Musar as a Challenge to the Justification of Mass Killing
Geoffrey Claussen
Credit: Kurt Hoffman
Geoffrey D. Claussen is Lori and Eric Sklut Professor in Jewish Studies, Professor of Religious Studies, and Chair of the Department of Religious Studies at Elon University. His books include Modern Musar: Contested Virtues in Jewish Thought (2022) and Jewish Ethics: The Basics (2025).
How can Jewish traditions best contribute to discussions about the ethics of war? I believe that musar traditions—ideas about moral character and about how we should be guided by virtues including justice, compassion, solidarity, equanimity, and humility—are key resources for those of us seeking guidance from the history of Jewish thought. Even when we are facing ethical dilemmas unique to the twenty-first century, ideas developed in earlier centuries about how to exemplify such virtues can provide guidance and raise important questions about the ethics of war. Reflection on musar approaches to justice and compassion, above all, may help us to articulate our moral concerns in the language of Jewish tradition.
Claims about the virtues of justice and compassion can serve many purposes at a time of war. Those who defend wars, even wars characterized by the foreseeable mass killing of innocent people, often argue that such violence is required by justice and compassion. Some argue that justice should lead us to support killing innocent people in enemy nations, even children, in order to protect innocent people on our own side. Some maintain that justice should guide us to excuse such killing so long as that killing is not intended but is merely a side effect of well-intentioned military operations. Some contend that those who appear innocent are in fact guilty, such that killing them is justified. And many who defend mass killing in war advocate for compassion for victims on their own side, even as they conclude that compassion must be limited for victims on the other side.
During the ongoing Israel-Hamas war, both those defending Hamas’s attacks on Israeli civilians and those defending Israel Defense Forces (IDF) attacks on Palestinian civilians in Gaza have made such claims. In this essay, I consider how such arguments have been made by Jews who have called on other Jews to join them in defending violence against innocent Palestinian civilians. I argue that reflecting on musar traditions regarding the pivotal virtues of justice and compassion—which are often invoked in discourse about war—may provide us with guidance, helping us to question such calls and to think critically about what constitutes a just war.
Justice
Musar traditions—that is, Jewish traditions about virtue and character—have been developed in nearly every time and place where Jews have lived. Within the history of these traditions, we can find many conceptions of justice as a virtue, a character trait that human beings may seek to cultivate. A number of these conceptions are valuable to consider when we confront calls to defend killing innocent people during war.
The traditions that I cite below stem largely from nineteenth and early twentieth-century musar teachers who were not teaching with an eye to war and were not considering questions of twenty-first century statecraft. They were, however, seeking to articulate key aspects of what it means to be characterized by justice—ideas that I believe are important not only at times of peace but also at times of war. As I have taught these musar traditions in Jewish communities over the past year, I have found that even people initially inclined to think that such ideas are inapplicable to contexts of war ultimately find great value in reflecting on how they may shape our judgments about war.
I will suggest three traditions of thinking about what it means to be just that may be valuable sources of reflection. First, being just means not doing to others what we would not want done to ourselves; second, being just requires attending not only to the ends we seek but also the means of achieving those ends; and third, being just requires not assuming the guilt of others.
Not Doing to Others What Is Hateful to Us
The nineteenth-century musar scholar, Menahem Mendel Lefin, taught that the key phrase to keep in mind when focusing on justice (tzedek) as a virtue is, “That which is hateful to you, do not do to another” (Sefer Heshbon Hanefesh). This golden rule is at the heart of what it means to be just—and might override any other moral principle; according to a famous story regarding Hillel in the Babylonian Talmud (Shabbat 31a), this principle encompasses the entire Torah (all else is commentary).
What might it mean to display this sense of justice when we are called to condone killing innocent people in war? When we learn of IDF operations that seem well intentioned but kill Palestinian families, we might reflect on how we would hate for similarly well-intentioned operations to cause the deaths of our own families. If we are considering supporting attacks aimed at terrorists that also kill Palestinian children, we might reflect on how we would never defend attacks aimed at terrorists that would kill our own children—or that would kill Israeli children.
Recognizing the moral equality of others in this way does not mean that we abandon our particular sense of responsibility to ourselves, our children, our families, our friends, or our people. Hillel’s formulation of the golden rule is not incompatible with his understanding that people need to be concerned for themselves, as indicated by his well-known question, “If I am not for myself, who will be for me?” And yet Hillel also asked, “When I am only for myself, what am I?” (mAvot 1:14). One must be “for oneself” and also extend a similar concern to others.
Those who are just may show special concern for those they see as part of their own community, but they do not treat the lives of those outside their community as having lesser worth. And they may well recognize that they also have particular responsibilities to innocent victims on the other side; Jews, for example, may recognize their responsibility to Palestinian civilians who have been victimized by other Jews, just as they would like Palestinians to show concern for Jews who have been the victims of Palestinian violence.
