resurrection body is now united to the glorified body. The soul provides the thread of personal identity that stretches continuously from before death, through the triduum, and into the resurrection. The body is transformed; the person is the same.⁹

On physicalism, the situation is much more troubling. If the body is all there is to the human person, and the body has been fundamentally changed at the resurrection, then on what basis can we say this is the same person? What makes the risen Jesus identical to the crucified Jesus? The physical continuity is there — the body in the tomb is the body that was raised — but it has been radically transformed. If there is no soul to anchor personal identity, the continuity depends entirely on the physical material, and that material has undergone a dramatic change.

Worse still, on physicalism, Jesus ceased to exist at death. For roughly thirty-six hours, there was no Jesus — just a corpse. Then, at the resurrection, a person exists again. But is this the same person who ceased to exist, or a new person who happens to be made from the same matter? This is what philosophers call the "replica problem." If I destroy a vase and then glue all the pieces back together, is it the same vase or a replica? The physical parts may be the same, but the continuity has been broken. On physicalism, the personal continuity of Christ was broken at death — and a broken chain of identity cannot be repaired simply by reassembling the physical parts.¹⁰

This matters enormously for our salvation. If the risen Jesus is not the same person who died for our sins, then the resurrection does not vindicate the one who bore our punishment. The saving work of Christ depends on the identity of the one who died and the one who rose. If physicalism creates even the possibility of an identity gap, it threatens the coherence of the gospel itself.

This argument will be developed fully in Chapter 24 ("The Resurrection, the Glorified Body, and Personal Identity").

Problem Four: The Virgin Birth and the Origin of Christ's Human Nature

The fourth problem concerns the beginning of the Incarnation — the moment when the Son of God assumed a human nature. On substance dualism, the picture is relatively clear: at the virgin conception, the Son assumed a concrete human nature consisting of a human body (formed miraculously in the womb of the Virgin Mary by the power of the Holy Spirit) and a human soul (created by God and united to the divine Person). The Incarnation was complete from the moment of conception because both components of the human nature — body and soul — were present from the very start.¹¹

On physicalism, things get complicated very quickly. If there is no soul, then the human nature just is the physical body. But at the moment of conception, the "body" is a single fertilized cell — a zygote. Is the Son of God hypostatically united to a single cell? When exactly does the Incarnation begin? At conception, when there is no brain, no nervous system, no consciousness whatsoever? At some later point of fetal development, when brain structures begin to form? At the point where the fetus becomes capable of consciousness?

This creates a deeply uncomfortable timeline. On physicalism, the features that make a human being distinctively human — consciousness, rationality, emotional experience, moral agency — are all products of the brain. But the brain does not develop all at once. Neural structures form gradually over the course of prenatal development. If the "human nature" that the Son assumes is constituted entirely by physical structures, then the human nature itself develops gradually. Was the Incarnation partial at first and then gradually became complete as the fetal brain developed? Was the Son "partly incarnate" at eight weeks and "fully incarnate" at forty weeks? This is deeply problematic.¹²

On dualism, none of these questions arise. The human soul — the immaterial substance that constitutes the core of the human person — is present from conception. The body develops around it and in union with it. The Incarnation is complete from the first moment because the essential components of human nature (body and soul) are both present from the start. The soul does not "emerge" from the brain; it is created directly by God and united to the body from the very beginning.

This problem is explored in Chapter 25 ("The Virgin Birth and the Origin of Christ's Human Nature").

Problem Five: The Ascension and the Permanent Incarnation

The fifth problem concerns the permanence of the Incarnation. Orthodox Christology teaches that the Son of God did not temporarily borrow a human nature for thirty-three years and then discard it. The Incarnation is forever. The Son assumed human nature permanently. He ascended bodily into heaven. He is, right now, and forever will be, both God and man — "seated at the right hand of the Father," as the creed declares. He will return in the same way He departed (Acts 1:11).¹³

On substance dualism, this is coherent. Christ's glorified human nature — consisting of His glorified body and His human soul, both permanently united to the divine Person — exists forever in the presence of the Father. The soul provides the natural connection between the material and the spiritual realms. The glorified body, though physical, has been transformed to exist in the heavenly dimension. The body-soul composite, united to the divine nature, constitutes the permanent Incarnation.

