Enlightenment Now: The Case for Reason, Science, Humanism, and Progress

by Steven Pinker

Specialization works only in a market that allows the specialists to exchange their goods and services, and Smith explained that economic activity was a form of mutually beneficial cooperation (a positive-sum game, in today’s lingo): each gets back something that is more valuable to him than what he gives up. Through voluntary exchange, people benefit others by benefiting themselves; as he wrote, “It is not from the benevolence of the butcher, the brewer, or the baker that we expect our dinner, but from their regard to their own interest. We address ourselves, not to their humanity but to their self-love.” Smith was not saying that people are ruthlessly selfish, or that they ought to be; he was one of history’s keenest commentators on human sympathy. He only said that in a market, whatever tendency people have to care for their families and themselves can work to the good of all.

The deepest is a bias that has been summarized in the slogan “Bad is stronger than good.”21 The idea can be captured in a set of thought experiments suggested by Tversky.22 How much better can you imagine yourself feeling than you are feeling right now? How much worse can you imagine yourself feeling? In answering the first hypothetical, most of us can imagine a bit more of a spring in our step or a twinkle in our eye, but the answer to the second one is: it’s bottomless. This asymmetry in mood can be explained by an asymmetry in life (a corollary of the Law of Entropy). How many things could happen to you today that would leave you much better off? How many things could happen that would leave you much worse off? Once again, to answer the first question, we can all come up with the odd windfall or stroke of good luck, but the answer to the second one is: it’s endless. But we needn’t rely on our imaginations. The psychological literature confirms that people dread losses more than they look forward to gains, that they dwell on setbacks more than they savor good fortune, and that they are more stung by criticism than they are heartened by praise. (As a psycholinguist I am compelled to add that the English language has far more words for negative emotions than for positive ones.)

What is progress? You might think that the question is so subjective and culturally relative as to be forever unanswerable. In fact, it’s one of the easier questions to answer. Most people agree that life is better than death. Health is better than sickness. Sustenance is better than hunger. Abundance is better than poverty. Peace is better than war. Safety is better than danger. Freedom is better than tyranny. Equal rights are better than bigotry and discrimination. Literacy is better than illiteracy. Knowledge is better than ignorance. Intelligence is better than dull-wittedness. Happiness is better than misery. Opportunities to enjoy family, friends, culture, and nature are better than drudgery and monotony. All these things can be measured. If they have increased over time, that is progress.

it happens, the world does agree on these values. In the year 2000, all 189 members of the United Nations, together with two dozen international organizations, agreed on eight Millennium Development Goals for the year 2015 that blend right into this list.31 And here is a shocker: The world has made spectacular progress in every single measure of human well-being. Here is a second shocker: Almost no one knows about it.

Poverty has no causes,” wrote the economist Peter Bauer. “Wealth has causes.” In a world governed by entropy and evolution, the streets are not paved with pastry, and cooked fish do not land at our feet. But it’s easy to forget this truism and think that wealth has always been with us. History is written not so much by the victors as by the affluent, the sliver of humanity with the leisure and education to write about it. As the economist Nathan Rosenberg and the legal scholar L. E. Birdzell Jr. point out, “We are led to forget the dominating misery of other times in part by the grace of literature, poetry, romance, and legend, which celebrate those who lived well and forget those who lived in the silence of poverty. The eras of misery have been mythologized and may even be remembered as golden ages of pastoral simplicity. They were not.”

Among the brainchildren of the Enlightenment is the realization that wealth is created.5 It is created primarily by knowledge and cooperation: networks of people arrange matter into improbable but useful configurations and combine the fruits of their ingenuity and labor. The corollary, just as radical, is that we can figure out how to make more of it.

For reasons we have seen, market economies can generate wealth prodigiously while totalitarian planned economies impose scarcity, stagnation, and often famine. Market economies, in addition to reaping the benefits of specialization and providing incentives for people to produce things that other people want, solve the problem of coordinating the efforts of hundreds of millions of people by using prices to propagate information about need and availability far and wide, a computational problem that no planner is brilliant enough to solve from a central bureau.

