This is quite a book. Its sheer heft is daunting, its central claim bold and sweeping, its data relentless. While the planet goes “cycling on according to the fixed law of gravity,” Steven Pinker argues, the human species has been progressing. We have reduced the fear of violent death for an ever-greater proportion of the population across the centuries. Pinker argues that every sort of violence has declined, from interpersonal cruelty to interstate war, beginning toward the end of the medieval period and extending to today. He then identifies the causes of decline so that we can know what can extend the trend into the future. This will allow us, as he puts it, to “obsess not just over what we have been doing wrong but also over what we have been doing right” (p. xxvi).

What have we been doing right? For those of us reading today, the answer is not very much. Mainly we are lucky to have been born into this moment. But the species as a whole has been doing something right. Thanks to the Age of Reason and the Enlightenment, we have been able increasingly to construct the type of political institutions that favor, by and large, the “better angels” more than the “inner demons” of human nature: “On top of all the benefits that modernity has brought us in health, experience, and knowledge, we can add its role in the reduction of violence” (p. 694).

This book calls on us to celebrate: We should “savor” and “cherish” this enormous achievement (p. 696). I agree, but only to a point, because there is something deeply unsettling about the argument of this book. While I began reading without either smug comfort in my own circumstances or indifference to the violence that remains, by Pinker's final sentence on page 696 it was impossible to muster any other reaction. Indeed, I want to suggest that Pinker's book produces the type of reaction that conceivably could stop this important trend dead in its tracks. A world of elites and foreign policy decision makers well-schooled by Pinker in the causes of the decline in violence would be a world unmotivated to work to sustain it.

To be sure, Pinker cautions his readers against complacency. There are no guarantees the trend will continue, he avers, and so our goal should be to discover “strategems to overcome the tragedy of the inherent appeal of aggression” (p. 695). We also ought not be complacent out of respect for the people who, in previous centuries, worked hard for this outcome: “[W]e enjoy the peace we find today because people in past generations were appalled by the violence and worked to reduce it, and so we should work to reduce the violence that remains in our time” (p. xxvi). But there are no theoretical resources in his argument to rationalize or support these appeals.

With this in mind, and because I think (and I think Pinker would agree) that the stakes of complacency are high, in this review I want to show, despite his exhortations, how that unhappy result is nonetheless the cumulative effect of Pinker's argument. The slide from engagement to complacency is gradual and sometimes subtle, but it is unrelenting. It is particularly manifest in his one-sided reading of modernity, his use of statistics, and his demotion of agency. To make this argument, I need to grant Pinker both his premise that there has been a decline in violence and his claim about the central role of reason and the Enlightenment. To be sure, the Enlightenment is not the only key moment Pinker highlights in the trend away from violence. It is the third of six trends that he says constitute the decline, but it is not wholly separable from the five historical forces to which the author grants particular causal power: the modern state, commerce, feminism, cosmopolitanism, and the escalator of reason. Its significance is that the Enlightenment marks a switch from accepting the authority of tradition to embracing the authority of reason.

As Pinker argues, reason is a powerful engine for human progress, teaching us to be skeptical of received truths and to commit ourselves only to conclusions that follow from its application. Reason also forces a rational humanism. Once we see that others, like ourselves, are capable of reason, we cannot justify violence toward them. From here, “there can be, in principle, a meeting of the minds. I can appeal to your reason and try to persuade you, applying standards of logic and evidence that both of us are committed to by the very fact that we are both reasoning beings” (p. 182). A morality rooted in reason is well suited for reducing violence both because it is universal and because it is independent of emotions and especially of our propensity to moralize our relationships (p. 183). In his words, “[t]he world has far too much morality” (p. 622). An important aspect of the decline of violence is the rise of a rational-legal mode of relating to one another, which substitutes the values of autonomy, fairness, and rationality for moral intuitions that privilege communal ties (p. 639). We cannot get rid of moral intuitions and they certainly can be channeled to good ends, but the author argues that as a force for peace they are unreliable. All are violence enhancers that the rise in reason has enabled us to better control.

