The international law of war owes a great deal to just war thinking. The earliest treatises on the law of war, penned by such scholars as Grotius, Gentili, Pufendorf, and Vattel, straddled both traditions. Likewise, the earliest black-letter law of war—documents such as the St. Petersburg Declaration—relied heavily on intuitions and principles drawn from the Christian just war tradition. Conversely, contemporary just war thinking—both its Walzerian and revisionist variants—also owes much to the laws of war. Michael Walzer's legalist approach uses the law itself as a source of the moral intuitions it claims to unpack. And the revisionist move, as much as it pushes back against Walzer's communalism, is nonetheless deeply indebted to the logic of the law, particularly the desire to create clear, consistent, and immutable standards. If just war thought evolved into the laws of war and the laws of war have now been incorporated by contemporary just war thought, do we still need to be doing just war thinking? What is the value added by a just war approach?
Just war thinking remains necessary because it serves a social and psychological role that international law cannot fill. Laws, after all, work on us primarily externally. We know that we can be held accountable by certain people and institutions. Sometimes we obey the law simply out of fear of sanction; more frequently, we obey because we believe the law reflects some collectively held judgment of the right.Footnote 1 Either way, we choose to obey the law because it affects how others see us, and so we feel shame when we break it.
Morality, by contrast, is inward-looking. We behave morally because it affects how we see ourselves. We feel guilt when we violate our own moral principles, even if no one is looking. Just war thinking is one language with which we explore and tune this internal moral compass. As such, just war thinking—at least of the classical and Walzerian type—relies on an appeal to conscience. As James F. Childress argued, conscience “is personal and subjective; it is a person's consciousness of and reflection on his own acts in relation to his standards of judgment.” And it is our “moral feelings,” Childress says, that reveal what our conscience has to say. Of these moral emotions, the two most significant are guilt and shame. Guilt, in Childress's view, reflects “society's basic morality,” while shame reflects its aspirations and ideals.Footnote 2
With this psychological insight in mind, I argue that just war thinking adds value by developing this inward, emotional focus. To this end, I first make the argument for why we should pay attention to moral emotions in the first place, arguing that emotion is as powerful a motivator of moral behavior as reason. Second, I differentiate the moral emotions of guilt and shame, using the contemporary psychological literature to make the case for the positive value of guilt. Finally, I conclude by pointing out how the just war tradition can usefully cultivate the individual propensity to appreciate guilt, while providing guidance for using our collective guilt in helpful ways.
What Are Moral Emotions Good For?
Moral emotions are emotions that encourage social behavior. The idea that emotions link our moral intuitions to our behavior is an old one. Augustine valued emotions, seeing them as potential connections to God.Footnote 3 Emotions, he argued, could serve as a powerful tool for differentiating the praiseworthy from the condemnable. Thus, if we tried to navigate the risky complexities of our earthly existence without any access to our emotions—as, for example, the Stoics were wont to do—then “there would really be something wrong with our life.”Footnote 4 Thomas Aquinas similarly valued emotions as markers of what is “suitable” versus what is “repugnant and hurtful.”Footnote 5 And Leon Kaas has noted that negative emotions are often felt the most keenly: Repugnance and anger can be “the emotional expression of deep wisdom, beyond reason's power to fully articulate it . . . because we intuit and feel . . . the violation of things we rightfully hold dear.”Footnote 6 Thus, for classical just war thinkers emotions serve as a moral sixth sense, alerting us to situations and choices that are morally risky. Despite the Enlightenment's emphasis on reason, some eighteenth- and nineteenth-century philosophers continued to believe that “moral sentiments” drove our ethical judgments.Footnote 7 David Hume, for example, argued that morality “is more properly felt than judged of.”Footnote 8 Adam Smith identified “social passions” as moral emotions that not only encourage individually good behavior but also lay the foundation for our communal societal life.Footnote 9 He particularly emphasized the important roles played by shame and guilt, arguing that despite each individual's tendency to be self-centered, “he dares not look mankind in the face, and avow that he acts according to this principle.”Footnote 10 When such emotions fail to prevent bad behavior, they punish the perpetrator afterward:
The violator of the more sacred laws of justice can never reflect on the sentiments which mankind must entertain with regard to him, without feeling all the agonies of shame, and horror, and consternation. . . . He dares no longer look society in the face, but imagines himself, as it were, rejected, and thrown out from the affections of all mankind.Footnote 11
According to Smith, to avoid the painful unpleasantness of shame and guilt, we are driven to cooperate and uphold justice—not out of other-love, but out of self-love.Footnote 12 In this view, it turns out to be in our self-interest to behave morally.