It’s important to add that the market economies which blossomed in the more fortunate parts of the developing world were not the laissez-faire anarchies of right-wing fantasies and left-wing nightmares. To varying degrees, their governments invested in education, public health, infrastructure, and agricultural and job training, together with social insurance and poverty-reduction programs.

Notwithstanding the horror that the word elicits in many parts of the political spectrum, globalization, development analysts agree, has been a bonanza for the poor. Deaton notes, “Some argue that globalization is a neoliberal conspiracy designed to enrich a very few at the expense of many. If so, that conspiracy was a disastrous failure—or at least, it helped more than a billion people as an unintended consequence. If only unintended consequences always worked so favorably.”

Snow’s argument is being echoed fifty years later by development experts such as Radelet, who observes that “while working on the factory floor is often referred to as sweatshop labor, it is often better than the granddaddy of all sweatshops: working in the fields as an agricultural day laborer.”

To appreciate the long-term benefits of industrialization one does not have to accept its cruelties. One can imagine an alternative history of the Industrial Revolution in which modern sensibilities applied earlier and the factories operated without children and with better working conditions for the adults. Today there are doubtless factories in the developing world that could offer as many jobs and still turn a profit while treating their workers more humanely.

Progress consists not in accepting every change as part of an indivisible package—as if we had to make a yes-or-no decision on whether the Industrial Revolution, or globalization, is a good thing or bad thing, exactly as each has unfolded in every detail. Progress consists of unbundling the features of a social process as much as we can to maximize the human benefits while minimizing the harms.

The point is made with greater nuance by the philosopher Harry Frankfurt in his 2015 book On Inequality.5 Frankfurt argues that inequality itself is not morally objectionable; what is objectionable is poverty. If a person lives a long, healthy, pleasurable, and stimulating life, then how much money the Joneses earn, how big their house is, and how many cars they drive are morally irrelevant. Frankfurt writes, “From the point of view of morality, it is not important everyone should have the same. What is morally important is that each should have enough.”

The confusion of inequality with poverty comes straight out of the lump fallacy—the mindset in which wealth is a finite resource, like an antelope carcass, which has to be divvied up in zero-sum fashion, so that if some people end up with more, others must have less. As we just saw, wealth is not like that: since the Industrial Revolution, it has expanded exponentially.

People are content with economic inequality as long as they feel that the country is meritocratic, and they get angry when they feel it isn’t. Narratives about the causes of inequality loom larger in people’s minds than the existence of inequality.

The historian Stephanie Coontz, a debunker of 1950s nostalgia, puts some numbers to the depictions: A full 25 percent of Americans, 40 to 50 million people, were poor in the mid-1950s, and in the absence of food stamps and housing programs, this poverty was searing. Even at the end of the 1950s, a third of American children were poor. Sixty percent of Americans over sixty-five had incomes below $1,000 in 1958, considerably below the $3,000 to $10,000 level considered to represent middle-class status. A majority of elders also lacked medical insurance. Only half the population had savings in 1959; one-quarter of the population had no liquid assets at all. Even when we consider only native-born, white families, one-third could not get by on the income of the household head.45

since 1970, when the Environmental Protection Agency was established, the United States has slashed its emissions of five air pollutants by almost two-thirds. Over the same period, the population grew by more than 40 percent, and those people drove twice as many miles and became two and a half times richer. Energy use has leveled off, and even carbon dioxide emissions have turned a corner, a point to which we will return. The declines don’t just reflect an offshoring of heavy industry to the developing world, because the bulk of energy use and emissions comes from transportation, heating, and electricity generation, which cannot be outsourced. Rather, they mainly reflect gains in efficiency and emission control. These diverging curves refute both the orthodox Green claim that only degrowth can curb pollution and the orthodox right-wing claim that environmental protection must sabotage economic growth and people’s standard of living.