Pinker further argues that being smart, liberal, and nonviolent all go together: “[C]lassical liberalism is itself a consequence of the interchangeability of perspectives that is inherent to reason itself” (p. 662). As abstract reasoning skills rise in a population, peaceable values rise and violence declines (pp. 660 ff). Applying his causal argument to European history since the eighteenth century, he shows that good political outcomes—outcomes that result in less violence—result from reason and liberalism, while spasms of violence and other bad political outcomes happen when tradition, religion, emotion, and romantic utopianism seep through. It might look as though today is especially violent because news media flood us with horrific images and stories, whether of contemporary slavery, violence against women, or genocide. But, Pinker stresses, we should focus less on those horrible practices and more on our own reflexive sense of horror. To be able to be horrified about these things is a real, and relatively recent, accomplishment. In previous generations, those who committed democides were proud, but today even Holocaust deniers feel compelled to deny it. They recognize that had the Holocaust existed, it would have been wrong (p. 335).

A crucial step toward reliably reducing violence is therefore an intellectual one: Engage the reason of a broad swath of people. Pinker draws on an experimental finding called the Flynn Effect (p. 660) to argue that the smarter a society is, the more likely reason can prevail. We therefore need to cultivate our reason because once reasoned arguments against violence are out there, the politics will follow: “The universe of ideas, in which one idea entails others, is itself an exogenous force, and once a community of thinkers enters that universe, they will be forced in certain directions regardless of their material surroundings” (p. 180). The timing cannot be predicted and there can be backsliding, but (and although Pinker stops short of using the term) the overall telos of reason in history is undeniable: “Once [reason] is programmed with a basic self-interest and an ability to communicate with others, its own logic will impel it … to respect the interests of ever-increasing numbers of others. It is reason too that can always take note of the shortcomings of previous exercises of reasoning, and update and improve itself in response” (pp. 669, 186).

Unfortunately, nothing in this argument generates anything other than a smug satisfaction with our situation in the liberal West. Indeed, step by step as he develops the argument, Pinker gradually absolves modernity and moderns from the violent splotches and stains of the past centuries, while dulling our sense that it is important to care about, much less feel a sense of responsibility toward, the distant others still mired in violence.

First, Pinker offers an airbrushed and uncomplicated portrait of liberalism and modernity, making us more comfortable with historical events that have often troubled us. Many scholars have argued, for example, that the French Revolution was the culmination of the contradictions of the Enlightenment. Pinker says no. It may have been inspired by Enlightenment thought, but it went awry because “many of the French philosophes from whom the revolutionaries drew their inspiration were intellectual lightweights” (p. 184), and the poor thinking they inspired allowed the revolution to succumb to illiberal ways of acting. What caused the excesses of that revolution were not Enlightenment products but the “messianic, apocalyptic [and] expansionist” ideas (p. 239) that overcame them.

He also smoothes over two more recent violent spasms, the Holocaust and the 1994 genocide in Rwanda. In Pinker's rendering, there is nothing specifically modern about either. Both are simply contemporary incarnations of killing by category, which has plagued human history for centuries (p. 332). Both implicated emotions of fear and anger and disgust; both demonstrate how the moral sense can be easily put in service of massive violence. But Pinker's categorization seems at least shortsighted to me. Reason and science were deeply implicated in both. Both genocides were rooted in attitudes toward the Other that were scientifically justified. Pinker casts out Hitler's “pseudoscience,” but Aryan supremacy was just an extreme version of a racial science that was widely taught and accepted and that rationalized public policy in the United States and Europe well into the twentieth century. Also, racial thinking colors the work of Enlightenment as much as counter-Enlightenment thinkers, Voltaire and Kant as much as Hegel and Herder. Finally, Rwanda's racial categories were so emotionally charged because they had been created by the modern Belgian colonizers who labeled the supposedly taller, lighter-skinned Tutsis and set them to govern the supposedly shorter, darker Hutu. In other words, simply blaming the emotions that reinforce categories while exonerating Enlightenment science from any role in legitimizing them glosses a complicated intellectual and political legacy, and it effectively erases hierarchies that themselves contributed to the patterns of violence.

