Appendix A

Glossary of Key Terms

A book that ranges from Greek metaphysics to Hebrew anthropology, from fourth-century church councils to twenty-first-century philosophy of mind, can pile up technical vocabulary fast. This glossary gathers the most important terms used throughout the book and defines each one in plain English. Where a word comes from Greek or Hebrew, I have given the transliteration and the original script so the reader can recognize it on the page. Where a term is associated with a particular thinker, council, or chapter of this book, I have noted the connection so the reader knows where to look for fuller treatment.

The goal here is not exhaustive scholarship but quick orientation. If you stumble on a word in the main chapters and want a one-paragraph reminder of what it means, this is the place to come. For deeper engagement, the chapter cross-references will point you to where each idea is developed at length.¹

A

Anhypostasia (Greek ἀνυποστασία, an- "not" + hypostasis "person")

The doctrine that Christ's human nature does not exist as a person on its own. Christ's humanity is real and complete, but it never has its own independent personhood apart from the Son of God. Together with enhypostasia, this term explains why the Incarnation does not produce two persons (see Chapter 19).

Apollinarianism

The fourth-century heresy taught by Apollinaris of Laodicea (c. 310–390), who argued that in the Incarnation the divine Logos took the place of Christ's human rational soul (nous). On this view, Christ had a human body but a divine mind, not a human one. The church condemned Apollinarianism at the Council of Constantinople (381), insisting that Christ has a complete human nature including a human soul (see Chapter 12). Gregory of Nazianzus's famous reply still stands: "What is not assumed is not healed."²

Athanasian Creed (Quicunque Vult)

A Western creed, probably from the fifth or sixth century, that gives one of the most precise statements of Trinitarian and Christological orthodoxy in the early church. It affirms that Christ is "perfect God and perfect man, of a reasonable soul and human flesh subsisting" — language directly relevant to the book's argument that Christ's human nature includes a soul.

B

Beatific Vision

The direct, unmediated vision of God enjoyed by the redeemed in the world to come (and, on most accounts, by Christ's human soul during His earthly life). Theologians have debated whether this vision is fundamentally an intellectual seeing or a fuller union of love and knowledge. Physicalism has trouble accounting for the beatific vision because a purely physical brain cannot see an immaterial God (see Chapter 29).

C

Chalcedonian Definition (451)

The Christological statement issued by the Council of Chalcedon, which confessed Christ as "one and the same Son" who is "truly God and truly man," made known "in two natures, without confusion, without change, without division, without separation." This four-fold negation has shaped orthodox Christology ever since.

Communicatio Idiomatum (Latin, "communication of attributes")

The traditional doctrine that what is true of either nature of Christ can be predicated of the one Person. So we can say "the Son of God died" (predicating a human experience of the divine Person) or "the man Jesus is omnipresent" (predicating a divine attribute of the human-natured Person), because there is one Person who possesses both natures (see Chapter 14).

Concrete Nature View

The view that Christ's human nature is a concrete particular — a specific body united to a specific human soul — and not merely an abstract bundle of properties. The author holds this view: when the Son became incarnate, He assumed a real, particular human nature, body and soul (see Chapters 17 and 19).

Conditional Immortality (CI)

The view that human beings are not naturally immortal; immortality is a gift granted to the redeemed, while the unredeemed finally pass out of existence rather than suffering eternal conscious torment. Many in the modern CI movement have also embraced physicalism, but the two positions are logically separable. Chapter 33 argues that conditional immortality does not require physicalism — and that physicalism creates serious problems for Christology that CI defenders should want to avoid.

Constitution View

A non-dualist view of human nature, defended especially by Lynn Rudder Baker and Kevin Corcoran, on which a person is constituted by a body without being identical to it (much as a statue is constituted by clay without being identical to clay).³ The view tries to preserve a distinction between person and body while denying any immaterial soul. As Chapter 22 argues, the constitution relation breaks down at death, leaving the same triduum-mortis problem facing other physicalist views.