On physicalism, things become very strange. If Christ's human nature is entirely physical — just a body, nothing more — then the permanent Incarnation means that a purely physical organism is "seated at the right hand of the Father." Where is this body? Is it located somewhere in the physical universe — on another planet, in another galaxy, in some other spatial location? If the heavenly realm is not a physical location (which is the traditional understanding), then how does a purely physical organism exist in a non-physical realm? What does it mean for a body with no immaterial component to exist in the spiritual presence of an immaterial God?

On dualism, the soul provides a natural bridge. The human soul, being immaterial, naturally connects to the spiritual dimension. The glorified body, being transformed, participates in that dimension through its union with the soul. On physicalism, there is no bridge. There is just matter — physical matter existing in a realm that transcends the physical. This does not seem coherent.

Furthermore, there is the question of what the permanent Incarnation means for Christ's ongoing experience. Is the ascended Christ conscious? Of course — He intercedes for us (Hebrews 7:25), He prepares a place for us (John 14:2–3), He rules at the Father's right hand (Ephesians 1:20–22). But on physicalism, consciousness is a product of brain activity, and brain activity requires a functioning biological brain with blood flow, oxygenation, neural firing, and all the biochemical processes that sustain it. Is the glorified Christ's brain still undergoing these biological processes? If so, the glorified body is not as different from our current bodies as Scripture suggests. If not, then consciousness must be possible apart from biological brain processes — which is exactly what substance dualism claims.

This argument will be developed in Chapter 26 ("The Ascension and the Permanent Incarnation — Christ Remains God and Man Forever").

Problem Six: Christ's Sinlessness and the Pelagian Dilemma

The sixth problem is one of the most striking. It concerns Christ's sinlessness — the unanimous biblical testimony that Jesus never sinned (Hebrews 4:15; 2 Corinthians 5:21; 1 Peter 2:22; 1 John 3:5). He was "tempted in every way as we are, yet without sin." His temptation was real. His sinlessness was genuine. How did He do it? On physicalism, the answer to this question leads straight into the ancient heresy of Pelagianism.

Here is the dilemma, and it has two horns — both of them sharp.

As Matthew Hart has argued in his important essay "Christian Materialism Entails Pelagianism," if materialism is true, then human mental properties supervene on human physical properties — meaning that the mental arises from the physical and depends entirely on it. If that is the case, then the physical states that produce faith, repentance, and righteousness are, in principle, achievable through natural physical processes — which is exactly what the Pelagians claimed.¹⁴

On substance dualism, Christ's sinlessness is explained by the unique constitution of His person. His human soul was created sinless — directly created by God, not generated through ordinary human reproduction. The indwelling divine nature and the empowerment of the Holy Spirit sustained His human soul in its sinless state. The soul is the seat of moral agency, and Christ's soul was uniquely constituted and empowered. This is not Pelagianism because Christ's sinlessness depends on the unique creative act of God in forming His soul and the ongoing work of the Holy Spirit — not on mere natural human effort.¹⁵

There is also the related problem of original sin. On physicalism, how is original sin transmitted? Through genetics? Through brain chemistry? Through social conditioning? If Christ had no soul, and if original sin is transmitted through physical means, then Christ either inherited original sin from Mary (which contradicts His sinlessness) or was miraculously exempted from the physical transmission (which means His body was different from ours — violating genuine humanity). On dualism, original sin is related to the soul's condition, and Christ's soul was uniquely created without the taint of inherited corruption.

This argument receives its full treatment in Chapter 27 ("Christ's Sinlessness, Temptation, and the Pelagian Problem for Physicalism").

Problem Seven: The Trinity, Personhood, and the Physicalist Challenge

The seventh problem is more subtle but no less serious. It concerns the concept of "personhood" — a concept that is central to both Christology and the doctrine of the Trinity.

The Christian doctrine of the Trinity teaches that there is one God who exists in three Persons: the Father, the Son, and the Holy Spirit. Each Person is fully God. Each Person is a distinct hypostasis (ὑπόστασις) — a distinct personal subsistence. Yet there is only one divine essence (ousia, οὐσία). The church fathers worked this out through centuries of careful theological reflection, using the term "person" (hypostasis, persona) to describe the distinct subjects within the one divine being.¹⁶

Now, notice something crucial. The divine Persons are not physical organisms. The Father does not have a body. The Holy Spirit does not have a brain. The Son did not have a physical body until the Incarnation. The three Persons of the Trinity are, by definition, immaterial — they are not composed of matter. They are spiritual beings. And yet they are persons in the fullest, most robust sense of the word.