Those who defend killing innocent people in war typically argue that such killing is necessary to protect people on their own side. “We should prioritize the safety of our brethren at the expense of increased enemy collateral damage. Not because we appreciate the divine image of all human beings any less, but because we value our filial responsibilities even more,” as Rabbi Shlomo Brody put it in a recent defense of the IDF’s approach to killing noncombatants when targeting Hamas operatives, published in Public Discourse. But Brody clearly does see some human beings as created more in God’s image than others, as he treats Palestinian lives with a sort of disdain that he would never extend to his Israeli brethren, supporting harms to them that he would never want inflicted on his own community.
When we are faced with such arguments, Lefin’s concept of justice provides a reminder to center the moral equality of all people, all of whom are equally created in the divine image. When we consider “filial responsibilities,” we are reminded that fulfilling responsibilities to protect our own innocent families must not come at the expense of another group of innocent people. When we are tempted to support killing other people’s children because we see this as the only path for protecting our children, the golden rule can help us to see other pathways forward. When we make judgments about whether to support killing those who are innocent, we might always bear in mind this key musar question about justice: are we supporting doing to another what would be hateful to us?
Pursuing Justice Justly
Another maxim that might orient a person of justice has been attributed to the early nineteenth-century rabbi, Simhah Bunim of Peshischa: “Pursue justice justly.” This phrase interprets the biblical injunction to pursue “justice, justice” (Deut. 16:20): the repeated word warns us to pursue not only just means but also just ends.
Those who defend killing innocent people during war often argue that doing so is justified when a war is motivated by a justifiable outcome. They argue that, if the goal is self-defense, then the killing must be justified. But the injunction to “pursue justice justly” suggests that war cannot be just when it produces significant new injustices. When we can foresee that the tactics used in a war will kill innocent people, we are not acting justly when we seek to excuse such killing because of the war’s intended goals.
Contemporary Jewish thinkers who disagree often invoke the “doctrine of double effect,” a doctrine developed within Catholic tradition that permits the proportionate killing of innocent people so long as one’s intent is self-defense and so long as that killing is a mere side effect. The goal of protecting some innocent lives is seen as justifying the unintended killing of other innocents, even when that killing is foreseeable. But as Brody admits, traditional Jewish sources are often suspicious of claims that outcomes are “unintended” when they are inevitable. When the deaths of noncombatants are foreseeable, he writes, “I cannot pretend that their deaths are inadvertent.”
Assertions that some innocent people must be killed to save other innocent people should give us pause. At the very least, when we face assertions about how anticipated ends justify such means, we should bear in mind these key musar questions about justice: Are we too easily excusing injustices made in the name of good intentions? Are we doing what we can to ensure that justice is pursued justly?
Not Assuming the Guilt of Others
A third piece of musar wisdom teaches us that a person of justice will not assume all people in a given place are guilty, and they will speak out against claims that a whole population deserves death. Abraham’s objection to the destruction of Sodom in Genesis provides a model, as Abraham challenged God’s plan “to bring death upon the innocent as well as the guilty, so that innocent and guilty fare alike” (Gen. 18:25). Commentators such as the early twentieth-century musar teacher, Avraham Shmuel Finkel, have emphasized that Abraham was exemplary in his efforts to show that even those who seemed guilty had redeeming qualities that should ensure their survival: “he argued at length for them, searching for any opening he could find, persistently, even just a small reason to save them” (Pathways of Musar). We learn that even when it is tempting to write people off because they are surrounded by wickedness, we should search out and recognize their good qualities, and we should certainly refrain from justifying their deaths.
If we should protest the killing of those who might be innocent, we should object even more to the injustice of killing those in war who are clearly innocent. According to one midrash, when Abraham fought to rescue his nephew Lot from captivity, he was deeply afraid that he might have killed even one righteous or God-fearing man. God affirmed that his concern was just (Genesis Rabbah 44:4).
In the story of Sodom and in this midrash, Abraham offers a model for how those motivated by justice should approach war: we should be aware that a justly motivated war may produce grave injustices, and we should be terrified that people might be killed who do not deserve to die. We should recoil from the potential death of even one innocent person, as Abraham did; we should regard the mass killing of innocent people as evil.
Some defenders of the IDF campaign in Gaza have argued that all Gazans share in the guilt of those who perpetrated the October 7 attacks on Israel, as Israeli President Isaac Herzog did when he asserted at the start of the war that “it’s an entire nation out there that is responsible.” Brody, meanwhile, even as he concedes that noncombatants should not be targeted, asserts that “the political solidarity of a nation compels them to share the same fate. Even when only soldiers are targeted, noncombatants will die alongside them.” Claims such as these often play an important role in justifying the killing of the innocent.
