





































Microsoft Word - 1 Prusak 12.1.docx


[Expositions 12.1 (2018) 1–7]  Expositions (online) ISSN: 1747–5376 
  

Just War or Just Peace? The Future of Catholic Teaching on War and Peace 

 

BERNARD G. PRUSAK 

King’s College (PA) 

 

 

It is a remarkable fact—if it isn’t a scandal!—that Christians have been crucial figures in the 

development of so-called just war theory. 

Here is one way the story is sometimes told. As two advocates of the rejection of just-war theory 

write, “Jesus’ nonviolence was once normative for the Church.”1 The key text here is Matthew 5, 

including the injunction not to resist an evildoer through violence; the key example may be Jesus’ 

submission to his arrest and crucifixion. The story goes on: “The Christian community’s 

programmatic, disciplined and theological nonviolence began to be compromised after Emperor 

Constantine legalized Christianity in 313 C.E.”2 Specifically, we are told, Constantine “dispensed 

with the Sermon on the Mount and the commandment to love one’s enemies, and turned to the 

pagan Cicero to justify Christian violence,” thereby “sowing the seeds” for the development of 

just war theory by Christians like Augustine in the fifth century, Thomas Aquinas in the thirteenth 

century, and Francisco de Vitoria and Francisco Suárez in the so-called Second Scholasticism of 

sixteenth and seventeenth centuries.3 The story, in brief, is one of accommodation and decline. 

The Church allowed itself to become “imperial” and “war-making.”4 It succumbed to paganism. 

It betrayed Jesus’ radical rejection of violence. In the words of a theologian who shares this 

perspective: 

 

When the Church used the “just war” approach to embody its teaching on issues of 

war and peace, it lost, or allowed to be muted, the strong, prophetic teaching of the 

gospels. Rarely was the bold call to peacemaking greatness in the Sermon on the 

Mount heard in the Church. No longer was the example of Jesus’ nonviolent life 

held up for study and emulation. Strangled was the call to restless, creative 

peacemaking.5 

 



The Future of Catholic Thinking on War and Peace  2 
 

Here is another way to tell the story. There is no doubting that the “[j]ust war tradition began 

to develop in the age of Constantine, and became dominant as Christians gained access to and 

responsibility for government and political power.”6 But it is open to question whether the 

development of just-war thinking by Christians must be considered “paradoxical if not self-

contradictory.”7 In the twentieth century and our own, some Christian theologians have argued, on 

the basis of texts like Matthew 5 and accounts of the life of the early Church, “that the foundational 

Christian value is […] nonviolence.”8 By contrast, medieval theologians tended to operate with 

“the presupposition that if there is an apparent conflict between the gospel and the natural law,” 

with its prerogative to self-preservation, “it is possible to reconcile them.”9 The important point 

against this background is that medieval natural law theory reflected a fundamental faith commit-

ment to the goodness of creation, rooted in the Hebrew Bible’s witness “to God’s work as Creator 

and provident Sustainer of the visible world.”10 Accordingly, medieval natural lawyers could not 

countenance that Christians with political power and responsibility should stand idly by while the 

blood of a neighbor was spilled.11 From this point of view, though the Way of the Cross calls us 

to nonviolent, willing-to-risk-suffering action—in other words, though the Way of the Cross calls 

us to practice the peaceable virtues exemplified by Jesus12—taking up arms to defend the innocent 

and the common good nonetheless might be not only morally permissible in some circumstances, 

but morally imperative. 

Note that, in this second story, the gospel witness to the power of nonviolent resistance is not 

denied, but neither is the biblical witness to the goodness of creation, which in our fallen world 

often needs defense. Instead, the new and the old stand in tension, and from this tension developed 

just war theory, which a critic acknowledges “was and is intended primarily to restrain, not validate 

war.”13 It is also worth noting in this regard that the principles of jus ad bellum—the criteria that 

need to be satisfied before going to war can be considered morally permissible—and the principles 

of jus in bello—the criteria concerning morally permissible conduct in war—historically derive 

from quite different traditions: “Jus in bello is the product of the medieval chivalric code, the self-

regulation of the warrior classes. Jus ad bellum, on the other hand, is the invention of churchmen 

and lawyers and represents a fundamental challenge to the assumptions build into chivalry,” 

namely, that “military life and warfare are an acceptable and potentially noble form of activity.”14 

Readers can probably tell that the author of this introduction is partial to the second way of 

making sense of the fact that Christians have been crucial figures in the development of just war 