Here is where the problem arises for physicalism. On physicalism, what does it mean to be a "person"? If a human person is nothing more than a physical organism — a body with a brain — then personhood is, at its core, a physical phenomenon. To be a person is to be a certain kind of biological entity. Consciousness, self-awareness, rationality, moral agency — all the features we associate with personhood — are products of physical brain processes on the physicalist view.

But the divine Persons are not physical organisms. They do not have brains. Their consciousness is not a product of neurons firing. If we define personhood physically — as physicalism about human nature seems to require — then the concept of "person" means something completely different when applied to God than when applied to humans. The word becomes equivocal — it has two entirely different meanings depending on whether we are talking about divine persons or human persons.

This matters because Chalcedonian Christology depends on a robust concept of personhood that can bridge the divine and the human. The Son is one Person with two natures — one divine, one human. The concept of "person" here must be analogically coherent — it must mean something genuinely similar in both cases, even if not exactly the same. On substance dualism, there is such coherence: both the divine Persons and the human soul are immaterial personal subjects. There is a natural analogy between divine personhood and human personhood because both involve immaterial consciousness, rationality, will, and agency. On physicalism, that analogy is broken. Human personhood is physical; divine personhood is spiritual. The "person" in "one person, two natures" becomes equivocal — and the Christological formula loses its coherence.

As Joshua Farris has argued in his Introduction to Theological Anthropology, the connections between anthropology and Christology run deep. How we define human nature has direct implications for how we understand the Incarnation, and how we understand personhood has direct implications for how we understand both the Trinity and the hypostatic union.¹⁷

This argument will be developed in Chapter 28 ("The Trinity, Personhood, and the Physicalist Challenge").

Problem Eight: Additional Christological Difficulties

Beyond the seven major problems already listed, physicalism creates a cluster of additional Christological difficulties that deserve mention, even though they will be treated in a single chapter rather than individually. Let me briefly preview three of them.

The Beatific Vision

Traditional theology has held that the blessed in heaven enjoy the "beatific vision" — a direct, unmediated knowledge of God. Christ Himself, during His earthly ministry, had a unique and direct knowledge of the Father. As Andrew Loke has argued in his Kryptic Model, Christ's divine knowledge was present at a "preconscious" level, available when needed, even though His waking conscious experience was genuinely human.¹⁸

Can a brain state constitute a direct knowledge of God? On physicalism, all knowledge is a function of physical brain processes. But God is not a physical object. He is not detectable by physical sense organs. He is not a pattern of neural firing. How can a purely physical brain — with no immaterial component — have direct knowledge of an immaterial God? On dualism, the soul, being immaterial itself, has a natural capacity for knowing and relating to an immaterial God. On physicalism, the gap between the physical brain and the immaterial God seems uncrossable without some form of dualism smuggled in.

Theosis — Participation in the Divine Nature

Second Peter 1:4 speaks of believers becoming "partakers of the divine nature" (theias koinōnoi physeōs, θείας κοινωνοὶ φύσεως). The Eastern Orthodox tradition has developed this into the doctrine of theosis (θέωσις) — divinization or deification, the process by which human beings are transformed by grace to share in the divine life. Christ's own human nature is the paradigm of this transformation — His humanity is the first humanity to be fully united to the divine.

Can a physical organism "participate in the divine nature"? What would that even mean on physicalism? Participation in the divine nature seems to require a point of contact between the human and the divine — an immaterial dimension of the human person that can be united to, transformed by, and made to share in the life of God. On physicalism, there is no such point of contact. The human being is just matter — and matter, however wonderfully organized, does not "participate" in an immaterial divine nature in any obvious way.

Sanctification — The Inner Transformation

Paul speaks of the "inner man" being renewed day by day (2 Corinthians 4:16). The language of "inner" and "outer" strongly suggests a dualist anthropology — the "outer man" (the body) is wasting away, while the "inner man" (the soul or spirit) is being transformed. On physicalism, the "inner man" is just the brain. Sanctification — the lifelong process of growing in holiness — is just neural rewiring. The work of the Holy Spirit in transforming believers is reduced to altering brain chemistry.

This is theologically unsatisfying, to say the least. The New Testament presents sanctification as a spiritual transformation of the whole person — a renewal of the mind, the heart, the will, and the character. On physicalism, it is just a matter of rearranging neurons. And if sanctification is just neural rewiring, then in principle it could be achieved by a neuroscientist with the right tools — which brings us back to the Pelagian problem from another angle.

These additional problems will be developed in Chapter 29 ("Additional Christological Problems — Beatific Vision, Theosis, and Sanctification").

