This article about the “twin wounds” of war, spiritual and moral injury in warriors, first appeared in the Winter 2016 issue of Providence’s print edition. To read the original in a PDF format, click here.

War Wounds

War is the most anti-human of experiences. It degrades, rends, and tears at us as people both in body and in soul. It degrades, rends, and tears at human societies in our familial and collective relationships and the created order. Yet despite its destructiveness, war remains an enduring and necessary reality because it checks unrestrained evil, corrects injustice, and restores, if only temporarily, a semblance of social cohesion and stability. In the Christian theological understanding, while war may destroy the body, it cannot destroy the soul—that which is created and sustained by God for eternity is beyond even the catastrophic power of war to ultimately destroy (Matt. 10:28a). Nevertheless, Christians can neither ignore the ways in which war can and does injure warriors and their families, nor ignore their responsibility on behalf of Christ to respond to these injuries with genuine caritas.[i] In essence, there is a cost to living Jesus’ ethic of love, paid, in part, through action. Exploring that cost and the landscape of suffering in war as spiritual injury is the exercise of this essay.

Specifically, much has been written in the past decade or more on the types of “woundedness” warriors suffer in combat, including physical, mental, emotional, and even moral injury. However, though U.S. joint forces are pursuing strategies for increasing “spiritual resilience” in warriors with an eye toward improving future training and operational readiness, the force has failed to explore a warrior’s spiritual injury in combat and its debilitating, life-long effects (including for a warrior’s family).[ii] I want to rectify this oversight by defining spiritual injury as related to, yet separate from, moral injury. I delineate twelve specific markers of spiritual injury resulting from combat and suggest how clergy, chaplains, clinicians, and concerned laypersons may identify and treat these wounds. Ironically, and yet in hope, I contend that trauma in war aids Christians in identifying the markers of spiritual injury and in authentically living a renewed and redemptive witness of Jesus’ self-emptying love for humanity.[iii]

Something More Than Moral

Since the close of the Vietnam War, the fields of psychiatry, psychology, and pastoral counseling have grown incredibly nuanced in their understanding of the complexity of trauma in war.[iv] Clinicians and scholars have helped map what moral injury looks like in warriors, including identifying markers such as pervasive guilt and shame, feelings of being beyond forgiveness, the development of a hopeless nihilism, social distance from community and creation, a diminished reflective capacity to render morally nuanced distinctions between right and wrong, and a degraded or corroded ability to exercise leadership, particularly to exhibit or develop tactical, operational, and strategic moral leadership.[v]

Beyond the impact on individuals, our deepened awareness of moral injury has helped spawn the rise of humanitarian intervention and the trans-national ideology of the responsibility to protect; has, more recently, catalyzed the development of military doctrine such as that for mass atrocity response operations; and has galvanized national will to empathically respond to warriors and veterans, leading to immense economic investments into care for post-war veterans and pensioners.[vi]

While it shouldn’t be lost in the midst of these martial examples that moral injury has relevance beyond the military, it’s not incidental that moral injury is most closely linked to combat trauma. Indeed, the standard definition of moral injury has come from experts in the field at the U.S. Department of Veterans of Affairs:

Like psychological trauma, moral injury is a construct that describes extreme and unprecedented life experiences including the harmful aftermath of exposure to such events (e.g. combat trauma). Events are considered morally injurious if they “transgress deeply held moral beliefs and expectations.” Thus, the key precondition for moral injury is an act of transgression, which shatters moral and ethical expectations that are rooted in religious or spiritual beliefs, or culture-based, organizational, and group-based rules about fairness, the value of life, and so forth.[vii]

While this definition is a helpful advance on earlier ones, my concern with it is three-fold. First, since the definition is descriptive in nature, it lacks specificity and leaves it open to misapplication, which I contend is indeed happening apace in academic, clinical, and pastoral settings. Essentially, the term moral injury is now being bandied about almost indiscriminately in order to describe any and every type of non-physical injury a warrior may suffer in combat, whether such injuries accord with the definition or not.

