Belief in human progress has always depended on a kind of provisional faith. Philosophers of the Enlightenment imagined that it was possible to break the chains of oppression and bring about the emancipation of all people. After the Scientific Revolution, priestcraft and superstition lost credibility, and after American independence, the French Revolution established hopes that liberty and equality for all were on the way, putting an end to material penury and social hierarchy. Yet things went south in the rise of empire and the victory of reaction, the explosion of a dehumanizing brand of capitalism, and two world wars, capped by Auschwitz and Hiroshima. The lesson from this history is not necessarily that progress is unavailable, but that to believe in it is not easy.

The Harvard psychologist Steven Pinker has long been a loud votary of progress. In his 2011 book, The Better Angels of Our Nature, he proposed that by one crucial measure, human life was improving across the world. Violence, he aimed to show, had long been in decline and had now reached an all-time low. No one could deny that the arguments were well-packaged and well-written. Statistics on murder rates showed that modern self-restraint had replaced a medieval tendency toward carnage, while social expectations had accentuated the positive in human nature, keeping “inner demons” in check. Joining defiant rationalism to political centrism in an irrepressibly upbeat tone, Pinker insisted that the sky is the limit on possibility if humanity sticks to its tried-and-true devices of pacification: the gentle sociability of commerce, the feminization of boorish men, and the continuing expansion of sympathy for others. He saw an escalator of reason raising humanity from indulgence in its basement passions.

In his new book, Enlightenment Now, Pinker makes a broader argument that, by all significant measures, humans are making progress. Whereas before he argued that people are more likely to stay alive, now he wants to show that they are also flourishing more than ever across a wide array of areas. Whatever the naysayers might think, human beings are healthier, better fed, and richer than ever before. In spite of some obvious reversals here and there, peace is on the rise, and more people demand and enjoy democracy. Finally, they are happier, by their own testimony. The data he reports shows, for example, that the world has grown 200 times wealthier since the Enlightenment, dwarfing growth in all of history to that point. In 1820, Pinker reports, more than 80 percent of human beings lacked basic education, and now more than 80 percent enjoy it.

Not only does Pinker argue that these advances fulfill Enlightenment hopes, he proposes they are a direct result of the Enlightenment itself, the period beginning after the Renaissance and Reformation when a group of thinkers insisted on the supremacy of rational inquiry over unthinking dogma, forged a commitment to the perfectibility of global life (in spite of the flaws of human nature), and promoted “humanism”—which Pinker defines as a reliance on institutions to counteract the evil and violent propensities of humankind while coaxing the capacity for cosmopolitan sympathy to its maximum. “The Scientific Revolution and the Enlightenment set in motion,” he writes, “the process of using knowledge to improve the human condition.” And their plan, Pinker contends, succeeded. As he puts it early in the book, “the Enlightenment has worked.”

Yet for some reason it hasn’t been duly credited with the transformation he sees in human experience. Largely because of apostates like Friedrich Nietzsche, Pinker thinks, intellectuals would rather fret over espresso and wear black than acknowledge that it is a great time to be alive and that human potential is boundless. Other holdouts include the religious, still caught up in dead mythologies, and a motley collection of populists and terrorists, who appear united by their rejection of humanism, whatever their stated grievances. He chastises his colleagues for blaming terrorism on economics or geopolitics when it is obvious that “many of the precepts of Islamic doctrine” are “floridly anti-humanistic,” like religion in general. Against prophecies of despair, Pinker wants to “restate the ideals of the Enlightenment in the language and concepts of the twenty-first century,” using a slew of evidence to disprove the populists and intellectuals and fire up new rounds of progress.

This approach holds a certain appeal for wonks who may hope that today’s problems can be fixed by a set of inspiring TED Talk slides. Nick Kristof has agreed that, notwithstanding global tragedies to which he often devotes his columns, life is, as Pinker argues, pretty great. Bill Gates loves Pinker’s creed. After recommending Better Angels for years, Gates recently proclaimed Enlightenment Now “my new favorite book of all time.” But Pinker’s view is catastrophic for anyone who seriously aims to foster progress, since those who claim too flimsy a warrant for optimism—and fail to recognize that it is a matter of faith—do not just fail to convince skeptics. Their complacency blinds them to unexpected reversals in history and conceals from them the threats to their own hopes.

Almost no one doubts that some things are indeed getting better along some dimensions. But most people realize that such improvements don’t necessarily make for a better life on the whole. It depends what else is going on and how likely it seems that the improvements will falter or reverse. How much does it matter, for instance, that growth has skyrocketed, if the one percent captures so substantial a part of the gains? How will a much-hyped modernity look 100 or 1,000 years from now, on a dying or dead planet?