Musar traditions can help us to reject these assertions of collective guilt. When we hear calls to view an entire nation as guilty, or to view individuals as destined to suffer severe consequences together with their compatriots regardless of their individual actions or views, we might imagine the exemplary moment in Abraham’s life when he objects to collective punishment or the moment when he trembles at the thought of having killed a righteous individual. We might bring to mind the righteous individuals and innocent children in Gaza who were killed without enough people crying out against their deaths. We might ask ourselves the key musar questions: are we assuming the guilt of others? Are we standing up to demand that the innocent not be punished along with the guilty? Are we arguing at length for them, searching for any opening we can find, persistently, looking for even a small reason to save their lives?
Compassion
Though some Jewish traditions see justice and compassion as conflicting with each other, others see justice and compassion as complementary and emphasize how being compassionate is a crucial part of being a just person. These traditions can help our moral judgments when we confront calls to condone the killing of innocents in war.
I will highlight two such traditions about compassion that may be helpful at these moments: first, that compassion requires seeing and responding to the suffering of others; and second, that compassion should be guided by the commitment to moral equality that justice demands. I have found that reflecting on both of these aspects of compassion can be fruitful even for people initially inclined to doubt their relevance for the context of war in the twenty-first century.
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Responding to Suffering with Compassion
In many musar sources, compassion requires responding to the suffering of others with empathy, altruism, and—insofar as it is possible—action to relieve it. Can such traditions guide our responses to war as we face the immense suffering brought about by Israel’s military campaign in Gaza?
It is extraordinarily difficult to focus our attention on the pain of those with whom we are at war when our own community is traumatized and suffering deeply, and the virtue of compassion for the other is often derided in such circumstances. Especially in the immediate wake of the October 7 attacks, even Israeli Jewish public figures known for their liberalism or moderation explicitly criticized those expressing compassion for people in Gaza. “Now is not the time for compassion. Now is not the time for humanitarian support and kindness,” the former Israeli politician Dov Lipman asserted in an open letter published in the Times of Israel. “Now is the time for ‘strength to the nation’ and nothing but brute force.”
Other Jewish public figures, however, pointed to the need to cultivate compassion for innocent victims at a time of war. Yehuda Kurtzer, for example, wrote in this journal of the need to sustain “an overflowing and undiscriminating reservoir of compassion for the victims of the power at our disposal” and insisted that “we dare not look away from the faces of the innocent victims in Gaza, and especially the children.” At the same time, he urged readers to support the war and worried that North American Jews’ focus on compassion might lead them to “lack the stomach for the fog, complexity, and violence that this war will entail,” including the deaths of innocent people. In the end, Kurtzer argued, “we cannot afford to be squeamish when it comes to military agency and the impossible and tragic but necessary choices that an army has to make in wartime.”
It may indeed be impossible to reconcile a commitment to undiscriminating compassion for victims with support for the violence that is causing the deaths of those victims. When we find ourselves drawn to support such violence, we might ask whether we are in fact viewing that violence as tragic and whether the faces of the victims are inscribed in our consciousness.
Musar traditions regarding the compassion of Moses can provide guidance. As taught by the nineteenth-century musar teacher, Rabbi Simhah Zissel Ziv, Moses exemplified compassion when he learned to empathically “share the burdens” of the enslaved and respond compassionately, even while he enjoyed power and tranquility as a prince in Pharaoh’s palace. Moses filled his mind with images of the enslaved Israelites’ suffering, and “habituated himself to seeing these mental images to such an extent that he felt their pain as if he himself was in such pain, and so he came to be sharing their burden” (Sefer Hokhmah U’musar).
Before he imprinted the suffering of the slaves in his mind, Moses might well have viewed enslaving and killing Israelites as a tragic necessity, following Pharaoh’s view that Israelite freedom represented an existential threat to Egyptian society. His ultimate refusal to justify violence against the enslaved Israelites, and the steps he then took to prevent further suffering, is an exemplary instance of compassion.
Can we, similarly, act with a sort of compassion that refuses to justify the suffering of innocent victims? Can we habituate ourselves to see the extraordinary suffering of innocent people in Gaza, to such an extent that we feel their pain as if we were in such pain, and then act responsively to alleviate that suffering?
Guiding Compassion with Justice
We may also draw guidance from musar traditions that explain how compassion must be guided by justice—by a commitment to equality, extending to others the concern that we would want for ourselves. As Simhah Zissel Ziv put it, “what one would ask from one’s fellow for oneself, that they should at least share in bearing one’s burden, so one should ask oneself to act for one’s fellow” (Sefer Hokhmah U’musar). Just as we want others to share our burdens, we should seek to share the burdens of others. Just as we want our suffering to be relieved, we should seek to relieve the suffering of others.