3  Prusak 
 

theory. The story of accommodation to paganism and power and abdication of the heart of the 

gospel seems overly simple and uncharitable to the figures in question. At the same time, it must 

be acknowledged that just war theory was not formulated with weapons of mass destruction in 

mind. As Thomas Merton forcefully wrote more than fifty years ago, in words that feel urgent 

again today: 

 

When a missile armed with an H-bomb warhead is fired by the pressing of a button 

and its target is a whole city, the number of its victims is estimated in “mega-

corpses”—millions of dead human beings […]. Under such conditions can there be 

serious meaning left in the fine decisions that were elaborated by scholastic 

theologians in the day of hand-to-hand combat?15 

 

Further, papal teaching over the last fifty years, and especially under John Paul II and Francis, 

has at the very least “recast […] the traditional just war doctrine within a more comprehensive 

theology of peace and reconciliation.”16 As the Catholic theologian Lisa Cahill writes, “Since the 

1960s, official Catholic teaching has uniformly deplored the destruction and disaster of war, 

pressing the point that it always represents a moral failure.”17 Nonetheless, as she acknowledges, 

“just-war thinking has never been repudiated”18—or at least not yet—including by Pope Francis, 

who opposed U.S. military intervention in Syria but affirmed that “it is licit to stop [an] unjust 

aggressor” such as ISIS, though he did not specify how.19 

This iteration of the forum “Ethics in Focus” is dedicated to the question brought before the 

Roman Catholic Church by an important, recent event in its life: the April 2016 conference 

“Nonviolence and Just Peace,” held in Rome and co-sponsored by the Pontifical Council for 

Justice and Peace and Pax Christi International. A document published by Pax Christi after the 

conference asserts that “there is no ‘just war,’” calls on the Church “no longer [to] use or teach 

‘just war theory,’” and advocates for “a new framework that is consistent with Gospel 

nonviolence”: more precisely, a just peace approach focused on nonviolent practices and 

strategies.20 To put the question in brief: Should the Roman Catholic Church reject just war 

theory—more fully, eliminate its “elaboration or refinement” as a Catholic social teaching project 

and “[r]eplace it with a theology and ethics of peace and peacebuilding”?21 Or is there reason to 

reject the rejection of just war theory and instead not only to engage in its elaboration and 



The Future of Catholic Thinking on War and Peace  4 
 

refinement, but to advocate for it politically?22 According to Cardinal Peter Turkson, Pope Francis, 

who has spoken forcefully against war,23 intends to convene a synod to address just such 

questions.24 

The contributors to this iteration of “Ethics in Focus” complicate the questions to consider. 

There are advocates for rejecting just war theory, and there are advocates for rejecting the rejection, 

but there are also contributors who reject the opposition of just war and just peace principles, who 

claim that the focus of both camps should be on peacebuilding, who call for renewed attention to 

the possibility of selective conscientious objection, and who draw attention to the growing edges 

of just war theory, which as it happens draw the just war tradition closer to its critics. Let there be 

a synod, or even an encyclical, but may it grapple with the many arguments represented here. 

Roger Bergman (“Preventing Unjust War: The Role of the Catholic Church”) is Professor 

Emeritus, Department of Cultural and Social Studies, Creighton University. Lisa Sowle Cahill 

(“The Future of [Catholic] Just War Theory: Marginal”) is J. Donald Monan Professor, Department 

of Theology, Boston College. Drew Christiansen, S.J. (“Just War in the Twenty-First Century: 

Nonviolence, Post-bellum Justice, and R2P”), is Distinguished Professor of Ethics and Global 

Human Development and Senior Research Fellow, Berkley Center for Religion, Peace, and World 

Affairs, Georgetown University. Robert Latiff, Major General, U.S. Air Force, retired (“Jumping 

into Combat without a Parachute—on Purpose?”), is Adjunct Professor, Reilly Center for Science, 

Technology, and Values, University of Notre Dame, and Research Professor and Director for 

Intelligence Community Programs, Department of Information Sciences and Technology, George 

Mason University. Maryann Cusimano Love (“Just Peace and Just War”) is Associate Professor 

of International Relations, Department of Politics, Catholic University of America, and a Fellow 

of Catholic University’s Institute for Policy Research and Catholic Studies. Eli McCarthy (“The 

Gospels Draw Us Further: A Just Peace Ethic”) is Adjunct Professor, Program on Justice and 

Peace, Georgetown University, and Director of Justice and Peace for the Conference of Major 

Superiors of Men. William R. O’Neill, S.J. (“Must the ‘Violent Bear It Away’? A Restorative 

Critique of Just War”), is Associate Professor of Social Ethics, Jesuit School of Theology, Santa 

Clara University. Gerard F. Powers (“Our Vocation Is Peacebuilding [Construo pacem est nostra 

vocatione]”) is Director, Catholic Peacebuilding Studies, and Coordinator, Catholic Peacebuilding 

Network, Kroc Institute for International Peace Studies, Keough School of Global Affairs, 

University of Notre Dame. Tobias Winright (“Why I Shall Continue to Use and Teach Just War 



5  Prusak 
 

Theory”) is Hubert Mäder Endowed Chair of Health Care Ethics, Albert Gnaegi Center for Health 

Care Ethics, and Associate Professor of Theological Ethics, Department of Theological Studies, 

Saint Louis University. 