ENLIGHTENMENT NOW by Steven PinkerViking, 576pp., $35.00

Critics of Pinker’s last book cautioned him to look more closely at the gains he lauded. In Better Angels, Pinker cited Norbert Elias, who in his 1939 book, The Civilizing Process, suggested that the cultivation of manners in early modern Europe had led to the decline of interpersonal violence over the past several centuries. But the development Elias studied wasn’t so simple. Although Pinker deemed Elias “the most important thinker you have never heard of,” he ignored Elias’s claim, inspired by Nietzsche, that as people carefully moderated their outward, visible relations, they also began to do the same inside, regulating themselves into a new kind of pacified state. Violence did not decline; it went inside. Is self-regulation better than physical violence, if it involves policing ourselves as if “a garrison in a conquered city,” as Sigmund Freud, also a Nietzschean, put it? (Freud thought so, but Nietzsche most definitely did not.)

As for the twentieth century, the charnel houses of the world wars showed that amid trends of rising peace, violence could more than exceed the tolls in prior conflicts and did so in frightening new ways. “No universal history leads from savagery to humanitarianism, but there is one leading from the slingshot to the megaton bomb,” Theodor Adorno remarked depressingly of this period. The antagonism between the United States and the Soviet Union surely did set up “a long peace” after 1945 in much of the world—though people across Africa and Southeast Asia may have had trouble noticing it, in the midst of the proxy wars fought there between the great powers. Even allowing for those clashes, it is hard to be certain, especially now, that the long peace was much more than a daydream between past and future eras of carnage. How could Pinker know he wasn’t elevating a temporary exception into an enduring rule?

In laying out his vision of betterment in Enlightenment Now, Pinker confronts alternative trends and looming threats for progress only in order to brush them off. He does not take seriously the risk of major catastrophes, such as the collapse of a recent era of peace or the outbreak of a global pandemic, which he believes is easy to magnify beyond reason. As for environmental degradation, humanity will surely find a way to counteract this in time. “As the world has gotten richer,” Pinker explains, “nature has begun to rebound”—as if the failure of a few prophecies of ecological disaster to come to pass on schedule means the planet is infinitely resilient. Once he gets around to acknowledging that climate change is an actual problem, Pinker spends much of his time attacking “climate justice warriors” for their anti-capitalist hysteria.

Or take inequality. Sure, some perceive a rampant crisis in most nations, but it is all sort of boring and overblown, by Pinker’s lights. “I need a chapter on the topic,” he writes, apparently willing himself to push through his fatigue with the subject, “because so many people have been swept up in the dystopian rhetoric and see inequality as a sign that modernity has failed to improve the human condition.” In his cursory treatment, Pinker tries to downplay currently exploding levels of national inequality, by pointing out that global inequality is declining: Even if the gap between the richest and the rest in individual countries is widening, on a world scale inequality is falling slightly. Never mind that it is within their individual countries that most people are experiencing and responding to inequality, and wreaking havoc because of it. In any case, Pinker argues, it does not matter morally if some people get extremely wealthy, so long as poverty decreases.

Just as in his somewhat literal understanding of violence, Pinker simply cannot see something so straightforward as class rule, which has been massively reestablished in our time of inequality, with all the baleful effects it has had on politics. In a world in which the outsized gains of the rich allow them to live a separate existence from the rest—stooping only to buy elections with dark money and even induce populists to act in their interest—rage is not only an expected but also an understandable result. The fact that these forms of domination and hierarchy are features of the very modernity he wants to lionize is not a possibility Pinker pauses to contemplate. Each of his arguments on the subject is a way of saying he doesn’t think inequality is that important—even as populists across the world are reaping gains from the obvious conclusion that it is.

It is disappointing and unconvincing to see Pinker wave these points aside or use debater’s tricks to minimize them, skating past the contemporary anger at regress or stagnation. This outright refusal to acknowledge a messy picture is revealing. Pinker cannot bring himself to admit the possibility that some things are getting better while others get worse, and that even the best trends are subject to frightening interruption or outright reversal. Pinker’s insistence that all potential qualms about progress—from the environment to inequality—are actually trivial suggests that he is trying to prove an unalloyed optimism no amount of facts could ever establish.

While Pinker elects himself the heir of Enlightenment, his whole approach betrays Enlightenment principles. The very past authorities Pinker invokes did not want to hawk psychic uppers for those in doubt and far more openly advertised the ambivalence of their own belief in progress. They neither claimed that progress was universal nor insisted so monotonously on its indefinite continuation. “Far from basking in cheerful certainty,” as historian of the Enlightenment Peter Gay once put it, thinkers of the time “qualified their hopes with reservations.” And speaking for many, Scottish historian and philosopher David Hume put it bluntly: “No advantages in this world are pure and unmixed.”

