Incarnation and Christology
By the close of the fourth century, the early Church had agreed that God the Son, the second
person of the Trinity, is no less divine than God the Father. But this Trinitarian settlement led
directly to another, equally vexing question: how could Jesus of Nazareth, a human man, also be
identical to God the Son? After another period of intense debate, the Church defined the doctrine
of the Incarnation, which asserts that Christ is one person (or one hypostasis) who exists in two
natures, one fully human, the other fully divine (Tanner 1990: 83; Kelly 1978: 338–343). Yet, as
with the doctrine of the Trinity, on its own, this conciliar terminology does not attempt to solve
the underlying philosophical problem.
In contemporary philosophy, this problem has been called the “fundamental philosophical
problem of Christology”. As Richard Cross puts it:
how is it that one and the same thing could be both divine (and thus, on the face of it, necessary,
and necessarily omniscient, omnipotent, eternal, immutable, impassible, and impeccable) and
human (and thus, on the face of it, have the complements of all these properties)? (Cross 2009:
453)
In other words, the fundamental philosophical problem of Christology is the problem that arises
when a single subject bears incompatible properties. Christ seems to be both necessarily
omniscient, as the divine Son, the second person of the Trinity, and yet also limited in
knowledge, as the human man, Jesus of Nazareth—and so on for other divine and human
attributes. Yet Christ is one person, not two: he just is the divine Son and he just is Jesus of
Nazareth. On standard interpretations of logical consistency, nothing can have logically
incompatible properties at the same time and in the same respect—hence the problem.
A venerable attempted solution to the problem of incompatible properties makes use of
grammatical modifiers to index Christological predications to their respective natures: Christ is
limited in knowledge qua his human nature, and omniscient qua his divine nature, where “qua”
means “with respect to” or “in virtue of”. More simply: Christ qua human is limited in
knowledge; Christ qua divine is omniscient. The thought of Thomas Aquinas furnishes a
foundational source for this solution (Summa Theologiae 3.16.1–12; for broader discussion of
patristic and medieval uses, see Cross 2002: 192–205). Thomas Senor forcefully argues that this
grammatical solution does not work, for it cannot block the relevant entailment: since the one
Christ really is human and really is divine, it follows that the one Christ is also limited in
knowledge (qua human) and omniscient (qua divine), and so the contradiction remains (Senor
2002; see also Morris 1986).
Kenotic Christologies hold that at the point of incarnation, in order to become a human being,
God the Son relinquished the divine attributes (Forrest 2000; Evans 2002, 2006). In a way, the
kenotic option neatly solves the problem of incompatible properties, since Christ is not
omnipotent and omniscient (etc.) at the same time as he is limited in power and knowledge.
Kenotic Christologies have a venerable pedigree, as well as some clear Biblical warrant
(Philippians 2; for discussion see Evans 2006; McGuckin 1994 [2004: 189]. But if omnipotence
and omniscience are essential divine attributes, then it is not possible for God the Son to
relinquish them during the incarnation and regain them after the incarnation while remaining
self-identical.
Compositional Christologies try to solve the problem of incompatible properties by appealing to
the various “parts” that together compose the whole Christ. According to Thomas V. Morris,
Christ is composed of the divine mind of God the Son, a human mind, and a human body. On his
telling, Christ counts as fully divine, because he has a divine mind, which is the seat of his
omnipotence and omniscience; he also counts as fully human because he has a human mind and
a human body (Morris 1986). Morris seeks to dispel the contradiction between divine and human
attributes by revising our understanding of Christ’s human attributes. Morris denies that human
beings as such are essentially limited in power and knowledge (etc.). This move clears the way
for attributing omnipotence and omniscience (etc.) even to the human, incarnate Christ, while
also denying that the human, incarnate Christ is limited in power and knowledge. Richard
Swinburne (1994) defends a similar Christology, but according to Swinburne, Christ is
composed only of God the Son and a human body, which together constitute both a human way
of thinking and acting and also a divine way of thinking and acting.
Other compositional Christologies appeal to supposed mereological facts about the incarnation to
ground a more sophisticated version of the “qua move” (discussed above). If God the Son has
human parts and divine parts, then perhaps the whole mereological composite can borrow
properties from its constituent parts without violating the law of non-contradiction. Analogously,
we might say that an apple is both colored and not colored, since it is red (colored) with respect
to its skin, but white (not colored) with respect to its flesh. There is a sense in which the apple as
a whole is both colored and not colored because it borrows properties from its parts. Perhaps
something similar can be said about Christ, understood as a mereological composite of God the
Son, a human body, and a human soul. Leading advocates of this sort of view include Brian
Leftow (1992, 2011) and Eleonore Stump (2002).