Moreover, in both genocides, the rational-legal ethic of bureaucracy played a key enabling role. Pinker praises this mode of relating because it “can be put in the service of a utilitarian morality that calculates the greatest good for the greatest number” (p. 635). It is true—and Pinker acknowledges—that because it is indifferent to emotion and morality, rational-legal thinking can be put in the service of a war machine (p. 635). But any acknowledgment that this cold mode of relating to others might help fuel violence is wholly lacking in Pinker's discussions of the Holocaust or Rwanda. He does not entertain the thought that bureaucratic man may have been crucial to the scale and success of the Holocaust. Rather, in his view, the special technology and modern bureaucracy were mere “trappings” and a “sideshow.” As Rwanda showed, even contemporary genocides hardly need fancy technology; machetes will do just fine (p. 643).

Nor does he consider how government man, driven by a similar ethic, may have been crucial to the success and scale of the Rwandan genocide. As Michael Barnett has argued (Eyewitness to a Genocide: The UN and Rwanda, 2003), the United Nations Secretariat was dominated by a rational-legal mind-set that produced indifference to the plight of the Rwandans. Arguably, many more Rwandans died than would have if decision makers at the UN had approached the situation with a morality-based ethic of responsibility instead. In short, in both cases science, rationality, and indifference worked hand in hand to enable and sustain mass violence. This is not to deny the role of emotion, romantic communal attachments, and so on. But it is hard to imagine either of these genocides without the additional fuel of science and rational-legal modes of relating.

I think that confronting the mixed legacy of the Enlightenment would have made for a deeper account of the trend; it certainly would be a more convincing one. But it is clear that Pinker does not want to be engaged on this aspect of his argument. Throughout the book he has no patience for modernity skeptics and is sharp-tongued and dismissive when it comes to counterarguments. Those who criticize modernity have “amnesia and ingratitude” (p. 133). Those who compare the slavery of old to contemporary slavery and trafficking are “statistically illiterate and morally obtuse” (p. 157), and to suggest that the Holocaust is linked to modernity is “ludicrous, if not obscene” (p. 643). If we overlook the forest of normative and political progress because of a few randomly placed despicable, violent trees, from Pinker's perspective we are stupid, or at least willfully unenlightened. If a goal of the book is to encourage us to think critically about how to reduce political violence so we can continue to foster the trend, then it is not clear how this one-sided reading of modernity moves us in that direction.

Pinker's second distancing move is the particular way he uses statistics to contextualize the severity of war across the ages. His trend of declining violence is a result of measuring the number of people who die violent deaths in a given year as a proportion of world population. That is, the focus is not on the absolute number of deaths in a given war but on the number relative to the total number of people worldwide. So, for example, while the twentieth century had more violent deaths than any previous century, it is crucial to keep in mind that world population in 1950 was 2.5 times that of 1800. A death count in 1600 must be multiplied by 4.5 in order to properly compare its destructiveness to a violent event of the mid–twentieth century (p. 193). This leads to a recalibration of violent conflicts across the centuries, which turns contemporary wisdom on its head. We tend to obsess over the extreme destructiveness of World War II, but this contemporary calamity does not even make the top five worst human-made horrors. So many people died in World War II, but so many more others throughout the world, inside and outside of Europe, lived through it; and they count, too. Once properly calibrated, the most destructive conflict was the eighth-century Lushan Revolt in China, a conflict that does not implicate either modernity or the West. World War II comes in at number nine.

Not only is the worst conflict well before our time, but our worst conflict was essentially a fluke. Pinker characterizes war over time as a Poisson process, which means that even where we see clusters of conflicts, these “events occur continuously, randomly, and independently of one another” (p. 203). When it comes to war, “Mars just keeps rolling the dice” (p. 205). Pinker also points out that trends can be robust without every data point fitting perfectly. Statistical flukes are possible. World War II is precisely that: no Hitler, no Holocaust. No war since then has had as high a number of casualties, and indeed interstate war has virtually disappeared while the enduring intellectual trend of the twentieth century is violence aversion and humanism.

Consider what Pinker has accomplished so far. The world's most horrific excesses are divorced intellectually and distanced statistically from our values and our time. World War II is a random fluke, reason is self-correcting, and the trend is a liberal wave whose crest we are riding on.

