The feather-ruffling Harvard psychologist’s new book, a defence of Enlightenment values, may be his most controversial yet • Read an extract from Enlightenment Now here

Say the word “enlightenment” and it tends to conjure images of a certain kind of new-age spiritual “self-improvement”: meditation, candles, chakra lines. Add the definite article and a capital letter and the Enlightenment becomes something quite different: dead white men in wigs.

For many people, particularly in the west, reaching a state of mindful nirvana probably seems more relevant to their wellbeing than the writings of, say, Immanuel Kant and Adam Smith. But according to Enlightenment Now, a new book by the celebrated Harvard cognitive psychologist Steven Pinker, this is precisely where we’re getting our priorities wrong.

For Pinker, the Enlightenment is not some distant era, of interest only to historians and philosophers, but instead the foundation for all the many benefits and advantages to which we scarcely give a second’s thought in the 21st century.

He lists some of the advancements made by modern societies: “Newborns who will live more than eight decades, markets overflowing with food, clean water that appears with a flick of a finger and waste that disappears with another, pills that erase a painful infection, sons who are not sent off to war, daughters who can walk the streets in safety, critics of the powerful who are not jailed or shot, the world’s knowledge and culture available in a shirt pocket.”

These were not inevitable developments, Pinker wants us to know, but the fruits of the methods and values that were first popularised in the 18th century.

It’s safe to say that few of us stop and marvel at the extraordinary progress that humankind has made in the past couple of hundred years – a mere blink of the eye in evolutionary terms. Instead we’re more likely to lament the state of the world, deplore the ravenous nature of humanity, rage at the political and financial elites and despair at the empty materialism of consumer society.

What we do to combat poverty: that’s far more important than reducing inequality

But for Pinker, that’s an indulgence we can no longer afford. His book is a sustained, data-packed argument in favour of the principles promoted by the Enlightenment, “The Case,” as its subtitle puts it, “for Reason, Science, Humanism, and Progress.”

By virtue of science, I’m able to see and speak to Pinker via Skype, from my office in north London, while he is in his office in Boston. He explores the issue of inequality in some depth in the book, so it’s not an entirely trivial observation to note that his office looks to be about eight times larger than mine. But more on the distribution of wealth later.

Pinker’s trademark mop of silver curls, more like that of an ageing hard rock guitarist than an Ivy League academic, a pair of twinkling blue eyes and a ready expression of amusement beam out from my screen.

So, I ask, why do the values of the Enlightenment require such staunch and detailed defence (the book is more than 550 pages long, filled with graphs, footnotes and an exhaustive wealth of references) at this particular juncture in time?

“Among other things,” he replies, “they are under threat from authoritarian populism, religious fundamentalism and radicalism of the left and right. The great successes the world has enjoyed over the past decades and centuries are taken for granted, because many of the ideas responsible for them have become part of the establishment and no one is willing to defend them. So anything that is going right is not associated with any movement, any values, and that has left a vacuum that forces of extremism have rushed into.”

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Pinker, however, is willing to defend these established, even establishment, ideas. He is, rather bravely, prepared to be the bearer of good news. I say bravely because it’s not a popular stance. Announce that the world has gone badly wrong, that there are too many people, the Earth has been despoiled, we’ve never been in greater danger of death and destruction, or more adrift in the spiritual void of materialism and you’ll have the nodding attention of the news media and the intellectual classes.

But painstakingly show that, actually, things are on the whole quite a bit better than they have ever been and you’ll meet a torrent of bafflement and denial. Pinker knows this because he’s already been through the process with his previous book, The Better Angels of Our Nature, which persuasively argued – again with graphs and a mountain of research – that humankind was becoming progressively less violent.

It was a message that seemed to run counter to everything we thought we knew or had been told. How, after two world wars, the advent of the nuclear bomb, the proliferation of the arms industry and the brutality and murder we saw on television each night, could we seriously entertain the notion that we are becoming less violent?

