I partly credit Steven Pinker for my realization, around the middle of my time in college, that I wasn’t a lefty. Suspicious of the assertion, popular in humanities courses, that the most important features of human life—gender, language, family, science, morality—were “social constructs” with no basis in the natural world, I downloaded a copy of Pinker’s 2002 book, The Blank Slate: The Modern Denial of Human Nature. The book argued that the idea of a blank slate—“that the human mind has no inherent structure and can be inscribed at will by society or ourselves”—was first posited by “Enlightenment thinkers” including Locke, Rousseau, and Mill and still clung to by social reformers and academics as “the secular religion of modern intellectual life.” But it could no longer withstand empirical scrutiny. In fact, Pinker showed, many traits that define human nature, good and bad, are encoded in our brains before birth.

Pinker is a psychologist, but his argument had obvious implications for political philosophy. The notion of a tabula rasa, he said, implied a “Utopian Vision” of human nature that in its headier versions helped justify such atrocities as the French Revolution and Maoism. By contrast, modern evolutionary psychology, with its understanding of the embeddedness of man’s vices, implied a “Tragic Vision” of human nature, which Pinker associated with Anglo-American conservative-leaning figures like Edmund Burke, Adam Smith, Alexander Hamilton, and James Madison. According to the tragic vision, “humans are inherently limited in knowledge, wisdom, and virtue, and all social arrangements must acknowledge those limits.” On this view, wide-eyed schemes for social transformation were likely to go badly wrong. Pinker was never a conservative in the contemporary capital-r Republican sense, and he believed that humane, progressive politics was possible without the blank-slate myth. But he argued that “the primacy of family ties in all human societies,” “the universality of dominance and violence,” “the biases of the human moral sense,” and the “inherent tradeoff between equality and freedom” ought at least to restrain the yearning for a society that comports perfectly with liberal ideals.

Pinker’s latest work, however, is an extended flirtation with the utopianism he once described as dangerously distorting. In Enlightenment Now: The Case for Reason, Science, Humanism, and Progress, Burke goes by the wayside. Pinker now argues humanity can and will progress toward ever greater cosmopolitanism, secularism, reason, and cooperation. “Some kinds of change really do seem to be carried along by an inexorable tectonic force,” he writes. “As they proceed, certain factions oppose them hammer and tongs, but resistance turns out to be futile.”

While The Blank Slate warned that human beings are incorrigibly programmed to favor in-groups over strangers, Enlightenment Now insists that “nothing can prevent the circle of sympathy from expanding from the family and tribe to embrace all of humankind” because “reason goads us into realizing that there can be nothing uniquely deserving about ourselves or any of the groups to which we belong.” While The Blank Slate highlighted the genetic basis of human aggression, Enlightenment Now suggests “war may be just another obstacle an enlightened society learns to overcome.” And while The Blank Slate recognized the possibility that religion and other institutions not fully justifiable by pure reason might offer “time-tested techniques that let us work around the shortcomings of human nature,” Enlightenment Now derides religious observance as a source of “Iron Age morality” and celebrates its reported decline across the world.

To be sure, the most limited thesis of Enlightenment Now—that life has gotten better in many ways over the past several hundred years—is clearly true. With a dizzying array of charts, Pinker illustrates the fantastic increases in wealth, health, safety, and longevity that have taken place since “the Scientific Revolution and the Enlightenment set in motion the process of using knowledge to improve the human condition.” He delivers some well-earned barbs against the “declinism” that prevails in certain quarters of the left and right. “The social critic’s standard formula for sowing panic,” Pinker writes, is to say, “here’s an anecdote, therefore it’s a trend, therefore it’s a crisis.” He rightly observes that forecasts of doom and gloom often have more intellectual currency than realistic assessments. Enlightenment Now is valuable for reminding us of the fruits of relatively recent moral and scientific achievements, from the elimination of smallpox to the abolition of public executions-by-torture.

The problem comes from Pinker’s accounting of the way these achievements have been secured and his inferences about the future of the social order. He gestures to a number of institutions, some of which originated in the Enlightenment, as sources of progress: limited governments, democratic decision-making, open markets, freedom of conscience, the peer-reviewed scientific process. Together, these are facets of what we now call liberalism. While thinkers like Notre Dame University’s Patrick Deneen purport to explain “why liberalism failed,” Pinker counters that Enlightenment liberalism is working as well as ever—that those institutions are continuing to make life better for almost everybody.

 But why are they making life better? The utopian vision and the tragic vision offer different answers. In the utopian vision, liberal institutions are worthwhile because they expand our autonomy, allowing us to inscribe our own story upon a blank slate. Markets free us to fulfill ourselves through industry. Elections offer us a chance at self-determination. Free speech allows us to express our thoughts as we please. All these freedoms mold human nature such that we become more reasonable, compassionate, and humane. The purpose of life is the ever greater actualization of liberal ideals—the expansion of autonomy, science, and self-expression into a growing number of spheres.