This leads to my second objection, which is that the definition borrows a manifestly theological concept such as transgression—which in Christian theology is tied to the antecedent concept of sin and the descendent concept of forgiveness—without any linkage between the three. Essentially, the definition is built on a theological understanding but with no integration of its theological roots or resolution; the warrior is simply presumed and diagnosed as to have somehow “transgressed” a moral code.[viii]

Third and finally, the definition seems to locate moral injury in a broader framework in which religious understanding or spiritual praxis resides. But in philosophical history, this is the wrong way around. Put another way, religious belief and spiritual praxis have almost universally been seen as the construct under which morality resides rather than the converse.[ix] In our spiritually apathetic and indifferent contemporary culture, it has become de rigueur to propose that moral leadership in a democratic polity can be (and for some proponents must be) divorced from any religious or spiritual moorings, but this remains, at the very least, a tenuous and debatable point.[x]

Notwithstanding these points, however, this definition of moral injury is a helpful starting point to explore the nature of a particular kind of combat injury, one located in the personal response to one’s actions taken or not taken at a given moment on the battlefield. But because of these shortcomings, there’s something missing.

In more than a quarter century of pastoral work with warriors and their families, I have sensed a growing affirmation that warriors suffer also from another kind of soul wound, which I’ve specified a spiritual injury, that is different than a moral injury as clinically understood. Coupling my observations and insights with those of fellow chaplains of all the services, we may go so far as to state that a warrior and family may often be suffering the effects of a spiritual injury without suffering the effects of moral injury.

Spiritual Injury

This bifurcation of moral and spiritual injuries as distinct, yet related, is intended to emphasize, if not reclaim, a basic, ontological understanding of human personhood that is consistent with a Christian theological understanding of the created order and God’s design for humanity. How so? As Martin Thornton adjures, “Fundamental to the Biblical doctrine of man is the principle of total integration. Human beings cannot be split up into parts and ‘faculties’; body and spirit form an indissoluble unity.”[xi] I propose that the addition of spiritual injury, as opposed to moral injury alone, is necessary in order to treat warriors and their families as precisely such indissoluble unities; that is, as whole persons.

Toward this end, I propose the following definition of spiritual injury that complements but is distinct from its sibling notion of moral injury, to wit:

Spiritual injury is the intra and inter-personal damage to souls brought on by significant trauma, including the rupture to foundational religious values, beliefs, and attitudes, the inability to healthfully participate in an immanent human faith community, and the temporary or permanent loss of a transcendent relationship to God (manifested particularly in questions about forgiveness, doubt, truth, meaning, and hope).[xii]

Importantly, this definition moves concentrically from describing spiritual injury and its effects on the individual to the effects on communal and divine relationships as well, each of which contributes to a theo-centric understanding of human flourishing. If this generally describes spiritual injury, then what demarcates this phenomenon within a given wounded warrior? I note twelve such markers, centering on:

The Loss of God in Relationship. The first and most prevalent distinctive is when a person struggles over whether they have irreparably been separated from God. For warriors, as with moral injury, such questioning may arise from guilt over actions taken or not taken in combat but not exclusively so. Rather, simply living through and surviving the experience of combat can produce such searching because war as an experience tends to strain personal assumptions, challenge lightly or deeply-held beliefs, and force even healthy persons to seek stronger connections with God (or to abandon Him altogether in despair). War can, and often does, produce a significant existential crisis for the warrior that is framed in questions of ultimate meaning, particularly in his or her relationship to God.

God’s Providence and/or Sovereignty. A Soldier once pointedly asked me after witnessing a horrific scene of carnage in combat, “Chaplain, what happened today, did God take the day off?” That question epitomizes the existential struggle some warriors face after a fight as they reflect on what they saw, heard, tasted, smelled, and touched in combat. War is visceral, yet ethereal, and can often cause warriors to challenge their own beliefs about how, or if, God was in control of a fight, and why He allowed such carnage to occur. Death, chance, horrific injury, and the social waste of combat can produce overwhelming questions about God’s omniscience, omnipresence, and omnipotence.

Suffering. The obvious catalyst for so much spiritual injury is simply the psychological, mental, and spiritual wounding produced by human suffering. To hear another cry out in agony and searing pain, to witness another’s body afflicted with burns, gunshot, or shrapnel wounds, to see another blown apart by rocket, mortar, artillery, or mine strikes…these cause even the strongest of warriors to suffer wounds in their soul. Moreover, when that warrior returns to his or her family and has no permission, ability, or desire to share that suffering (though the family as a system often knows of the warrior’s spiritual injury and longs to participate in their healing), then the spiritual injury of suffering within that soul can become permanent and debilitating. It can then lead to injuries in other facets of their humanity; that’s to say mental, emotional, or even physical injury.