But we are, and Pinker showed it with such an abundance of apparently irrefutable data that his detractors were left scrambling to redefine the meaning of violence.

“One of the surprises in presenting data on violence,” he says, “was the lengths to which people would go to deny it. When I presented graphs showing that rates of homicide had fallen by a factor of 50, that rates of death in war had fallen by a factor of more than 20, and rape and domestic violence and child abuse had all fallen, rather than rejoice, many audiences seemed to get increasingly upset. They racked their brains for ways in which things could not possibly be as good as the data suggested, including the entire category of questions that I regularly get: Isn’t X a form of violence? Isn’t advertising a form of violence? Isn’t plastic surgery a form of violence? Isn’t obesity a form of violence?”

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This time round, Pinker appears to have written with his doubting audience more firmly in mind. It’s as if he’s thought up every counter-argument before it can be made, and met each one with statistical refutations. It makes for a chewy but, well, enlightening read.

The idea for the book came out of a debate that Pinker had with the cultural critic Leon Wieseltier in the pages of the New Republic back in 2013. Wieseltier accused Pinker of invading the humanities with “scientism” – belief in the all-conquering value of science. Pinker replied that there was a false distinction between the humanities and science, that both were once the domain of educated thinkers, and that they were complementary in reaching a better understanding of the world and our place in it.

The debate, as they say, went viral, and Pinker was soon signing a book contract.

“But,” says Pinker, “ I quickly realised that a spat between a couple of magazine intellectuals was not worthy of a book-length treatment. So I submerged that particular debate in a larger defence of Enlightenment values, of which science is a part.”

The Enlightenment is a period placed by historians largely in the 18th century, and it remains a subject of much scholarly dispute about what it constituted and who were members of it. Even at the time, its adherents wrestled with definitions. In his 1784 essay An Answer to the Question: What is Enlightenment?, Kant said that it amounted to “humankind’s emergence from its self-incurred immaturity”. He exhorted his readers to “dare to understand”.

In Pinker’s conception, although the Enlightenment featured many different creeds, there was a unifying rejection of the constraints of religious faith and tribal loyalties, and in their place a belief in human universalism, the power of reason and the progressive role of science. For him it’s no coincidence that slavery and cruel punishments (such as being hanged, drawn and quartered) were outlawed in the wake of the Enlightenment. Nor that health, wealth and life expectancy began to rapidly improve.

Right from its inception, the Enlightenment had to do battle with the counter-Enlightenment – formed from the massed ranks of traditionalists, the religiously orthodox, and Romantics who recoiled from the unblinking gaze with which the Enlightenment thinkers felt emboldened to observe the world.

The struggle has continued ever since, with the Enlightenment being blamed for racism, imperialism and Nazi eugenics by critics from the left, and by the right for the moral void of atheism and materialism that found its murderous apogee in the Soviet Union and communist China. More recently, postmodernists have looked upon the Enlightenment as yet another false grand narrative, in which humanism, science and reason are just more belief systems, no more nor less valid than any others.

Pinker rejects all three positions. Far from sanctioning racism or nazism, he says, the Enlightenment laid the philosophical groundwork for universalism, the belief in equal rights for all, which ultimately triumphed over fascism and imperialism. Pinker argues that the inspiration for Nazi ideology should be more appropriately traced to Friedrich Nietzsche, who attacked the Enlightenment’s dependence on reason and argued for a “will to power” and the idea of “übermensch”, or superman. Nietzsche’s supporters won’t take that lying down.

And Marxism, he maintains, was not a legacy of the Enlightenment, but instead a pseudoscience that has more to do with German Romanticism. We can also expect Marxists to revolt.

As for postmodernism, Pinker is scathing.