Similarly, some contemporary theologians argue that “the evolution of morality is tied to the evolution of emotion—that without emotion there would be no human morality.”Footnote 13 Today, psychologists describe moral emotions as “linked to the interests or welfare of society as a whole or of other people.”Footnote 14 Moral emotions, unlike some other daily emotions, “are easily triggered by triumphs, tragedies, and transgressions that do not directly touch the self.”Footnote 15 We can feel the angry sting of injustice just by reading about it, even when we have no direct stake in the event itself or the people affected. Moral emotions can thus be felt across the academic community of just war thinkers, just as they are felt in the halls of political power and on the front lines.
More relevant to our concerns here, moral emotions are not just something we feel—they motivate us to act.Footnote 16 Modern psychology has uncovered what Aquinas understood intuitively:Footnote 17 that moral emotions encourage us to reaffirm and strengthen our social bonds, leading to cooperative actions.Footnote 18 Anger, disgust, and contempt lead us to behave as moral guardians, whether by excluding the norm violator from our midst or by seeking “to repair the moral order and to make violators mend their ways.”Footnote 19
Unlike anger and disgust, which are primarily directed at others, shame and guilt are self-conscious emotions that caution us to monitor and discipline ourselves.Footnote 20 But even this self-control has a social element. As the philosopher George Herbert Mead put it nearly a century ago, self-criticism reflects the intimate internalization of social norms, so “behavior controlled by self-criticism is essentially behavior controlled socially.”Footnote 21 Foucault also recognized the way in which moral emotions lead us to discipline ourselves. We simultaneously play the roles of both the judge and the judged when we avoid negative behaviors because of an imagined social audience.Footnote 22 In other words, the moral emotions can be powerful forces of social discipline, even when no one is actually watching. Thus, insofar as just war thinking taps into and develops our moral emotions, it thus serves two useful functions: it helps us intuitively know when moral issues are at stake, and it motivates us to take action to rectify wrongs.
What Distinguishes Shame from Guilt?
Shame and guilt are both moral emotions. Broadly speaking, they are self-conscious moral emotions that compel us to discipline ourselves, and to seek to treat others in ways that we understand to be just. By serving as the “glue” that connects identity and morality, they help us to understand what constitutes not only appropriate behavior but also appropriate social relationships.Footnote 23 Thus, both guilt and shame are universally felt emotions, and when we experience one or the other, both motivate similar responses. Despite these similarities, shame and guilt do not function in the same way, nor are they sparked by the same sorts of considerations. Anthropologists have long been interested in the distinction between guilt and shame, following Ruth Benedict's influential work on Japanese culture. Benedict identified shame as “a reaction to other people's criticism . . . requiring an audience or at least a man's fantasy of an audience.”Footnote 24 Guilt, being internal, requires no other. Drawing on this distinction, Benedict argued that “true shame cultures rely on external sanctions for good behavior, not, as true guilt cultures do, on an internalized conviction of sin.”Footnote 25 While guilt arises from a reaction “inside the individual” to the sense that internalized norms have been transgressed, shame has to do with the fear that one's behavior will result in “rejection by or expulsion from the group.”Footnote 26 Psychologists have found that this internal/external distinction between guilt and shame holds up cross-culturally.Footnote 27
Guilt reflects the disjuncture between the actions an individual thinks she should have taken and the ones she actually took.Footnote 28 In this way, feeling “bad” or guilty after an interaction warns us that we have violated a significant norm. Guilt is an especially pro-social emotion, encouraging cooperation and discouraging violence. The prospect of feeling guilty changes the way individuals approach strategic cooperation in experiments.Footnote 29 Indeed, individuals behave much as Smith imagined two hundred years ago: To avoid guilty feelings in the future, they often act against their short-term self-interest.Footnote 30 Furthermore, guilt discourages violence against others.Footnote 31 While psychologists have found that shame triggers the desire to harm others, the prospect of future guilt counteracts this response.Footnote 32 Guilt also prompts us to seek reconciliation, to restore relationships that have gone awry.Footnote 33 Guilt-prone individuals tend to have a higher capacity for empathy, and are better able to address conflict constructively.Footnote 34
But guilt is not only a lonely pursuit. We can also feel guilty on behalf of our social group.Footnote 35 While Walzer argues that it is difficult to move from the “ache of guilt” to “hard talk about responsibility,” psychological research suggests that guilt is actually a very powerful motivator.Footnote 36 Although the feeling of group belonging is also a powerful emotion that somewhat dampens the effect of guilt, psychological studies have shown a direct relationship between feelings of guilt and support for policies of restitution, including calls for official governmental apologies to historically oppressed groups and even reparations to former colonies and indigenous peoples.Footnote 37