Forgiveness. Especially related to suffering but also to moral injury is the human need for forgiveness. Here, however, I mean something apart from a clinical therapeutic practice that helps a warrior explore past events and his or her moral agency or decision-making within it, with the aim to sanction their combat actions. Sometimes warriors suffering spiritual injury need more than just a psychological exploration or justification of their role in combat; they really do need to be forgiven for what they did or did not do. Notwithstanding that in contemporary democracies military forces are often composed only of highly skilled professionals, even such warriors can find that the moral and spiritual consequences of their volunteerism are immense and repetitive. Even just warriors are human beings and, even with serving with moral probity, often both want and need forgiveness for their actions or attitudes in combat that do not fully align with the ethical or attitudinal requirements of their faith. Such forgiveness cannot come from the clinic but must be found in community, including through civilian religious leaders or military chaplains who can with authority from within their faith tradition, but also from the wider community of friends and family who more informally compose the body of Christ. Indeed, the psychotherapist and PTSD expert, Edward Tick has pointedly criticized Western democracies for sending off warriors to combat and redeploying them home without any type of religious ministration that frames such deployments and that intentionally seeks to re-integrate the warrior into the civilian society.[xiii]

Paralyzing Doubt. Post-combat, many warriors, believing they have rendered themselves irreparably unacceptable to God, suffer lingering, deeply existential doubt about their relationship to the Divine. Alternatively, the warrior often projects his or her own self-doubt onto the figure of God Himself, turning it into divine judgment. Rather than admitting and locating this doubt within the self, the warrior might then defend against the Divine condemnation, turning his own self-doubt into critique of God. Here is an important potential vein for treatment, in that clinicians, chaplains, and clergy can recognize such projection and gently turn the warrior back toward a self-understanding and acceptance of existential doubt. Such doubt, then, becomes a healthy (and not fatal) part of the life of the soul. On the other hand, failure to treat such doubt can become debilitating, in that a warrior might come to an unhealthy point of stasis, in which perpetual, existential doubt is simply the permanent state of the soul. The cost of this might be never recovering a sense of God’s abiding peace or the transcendent hope that marks a healthy posture for the soul.

Excessive Sorrow. Sorrow is an appropriate response to combat. Christ himself, exposed to the human tragedies unfolding all around him, grieved deeply at the experience. As with Christ’s sorrow, the warrior experiencing grief due to the trauma of combat need not be consumed by it, however far beyond simple empathetic pity or compassion it extends. That qualification noted, if such sorrow is left unchecked, it can envelop the soul and hold it hostage to a past experience. Such a spiritual injury is, here, allied with moral injury in that the trauma can arrest mental cognition, compromise reasoning, and short-circuit memory. However, unlike moral injury, sorrow here connotes a spiritual weight that anchors the warrior to an ever-present past in a grieving process without end that comes to dominate everyday life, present reality, and certainly any capacity for future hope.

Justice and Reconciliation. Rage has been a part of warrior character from the age of Achilles to the present day. This passion is often expressed in a desire for evening the score, paying the enemy back, and seeking vengeance. However, I actually see these as potentially healthy signs in a trauma-afflicted warrior. I say this because when I or other chaplains encounter a warrior’s anger, however disproportionate, it is often proof of a still functioning soul. While desire for justice is a right response to injustice, it is a virtue that, like all virtues, can be knocked out of balance. But it is better than apathy and disregard. Still, theological questions remain over whether and how war is right and just and whether actions conducted within combat are geared toward restoration of justice and, through that, peace (perhaps in the long-term through reconciliation of warring parties or individual enemies). These and other inquiries can serve as potential pathways to healing for spiritual injury. Warriors need to rationally think through the process of both how and why they went to war, and how and what they did during war in order to effectively integrate the experience into their person.