Like all demonstrations of progress, reports on the improving state of the environment are often met with a combination of anger and illogic. The fact that many measures of environmental quality are improving does not mean that everything is OK, that the environment got better by itself, or that we can just sit back and relax. For the cleaner environment we enjoy today we must thank the arguments, activism, legislation, regulations, treaties, and technological ingenuity of the people who sought to improve it in the past.35 We’ll need more of each to sustain the progress we’ve made, prevent reversals (particularly under the Trump presidency), and extend it to the wicked problems that still face us, such as the health of the oceans and, as we shall see, atmospheric greenhouse gases. But for many reasons, it’s time to retire the morality play in which modern humans are a vile race of despoilers and plunderers who will hasten the apocalypse unless they undo the Industrial Revolution, renounce technology, and return to an ascetic harmony with nature. Instead, we can treat environmental protection as a problem to be solved: how can people live safe, comfortable, and stimulating lives with the least possible pollution and loss of natural habitats? Far from licensing complacency, our progress so far at solving this problem emboldens us to strive for more. It also points to the forces that pushed this progress along.

Even when it comes to the purely rhetorical challenge of “moving people’s hearts,” efficacy matters: people are likelier to accept the fact of global warming when they are told that the problem is solvable by innovations in policy and technology than when they are given dire warnings about how awful it will be.55

The enlightened response to climate change is to figure out how to get the most energy with the least emission of greenhouse gases. There is, to be sure, a tragic view of modernity in which this is impossible: industrial society, powered by flaming carbon, contains the fuel of its own destruction. But the tragic view is incorrect. Ausubel notes that the modern world has been progressively decarbonizing.

For what it’s worth, I think we’ll rise to the challenge, but it’s vital to understand the nature of this optimism. The economist Paul Romer distinguishes between complacent optimism, the feeling of a child waiting for presents on Christmas morning, and conditional optimism, the feeling of a child who wants a treehouse and realizes that if he gets some wood and nails and persuades other kids to help him, he can build one.108 We cannot be complacently optimistic about climate change, but we can be conditionally optimistic. We have some practicable ways to prevent the harms and we have the means to learn more. Problems are solvable. That does not mean that they will solve themselves, but it does mean that we can solve them if we sustain the benevolent forces of modernity that have allowed us to solve problems so far, including societal prosperity, wisely regulated markets, international governance, and investments in science and technology.

Here is Eisner’s one-sentence summary of how to halve the homicide rate within three decades: “An effective rule of law, based on legitimate law enforcement, victim protection, swift and fair adjudication, moderate punishment, and humane prisons is critical to sustainable reductions in lethal violence.”32 The adjectives effective, legitimate, swift, fair, moderate, and humane differentiate his advice from the get-tough-on-crime rhetoric favored by right-wing politicians. The reasons were explained by Cesare Beccaria two hundred and fifty years ago. While the threat of ever-harsher punishments is both cheap and emotionally satisfying, it’s not particularly effective, because scofflaws just treat them like rare accidents—horrible, yes, but a risk that comes with the job. Punishments that are predictable, even if less draconian, are likelier to be factored into day-to-day choices.

Yet even with the double counting of terrorism and war during the 21st century’s worst year for war deaths, a global citizen was 11 times as likely to have died in a homicide as in a terrorist attack, more than 30 times as likely to have died in a car crash, and more than 125 times as likely to have died in an accident of any kind.

Though terrorism poses a minuscule danger compared with other risks, it creates outsize panic and hysteria because that is what it is designed to do. Modern terrorism is a by-product of the vast reach of the media.11 A group or an individual seeks a slice of the world’s attention by the one guaranteed means of attracting it: killing innocent people, especially in circumstances in which readers of the news can imagine themselves. News media gobble the bait and give the atrocities saturation coverage. The Availability heuristic kicks in and people become stricken with a fear that is unrelated to the level of danger. It’s not just the salience of a horrific event that stokes the terror. Our emotions are far more engaged when the cause of a tragedy is malevolent intent rather than accidental misfortune.12 (I confess that as a frequent visitor to London, I was far more upset when I read the headline RUSSELL SQUARE “TERROR” KNIFE ATTACK LEAVES WOMAN DEAD than when I read RENOWNED ART COLLECTOR DIES AFTER BEING HIT BY BUS IN OXFORD STREET TRAGEDY.) Something is uniquely unsettling about the thought of a human being who wants to kill you, and for a good evolutionary reason. Accidental causes of death don’t try to do you in, and they don’t care how you react, whereas human malefactors deploy their intelligence to outsmart you, and vice versa.