Pinker is especially unfaithful to his Enlightenment source in treating progress as a fact that can be proved through endless statistics and information gathering. Immanuel Kant wisely observed that “the problem of progress cannot be solved directly from experience.” “Even if it were found that the human race as a whole had been moving forward and progressing for an indefinitely long time,” he wrote, “no one could guarantee that its era of decline was not beginning at that very moment.” One would simply have to believe it was or was not. A compilation of facts about how awesome life is becoming does not guarantee that it will continue that way. A data dump is not a philosophy of history.

Many Enlightenment thinkers recognized that progress is a provisional faith, precisely because they knew how closely belief in progress resembled the very religion they otherwise wanted to transcend. They understood that the impulse to see human history as a story of progress was closely related to Christian belief. No ancient thinkers had propounded such a doctrine. Christians committed to the idea of reform, however, developed the notion of history as a proving ground for humans, allowing them to participate, to some degree or other, in the unfolding of God’s design. For most Enlightenment thinkers, progress would have to represent Christian beliefs in a more reasoned form.

Kant, for example, thought he could discern a “hidden plan” for universal freedom and equality in the shape of events. To those who sought a guarded optimism, facts served as “signs” of this future, Kant concluded, and he cited the French Revolution as the most startling herald of universal freedom and equality. But he insisted that even an abundance of such signs could never, on their own, establish belief in progress. What facts provide is a catapult for a leap into rational faith. “Hopes for the future perfection of men,” the German philosopher Karl Löwith explained bluntly in a classic study of the philosophy of progress, are “not the result of scientific inference and evidence but a conjecture, the root of which [is] hope and faith.” It is a devastating verdict on Pinker’s enterprise.

Pinker attempts valiantly to sidestep the need for what Kant called “rational faith,” partly by narrowing his inquiry to the most minimal terms of advancement, terms he imagines no one could dispute. From the outset, Pinker insists that he can read progress off simple metrics such as how many people survive childhood and live relatively long. And who could deny that, whatever ultimate ends people care about, they would all like to survive and thrive? But if one claims to be making “the case for humanism,” as Pinker does, isn’t the way people live also important? A lot of people actually care about meaning and even transcendence—living well rather than just living. This is a secondary consideration for Pinker. “It’s easy to extol transcendent values,” he observes, in this spirit, “but most people prioritize life, health, safety, literacy, sustenance, and stimulation.”

Sensing the limitations of his first tactic, Pinker claims that what really matters for progress is that people get what they want. Beyond basic creaturely survival, Pinker concludes, progress consists in allowing more and more people to define and embrace their own good. “The ultimate goal of development,” he observes, paraphrasing Amartya Sen, “is to enable people to make choices.” But the real question is not whether individuals believe they are better off—votaries of universal emancipation in the Enlightenment and since have always worried that without sufficient education people are as apt to throw their freedom away as to use it well. Pinker’s vision of a utopia of lifestyle choices might convince people who already believe that universal progress will involve ample e-commerce and plane travel. But it is unlikely to captivate those who think we are very far from the economic and political institutions that would bring humanity genuine liberation.

As if Pinker’s failure to establish his own case for optimism were not enough, he ends his book with a lengthy screed against holdouts and malcontents. Some of his ire is justified—there is a lot of obscurantism in the world—but most works to bypass rather than engage. Pinker takes up his chief bête noire, Nietzsche, not by reading his works but by culling inflammatory quotations from another intellectual brief in favor of Enlightenment values. True, Nietzsche said some foolish things. (Pinker takes issue with his call for “the merciless extermination of everything degenerate and parasitical.”) But he was in his own way a scion of the Enlightenment. Like his great forebear Jean-Jacques Rousseau, Nietzsche was sensitive to the fact that progress and regress can coexist, and he worried that it is all too easy to misrepresent conformity as freedom.

That there are different ways of defending the Enlightenment, and that modern intellectual history is mostly a debate about how to do so, is not a possibility that registers in this book. Its author has not even begun to think about what it would take to preach uplifting optimism about the future in a time when crushing dereliction threatens more openly each day. Big changes rather than gleeful self-congratulations are in order if progress is to become our mantra anytime soon. The most formidable challenge to Pinker’s vision ultimately comes from the Enlightenment itself. Not only is authentic optimism not data-driven, but it may have to be established by heirs of reason and humanism who make Pinker look complacent.