Timothy Pawl (2014, 2016) seeks to dispel the fundamental problem by revising the truth
conditions of Christological predications like “Christ is omniscient” and “Christ is limited in
knowledge”. According to Pawl, it is incorrect that “being omniscient” and “being limited in
knowledge” are logically contradictory properties at all. In fact, according to Pawl, once we
correctly understand their truth conditions, we can see that they can both be true of the same
subject after all. On Pawl’s account, “Christ is omniscient” is true just in case Christ has a nature
that is omniscient and “Christ is limited in knowledge” is true just in case Christ has a nature that
is limited in knowledge. Because Christ, and only Christ (so far as we know) has two natures,
only Christ can be both omniscient and limited in knowledge. At first glance, Pawl’s proposed
solution might seem to be the “qua move” once again, in different dress. But it is importantly
different: Pawl is content to affirm the very entailments (e.g., “Christ is omniscient and limited in
knowledge”) that the qua move seeks to block; he simply denies that this entailment is logically
contradictory.
JcHBeall goes a step further and argues that some predicates really are both true and false of
Christ, because Christ really is a contradictory being (2019, 2021). Beall defends a contradictory
Christology because he accepts a non-standard model of logic, one on which some predicates can
be neither true nor false of a subject, and other predicates can be both true and false of a subject.
According to Beall, logic as such—that is, his favored account of logic—is neutral about whether
any given substantive theory contains true contradictions. To determine whether it does, we must
examine the theory’s axiomatic statements. When we examine the axioms of orthodox
Christology, according to Beall, we find that they include authoritative conciliar statements that
are most naturally read as contradictory—e.g., “Christ is passible and impassible” (2019: 415).
Rather than revise or reinterpret such statements so that they are not contradictory, we should
accept that they are.
2.3 Atonement and Salvation
Arguably, the deepest and most fundamental Christian affirmation is that Christ saves. In
traditional terminology, another way to express the same affirmation is that Christ “atones” for
the sins of human beings. Unlike the doctrines of the Trinity and the Incarnation, however, the
early Church never formally defined a single orthodox account of exactly how Christ saves or
what it is about his life, death, and resurrection that accomplishes that saving work. As a result, a
variety of theories or models of atonement have proliferated throughout the centuries.
Contemporary work in analytic philosophical theology typically builds on these models,
reformulates them in contemporary language, and seeks to defend them from criticism.
Satisfaction models argue that as a result of their sinfulness, human beings have a debt or
obligation to God that they cannot possibly repay. By becoming incarnate, living a sinless life,
and voluntarily dying for the sake of humanity, Christ successfully discharges the debts and
obligations that human beings owe to God. Anselm’s “Why God Became Human” (Cur deus
homo) is the locus classicus for the satisfaction theory, which has more recently been defended
by Swinburne (1988). Closely related to satisfaction models, penal substitution models claim that
human beings deserve punishment from God as a result of their sinfulness. Christ saves by freely
agreeing to be punished in their place. Mark Murphy (2009) proposes a similar model of
“vicarious punishment”, on which Christ’s suffering actually counts as the required punishment
for guilty human beings, since knowing that a loved one suffers in one’s place is itself a form of
punishment.
Satisfaction and penal substitution theorists must explain why a perfectly merciful God would
require satisfaction or punishment from human beings at all, and why a perfectly just God would
allow an innocent person to play the required role (Porter 2004). Accordingly, satisfaction and
penal substitution views have been heavily criticized by modern and contemporary theologians
for depicting God as a petty, wrathful tyrant. Adolph von Harnack’s nineteenth-century criticism
of Anselm remains representative. According to Harnack, Anselm’s account depends on a
mythological conception of God as the mighty private man, who is incensed at the injury done to
His honor and does not forego His wrath till He has received an at least adequately great
equivalent. (1899: 77)
More recently, feminist theologians and philosophers have criticized satisfaction and penal
substitution views for valorizing suffering (Brown and Parker 1989).
Eleonore Stump (2018) argues that typical satisfaction and penal substitution accounts cannot
address the sinner’s persistent dispositions toward wrongdoing and concomitant feelings of
shame. She dubs her positive proposal the “Marian” interpretation of atonement, and argues that
it can explain how sinners are freed from shame and restored to fellowship with God. The
proposal defies easy summary but it advances an account of atonement as union with God that is
further explained using second-personal, psychological notions like “mind-reading” and empathy
(2018: 138–139). Christ on the cross mind-reads—that is, psychically experiences—the mental
states of every human sinner. Sinful human beings are thereby united to Christ, and so to God.