Indeed, the rise of terrorism in public awareness is not a sign of how dangerous the world has become but the opposite. The political scientist Robert Jervis observes that the placement of terrorism at the top of the list of threats “in part stems from a security environment that is remarkably benign.”

Instead, countries could deal with terrorism by deploying their greatest advantage: knowledge and analysis, not least knowledge of the numbers. The uppermost goal should be to make sure the numbers stay small by securing weapons of mass destruction (chapter 19). Ideologies that justify violence against innocents, such as militant religions, nationalism, and Marxism, can be countered with better systems of value and belief (chapter 23). The media can examine their essential role in the show business of terrorism by calibrating their coverage to the objective dangers and giving more thought to the perverse incentives they have set up. (Lankford, together with the sociologist Erik Madfis, has recommended a policy for rampage shootings of “Don’t Name Them, Don’t Show Them, but Report Everything Else,” based on a policy for juvenile shooters already in effect in Canada and on other strategies of calculated media self-restraint.)20 Governments can step up their intelligence and clandestine actions against networks of terrorism and their financial tributaries. And people could be encouraged to keep calm and carry on, as the British wartime poster famously urged during a time of much greater peril.

Yet the single best predictor of emancipative values is the World Bank’s Knowledge Index, which combines per capita measures of education (adult literacy and enrollment in high schools and colleges), information access (telephones, computers, and Internet users), scientific and technological productivity (researchers, patents, and journal articles), and institutional integrity (rule of law, regulatory quality, and open economies).44 Welzel found that the Knowledge Index accounts for seventy percent of the variation in emancipative values across countries, making it a far better predictor than GDP.45 The statistical result vindicates a key insight of the Enlightenment: knowledge and sound institutions lead to moral progress.

So much changes when you get an education! You unlearn dangerous superstitions, such as that leaders rule by divine right, or that people who don’t look like you are less than human. You learn that there are other cultures that are as tied to their ways of life as you are to yours, and for no better or worse reason. You learn that charismatic saviors have led their countries to disaster. You learn that your own convictions, no matter how heartfelt or popular, may be mistaken. You learn that there are better and worse ways to live, and that other people and other cultures may know things that you don’t. Not least, you learn that there are ways of resolving conflicts without violence. All these epiphanies militate against knuckling under the rule of an autocrat or joining a crusade to subdue and kill your neighbors. Of course, none of this wisdom is guaranteed, particularly when authorities promulgate their own dogmas, alternative facts, and conspiracy theories—and, in a backhanded compliment to the power of knowledge, stifle the people and ideas that might discredit them.

The philosopher Martha Nussbaum has taken the idea a step further and laid out a set of “fundamental capabilities” that all people should be given the opportunity to exercise.3 One can think of them as the justifiable sources of satisfaction and fulfillment that human nature makes available to us. Her list begins with capabilities that, as we have seen, the modern world increasingly allows people to realize: longevity, health, safety, literacy, knowledge, free expression, and political participation. It goes on to include aesthetic experience, recreation and play, enjoyment of nature, emotional attachments, social affiliations, and opportunities to reflect on and engage in one’s own conception of the good life.

Foremost is a historical discovery summarized by the political scientist Robert Jervis: “The Soviet archives have yet to reveal any serious plans for unprovoked aggression against Western Europe, not to mention a first strike against the United States.”89 That means that the intricate weaponry and strategic doctrines for nuclear deterrence during the Cold War—what one political scientist called “nuclear metaphysics”—were deterring an attack that the Soviets had no interest in launching in the first place.90 When the Cold War ended, the fear of massive invasions and preemptive nuclear strikes faded with it, and (as we shall see) both sides felt relaxed enough to slash their weapon stockpiles without even bothering with formal negotiations.91 Contrary to a theory of technological determinism in which nuclear weapons start a war all by themselves, the risk very much depends on the state of international relations. Much of the credit for the absence of nuclear war between great powers must go to the forces behind the decline of war between great powers (chapter 11). Anything that reduces the risk of war reduces the risk of nuclear war.