But there is more. The mechanisms of Pinker's causal argument suggest that there is not a whole lot we as individual agents can or ought to do about the violence that remains, especially violence outside of the liberal West. This is his third distancing move. Sometimes Pinker talks in a way that highlights a society's agency, such as when he notes that it is not inevitable for reason to take root and a society must choose to be governed by reason. Once societies make the choice and organize themselves in a way that permits free expression, they make it possible to “collectively reason their way to sounder conclusions in the long run” (p. 181). As reason unfolds, on this view, societies eventually adopt rational-legal morality, and violence will decline. The West made this choice in the eighteenth century, but not all societies have yet done so, and in any case the timing must be right as well.

That is, for that choice to stick, a society must have in place the right sorts of customs and habits. In the eighteenth century, for example, the French did not have the right habits and the Americans did. Today, a lack of proper habits “may explain why … it is so hard to impose liberal democracy on countries in the developing world that have not outgrown their superstitions, warlords, and feuding tribes” (p. 185). A society's habits develop in stages. The moralities of community and authority are the earliest stages of development, and these are most vulnerable to the accepting and legitimating of violence. Religious morality fits here. The Muslim world still “indulges kinds of violence that the west has outgrown,” and Pinker suggests that the problem might be that “the dead head of religion [has] impeded the flow of new ideas” (p. 365). But societies can outgrow the need to relate emotionally and mature into reason-based ethics (pp. 628, 635). The rational-legal mode of relating is a relatively recent phenomenon and is not a natural way to relate to one another (p. 669), however. It can emerge only in technologically advanced, “literate and numerate” societies, and it “might not occur spontaneously to untutored minds” (p. 628). Islam's lack of separation between church and state has “lock[ed these societies] in an illiberal stage of development” (p. 365). The implication is that, until they can make that separation, we should not expect violence to decline in, among, or by these societies.

Given such an argument, it is difficult to know how to orient ourselves toward regimes that remain at the margins of the author's trend and are still mired in violence. Pinker does not advocate a missionary approach, and he certainly is not encouraging hostility. But nor does he give us the theoretical resources to rationalize engagement, much less responsibility. Technologies that allow us to see the distant Others, travel to their countries, and understand that they are human enable our circle of empathy to increase. But empathy cannot prevent violence, and Pinker downplays its role (e.g., pp. 573–78, 668). To achieve a reliable reduction in violence, a society must first be ready for reason and then must choose it. The choice for reason, and the habits that enable it, are domestically rooted. These progressive, violence-dampening ideas may not yet have reached them, but it is not up to us to spread them. The responsibility is their own. Indeed, since the global trend toward less violence is powered essentially behind our backs, it is not particularly necessary for us to be attentive to the worldwide ebb and flow. When societies are ready, change will happen, when they aren't it won't.

Pinker thus leaves us Westerners in an odd relationship with the rest of the world. On the one hand, the global population is crucial to the celebration he initially calls for. Without these billions we would have nothing to savor or cherish. Their presence is crucial in that their live bodies create the numeric baseline that establishes Pinker's fortuitous trend. But on the other hand, the trend itself is ours and not theirs. Our ideas and politics caused it, and we are justified in standing slightly aloof. The author argues early on in the book that it is an improvement to live in a world where lives are valued more than souls, that is, where the Enlightenment has defeated religion. But his argument is concerned with non-liberal, non-Western lives only in this limited, instrumental sense. Once we finish counting them we need not concern ourselves with them. Their physical life might be necessary but their political lives are incidental.

In sum, over the course of the book Pinker gradually feeds us a glossy modernity and clever statistics that steadily lead us away from political engagement by helping us feel good about ourselves and distant from the causes and victims of violence. Ironically, in his own terms what the author has given us is as much ideology as argument (see pp. 567–69); and our susceptibility to ideology is decidedly not one of the better angels of our nature. Undoubtedly Pinker would disagree with this characterization. But even if we grant him that there is a trend and that he has identified its causes, it is difficult not to conclude that this is a work of ideology, too. He may tell us to care about the violence that remains, but the logic of the argument does not point that way.