When the indwelling Holy Spirit leads sinners to respond to Christ with love, they also will what
God wills. The resulting state of union with God also heals the stain on the soul that is the
sinner’s shame.
Several other models, also prominent in the Patristic and medieval tradition, have so far received
little attention from analytic philosophers of religion. These include “ransom” theories on which
human beings are freed from Satan’s grasp, and especially “theosis” or “divinization” accounts
of atonement and salvation, on which Christ’s saving work consists in perfecting human beings
so that they become as divine as a creature can be. (Jacobs 2009 and Mosser 2021 are important
exceptions). Similarly, few contemporary philosophers defend the modern “moral exemplar”
model, on which Christ saves by being a perfect moral example for other human beings to
imitate. (Quinn 1993 offers a highly qualified defense, but holds that Christ is more than just a
moral exemplar).
2.4 Sin, Original Sin, and the Fall
The doctrine of sin and the doctrine of atonement are correlative in the same way that a disease
and its remedy are correlative. If sin is that from which Christ saves us, then the strength of the
remedy (atonement) must vary according the severity of the disease (sin). As a first
approximation, a sinful act can be thought of as a morally bad act for which the sinner is
responsible. But the language of “sin” adds something to the language of moral wrongdoing: a
sin is a failure or fault with respect to God. Like other Christian doctrines, the doctrine of sin
poses tricky philosophical problems. To see those problems more clearly, it is useful to
disambiguate the doctrine of sin into several distinct components: the first sin, the Fall, original
sin, and personal sin.
2.4.1 The First Sin
The problem of the first sin is the problem of how the very first sinful act is even possible, given
various Christian axioms about the goodness and creative power of God, and various
philosophical assumptions about the nature of freedom and moral responsibility. The problem of
the first sin is sometimes treated as a question about the fall of Satan. It turns out to be
surprisingly difficult to explain how Satan—by hypothesis, an angel created by God with a
rational intellect, an upright will, and wholly good desires and dispositions—could ever make the
sinful choice to reject God. Augustine (City of God, Book 12), Anselm (“On the Fall of the
Devil” De casu diaboli), and Duns Scotus (Ordinatio 2, dist. 6, q. 2 ) all wrestle with this
problem. Contemporary philosophers who try to improve on their efforts include Barnwell
(2009, 2017), MacDonald (1999), Rogers (2008), and Timpe (2012). Their responses all seek to
explain how Satan’s choice is metaphysically possible, by appealing to their own favored
accounts of human freedom and conscious attention. Wood (2016) further distinguishes between
the “hard problem” of how Satan’s sinful choice is metaphysically possible, and the “harder
problem” of how it can be subjectively rational—rational from the point of view of Satan
himself.
2.4.2 The Fall of Adam and Eve
The biblical story of Adam and Eve (Genesis 3) recounts the story of the first human sin and its
consequences. The traditional story of the fall of Adam and Eve does not seem consistent with
either an evolutionary account of human origins or what we know about human history more
generally. On some understandings, questions about the historicity of the Fall are not properly
philosophical questions at all. Yet it does seem like a properly philosophical task to articulate a
doctrine of the fall that is both internally consistent and consistent with other things we know to
be true. Moreover, the doctrine of the Fall is conceptually connected to other aspects of the
doctrine of sin as well as to the doctrine of salvation.
Peter van Inwagen presents an account of the Fall that maintains many of its most important
elements and, he claims, is consistent with evolutionary theory. Importantly, van Inwagen does
not assert that this account is true, but only “true for all we know” (2004). In a similar vein, Hud
Hudson (2014) offers an ingenious defense of a literal reading of the Genesis account that
appeals to contemporary “growing block” theories of time. Despite initial impressions, neither
van Inwagen nor Hudson are really concerned with defending quasi-literal readings of Genesis.
Instead, they want to show that objections to those readings presuppose highly contestable
philosophical—rather than empirical or scientific—assumptions.