My point in presenting the state of the world in these two ways is not to show that I can focus on the space in the glass as well as on the beverage. It’s to reiterate that progress is not utopia, and that there is room—indeed, an imperative—for us to strive to continue that progress. If we can sustain the trends in the first eight paragraphs by deploying knowledge to enhance flourishing, the numbers in the last three paragraphs should shrink.

Authoritarian populism can be seen as a pushback of elements of human nature—tribalism, authoritarianism, demonization, zero-sum thinking—against the Enlightenment institutions that were designed to circumvent them. By focusing on the tribe rather than the individual, it has no place for the protection of minority rights or the promotion of human welfare worldwide. By failing to acknowledge that hard-won knowledge is the key to societal improvement, it denigrates “elites” and “experts” and downplays the marketplace of ideas, including freedom of speech, diversity of opinion, and the fact-checking of self-serving claims. By valorizing a strong leader, populism overlooks the limitations in human nature, and disdains the rule-governed institutions and constitutional checks that constrain the power of flawed human actors. Populism comes in left-wing and right-wing varieties, which share a folk theory of economics as zero-sum competition: between economic classes in the case of the left, between nations or ethnic groups in the case of the right. Problems are seen not as challenges that are inevitable in an indifferent universe but as the malevolent designs of insidious elites, minorities, or foreigners. As for progress, forget about it: populism looks backward to an age in which the nation was ethnically homogeneous, orthodox cultural and religious values prevailed, and economies were powered by farming and manufacturing, which produced tangible goods for local consumption and ...

Populist voters are older, more religious, more rural, less educated, and more likely to be male and members of the ethnic majority. They embrace authoritarian values, place themselves on the right of the political spectrum, and dislike immigration and global and national governance.

Inglehart and Norris concluded that supporters of authoritarian populism are the losers not so much of economic competition as cultural competition. Voters who are male, religious, less educated, and in the ethnic majority “feel that they have become strangers from the predominant values in their own country, left behind by progressive tides of cultural change that they do not share. . . . The silent revolution launched in the 1970s seems to have spawned a resentful counter-revolutionary backlash today.”41 Paul Taylor, a political analyst at the Pew Research Center, singled out the same counter-current in American polling results: “The overall drift is toward more liberal views on a range of issues, but that doesn’t mean the whole country’s buying in.”

As we saw in chapter 15, people carry their emancipative values with them as they age rather than sliding into illiberalism. And a recent analysis of 20th-century American voters by the political scientists Yair Ghitza and Andrew Gelman has shown that Americans do not consistently vote for more conservative presidents as they age. Their voting preferences are shaped by their cumulative experience of the popularity of presidents over their life spans, with a peak of influence in the 14–24-year-old window.46 The young voters who reject populism today are unlikely to embrace it tomorrow.

Since populist movements have achieved an influence beyond their numbers, fixing electoral irregularities such as gerrymandering and forms of disproportionate representation which overweight rural areas (such as the US Electoral College) would help. So would journalistic coverage that tied candidates’ reputations to their record of accuracy and coherence rather than to trivial gaffes and scandals. Part of the problem, over the long term, will dissipate with urbanization: you can’t keep them down on the farm. And part will dissipate with demographics. As has been said about science, sometimes society advances funeral by funeral.

The problem with dystopian rhetoric is that if people believe that the country is a flaming dumpster, they will be receptive to the perennial appeal of demagogues: “What do you have to lose?” If the media and intellectuals instead put events into statistical and historical context, they could help answer that question. Radical regimes from Nazi Germany and Maoist China to contemporary Venezuela and Turkey show that people have a tremendous amount to lose when charismatic authoritarians responding to a “crisis” trample over democratic norms and institutions and command their countries by the force of their personalities.