Creationism (about the soul)

The view that God directly creates each individual human soul at conception (or at some early point in embryonic development) rather than the soul being passed down through natural generation. This view contrasts with traducianism (the view that the soul is generated along with the body from the parents). Most substance dualists hold creationism.

D

Dualism, Substance

See Substance Dualism.

Dualism, Holistic

John W. Cooper's term for a substance dualism that strongly emphasizes the integration of body and soul during earthly life, while still affirming that the two are ontologically distinct and that the soul can survive bodily death.⁴ The author embraces holistic dualism rather than a more "Cartesian" picture that pictures soul and body as loosely connected substances.

Dyothelitism (Greek dyo- "two" + thelēma "will")

The doctrine, defined at the Third Council of Constantinople (681), that Christ has two wills — one divine and one human — corresponding to His two natures. The two wills operate in harmony, the human freely submitting to the divine, as in Gethsemane: "Not my will, but yours be done" (Luke 22:42). Opposed to monothelitism (see Chapter 13).

E

Emergent Dualism

William Hasker's view that the soul genuinely emerges from the brain's complex organization but, once it emerges, is a distinct immaterial substance that can survive bodily death (if God sustains it). This is a middle position between strict physicalism and traditional substance dualism. The author treats it sympathetically but argues it still creates Christological problems regarding the timing and origin of Christ's human soul (see Chapters 2 and 25).

Emergentism

The broader view that consciousness and mental properties "emerge" from the complexity of the physical brain. In its non-dualist form (e.g., Philip Clayton), the emergent properties remain dependent on the physical substrate and cannot survive its destruction. Distinguished from emergent dualism by the absence of any new substance.

Enhypostasia (Greek ἐνυποστασία, "in-personhood")

The doctrine that Christ's human nature, while not having its own personhood, has its personhood in the Person of the Son. The human nature exists, but it exists in (en-) the divine hypostasis. Together with anhypostasia, this technical pair explains how the Incarnation produces one Person in two natures (see Chapter 19).

H

Homoousios (Greek ὁμοούσιος, "of the same essence/substance")

The decisive term used at Nicaea (325) to affirm that the Son is of the same divine essence as the Father — not a created being or a lesser deity. This single word stands at the heart of Trinitarian orthodoxy (see Chapter 11).

Hylomorphism

From the Greek hylē (matter) and morphē (form), the Aristotelian-Thomistic view that the soul is the substantial form of the body — not a separate substance in the Cartesian sense, but the organizing principle that makes the body a living human being. On Aquinas's hylomorphism, the soul can survive bodily death in a separated state, though such existence is unnatural and incomplete until the resurrection. The author treats hylomorphism as broadly compatible with substance dualism for Christological purposes (see Chapter 2).

Hypostasis (Greek ὑπόστασις)

A Greek term that came to mean, in Trinitarian and Christological usage, "person" or the concrete subject of an experience. Whereas ousia (essence) is what something is, hypostasis is who or which something is. The Trinity is one ousia in three hypostases; Christ is one hypostasis in two natures (see Chapter 14).

Hypostatic Union

The union of the divine and human natures in the one Person (hypostasis) of the Son of God. The two natures are not blended, separated, or replaced; they are united in the single subject of the eternal Son. This union, on the author's view, requires that Christ's human nature includes both a body and a soul, and is preserved unbroken even through death (see Chapter 14 and especially Chapters 21 and 22).

I

Intermediate State

The state of the believer (or unbeliever) between bodily death and the final resurrection. The author affirms a conscious intermediate state: the soul remains aware and active, "with Christ" (Phil. 1:23) for the believer, awaiting the resurrection of the body. Physicalist views generally deny any intermediate state, treating death as a gap that God bridges by re-creating the person at the resurrection (see Chapter 3).