By contrast, shame is external in its orientation. Shame requires an “other” who judges us and finds us wanting. When we feel shame, we feel naked and exposed in front of people whose respect we crave.Footnote 38 As Dietrich Bonhoeffer put it, shame results from a “lost unity,” a “kind of yearning” to belong.Footnote 39 In psychological terms, we feel shame as a defensive response against the persistent desire to be loved by those same people we believe see us as deficient.Footnote 40 Wanting to be loved yet feeling unlovable makes shame a highly volatile emotion. While guilty feelings lead us to engage with others, shame pushes us toward isolation.Footnote 41 When we feel shame, we want to withdraw, to hide.Footnote 42 (Who has never wished the ground could swallow them up?) But shame does not only trigger our flight response. Experimental studies show that it also triggers hostility.Footnote 43 A growing body of evidence suggests that feelings of shame lead us to project anger and blame outward.Footnote 44 Some sociologists even go so far as to argue that the underlying psychological motive of violence is the need to push away the sense of humiliation caused by shame.Footnote 45
Like guilt, shame can also be felt on behalf of one's group. However, as a collective emotion, shame is less likely than guilt to be causally linked to reparation attitudes.Footnote 46 In experiments, while guilt provoked the “desire to make amends for another's wrongdoing, shame predicted a desire to distance oneself from the situation and the wrongdoer.”Footnote 47 Simply put, while both guilt and shame may be uncomfortable, guilt encourages self-restraint and efforts at reconciliation, while shame drives us in the best of cases to avoid those we have wronged, and in the worst of cases to lash out at them.
Just War Thinking and the Value of Guilt
If law generally relies on sanction to be effective, then the laws of war must be enforceable and publicly enforced. Insofar as shame also contributes to one's willingness to follow the law, the laws of war must be issued by a proper authority—one that is understood to have the legitimacy to issue such rules.Footnote 48 Furthermore, because shame is a social response, it requires not only that we feel others’ eyes on us but that we know and care about what they want from us. Although liberal approaches to international relations suggest that an international society of states is emerging, as a realist I remain skeptical. This is doubly so in the case of the laws of war. If realists are right that states care first and foremost about their own survival, then states are unlikely to care much about the critical gaze of others in the international system.Footnote 49 In the case of international humanitarian law, political, socioeconomic, cultural, and religious differences between combatants on each side make it rather unlikely that they will perceive their opponents as members of the same society. Thus, the law's ability to generate shame is likely to be weaker in the case of (interstate) war than it might be in other contexts. Furthermore, on the domestic level, law presumes that the “normal” condition is one in which the laws are generally upheld.Footnote 50 So the law of war is already operating in an unusual context, attempting to govern a condition that is usually taken to be a state of moral exception.
Attempting to bring the “exceptional” case of war into the international legal order has already required what the legal scholar Martti Koskenniemi calls “a turn to ethics in the profession.”Footnote 51 Humanitarian intervention, for example, was initially justified within legal discourse primarily by appealing to morality. But as Koskenniemi warns, the shift from formalism to ethics is rife with dangers. Ethics is too often driven by the interests and norms of the great powers. In a word, ethics is political. Ethics, in his view, relies too much on the individual consciences of statesmen and soldiers, looking for a purity of intent that it is unlikely to find. This is a fair criticism of some of what is done by classical and Walzerian just war thinkers, including myself, and a reminder of the importance of being practical in our thinking. And this is exactly why law must stick to a rationalist path. While exceptions to the rule may make moral sense, building an international system that would legalize such exceptions is a dangerous and destabilizing endeavor. Here, I again agree with Koskenniemi that the laws of war—and international law more generally—should primarily be about “upholding the status quo,” providing a useful check on our moral (and not so moral) impulses.Footnote 52 Order is a value, and we must always remain cautious about justifying any attempts to overturn it.
With all this in mind, I recognize that, in claiming just war thinking has something uniquely valuable to offer precisely because it is tied to our moral emotions, I am treading on dangerous ground. However, while I think that Koskenniemi's critique of the ethical turn is a valuable caution for legal scholars and professionals, I see nothing in it to deny that ethics itself is a worthy pursuit. Instead, I argue that just war thinking and the international laws of war are doing vastly different but equally valuable things. If law is meant to address the “ordinary” practices of war, just war thinking is especially relevant for helping navigate the gray spaces outside the law. It can help us think critically about precisely when violations of the law might be morally permissible in extraordinary circumstances.