Kevin Kelly explains how this dialectic can nonetheless result in forward motion: Ever since the Enlightenment and the invention of science, we’ve managed to create a tiny bit more than we’ve destroyed each year. But that few percent positive difference is compounded over decades into what we might call civilization. . . . [Progress] is a self-cloaking action seen only in retrospect. Which is why I tell people that my great optimism of the future is rooted in history.53 We don’t have a catchy name for a constructive agenda that reconciles long-term gains with short-term setbacks, historical currents with human agency. “Optimism” is not quite right, because a belief that things will always get better is no more rational than the belief that things will always get worse. Kelly offers “protopia,” the pro- from progress and process. Others have suggested “pessimistic hopefulness,” “opti-realism,” and “radical incrementalism.”54 My favorite comes from Hans Rosling, who, when asked whether he was an optimist, replied, “I am not an optimist. I’m a very serious possibilist.”

The ideas of economists and political philosophers, both when they are right and when they are wrong, are more powerful than is commonly understood. Indeed, the world is ruled by little else. Practical men, who believe themselves to be quite exempt from any intellectual influences, are usually slaves of some defunct economist. Madmen in authority, who hear voices in the air, are distilling their frenzy from some academic scribbler of a few years back. I am sure that the power of vested interests is vastly exaggerated compared with the gradual encroachment of ideas. —John Maynard Keynes

In The Last Word, the philosopher Thomas Nagel drives home the point that subjectivity and relativism regarding logic and reality are incoherent, because “one can’t criticize something with nothing”: The claim “Everything is subjective” must be nonsense, for it would itself have to be either subjective or objective. But it can’t be objective, since in that case it would be false if true. And it can’t be subjective, because then it would not rule out any objective claim, including the claim that it is objectively false. There may be some subjectivists, perhaps styling themselves as pragmatists, who present subjectivism as applying even to itself. But then it does not call for a reply, since it is just a report of what the subjectivist finds it agreeable to say. If he also invites us to join him, we need not offer any reason for declining, since he has offered us no reason to accept.

It’s in the very nature of argument that people stake a claim to being right. As soon as they do, they have committed themselves to reason—and the listeners they are trying to convince can hold their feet to the fire of coherence and accuracy.

The standard explanation of the madness of crowds is ignorance: a mediocre education system has left the populace scientifically illiterate, at the mercy of their cognitive biases, and thus defenseless against airhead celebrities, cable-news gladiators, and other corruptions from popular culture. The standard solution is better schooling and more outreach to the public by scientists on television, social media, and popular Web sites. As an outreaching scientist I’ve always found this theory appealing, but I’ve come to realize it’s wrong, or at best a small part of the problem.

Professing a belief in evolution is not a gift of scientific literacy, but an affirmation of loyalty to a liberal secular subculture as opposed to a conservative religious one. In 2010 the National Science Foundation dropped the following item from its test of scientific literacy: “Human beings, as we know them today, developed from earlier species of animals.” The reason for that change was not, as scientists howled, because the NSF had given in to creationist pressure to bowdlerize evolution from the scientific canon. It was that the correlation between performance on that item and on every other item on the test (such as “An electron is smaller than an atom” and “Antibiotics kill viruses”) was so low that it was taking up space in the test that could go to more diagnostic items. The item, in other words, was effectively a test of religiosity rather than scientific literacy.

Believers in human-made climate change scored no better on tests of climate science, or of science literacy in general, than deniers. Many believers think, for example, that global warming is caused by a hole in the ozone layer and that it can be mitigated by cleaning up toxic waste dumps.13 What predicts the denial of human-made climate change is not scientific illiteracy but political ideology. In 2015, 10 percent of conservative Republicans agreed that the Earth is getting warmer because of human activity (57 percent denied that the Earth is getting warmer at all), compared with 36 percent of moderate Republicans, 53 percent of Independents, 63 percent of moderate Democrats, and 78 percent of liberal Democrats.