The Overarching Argument: Physicalism as Neo-Apollinarianism

Now let me pull all of this together. We have surveyed eight distinct Christological problems that physicalism creates. Each one is serious. Taken together, they are overwhelming. But there is an overarching argument that ties them all together, and it is the most important claim of this entire book:

Let me explain what I mean by this. In the fourth century, a bishop named Apollinarius of Laodicea proposed a model of the Incarnation that was designed to protect the unity of Christ's Person. Apollinarius was not a villain. He was a devout Christian who was genuinely worried about a real theological problem: if Christ has a complete human nature — with a body, a lower soul, and a rational mind — doesn't that amount to having two complete persons? Apollinarius's solution was radical: the divine Logos replaced Christ's human rational soul (nous, νοῦς). Christ had a human body, and perhaps a lower "animal" soul for basic life functions, but His rational mind was the divine Logos itself. This preserved unity — one mind, one will — but at the cost of completeness. Christ lacked a human rational soul.¹⁹

The church responded with overwhelming force. Gregory of Nazianzus penned his famous axiom in Epistle 101: "What has not been assumed has not been healed" (to gar aproslepton, atherapeuton; τὸ γὰρ ἀπρόσληπτον, ἀθεράπευτον). The argument was simple and devastating: human beings need redemption in every aspect of their nature — body, soul, and mind. Redemption requires assumption — the Son must take on what He intends to save. If Christ did not assume a human rational soul, then the human rational soul is not redeemed. But the human rational soul is the very seat of sin, decision-making, and relationship with God — it is the most important part to redeem. Therefore, Apollinarianism defeats the very purpose of the Incarnation.²⁰

Gregory of Nyssa added his own critique: Apollinarianism makes Christ a hybrid creature — part God, part animal, but not fully human. A human body without a human mind is an animal, not a person. The Incarnation requires the Son to become what we are — and we are rational souls embodied, not merely animated flesh.²¹

Apollinarianism was condemned at the Synod of Alexandria (362), the Council of Rome (377), the First Council of Constantinople (381), and the condemnation was reiterated at Chalcedon (451) and Constantinople II (553). The repeated condemnations demonstrate that the church regarded this issue as non-negotiable. Denying that Christ has a human rational soul is not a matter of theological preference. It is heresy — a position that the church has formally excluded from the boundaries of orthodoxy.²²

Now, here is the parallel to physicalism. Let me be careful and fair about this. I am not saying that Christian physicalists are intentionally Apollinarian. They are not. Apollinarius denied that Christ had a human soul while affirming that souls exist — he simply thought the divine Logos replaced Christ's. Physicalists deny that anyone has a soul — Christ or otherwise. They believe they are affirming Christ's complete humanity by affirming His complete physical body.

But — and this is the critical point — the structural result is the same. Both Apollinarianism and physicalism produce a Christ who lacks an immaterial human soul. Both produce a Christ whose human nature is incomplete by the standards of the ecumenical councils. The Chalcedonian Definition explicitly states that Christ is "truly man of a rational soul (ek psychēs logikēs, ἐκ ψυχῆς λογικῆς) and a body." That is not incidental language. It is a deliberate anti-Apollinarian clause. The council defines Christ's human nature as consisting of a rational soul AND a body. On physicalism, Christ has no rational soul. Physicalism contradicts the Chalcedonian Definition at its most explicit point.²³

Consider the parallel:

Apollinarianism says: Christ has a human body but not a human rational soul — the Logos replaces it.

Physicalism says: No human being has an immaterial soul — the soul does not exist.

In both cases, the result for Christology is the same: Christ lacks an immaterial human soul.

If the councils condemned Apollinarianism for denying Christ's human soul, then by the same logic, physicalism falls under the same condemnation — because it produces the same Christological outcome. The road is different, but the destination is identical.