Unfortunately, especially during war, compassion tends to be highly selective. We will often take compassion very seriously, but only for ourselves, for our own group, for our own people, or for our own nation. During the Israel-Hamas war, we have seen that just as many who align themselves with Palestinians will only feel their pain and will only focus on their suffering, many who align themselves with Israeli Jews will feel only their pain and will only focus on their suffering.
Just as we should consider our responsibilities when it comes to justice, so, too, should we consider our responsibilities when it comes to compassion. I believe that while we have a duty to show compassion to those who are closest to us, we also have a duty to show compassion to those whose suffering stems from attempts to defend our own community. Compassionate people do not respond to the suffering of those in their community by supporting the infliction of great suffering on innocent people in other communities.
Compassion guides us to recognize the humanity of people on both sides and to grant them the benefit of the doubt when we consider their suffering. Kurtzer, in his defense of Israel’s war effort, wrote that compassion allows him to respond to slander against the IDF “by visualizing the faces of my nephews and cousins and friends and colleagues who make up its ranks. This helps me remember that wars are fought by people doing their best, people to whom I ordinarily grant the benefit of the doubt and must continue to do so.” When we find ourselves moved by compassion of this sort for Israelis, and ask others to have compassion for them, we should then show the same benefit of the doubt to Palestinians. When Palestinians are subject to slander—including the horrific refrain that their lives are more expendable than the lives of Israelis—we should recognize their full humanity and give them the same compassionate benefit of the doubt that we would want extended to ourselves. Giving people the benefit of the doubt, at the very least, means not seeking to justify their deaths as a tragic necessity. Ideally, as Simhah Zissel Ziv taught, compassion means actively sharing their burdens, just as we want our own burdens to be shared.
We, too, can emulate the way that Moses turned away from a life of tranquility to show compassion for those whom he previously did not see as his people. Are we doing what we can to respond to—and, if possible, alleviate—the suffering of those we do not see as our people, including those whose suffering we might prefer to ignore?
Critical Reflection at a Time of War
Can we describe a war as just when it leads to the mass killing of innocent people? People adhering to the virtues of justice and compassion as I have described them here will struggle to do so. Justice guides us to object when war inflicts such harms on others that we would not accept for ourselves, to recognize that good intentions are insufficient to justify such killing, and to refuse to assume the guilt of others. Compassion further guides us to do what we can to alleviate suffering, extending the concern to others that we would want for ourselves. We should not seek to justify a military campaign, even if we recognize that it is well-intentioned, when it inflicts foreseeable, intolerable harms on innocent people, sweeps away the innocent along with the guilty, and fails to recognize the equal humanity of the other.
Those seeking to defend Israel’s military campaign in Gaza might object to this framework because they cannot imagine a way for Israel to protect its citizens that does not involve the mass killing of innocent people. In some communities, the conviction that there is no other possible approach has become an article of faith, even when there is no evidence to show that mass killing will ultimately save lives. Many people traumatized by the October 7 attacks are consumed by the fear that Hamas represents an “existential threat” that can only be eliminated by mass killing, no matter how much evidence suggests otherwise. And given that popular conceptions of “just war” doctrines easily permit killing innocent people, many defenders of Israel have been content to assume that justice is on their side and to ignore alternative approaches to national defense that do not condone such killing.
Engaging in critical reflection on musar traditions about justice and compassion may help those who are stuck in a mindset of justifying the killing of innocent people. Longstanding musar traditions emphasize the importance of self-criticism through engaging with difficult questions such as those considered in this essay, both as part of an individual practice (e.g., meditation, contemplation, or journaling) and in community (e.g., in groups dedicated to discussion and dialogue). I hope that even those who disagree with my perspectives on the Israel-Hamas war will benefit from considering, reflecting on, and discussing the questions I raise here. My own positive experiences with facilitating discussion about questions of musar in Jewish institutional settings over the past year suggests to me that communal engagement with such questions can be morally fruitful—for people of all sorts, regardless of their political or religious commitments. When communities regularly encourage reflection and dialogue on justice and compassion, these virtues can be nurtured in significant ways.
Unfortunately, finding Jewish institutions that will nurture such virtues along the lines discussed here may be difficult at the present time. Over the course of this war, many leaders of Jewish institutions have been inclined to turn away from practices of self-criticism, dialogue, and moral reflection, perhaps believing that they must show strength in defense of Israel and that self-critical reflection would be a sign of weakness. Some have been so traumatized by violence committed against Jews by Palestinians that they have been unable to cultivate compassion for Palestinians suffering at the hands of Jews. Some cannot imagine non-violent solutions to the crisis and fear that centering justice and compassion will erode support for the violence that they are sure is necessary. But especially as greater numbers of Jews around the world come to doubt the justice and necessity of the ongoing war, there might be hope for the growth of Jewish institutions that will better nurture the virtues of justice and compassion that will help us to make better judgments about war.