Kahan notes that people’s tendency to treat their beliefs as oaths of allegiance rather than disinterested appraisals is, in one sense, rational. With the exception of a tiny number of movers, shakers, and deciders, a person’s opinions on climate change or evolution are astronomically unlikely to make a difference to the world at large. But they make an enormous difference to the respect the person commands in his or her social circle. To express the wrong opinion on a politicized issue can make one an oddball at best—someone who “doesn’t get it”—and a traitor at worst. The pressure to conform becomes all the greater as people live and work with others who are like them and as academic, business, or religious cliques brand themselves with left-wing or right-wing causes. For pundits and politicians with a reputation for championing their faction, coming out on the wrong side of an issue would be career suicide. Given these payoffs, endorsing a belief that hasn’t passed muster with science and fact-checking isn’t so irrational after all—at least, not by the criterion of the immediate effects on the believer. The effects on the society and planet are another matter. The atmosphere doesn’t care what people think about it, and if it in fact warms by 4° Celsius, billions of people will suffer, no matter how many of them had been esteemed in their peer groups for holding the locally fashionable opinion on climate change along the way. Kahan concludes that we are all actors in a T...

But all this changed in a version of the experiment in which the treatment was switched from boring skin cream to incendiary gun control (a law banning citizens from carrying concealed handguns in public), and the outcome was switched from rashes to crime rates. Now the highly numerate respondents diverged from each other according to their politics. When the data suggested that the gun-control measure lowered crime, all the liberal numerates spotted it, and most of the conservative numerates missed it—they did a bit better than the conservative innumerates, but were still wrong more often than they were right. When the data showed that gun control increased crime, this time most of the conservative numerates spotted it, but the liberal numerates missed it; in fact, they did no better than the liberal innumerates. So we can’t blame human irrationality on our lizard brains: it was the sophisticated respondents who were most blinded by their politics. As two other magazines summarized the results: “Science Confirms: Politics Wrecks Your Ability to Do Math” and “How Politics Makes Us Stupid.”

If the left and right are equally stupid in quizzes and experiments, we might expect them to be equally off the mark in making sense of the world. The data on human history presented in chapters 5 through 18 provide an opportunity to see which of the major political ideologies can explain the facts of human progress. I’ve been arguing that the main drivers were the nonpolitical ideals of reason, science, and humanism, which led people to seek and apply knowledge that enhanced human flourishing. Do right-wing or left-wing ideologies have anything to add? Do the seventy-odd graphs entitle either side to say, “Bias, shmias: we’re right; you’re wrong”? It seems that each side can take some credit while also missing big parts of the story. Foremost is the conservative skepticism about the ideal of progress itself. Ever since the first modern conservative, Edmund Burke, suggested that humans were too flawed to think up schemes for improving their condition and were better off sticking with traditions and institutions that kept them from the abyss, a major stream of conservative thought has been skeptical about the best-laid plans of mice and men. The reactionary fringe of conservatism, recently disinterred by Trumpists and the European far right (chapter 23), believes that Western civilization has careened out of control since some halcyon century, having abandoned the moral clarity of traditional Christendom for a decadent secular fleshpot that, if left on its current course, w...

The totalitarian governments of the 20th century did not emerge from democratic welfare states sliding down a slippery slope, but were imposed by fanatical ideologues and gangs of thugs.41 And countries that combine free markets with more taxation, social spending, and regulation than the United States (such as Canada, New Zealand, and Western Europe) turn out to be not grim dystopias but rather pleasant places to live, and they trounce the United States in every measure of human flourishing, including crime, life expectancy, infant mortality, education, and happiness.42 As we saw, no developed country runs on right-wing libertarian principles, nor has any realistic vision of such a country ever been laid out.

A real society comprises hundreds of millions of social beings, each with a trillion-synapse brain, who pursue their well-being while affecting the well-being of others in complex networks with massive positive and negative externalities, many of them historically unprecedented. It is bound to defy any simple narrative of what will happen under a given set of rules. A more rational approach to politics is to treat societies as ongoing experiments and open-mindedly learn the best practices, whichever part of the spectrum they come from. The empirical picture at present suggests that people flourish most in liberal democracies with a mixture of civic norms, guaranteed rights, market freedom, social spending, and judicious regulation. As Pat Paulsen noted, “If either the right wing or the left wing gained control of the country, it would fly around in circles.”

Reason tells us that political deliberation would be most fruitful if it treated governance more like scientific experimentation and less like an extreme-sports competition.