As Michael Wilkinson has argued in Crowned with Glory and Honor, Christology should norm our anthropology, not the other way around. We should not begin with a philosophical theory about what human beings are and then try to force Christ into that mold. Rather, we should look at what Christ's human nature is — as defined by the councils — and let that inform our understanding of human nature. The councils tell us Christ has a rational soul and a body. Therefore, human nature includes a rational soul and a body. Physicalism, by denying the soul, gets the relationship exactly backwards: it starts with a philosophical commitment (no souls exist) and then tries to fit Christ into it. The result is a Christ who does not match the councils' definition — a Christ with an incomplete human nature.²⁴

Engaging the Key Scholarly Conversation

I want to take a moment to acknowledge the excellent scholarly work that has been done on this topic, because this chapter is building on the labors of others. The volume Christian Physicalism? Philosophical Theological Criticisms, edited by R. Keith Loftin and Joshua Farris, is the most important collection of essays addressing the Christological problems that physicalism creates. The book brings together a dozen scholars who approach the issue from different angles — patristic, philosophical, Christological, soteriological — and the cumulative case is powerful.²⁵

In the foreword to that volume, Thomas McCall frames the issue with clarity: Christian physicalists have refined their biblical and theological arguments considerably over recent decades, dealing extensively with the implications of physicalism for things like spiritual growth, free will, and the resurrection. But until recently, few had given any significant attention to Christology in their discussions — often making no more than a passing comment about the "mystery" of the Incarnation, as if it were inappropriate to try to solve one mystery (the mind-body problem) by appealing to another (the hypostatic union).²⁶

I believe this is exactly backwards. The Incarnation is not a mystery we should set aside while we work out our anthropology. The Incarnation is the supreme test case for any theory of human nature. If your anthropology cannot handle the Incarnation — if it cannot give a coherent account of how the Son of God assumed a human nature, maintained that nature through death, remained active during the triduum, and preserved personal identity through the resurrection — then your anthropology has failed the most important test there is.

Several individual chapters in the Loftin and Farris volume are especially relevant to the problems we have surveyed in this chapter. Jason McMartin's essay on Holy Saturday and Christian theological anthropology develops the triduum problem with careful attention to the theological principles at stake.²⁷ Marc Cortez's essay on physicalism, the Incarnation, and Holy Saturday engages Karl Barth's anthropology and shows how even Barth's nuanced physicalism cannot resolve the triduum problem.²⁸ R. T. Mullins contributes two important chapters — one on "Physicalist Christology and the Two Sons Worry" (exploring whether the pre-death Jesus and the post-resurrection Jesus are really the same incarnation), and one on "Physicalism and the Death of Christ" (examining what Christ's death means on a physicalist ontology).²⁹ And Matthew Hart's essay "Christian Materialism Entails Pelagianism" develops the sinlessness problem with rigorous philosophical argumentation.³⁰

We will engage with each of these essays in depth in the chapters that follow. But I want to stress here that the case against physicalist Christology is not the work of a single scholar or a single argument. It is a cumulative case built from multiple independent lines of reasoning — biblical, historical, philosophical, and theological — all converging on the same conclusion: physicalism about human nature is incompatible with orthodox Christology.

Why the Physicalist Cannot Appeal to Mystery

At this point, I can anticipate an objection. Some physicalists might respond: "The Incarnation is a mystery. We don't fully understand how two natures are united in one Person. So why should we expect physicalism to give a complete account of what happens during the triduum or at the resurrection? Mystery is an appropriate response to the deepest truths of the faith."

I want to be very careful here, because I believe mystery has a genuine and important place in Christian theology. The Incarnation is a mystery — a truth that transcends our full comprehension. I have no desire to flatten the mystery of Christ into a neat philosophical formula. We are talking about the infinite God becoming a finite human being. That will always exceed our understanding.

But there is a crucial difference between mystery and incoherence. A mystery is something we cannot fully explain but that does not involve a logical contradiction. The Trinity is a mystery — one God in three Persons is difficult to understand, but it is not logically contradictory (as Pawl has shown at length in his In Defense of Conciliar Christology).³¹ The hypostatic union is a mystery — two natures in one Person is hard to comprehend, but it does not violate the law of non-contradiction (as Loke has demonstrated in his Kryptic Model).³²

But physicalism does not create mystery. It creates incoherence. When physicalism says that the Incarnation was interrupted at the cross — that for thirty-six hours, the Son was not united to a living human nature — it does not leave us with a mystery to contemplate. It leaves us with a flat contradiction of the Chalcedonian "without separation." When physicalism says that there was no Christ to descend to the dead, it does not deepen the mystery of Christ's saving work. It eliminates it. When physicalism cannot explain how the risen Jesus is the same person as the crucified Jesus, it does not gesture toward an unfathomable truth. It creates a problem that undermines the coherence of the resurrection.

Mystery says: "This is true, and we cannot fully explain how." Incoherence says: "This cannot be true, given our other commitments." Physicalism, applied to the Incarnation, produces the latter — not the former.