Facebook Twitter Pinterest Steven Pinker in 1994, the year he published The Language Instinct: How the Mind Creates Language. Photograph: Boston Globe/Getty Images

“If scientific beliefs are just a particular culture’s mythology, how come we can cure smallpox and get to the moon, and traditional cultures can’t? And if truth is just socially constructed, would you say that climate change is a myth? It’s the same with moral values. If moral values are nothing but cultural customs, would you agree that our disapproval of slavery or racial discrimination or the oppression of women is just a western fancy?”

No doubt Pinker will be admonished for mischaracterising the views of his opponents. But while there are certainly some polemical flourishes, Enlightenment Now is a careful and deeply researched piece of work. That is more than can be said of the accusations directed at him by some of his critics. A few weeks ago the biologist and blogger PZ Myers launched an attack on Pinker by putting out an edited clip of the Harvard professor in a public debate. The edited version seemed to suggest Pinker’s approval of supporters of the “alt-right”.

In fact, as the New York Times was quick to note, the unedited video showed Pinker was denouncing far-right ideas, and arguing that the left needs to make better arguments against them. It was a vivid example of how easy it can be, in the age of fake news and social media, to tarnish reputations with doctored evidence.

There have been several examples in recent years in which careers, including those of academics, have been brought to an ignominious end after social media campaigns based on disputed testimonies. Does this overheated climate of denunciation make Pinker more inhibited with his opinions?

“In my case, no,” he says. “But I think in the broader community that is a real danger. I think I have the reputation and the social capital to withstand distortions like that, but for younger and less established people, they might think twice about saying something that could be taken out of context, doctored, and go viral. So I do think it has a pernicious effect on the quality of intellectual discourse.”

Canadian-born, Pinker has done the faculty rounds of MIT, Stanford and Harvard, where he has built a formidable reputation as a multidisciplined thinker. But it is his books that have elevated him to the coveted position of public intellectual.

He wrote a series of well-received books about linguistics and psychology before publishing The Blank Slate in 2002, which argued that human behaviour was not simply or even largely a matter of environmental influence but instead shaped mostly by evolutionary adaptations. The book had its critics, but it became a bestseller. Ever since, Pinker’s audience has only grown in number – as have his critics.

It’s likely that Enlightenment Now will prove his most controversial book to date. His targets are many and he pulls few punches. For example, he takes the green movement to task for a “misanthropic environmentalism” that views modern humans as “vile despoilers of a pristine planet”.

Underpinning the belief that humans are destroying the Earth is the assumption that progress is not sustainable. Pinker disagrees, or at least argues that such doomsday conclusions have a long and fallible history. A fundamental tenet of the Enlightenment was that all problems, if studied long and hard enough, could be understood, and therefore at some point solved. And environmental problems, writes Pinker, are no exception.

He argues that progress is not only sustainable, but essential for attaining the knowledge that will enable us to find the cleanest and most efficient use of energy. In other words, scientific progress is what will make economic progress work. The book is a kind of rallying call to replace moral posturing with clear-eyed realism. Pinker’s message is that if we are not going to return to hunter-gathering – and we’re not – we had better face up to the task at hand.

That probably means using more nuclear reactors in the immediate future, something that, as with GM crops and shale gas, the green movement has responded to with apocalyptic protestations. And we may also have to acknowledge that to cut down on carbon emissions, the developing world first needs to attain a level of material wealth, by burning more energy, at which point it can turn its attention to the environment.

But perhaps he will be most in need of a tin hat for his unapologetic dismissal of the kind of anti-capitalists who see globalism as an international conspiracy bent on impoverishing the world for the enrichment of a tiny elite. A rave review by Microsoft founder Bill Gates, who called Enlightenment Now “My new favourite book of all time” (his previous favourite was The Better Angels of Our Nature), is unlikely to improve Pinker’s credentials in radical circles. Although he emphasises the need for strict regulation of capitalism, Pinker points to the data that shows that history has never seen such a massive movement out of poverty as that witnessed by the late 20th-century capitalist revolutions in China and India. It’s for this reason that he believes the dangers of inequality have been overstated.