Truth or Faith Claims. Combat has a way of compelling a warrior to reassess often long-held claims to truth and faith related to their individual confessional beliefs. Again, this process is not necessarily to be avoided as it can be a potential pathway to healing, especially when undertaken in the care of a capable guide. That said, the effective guide—whether a clinician, chaplain, clergy person, or simply a wise friend—will have to refrain from aggressively challenging a warrior’s crisis of doubt, their faltering faith, or the validity of their questions, however blasphemous, trite, or beside-the-point they may appear to anyone else. Warriors will often have viscerally intuited war in such a way that previously accepted tenants of their faith may be called into question in ways that are sometimes surprising but which represent genuine spiritual crisis. For instance, when one has seen a friend so completely disintegrated through the explosive force of a massive IED so that there are no remains to be recovered, ideas such as the bodily resurrection can suddenly become pain-filled, conceptually problematic, and deeply urgent.

Identity, Meaning, or Purpose. This set of ideas is perhaps one of the more evident markers of spiritual injury and, collectively, can often be summed up by the warrior in the inquiry, “Who am I now, what does this experience mean for me, and what am I to do with it in the future?” The process in play is really one of integrating the experience of war into one’s sense of personhood. This process very often centers around the self and the self’s relationship to God. God is typically the unspoken object of the above questions, even if God is only tacitly acknowledged in the questioning. That said, this exchange is imperative for the holistic healing of the warrior; war must be integrated into a conception of the self. Therefore, a thorough exploration of identity, meaning, and purpose relative to combat experience, especially traumatic experience, is a painful yet necessary process of faith seeking understanding. This is a soul’s attempt to place spiritual injury into a type of ontological context, as it were.

Theology of the Body. Due to a variety of factors, most especially advances in combat medicine, over the course of the current conflict in which the United States has been fighting for over 15 years, the ratio of battlefield “killed in action” to “died of wounds” has dropped from historical trend of 1/3 to 1/7. Warriors are surviving physical traumas for longer than they would have in the past. It follows that not only are some surviving longer, some are surviving outright: wounds that would have killed warriors in the near past are not necessarily killing them now. One additional corollary is that not only are more warriors surviving horrific injuries, but other warriors are witnessing their survival. While downplaying neither the joy of saved lives nor gratitude for the medical advances that have made them possible, it is also true that such injuries—multiple amputations, catastrophic burns, obliterated faces (and thus all corresponding sensory perception)—provoke in some exposed to them new and potentially alarming questions about such things as the sacred nature of human creation, what it means to be a whole-person, the possibilities of intimacy without physical beauty or functionality, the status of the severely handicapped, and, as mentioned above, the doctrine of a bodily resurrection. Coupled with earlier questions regarding identity, all of this is exacerbated in a post-modern social context in which human bodies are reduced to little more than biological organisms, devoid of either transcendent or eternal meaning, purpose, or value. However, far from an insurmountable barrier, I contend these difficulties provide those who heal warriors with an opening to re-explore the sacred nature of human creation and redemption, the miracle—and model—of Christ’s bodily resurrection, and the eschatological hope of something (e.g. the soul, the heavenly body) that will exist beyond this mortal, earth-bound, sin-ravaged body, which is destined to decline, damage, and decay in the best of circumstances.

Hope and Eternal Life. This leads to another personal marker of spiritual injury, and that is an inability to live from a posture of certain hope in eternal life. Perhaps attenuated by the post-modern context, many warriors already have little (if any) understanding of the need to see themselves as eternal beings worthy of and possibly destined for eternal life in God, much less to draw a temporal hope from that belief. Indeed, a persistent nihilistic attitude marks the present generations who serve in the modern armed forces, where warriors without combat trauma see themselves only in the present moment, whose decisions are devoid of life-long, let alone eternal import. Add to such a perspective the trauma of combat, and such warriors are even less likely to understand, let alone appropriate, an existential hope in their possibility for eternal life in God. Still, not only is such a hope possible, it is often the most potent antidote to the immense suffering of either moral or, certainly, spiritual injury.

Sanctorum Communio. Lastly, Warriors suffering from spiritual injury are almost often devoid of any meaningful social connections or relationships with others. Dietrich Bonhoeffer wrote extensively of the nature of God’s people as “the community of saints.”[xiv] Later, he would express the same thought more relative to the decisive presence of Jesus Christ when he termed the Church as “the community of the Crucified,” a people who only find their identity, meaning, and purpose in the crucified and risen Lord.[xv] Sadly, during the present conflicts that mark Western coalition nations, there is little visceral evidence that Christians of any major communion have genuinely attempted to reach spiritually injured warriors, in order to welcome them into (and find healing amongst) “the community of the saints.”