The Dualist Alternative: How Substance Dualism Preserves the Incarnation

Before I close this chapter, I want to make sure we see not just what physicalism destroys but what substance dualism preserves. It is not enough to show that physicalism fails the Incarnation. We need to show that dualism succeeds — that it provides a coherent, biblical, historically grounded framework for understanding every aspect of the Incarnation.

And it does. Consider the contrast:

On the triduum: Dualism says Christ's soul separated from His body at death, but the Son remained united to both. The Incarnation continued without interruption. Physicalism says there was nothing to survive death — the Incarnation was broken.

On the descent: Dualism says Christ's soul descended to the dead, preached to the spirits in prison, and was with the thief in paradise. Physicalism says there was no Christ to descend anywhere.

On the resurrection: Dualism says the same soul was reunited with the (now glorified) body, preserving personal identity seamlessly. Physicalism creates a gap in personal identity that cannot be bridged without the soul.

On the virgin birth: Dualism says the soul was created and present from conception, making the Incarnation complete from the first moment. Physicalism makes the Incarnation gradual and uncertain.

On the ascension: Dualism says the soul naturally bridges the material and spiritual realms, making the heavenly session coherent. Physicalism has no bridge between a physical body and a non-physical heaven.

On sinlessness: Dualism says Christ's sinless soul, uniquely created by God and empowered by the Holy Spirit, explains His moral perfection without Pelagianism. Physicalism either makes Christ's brain different from ours or falls into Pelagianism.

On personhood: Dualism says both divine and human persons are immaterial subjects, making the concept of "person" analogically coherent across the divine and human domains. Physicalism makes personhood equivocal.

On the beatific vision, theosis, and sanctification: Dualism says the immaterial soul has a natural capacity for relating to the immaterial God, participating in the divine nature, and being transformed by the Spirit. Physicalism reduces all of this to brain chemistry.

At every single point — every one — substance dualism provides a coherent account of the Incarnation while physicalism creates a serious, often fatal, problem. I want the reader to pause and let the weight of this settle in. This is not a situation where physicalism handles six out of eight issues well and struggles with two. It fails at every point. There is not a single major aspect of orthodox Christology where physicalism performs as well as substance dualism. Not one.

Why is this? The pattern is not coincidental. It reflects a deep structural truth: the Incarnation was designed — by God Himself — to work with the body-soul structure of human nature. The Son of God did not assume a mere physical organism. He assumed a complete human nature: a body and a soul. That is what Genesis 2:7 tells us human nature is — the breath of life (neshamah, נְשָׁמָה) breathed into a body formed from the dust of the ground. That is what the councils define Christ's human nature to be — "a rational soul and a body." That is what Scripture teaches. That is what the church has always believed. Physicalism, by removing one of the two essential components of human nature, breaks the system at every joint.

Think of it this way. The human soul, on the dualist view, functions like the keel of a ship. A keel is the structural backbone that runs along the bottom of a vessel and keeps it stable through storms, high waves, and rough seas. Without the keel, the ship capsizes the moment conditions get rough. In the same way, the soul is the structural backbone of Christ's human nature. During calm waters — during Christ's earthly life, when body and soul were together and functioning normally — you might not even notice the keel. Everything seems to work just fine. But when the storm hits — when Christ dies on the cross and the body ceases to function — the keel is what keeps the whole vessel from capsizing. The soul maintains the continuity of the Incarnation through the storm of death. It preserves personal identity. It enables Christ's activity during the triduum. It provides the bridge between the material and the spiritual realms. Without it, the ship goes down. And that is exactly what happens on physicalism: the Incarnation capsizes at the cross.

I want to say something personal here, because this is not just a matter of academic theology for me. As I have studied these questions — reading the church fathers, working through the councils, engaging with the philosophy — I have come to see more and more clearly how beautiful the dualist account of the Incarnation really is. There is an elegance to it. The Son assumes a body and a soul. He lives a genuinely human life through that body and soul. He dies — and the body and soul separate, as they do for every human being. But the Son holds onto both. He does not let go of either component. The body rests in the tomb, still His. The soul descends to the dead, still His. And on the third day, He reunites them — body and soul brought back together, now glorified, never to be separated again. The whole arc of the Incarnation — from the virgin conception to the eternal heavenly session — is a seamless, unbroken story of the Son united to a complete human nature. Physicalism shatters that seamless arc. It puts a gap in the story at the most critical moment. And once the gap is there, it cannot be closed.