 

 

Notes 

 

1. John Dear and Ken Butigan, “An Overview of Gospel Nonviolence in the Christian 

Tradition” (background paper commissioned for the Nonviolence and Just Peace 

Conference, Rome, Italy, April 11–13, 2016), 1, 

https://nonviolencejustpeacedotnet.files.wordpress.com/2016/05/our_nonviolence_traditi

on.pdf. 

2. Ibid., 3. 

3. Ibid., 4. 

4. Ibid. 

5. Terrence J. Rynne, “An Overview of Contemporary Scriptural Exegesis and Ethics on 

Jesus’ Nonviolence” (background paper commissioned for the Nonviolence and Just Peace 

Conference, Rome, Italy, April 11–13, 2016), 9–10, 

https://nonviolencejustpeacedotnet.files.wordpress.com/2016/05/contemporary_scriptural

_exegesis_ethics_on_jesus_nonviolence.pdf. 

6. Lisa Sowle Cahill, “Official Catholic Social Thought on Gospel Nonviolence” 

(background paper commissioned for the Nonviolence and Just Peace Conference, Rome, 

Italy, April 11–13, 2016), 1, 

https://nonviolencejustpeacedotnet.files.wordpress.com/2016/05/official_cst_on_gospel_

nonviolence.pdf. 

7. Cahill, “A Church for Peace,” Commonweal, September 9, 2016, 9–11, at 10, 

https://www.commonwealmagazine.org/church-peace. 



The Future of Catholic Thinking on War and Peace  6 
 

8. See for discussion Jean Porter, Natural and Divine Law: A Thomistic Theory of the Natural 

Law (Grand Rapids: Eerdmans, 2005), 284. 

9. Ibid., 292. 

10. Ibid., 305. 

11. See Leviticus 19:16. 

12. See Rynne, “An Overview of Contemporary Scriptural Exegesis and Ethics on Jesus’ 

Nonviolence,” 3. Compare Eli McCarthy, Becoming Nonviolent Peacemakers: A Virtue 

Ethic for Catholic Social Teaching and U.S. Policy (Eugene, OR: Pickwick, 2012), 58: 

“carrying the cross is about voluntarily risking suffering in order to expose and transcend 

both injustice and violence.” See also 62 on “the willingness to risk torture, imprisonment 

and even being killed.” 

13. Cahill, “Official Catholic Social Thought on Gospel Nonviolence,” 2. 

14. David Rodin, War and Self-Defense (Oxford: Oxford University Press, 2002), 167. 

15. Thomas Merton, “Nuclear War and Christian Responsibility,” Commonweal, February 6, 

1962, https://www.commonwealmagazine.org/nuclear-war-and-christian-responsibility. 

16. See James L. Heft, “John Paul and the ‘Just War’ Doctrine: ‘Make Peace through Justice 

and Forgiveness, Not War,’” in Religion, Identity, and Global Governance: Ideas, 

Evidence, and Practice, ed. Patrick James (Toronto: University of Toronto Press, 2011), 

203–219, at 216. 

17. Cahill, “Official Catholic Social Thought on Gospel Nonviolence,” 2. 

18. Cahill, “A Church for Peace,” 10. 

19. See Cahill, “Official Catholic Social Thought on Gospel Nonviolence,” 8. 

20. See “An Appeal to the Catholic Church to Re-Commit to the Centrality of Gospel 

Nonviolence,” https://nonviolencejustpeace.net/final-statement-an-appeal-to-the-catholic-

church-to-re-commit-to-the-centrality-of-gospel-nonviolence/. 



7  Prusak 
 

21. See Cahill, “Official Catholic Social Thought on Gospel Nonviolence,” 12. 

22. See, along these lines, Peter Steinfels, “The War against Just War,” Commonweal, June 5, 

2017, https://www.commonwealmagazine.org/war-against-just-war. 

23. See for quotations Lisa Cahill’s contribution to this forum. 

24. Cardinal Turkson made this announcement at a meeting at Georgetown University, May 

31–June 2, 2017. 

 