Future War & Present Hope

Contemporary war is often a confusing morass of different mission types, including stability operations, peacekeeping missions, and humanitarian interventions; each has differing rules of engagement, command and control structures, and political authorities.[xvi] Especially in a combat environment in which insurgents hide among the civilians, intentionally draw the battle into population centers, and regularly shield themselves with the bodies of children, contemporary war can and does produce increasingly complex and ambiguous moral situations for warriors. This trajectory will only increase as war becomes evermore dominated by fifth domain warfare in a borderless cyberspace, integrates new technologies such as autonomous warfare systems, encounters public health crises such as pandemics, and navigates resource challenges like competition for water, arable land, and food supplies. Nevertheless, I contend that despite this changing context of war, both moral and spiritual injury will continue to mar the souls of warriors and their families. However much war changes, there are certain aspects of its grim reality that never will.

I have argued in this essay that though wounded warriors often do experience moral injury as currently defined, they also often suffer something else—what I have called “spiritual injury.” This specific combat trauma has debilitating, life-long effects; some perhaps are most acutely experienced by the wounded warrior’s families and close intimates. Moral injury and spiritual injury are sibling twins of the same mother, yet they are undoubtedly distinct; like all twins, they must be treated as individuals.

I trust the twelve specific markers of spiritual injury I’ve outlined above can serve as a primer in helping identify and treat those warriors who return to us injured and in need of both temporal and eternal healing. This is not simply the responsibility of seasoned professionals. The community, not simply the clinic, has a role to play. Perhaps ironically, but certainly in hope, I reiterate that war trauma can aid the “Community of the Crucified” in identifying the markers of spiritual injury and authentically living a renewed and redemptive witness of Jesus’ self-emptying love for humanity. While well intentioned, an occasional “thank you for your service” offered in an airport or a seasonal care package addressed “to any Soldier” are hardly apt expressions of a community of faith, not one that claims to confess at the core of its identity that it is a “royal priesthood, a holy nation, and kingdom of saints unto our God” (1 Pet. 2:9a).[xvii] The Church as the Body of Christ has an immense opportunity to offer warriors and families suffering from spiritual injury the only real and lasting context in which injury may find final healing in Jesus Christ. If this is an enduring witness that the Church can make relative to war, then it is one faithful to Christ, who first gave Himself for us and, in so doing, endured our own spiritual injury within Himself.

Timothy Mallard is a career U.S. Army Chaplain, a veteran of multiple overseas deployments, and holds a Ph.D. in Christian Ethics from the Univ. of Wales Trinity Saint David. The views expressed in this article are the author’s opinions and not those of the U.S. government.

Photo Credit: A grief stricken American infantryman whose buddy has been killed in action is comforted by another soldier. In the background a corpsman methodically fills out casualty tags, Haktong-ni area, Korea. August 28, 1950. Sfc. Al Chang. (Army)

[i] Nigel Biggar, In Defence of War (Oxford: OUP, 2013), 328.

[ii] Patrick J. Sweeney, Jeffrey E. Rhodes, and Bruce Boling, “Spiritual Fitness: A Key Component of Total Force Fitness,” in Joint Forces Quarterly 66/3rd Quarter (2012), 35-41 and Patrick J. Sweeney and Louis W. Fry, “Character Development Through Spiritual Leadership,” in Consulting Psychology Journal: Practice and Research 64/2 (2012), 89-107.

[iii] Nathan Wheeler, “For a Holy Priesthood: A Petrine Model for Evangelical Cultural Engagement,” in Journal of the Evangelical Theological Society 59/3 (September 2016), 523-539. Wheeler specifically and convincingly argues that by such a sacrificial ethic the church takes on the responsibility to become the vessel of “redemptive responsibility for the godliness of the world.”

[iv] See, among others: Jonathan Shay, Achilles in Vietnam: Combat Trauma and the Undoing of Character (New York: Scribner, 2003), 3-102; Edward Tick, War and the Soul: Healing Our Nation’s Veterans from Post-traumatic Stress Disorder (Wheaton, IL: Quest Books, 2005), 115-ff; Larry Dewey, War and Redemption: Treatment and Recovery in Combat-related Posttraumatic Stress Disorder (Burlington, VT: Ashgate Publishing, 2004), 115-222.