K

Kenosis / Kenoticism (Greek κένωσις, "emptying")

The view, drawn from Philippians 2:7 ("emptied himself"), that the Son surrendered or set aside certain divine attributes (such as omniscience and omnipotence) in order to become incarnate. The author rejects kenoticism because divine attributes are essential to the divine nature; the Son cannot cease to be omniscient and remain God (see Chapter 15).

Krypsis / Kryptic Christology (Greek κρύψις, "hiding, concealment")

The view, classically associated with Lutheran theologians and developed in a sophisticated contemporary form by Andrew Ter Ern Loke, that the divine attributes were not surrendered in the Incarnation but concealed.⁵ Loke's "Divine Preconscious Model" places Christ's divine knowledge and power at a preconscious level — present and accessible, but not flooding His ordinary human consciousness. This is the author's preferred model of the Incarnation (see Chapter 17).

L

Logos (Greek λόγος, "word, reason")

A title of the eternal Son of God, drawn especially from John 1:1: "In the beginning was the Word, and the Word was with God, and the Word was God." In the Incarnation, "the Word became flesh" (John 1:14) — which the book argues must mean a complete human nature, body and soul.

M

Monophysitism (Greek monos "one" + physis "nature")

The heresy that Christ has only one nature — typically a divine nature that has absorbed or replaced the human nature. Condemned at Chalcedon (451). Modern Christian physicalism, by reducing Christ's "human nature" to a body that ceases at death, comes uncomfortably close to a functional monophysitism during the triduum mortis.

Monothelitism (Greek monos "one" + thelēma "will")

The seventh-century view that Christ has only one will — a divine will. Condemned at the Third Council of Constantinople (681), which defined dyothelitism as orthodox (see Chapter 13). Monothelitism is sometimes called a "compromise" position, but the church judged that to deny a human will is to deny a complete human nature.

N

Nephesh (Hebrew נֶפֶשׁ)

A rich Hebrew term often translated "soul," but with a wider semantic range including "life," "self," "person," "appetite," and "throat." Genesis 2:7 calls man a nephesh chayyah ("living soul/being"). Later passages (Gen. 35:18; 1 Kings 17:21–22) speak of the nephesh departing at death and returning at resuscitation — language that, the author argues, points to a real immaterial reality (see Chapter 3).

Nestorianism

The fifth-century view associated with Nestorius, condemned at the Council of Ephesus (431), which was perceived to divide Christ into two persons rather than one Person in two natures. Whether the historical Nestorius actually held the view named after him is debated, but "Nestorianism" stands as a warning against any Christology that fractures the unity of Christ's Person.

Nonreductive Physicalism

The view, defended by Christian philosophers Nancey Murphy and Joel Green, that mental properties are real and not reducible to physics or chemistry, but that there is no immaterial soul.⁶ The "nonreductive" qualifier tries to preserve the dignity of mental life while still denying any second substance. The author argues that nonreductive physicalism faces all the major Christological problems of stricter physicalisms (see Chapters 20–24).

Nous (Greek νοῦς, "mind, intellect")

The rational, intellectual aspect of the soul in Greek thought. Apollinaris claimed that in Christ the divine Logos took the place of the human nous; the church responded by insisting that Christ has a full human nous, because what is not assumed is not healed (see Chapter 12).

O

Ousia (Greek οὐσία, "being, essence")

The fundamental "what" of a thing — its essence or substance. In Trinitarian theology, the Father, Son, and Holy Spirit share one ousia; in Christology, Christ has two natures (each with its own kind of ousia) united in one hypostasis.

P

Persona (Latin)

The Latin term used to translate the Greek hypostasis; "person" in the Trinitarian and Christological sense. Augustine and Boethius helped fix the technical Western usage. A "person" in this technical sense is not exactly the modern psychological "person"; it is the bearer of a nature, the "who" that has a "what."

Physicalism (Reductive)

The view that mental states are nothing but brain states — identical to neural activity, with no remainder. Reductive physicalists deny qualia, immaterial souls, and any non-physical reality. Few Christian philosophers hold this strict version, but it represents the baseline physicalist commitment.