The Christological Framework: Loke's Kryptic Model and Why It Requires Dualism

As I have discussed in Chapter 17, I follow Andrew Loke's Kryptic Model of the Incarnation — the Divine Preconscious Model. On this view, the Son's divine attributes (omniscience, omnipotence, omnipresence) were not surrendered at the Incarnation (contra kenoticism) but were concealed (krypsis) — present at a "preconscious" level but not actively accessed in Christ's waking human conscious experience unless the Father willed it. Christ had a single stream of consciousness — genuinely human — while His divine knowledge and powers operated "behind the scenes."³³

This model requires substance dualism. The "preconscious" level where the divine attributes are concealed is not a brain state. It is not a neurological phenomenon. It is an immaterial reality — a dimension of the Person of the Son that exists beyond the physical brain. On physicalism, there is no "preconscious" level beyond the brain. There is no immaterial dimension where divine attributes can be stored. Everything about Christ's experience would have to be a product of His physical brain — and a physical brain cannot hold omniscience "in storage." The Kryptic Model, which I believe is the best available account of how Christ's two natures relate, simply cannot work on a physicalist ontology.

Similarly, Timothy Pawl's Conciliar Christology — which provides the most rigorous contemporary philosophical defense of the conciliar definitions — presupposes that Christ's human nature includes an immaterial rational soul, because that is what the councils explicitly require. Pawl's work demonstrates that the Chalcedonian Definition is philosophically coherent, but only on the assumption that the terms mean what the councils said they mean — and the councils said Christ has "a rational soul and a body."³⁴

Anticipating Physicalist Responses

In the chapters that follow, we will engage with various physicalist attempts to address these problems. Let me briefly preview the main strategies that physicalists have employed, so that readers know what to expect:

Some physicalists have suggested that the Son remained united to the body in the tomb during the triduum — maintaining the hypostatic union with a corpse. We will show in Chapter 21 that a corpse is not a human nature. Dead biological matter is not a person.

Some have proposed that Christ was immediately resurrected at death — so there was no gap at all. We will show in Chapter 21 that this contradicts the biblical narrative (the body was in the tomb for three days), eliminates Holy Saturday entirely, and contradicts the creed ("was buried").

Some have argued that God "reconstituted" or "re-created" the same person at the resurrection, so that personal identity is preserved by divine fiat. We will show in Chapter 24 that this creates the replica problem: if the person ceased to exist and was then re-created, the continuity of identity is broken, and no amount of divine power can make a replica into an original.

Some have claimed that "constitution Christology" — the view that the Son constitutes the human nature without being identical to it — can save physicalism. We will show in Chapter 22 that even on the constitution view, the human person ceases to exist at death, and the triduum problem remains.

Some have argued that the problems of physicalist Christology are no worse than the problems of dualist Christology — that dualism has its own puzzles (the interaction problem, the pairing problem). We will show in Chapter 35 that the interaction problem is an unsolved puzzle, not a refutation. It is a question about how two things that exist interact. The problems of physicalist Christology are not puzzles about how — they are demonstrations that the Incarnation cannot work on physicalist assumptions. These are fundamentally different kinds of problems.³⁵

Each of these responses will receive careful, fair treatment in the chapters ahead. I want to be clear: I take these responses seriously. These are thoughtful scholars doing their best to reconcile their philosophical commitments with their theological convictions. But I am convinced — and I believe the evidence will demonstrate — that none of these responses succeeds. The problems are not peripheral. They are structural. They arise from the very core of what physicalism claims, and they cannot be fixed without abandoning physicalism itself.

Conclusion: The Stakes Could Not Be Higher

Let me close this chapter with a word about what is at stake. I want to speak not just as a scholar but as a Christian — as someone who loves the Lord Jesus Christ and who cares deeply about getting Christology right.

The Incarnation is not an abstract doctrine. It is the very beating heart of the Christian faith. Everything depends on it. The entire gospel — Creation, Fall, Redemption, Consummation — turns on the hinge of this one incredible truth: the eternal Son of God, the second Person of the Trinity, the one through whom all things were made, became a human being. He took on our nature. He was born, nursed, grew, wept, hungered, suffered, and died. He took our sins upon Himself. He bore our punishment. He died in our place. He was buried. And on the third day, He rose again — the same Jesus, body and soul, glorified and triumphant.