[v] A type of social nihilism, as I term it, is really more indicative of both moral injury in and the post-modern ethos of the Millennial Generation. For how this reality pervades warriors of this generation (who ironically also often exhibit an intense interest in spirituality), see Stephen Mansfield, The Faith of the American Soldier (New York: Tarcher Press, 2005), 36-39. For a fine theological exploration of the moral risk to the warrior for reflective capacity, see Marc LiVecche, “The Fifth Image: Seeing the Enemy With Just War Eyes,” in Providence 1/4 (Summer 2016), 50-56.

[vi] Timothy S. Mallard, “A Call to Arms: An American Survey of War in the 21st Century,” Providence 1/1 (Fall 2015), 46-52. For the care and treatment of veterans, see Shira Maguen and Brett Litz, “Moral Injury in Veterans of War,” in PTSD Research Quarterly 23/1 (2012), 1-3.

[vii] Shira Maguen and Brett Litz, ‘‘Moral Injury in the Context of War,’’ U.S. Department of Veterans Affairs National Center for PTSD, accessed online at < > on 25 Feb 2016.

[viii] For a compelling fictional account of how true moral injury becomes a lived reality in a warrior’s life, see William Brodrick, The Discourtesy of Death (New York: The Overlook Press, 2013), 126-127. In this story, Michael (a former British Lieutenant in Northern Ireland in the Troubles) contrasts with his brother Nigel, an Anglican Priest, who had once delivered a decisive sermon on duty in war to Michael’s regiment. The voice Michael hears at the point of action reflects his foundational faith and moral conflict and mirrors that heard by the Prophet Elijah in the cave while fleeing King Ahab (1 Kings 19:9-15).

[ix] Cf. James H. Burtness, Consequences: Morality, Ethics and the Future (Minneapolis: Augsburg Fortress Press, 1999), 27—ff. and Tom Beauchamp, Philosophical Ethics: An Introduction to Moral Philosophy (New York: McGraw-Hill, 1982), 21—ff.

[x] For example, see Timothy Challans, Awakening Warrior: Revolution in the Ethics of Warfare (Albany, NY: SUNY Press, 2007), 43—ff. Challans believes that military chaplains should be removed from all ethical professional military education because he believes chaplains have an inability to present philosophical theories about ethics without infusing the same with religious bias. For a counter view, see Shannon E. French, “Book Discussion: Timothy L. Challans, Awakening Warrior: Revolution in the Ethics of Warfare,” in Journal of Military Ethics 6/4 (2007), 317. For a more extended and recent scholarly treatment, see Don M. Snider and Alexander P. Shine, A Soldier’s Morality, Religion, and Our Professional Ethic: Does the Army’s Culture Facilitate Integration, Character Development, and Trust in the Profession? Vol. 6 (Carlisle, PA: Strategic Studies Institute and U.S. Army War College Press, 2014).

[xi] Martin Thornton, English Spirituality: An Outline of Ascetical Theology According to the English Pastoral Tradition (Cambridge, MA: Cowley Publications, 1986), 35.

[xii] Timothy Mallard, “Spiritual Injury: Toward a Definition, Criteria, and Treatment Response for Wounded Warriors and Families,” D.D. Eisenhower Army Medical Center Department of Behavioral Health and U.S. Army Cyber Center of Excellence Unit Ministry Team Interdisciplinary Moral and Spiritual Injury Symposium, Fort Gordon, GA (26 May 2016).

[xiii] Tick (2005), 104.

[xiv] Dietrich Bonhoeffer, Sanctorum Communio: A Theological Study of the Sociology of the Church, ed. by Clifford Green and Reinhard Krauss and Nancy Lukens (Minneapolis: Fortress Press, 1998), 33 (term) and 34, where Bonhoeffer writes “What one understands about person and community simultaneously makes a decisive statement about the concept of God. The concepts of person, community, and God are inseparably and essentially interrelated.”

[xv] Dietrich Bonhoeffer, Discipleship, ed. by John D. Godsey and trans. by Geffrey B. Kelly (Minneapolis: Fortress Press, 2003), 98-99.

[xvi] George R. Lucas, Jr., “‘This is Not Your Father’s War’—Confronting the Moral Challenges of ‘Unconventional’ War,” in The Journal of National Security Law and Policy 3/329 (2009), 329-340.

[xvii] Wheeler (2016).