Physicalism (Nonreductive)

See Nonreductive Physicalism.

Physis (Greek φύσις, "nature")

The Greek term for "nature" in Christological usage. Chalcedon affirmed that Christ exists "in two physeis" (natures) — divine and human — without confusion or separation. The Greek term carries connotations of an active, living kind of being, not a static set of properties.

Pneuma (Greek πνεῦμα, "spirit, breath, wind")

A New Testament term often used for the human spirit, the Holy Spirit, or the immaterial side of human life. Jesus "gave up his pneuma" at the cross (Matt. 27:50; John 19:30) — language the author argues points to a real immaterial reality that survives bodily death (see Chapter 8).

Psyche (Greek ψυχή, "soul, life")

The standard New Testament term for "soul" or sometimes simply "life." Jesus warns of those who can kill the body but not the psychē (Matt. 10:28) — a passage that strongly suggests body and soul are distinct realities, with the soul able to survive bodily death (see Chapter 3).

Q

Qualia (singular: quale)

The "what it is like" character of conscious experience — the redness of red, the pain of a stubbed toe, the taste of coffee. Many philosophers (most famously Frank Jackson and David Chalmers) have argued that qualia cannot be reduced to neural firings, posing a serious challenge to physicalism (see Chapter 4).

R

Reductive Physicalism

See Physicalism (Reductive).

Ruach (Hebrew רוּחַ, "spirit, wind, breath")

A Hebrew term for "spirit" used both for God's Spirit and for the human spirit. Ecclesiastes 12:7 says "the dust returns to the earth as it was, and the ruach returns to God who gave it" — a key text for the biblical case for substance dualism (see Chapter 3).

S

Soul

The immaterial dimension of a human being, distinct from the body, which is the seat of consciousness, intellect, will, and personal identity, and which can exist apart from the body in the intermediate state. The author affirms that human beings — including Christ in His human nature — possess such souls. The major biblical terms behind "soul" are nephesh, psychē, and (often interchangeably for our purposes) ruach and pneuma.

Substance Dualism

The view that a human being is composed of two distinct substances — a material body and an immaterial soul — which are deeply integrated in life but can be separated at death. The soul is not merely a property or function of the body; it is its own kind of thing, with its own ontological status. This is the author's position throughout the book and the framework within which the case against physicalist Christology is built.⁷

T

Theosis (Greek θέωσις, "deification")

The doctrine, especially prominent in Eastern Orthodox theology, that the redeemed are called to "become partakers of the divine nature" (2 Pet. 1:4) — to be transformed by grace into the likeness of God. Athanasius's classic formula: "God became man so that man might become God." The author argues that physicalism struggles to account for theosis: it is hard to see how a purely physical organism could "participate" in the divine life, while substance dualism locates theosis primarily in the soul's transformation (see Chapter 29).

Theotokos (Greek Θεοτόκος, "God-bearer")

The title given to Mary at the Council of Ephesus (431), affirming that the One she bore is truly God, not merely a man whom God later joined. The title is fundamentally a Christological claim: it protects the unity of Christ's Person across both natures.

Triduum Mortis (Latin, "the three days of death")

The period from Christ's death on Good Friday to His resurrection on Easter Sunday. On the author's view, this period is the single most decisive test of any Christology: was the hypostatic union preserved during the triduum, and if so, how? Substance dualism answers easily — Christ's human soul survived death and remained united to the Son. Physicalism struggles to answer at all (see Chapter 21).

Two-Minds View

Thomas V. Morris's model of the Incarnation, on which Christ has two distinct minds or streams of consciousness — one divine (omniscient) and one human (limited).⁸ The divine mind has access to the human mind's contents, but not vice versa. The author engages this view in Chapter 16 and ultimately prefers Loke's Kryptic Model, which posits one stream of consciousness with a divine "preconscious" backdrop.