In the tragic vision, by contrast, liberal institutions work not through liberation but rather through constraint. The function of markets is to distribute economic power across society and therefore minimize the chances of misjudgment by central planners. The function of elections is to reduce the likelihood of violence by offering an alternative means for transferring political power. The function of free speech is not to give everyone a megaphone but to make sure that bad ideas can be falsified. In the tragic vision, individuals are and will always be status-oriented, tribal, and aggressive, but a society can become incrementally more peaceful and humane by virtue of the liberal machinery for creating knowledge, limiting violence, and protecting certain rights. In this view, liberalism is not the purpose of life but a means of creating a society that people want to live in.

Enlightenment Now abandons the tragic vision, veering into a utopianism that Pinker’s own evidence cannot support. Without backing off from his repudiation of the blank slate, Pinker seems to suggest that society can, in fact, rearrange the intrinsic character of the human mind to comport with the values of “reason, science and humanism.” He is confident that education can inoculate “people against conspiracy theories, reasoning by anecdote, and emotional demagoguery” and that “liberal values are on a long-term escalator.” Each birth cohort is “more tolerant and liberal than the one that came before”; therefore, anti-Enlightenment sentiments will “dissipate with demographics.” As people become more rational, their tribal allegiances will steadily weaken, including to their country, which is merely “a collection of tens of millions of human beings who just happen to occupy a patch of land.” As people become more autonomous by virtue of technological progress and the decline of religious authority, they will become happier. To the extent that they are not happier, it is because “they have an adult’s appreciation of life, with all its worry and all its excitement.”

Considering developments on elite college campuses, I would question whether the regime that awaits us when today’s students are in power is really limited-government Enlightenment humanism. Turning to the rise of astrology on the secular left and fascism on the secular right, I also wonder whether the retreat of organized religion heralds the triumph of reason rather than inviting new and perhaps less salutary forms of unreason. But put aside Pinker’s empirical claims, which number crunchers could litigate forever. The bottom line is that Enlightenment Now is a brief for a more all-encompassing liberalism than Pinker has endorsed before, one where reason, science, humanism, and progress can overwrite the nonliberal tendencies that The Blank Slate argued were written into our very brains.

The old Pinker occasionally reemerges in Enlightenment Now, leading to a kind of incoherence. On one page, Utopian Pinker touts the spread of democracy and reason as going hand in hand. On another, Tragic Pinker acknowledges that “reforms that are designed to make government more ‘democratic’ . . . may instead have made governance more identity-driven and irrational.” Utopian Pinker sees the spread of education as neutralizing resistance to Enlightenment thinking. Tragic Pinker acknowledges that “expertise, brainpower, and conscious reasoning . . . can be weapons for ever-more ingenious rationalization.” While Utopian Pinker dismisses “the mythical ‘stability’ of Cold War confrontation” and the notion that self-interested geopolitics can reduce the likelihood of catastrophic violence, Tragic Pinker recognizes that the “massive destructive powers of the American and Soviet armies . . . made Cold War superpowers think twice about confronting each other on the battlefield.”

Conflicts between the utopian and tragic visions multiply when Pinker tries to defend a moral system based on the arguments of Enlightenment Now. One of Pinker’s chief concerns in The Blank Slate was to show that the principle of equal treatment could survive the recognition that people are not all born the same. To that end, he wrote that “humans are sentient, possessing of dignity and rights, and infinitely precious.” He appealed to the religiously inflected Declaration of Independence to argue that “political equality is a moral stance, not an empirical hypothesis.” In other words, because it is beyond what can be proved by science, equality is self-evident, nonfalsifiable, and nonnegotiable.

This argument is an awkward fit with the Utopian Pinker of Enlightenment Now. Because moral absolutes like rights and equality are impossible to justify scientifically, Enlightenment Now argues that morality should be based on a modified form of utilitarianism. Securing the pleasure and fulfillment of the greatest number of individuals is “the moral code that people will converge on when they are rational,” Pinker writes. Aggregate human well-being may be measured scientifically; we should be skeptical of moral codes based on “nebulous rubrics like ‘dignity,’ ‘sacredness,’ and ‘social justice.’ ” (Notably, Pinker lets slip that “life is sacred” when arguing against the death penalty, recalling his earlier moral position.) According to the Pinker of Enlightenment Now, we should generally abide by principles of equality and liberty because they tend to lead to more human flourishing, not because they are true in any deeper sense. But when these principles are no longer “inalienable,” as they must be under the tragic vision of liberalism, one can’t help but wonder if they are less secure.

What accounts for Pinker’s progression from tragic liberal, cognizant of the limits of reason, to utopian liberal, triumphantly pronouncing that all nonliberal values and institutions will dissolve in a sea of Enlightenment? Part of the story may be the changing political landscape. In 2002 it may have appeared that the academic left presented the greatest intellectual challenge to liberal values in the West. Today these values need defending against an empowered populist right. But maybe in populism we aren’t seeing, as Pinker suggests, the last gasps of a dying parochialism as it is eclipsed by Enlightenment reason. Perhaps the right message for our age is the one from The Blank Slate—namely, that Western liberals, intoxicated by Enlightenment excesses, have conjured up a vision of society that is untethered to the realities of human experience. And perhaps many citizens, recognizing that utopian liberalism is not liberalism at all, are demanding that the more chastened version be restored. ♦

Jason Willick is an assistant editorial features editor at the Wall Street Journal and a 2017–18 Robert Novak Journalism Fellow.