Every single element of that story depends on Christ having a complete human nature — a body AND a soul. Without the soul, the story falls apart. The Incarnation is interrupted at the cross. The descent to the dead is eliminated. The personal identity of the risen Christ is compromised. The permanent Incarnation is undermined. The sinlessness of Christ becomes either a biological anomaly or a Pelagian achievement. The concept of personhood that holds together both the Trinity and the hypostatic union loses its coherence.

I realize these are strong claims. I have tried to present the case fairly and clearly. In the nine chapters that follow, we will develop each of these arguments in full detail, engaging with the best scholarship on all sides. But the destination is already in view. Physicalism cannot account for the Incarnation. The Word made flesh demands the soul.

As we begin this journey through Part V, I invite the reader — whether you agree with me right now or not — to follow the arguments with an open mind. Consider the evidence. Weigh the alternatives. And ask yourself this question: if physicalism creates even one of the problems we have identified — if it threatens the continuity of the Incarnation at even one point — is that not reason enough to reconsider whether physicalism is compatible with the faith once delivered to the saints?

I believe the answer is yes. And I believe the cumulative case, as it unfolds carefully and thoroughly over the next nine chapters, will make that answer truly inescapable.

Bibliography

Aquinas, Thomas. Summa Theologiae. Translated by the Fathers of the English Dominican Province. London: Burns, Oates & Washbourne, 1920.

Cooper, John W. Body, Soul, and Life Everlasting: Biblical Anthropology and the Monism-Dualism Debate. Grand Rapids, MI: Eerdmans, 2000.

Cortez, Marc. "Physicalism, the Incarnation, and Holy Saturday: A Conversation with Karl Barth." In Christian Physicalism? Philosophical Theological Criticisms, edited by R. Keith Loftin and Joshua R. Farris, chap. 7. Lanham, MD: Lexington Books, 2018.

Crisp, Oliver D. Divinity and Humanity: The Incarnation Reconsidered. Current Issues in Theology. Cambridge: Cambridge University Press, 2007.

Davis, Stephen T. Christian Philosophical Theology. Oxford: Oxford University Press, 2006.

Farris, Joshua R. An Introduction to Theological Anthropology: Humans, Both Creaturely and Divine. Grand Rapids, MI: Baker Academic, 2020.

Gregory of Nazianzus. Epistle 101 (To Cledonius, Against Apollinarius).

Gregory of Nyssa. Antirrheticus adversus Apollinarem.

Hart, Matthew J. "Christian Materialism Entails Pelagianism." In Christian Physicalism? Philosophical Theological Criticisms, edited by R. Keith Loftin and Joshua R. Farris, chap. 10. Lanham, MD: Lexington Books, 2018.

Kelly, J. N. D. Early Christian Doctrines. 5th rev. ed. London: A&C Black, 1977.

Loftin, R. Keith, and Joshua R. Farris, eds. Christian Physicalism? Philosophical Theological Criticisms. Lanham, MD: Lexington Books, 2018.

Loke, Andrew Ter Ern. A Kryptic Model of the Incarnation. Routledge New Critical Thinking in Religion, Theology, and Biblical Studies. London: Routledge, 2014.

McCall, Thomas H. Foreword to Christian Physicalism? Philosophical Theological Criticisms, edited by R. Keith Loftin and Joshua R. Farris. Lanham, MD: Lexington Books, 2018.

McMartin, Jason. "Holy Saturday and Christian Theological Anthropology." In Christian Physicalism? Philosophical Theological Criticisms, edited by R. Keith Loftin and Joshua R. Farris, chap. 6. Lanham, MD: Lexington Books, 2018.

Mullins, R. T. "Physicalist Christology and the Two Sons Worry." In Christian Physicalism? Philosophical Theological Criticisms, edited by R. Keith Loftin and Joshua R. Farris, chap. 8. Lanham, MD: Lexington Books, 2018.

———. "Physicalism and the Death of Christ." In Christian Physicalism? Philosophical Theological Criticisms, edited by R. Keith Loftin and Joshua R. Farris, chap. 9. Lanham, MD: Lexington Books, 2018.

Pawl, Timothy. In Defense of Conciliar Christology. Oxford Studies in Analytic Theology. Oxford: Oxford University Press, 2016.

Wilkinson, Michael A. Crowned with Glory and Honor: A Chalcedonian Anthropology. Studies in Historical and Systematic Theology. Bellingham, WA: Lexham Academic, 2024.

Zimmerman, Dean. "The Compatibility of Materialism and Survival: The 'Falling Elevator' Model." Faith and Philosophy 16, no. 2 (1999): 194–212.