“If wealth consisted of a finite pot that was divided in a zero-sum fashion,” he says, “then maybe poverty and inequality would be the same issue. But we know that isn’t true, that prosperity has increased maybe a hundred-fold since the Industrial Revolution. A second point that gets omitted from discussions on inequality: although it’s true that inequality within many rich western countries, especially the Anglosphere, UK, US and Canada, has grown, globally, inequality has fallen because the poor are getting richer faster than the rich are getting richer. China and India and Africa and Latin America are getting richer and that has reduced the global indices of poverty.”

Pinker accepts that, to a degree, the decreased inequality between the developing world and the west has come at the expense of increased inequality within the west, as manufacturing jobs that once benefited the lower middle class in America and Europe now benefit the lower middle class in China and India.

“If we were to step back and look at the progress of the world’s poor, we’d have to say this is a marvellous development. If you’re a British or American politician, of course it’s much harder to make that argument. More generally, the political issue that should engage us is how well off the people at the bottom of the ladder are. What we do to combat poverty: that’s far more important than reducing inequality.”

But what of the argument that this ever-expanding cycle of production and commercialisation is turning us into mindless consumers, who can only see value in disposable commodities?

Pinker laughs. “The intellectual and cultural critics who make that argument never seem to include trips to the continent or fine food and wine as a sign of soulless materialistic consumption. It’s always consumption by the other guy that they think of as morally compromising. There’s an issue with the effects on the environment: it really is not good to pollute the environment, particularly when it comes to carbon emissions, but the way to deal with that is not to rail against consumption. There are a lot of aspects of consumption, like being able to travel, see the world, be warm in the winter, cool in the summer, that are human goods. The challenge is: how do we get the most human benefit with the least environmental damage?”

Even Pinker’s fiercest enemies would acknowledge that, however it may have been distributed, there has been scientific and material progress since the advent of the Enlightenment. But many, perhaps most notably the philosopher John Gray, argue that it has not been – and cannot be – accompanied by moral progress.

Pinker disagrees. He thinks that the Enlightenment has been misunderstood as a doomed project aimed at perfecting humanity by repressing emotion. But that was never the intention, says Pinker, because humans are inescapably emotional beings, made from what Kant famously called the “crooked timber of humanity”.

Those unpredictable impulses that lead to strife, violence and war will always be with us. What’s at issue is how we govern those impulses – through religious dogma, tribal lore and superstition, or by reason, debate, the rule of law? Pinker suggests that latter approach has delivered undeniable moral advancement.

“Slavery used to be practised by every single civilisation,” he says. “Now it is illegal everywhere on Earth. The concept of equal rights for women wasn’t a concept until a couple of hundred years ago. Now it is part of the explicit belief of all world bodies and most countries. The rights of children not to be exploited for their labour, racial equality, religious tolerance, freedom of speech… it’s very difficult to find clear statements of these values before the Enlightenment. There were some statements in ancient Greece, but they certainly didn’t carry the day then. In almost everything that you could take as an index of moral progress, the data show that we have been making it.”

It’s just the kind of speech that will be pilloried as “Panglossian”, after Voltaire’s relentlessly optimistic Professor Pangloss in Candide. But as Pinker correctly notes, Pangloss was a satire on theodicy, the belief that God had created the best of all possible worlds. Professor Pinker, by contrast, believes the world is inherently unstable and nothing is guaranteed. His concern is to make things better. And you can only do that if you first acknowledge the improvements that have been made. Enlightenment Now has made it extremely difficult to ignore them, even if you’d much prefer a spot of crystal healing and a Deepak Chopra tape. Namaste.

• Enlightenment Now by Steven Pinker is published by Allen Lane (£13.99). To order a copy for £11.89 go to guardianbookshop.com or call 0330 333 6846. Free UK p&p over £10, online orders only. Phone orders min p&p of £1.99