On my evaluation, there are at least four ways in which emotions provide added value to just war thinking in ways that make it distinct from law. First, the fact that just war thinking is tied to guilt may make it a more effective approach to developing an ethic of accountability, especially as part of a professional military ethic. While the disciplinary aspects of international law are still relatively weak, just war thinking can tap into intuitive moral standards in a helpful way. This, after all, is Walzer's claim—that the basic principles of just war thinking are intuitively available to us.Footnote 53 There is some evidence to suggest that he might be right. Although the just war traditions of Christianity, Islam, and Hinduism differ from each other in significant ways, they are also clearly motivated by similar moral impulses: a concern with justice, a recognition of the value of human life and society, and a desire to regulate violent and destructive conflicts so that they remain proportionate to the goods they are meant to achieve.Footnote 54 Empirical research also supports the claim that some basic moral principles—such as the Golden Rule—are universal, although the details of their application may be disputed.Footnote 55
So if just war principles reflect deeply held intuitions, then they seem to be the sort of principles that would naturally trigger the emotion of guilt when they are violated. This suggests that taking actions to encourage individuals to examine their moral intuitions through the lens of just war thinking may be a helpful way to foster a society in which individuals think critically about when and how to go to war, and are willing to take action to ensure that moral principles are upheld. If the empirical research about guilt is correct, individuals are more likely to moderate their behavior when their own conscience warns them about potential moral violations as opposed to an external other, whether that be a scholar, a lawyer, or the law itself.
Second, if the strictures of just war thinking can indeed trigger individual and collective guilt when violated, then perhaps there are ways in which we can harness appreciation of that guilt to address problems of moral injury. In cases where the transgressive act is legal, but feels morally wrong, being told that one's actions are fully legal will be of little comfort. Because the just war tradition considers the subjective effects of one's actions on one's own conscience, it can provide a framework for talking about guilt as separate from legal liability. And this, in turn, can make it possible to consider institutionalized means of making personal reparations. After all, as mentioned above, empirical studies suggest that feelings of guilt prompt us not only to restrain our behavior but also to make reparations when we have failed to do so. Indeed, psychological research indicates that some veterans who have experienced moral injury find efforts to make amends helpful.Footnote 56 By contrast, studies suggest that when individuals feel that there is no way to compensate for (perceived) wrongs, they may turn to self-harm as a form of penance.Footnote 57 This implies that the contemporary just war tradition's interest in matters of jus post bellum is of particular importance. In some ways, this is nothing new: the Christian just war tradition of the early Middle Ages required penance for returning soldiers who had killed in battle.Footnote 58
Third, just war thinking provides a common language through which soldiers can analyze, debate, and share their moral experiences with society as a whole. This, too, is tied to its intuitive and emotional nature. It permits us to (at least partly) share a moral imagination, and thus to be more empathetic in our interactions with others. Our moral emotions can enable us to “mentally transpose” ourselves into another's shoes, permitting us to understand his or her choices from the inside.Footnote 59 Just war thinking across the traditions is particularly concerned with intent, which reflects this concern with understanding the other. Similarly, legal scholars also argue that in order to understand someone's behavior we cannot merely consider the consequences of her actions, but we must also explore her motivations, including emotional ones.Footnote 60 In liberal democracies, where only a very small percentage of the population is engaged in military service, it is difficult to engage in serious public debate and reflection about war's moral implications if civilians are presumed (sometimes even by themselves) to be incapable of understanding what war is like. Insofar as just war thinking invokes our moral emotions, it can give us as a society a common language that could enrich discussions of the costs of war.
Finally, attention to our moral emotions can help us recognize ethical problems even in radically new contexts that may have no legal precedents. This is especially true in a world of rapidly changing technology. It can sometimes be difficult to imagine in advance what the moral stakes of a particular new tactic or tool might be. But attention to our emotional responses can alert us to when we might be treading on morally hazardous ground, such as in the relatively new field of drone warfare. For this reason, ethicists concerned about the use of artificial intelligence in autonomous weapons systems are interested in the possibility of programming robots with a set of moral emotions of their own.Footnote 61
Ultimately, while some legal scholars (and even some revisionist just war thinkers) might argue that the use of emotional intuition in classical and Walzerian just war thinking is a weakness, I argue that the use of the moral imagination is actually one of its strong points. Indeed, to remain relevant in a world in which international law is developing increasingly clear, precise, and objective rules of war, just war thinkers must avoid the temptation to cede too much to the lawyers. There is a gap between law and morality, and just war thinkers can help us mind it.