2.4.3 Original Sin
In Christian theology, “original sin” in the strictest sense refers to the human condition after the
Fall and not to the first human sin itself. The fall is the cause of the condition of original sin:
because of Adam and Eve’s sin, subsequent human beings somehow “inherit” a disposition
toward sin and an attraction toward evil that makes it inevitable that they will sin. On some
stronger interpretations, all subsequent human beings are also justly regarded as guilty by God
from birth, even before they have sinned themselves. Even apart from worries about the
historicity of the fall, the philosophical challenges posed by this doctrine are obvious. How can
people living now be morally responsible for the sins of the first human beings? What is the
mechanism by which sin and guilt are “inherited” from past generations? If it is inevitable that
all human beings will sin, can God justly punish them?
Some Christian philosophers have simply rejected the stronger versions of the doctrine of
original sin as incoherent. Swinburne, for instance, denies that all human beings are born guilty
as a result of the sin of their first parents and argues that the condition of original sin only makes
it very likely, rather than inevitable, that they will sin themselves (1989: 141–43). Other
philosophers have attempted to show that even a strong doctrine of original sin can be
philosophically coherent, given the right metaphysical framework. Michael Rea, for instance,
draws on fission theory and the metaphysics of temporal parts to suggest a way that
contemporary humans might bear responsibility for the sin of Adam by virtue of being
counterparts or stages of Adam himself (2007). He also argues that a Molinist-inspired doctrine
of “transworld depravity” might accomplish much of what Christians want from the traditional
doctrine of original sin (2007). John Mullen (2007) also constructs a Molinist account of original
sin and inherited guilt. On Molinism, God knows all the true counterfactuals of creaturely
freedom, which means that God knows every free choice that every human being would make in
every possible situation. According to Mullen, if it were true that every free creature would sin in
an ideal, garden of Eden situation, then God could justly punish them in the actual world for
what they would have done in that counterfactual world.
2.4.4 Personal Sin
“Personal sin” refers to individual sinful acts. Because the philosophical problems associated
with personal sin initially seem very similar to the problems associated with moral wrongdoing,
there has been comparatively little philosophical work on personal sin. Still, important
definitional questions remain about exactly how, if at all, sin should be distinguished from moral
wrongdoing, whether there are sinful actions that are not immoral actions, and, conversely,
whether there are immoral actions that are not sinful (Mitchell 1984; Dalferth 1984; Adams
1991; Couenhoven 2009).
2.5 Other Topics
There are philosophical questions raised by nearly all Christian doctrines and practices, and so
there are many fertile areas of inquiry that still remain comparatively underexplored. This brief
survey has focused on the most widely treated areas of analytic philosophical theology. But some
of the most creative work has branched out into other domains including the Eucharist (Arcadi
2018; Pickup 2015); liturgy, ritual, and worship (Cuneo 2016); bodily resurrection and personal
identity (van Inwagen 1978; Merricks 1999; Zimmerman 1999; Rudder Baker 2001); heaven
(Walls 2002; Ribeiro 2011), hell (Walls 1992; Adams 1993; Kvanvig 1993; Sider 2002;
Buckareff & Plug 2005) and purgatory (Walls 2011; Dumsday 2014).
2.6 The Rise of “Analytic Theology”
In 2009 Oliver Crisp and Michael Rea published their edited volume Analytic Theology: New
Essays in the Philosophy of Theology. The volume’s contributors collectively try to make the
case that analytic philosophy offers a valuable and neglected resource for Christian theologians.
A new research program developed in its wake, and the ensuing years have seen the rise of a
self-identified school of “analytic theologians”, who use the tools and methods of analytic
philosophy to address Christian theological topics.
At present, it is not clear whether there is any meaningful difference between Christian “analytic
theology” and Christian “philosophical theology”, which has been treated as a kind of
philosophy. As the discussion above indicates, analytic philosophical theology has been
produced largely by Christian philosophers working in philosophy departments, rather than by
theologians in departments of theology or divinity schools. Classic works of philosophical
theology like Swinburne (1994) and Adams (2000) seem like analytic theology avant la lettre,
for example, and much recent work called “analytic theology” seems quite similar to previous
work called “philosophical theology” or even “philosophy of religion” (e.g., Mullins 2016). Yet
some self-described analytic theologians have also insisted that Christian analytic theology is
really a form of theology (Torrance [Alan] 2013; Torrance [Andrew] 2019; Crisp, Arcadi, &
Wessling 2019). They emphasize that Christian analytic theology is an internal project of faith
seeking understanding that, as theology, holds itself accountable to scripture and Church
tradition. Yet whether Christian analytic theology is properly regarded as a kind of philosophy or
a kind of theology depends on how we draw the underlying distinction between philosophy and
theology—if indeed we draw such a distinction at all.
