Left-brain Thinking is Destroying Human Civilization

Some things are key to human flourishing: proximity to nature; a culture; and some sense of something beyond this realm. They make people healthier, both physically and mentally. We’ve done away with that and now all we’re left with is public debate.


What has an esoteric theory about the differing functions of the two hemispheres of the brain got to do with everyday politics, or science, or arguments on Twitter? Potentially, rather a lot. Dr Iain McGilchrist is a neuroscientist and philosopher who has amassed a huge following since the publication of The Master and his Emissary (2009), which sets out the idea that our society has become dominated by narrow left-brain thinking, while the wiser right-brain should properly be in charge.

Freddie Sayers: Let’s start at the beginning. What is the difference between the Left-brain and the Right-brain?

Iain McGilchrist: You may think, if you know anything about hemisphere difference, that the left hemisphere is boring but reliable — like a decent accountant, it keeps good records but is not actually great company. And that the right hemisphere is this flighty thing that is given to fits of passion and painting. This is not a good way to think about it at all.

The brain is billions of neurons — nerve cells that connect — and its power consists in those connections. So why would nature have endowed us with a brain that has a whopping divide down the middle, with just a small connection between the two? The world around us doesn’t divide neatly into a left world and a right world, so why would the brain?

What my research over 30 years — and my collaboration with John Cutting in the initial phases of that — reveals is that these two manners of being in the world are to do with the way in which we attend. Now, that may not sound very exciting. In fact, when I first realised that the basic thing here was attention, the penny didn’t immediately drop. What’s special about attention? Well, attention is actually how our world comes into being. If you attend to something in one way, you see one thing. If you attend to it in another, you’ll see something quite different.

These two kinds of attention came about for an evolutionarily important reason. Every creature has to solve this conundrum: how can I eat and yet stay alive? That doesn’t sound difficult, but if you think back: for most of history, a creature has to be able to target something, follow it with its eyes, and get it very accurately. To do that it has to have very narrow attention. But if that’s the only attention it is paying, it won’t last very long, because he won’t see the predator overhead, it won’t see its mate and its offspring that also need feeding. So there needs to be two kinds of attention, and so different are these kinds of attention that they can only come about by having two centres of awareness.

The left hemisphere has a very narrow beam, targeted on a detail which it can see very precisely. It fixes it and grabs it (and the left hemisphere controls the right hand with which most of us do the grabbing and the getting). Whereas the right hemisphere has a broad, open, sustained vigilant attention, which is on the lookout for everything else without preconception. So on the one hand you’ve got an attention that produces a world of tiny fragments that don’t seem connected to one another — a bit here a bit there, a bit elsewhere — that are decontextualised, disembodied. Whereas with the right hemisphere we see that nothing really is completely separated from anything else — that ultimately, all this is on some level seamlessly interconnected, that it’s flowing and changing rather than fixed and static. Uniqueness is something the right hemisphere sees, while the left hemisphere sees just an example of something that it uses or needs. The right hemisphere is the world in which we live; the left hemisphere’s world is, if you like, a map, a schema, a diagram, a theory — something two dimensional. So we’ve got this one world, which is composed of things that are mechanical, useful, inanimate, reducible to their parts, abstracted, decontextualised, dead; and another world, which is flowing, complex, living, changing and has all the qualities that make life worth living.

FS: These two modes of attending have with them accompanying philosophies, accompanying ways of seeing the world. And your thesis seems to be that as a whole society, not just as individuals, we have become overly dependent on the left hemisphere, and are neglecting the wiser right hemisphere. How has this happened?

IM: Things work well as long as the left hemisphere is carrying out work it’s deputed to do by the right hemisphere. Rather like we use a computer. The computer doesn’t really understand the data we draw from the complexity of life. That’s not its job: its job is to process data very fast, and hand us back some that we then make sense of.

The Greek and the Roman civilisation began with a sudden outburst of flourishing in which the two sides worked very well together. Then over time, they moved more and more towards the left hemisphere’s point of view. I think this is because civilisations tend to overreach themselves. They tend to amass an empire, and then everything has to be administered: there are rules and procedures, and everything is rolled out under a bureaucracy. And what this privileges is a simple, sequential, analytic way of understanding, rather than the more complex, holistic understanding that is required and is provided by the right hemisphere.

What I think happened during the Renaissance was this sudden flowering in which there were great steps forward in so many aspects of life — a great richness. (This is not about the humanities versus the sciences by the way, nor is it true that the humanities are somehow right hemisphere and sciences somehow left hemisphere; good science and good reasoning involve the right hemisphere as much as the left.) Then towards the end of the 17th century came a sense that science had solved all our problems and we were beginning to understand how to control everything ourselves.

Unfortunately, we now believe that if we just had a little bit more power (which is the raison d’etre of the left hemisphere: to grasp, to get) — if only we could do a bit more manipulation — we would solve everything. But at the same time, we’re making an unholy mess of the world in so many respects. We’re destroying nature, we’re destroying humanity. We’re certainly destroying this civilisation. I’d say we’re taking a sledgehammer to it. And so, this is a very sad outcome for this know-it-all left hemisphere.

There are several reasons why I think the left hemisphere has become more potent. One is that it’s the one that makes you rich. It’s the one with which you do the grabbing and getting. Another is that it’s much easier to explain the left hemisphere’s point of view: “If we do this, it leads to that.” When you start to openly analyse what your civilisation is about, rather than getting on with it, then you lean more and more into this left hemisphere point of view. A.N. Whitehead, who I consider one of the all-time greatest philosophers, said: “A civilisation flourishes until it starts to analyse itself.” And that’s remarkable because Whitehead was a mathematician and a physicist, but he was able to see the limitations of science and reason.

I happen to believe our science is not scientific enough. It’s too dogmatic. I happen to believe our reason is not reasonable enough, it’s too dogmatic — and it’s dogma that’s always the problem. We need science, we need reason, but we also need to see that they can’t answer all our questions. Love is very real. Anyone who’s experienced it knows that it’s one of the realest things that can happen to you — but according to science, for it to be real, you’ve got to be able to see it in the lab, measure it, manipulate it.

And then you start thinking about all the other amazing things that we experience. Music: it’s wonderful, it can change your life, but it’s just notes. What is the note? Absolutely nothing? Thirty thousand nothings make up Bach’s B minor Mass, one of the most powerful things you can hear. How did that happen by amalgamating so many nothings? It’s because it’s all in relation. What I’m suggesting is that relationships are primary. The things we notice only become what they are because of the relationships.

FS: You kicked off with the Enlightenment. Is that where it all went wrong? Have we become gradually more and more left-brained, or are there particular points when the left brain has been dominant?

IM: There have been movements back and forwards, corrections at various times. After the Enlightenment came Romanticism — the name “Romantic” seems to imply that it’s not serious or important, but in fact, the thinking and the art that came out of the period is very great indeed. There was a correction. But then the power of the Industrial Revolution led to this machine-like way of thinking about living things, and we’ve never really lost that.

There are great artists in Modernism and Postmodernism. But it’s interesting: the ways of seeing the world that normally would only happen to somebody who had an injury in the right hemisphere began to be represented in the visual arts in the 20th century. There’s a wonderful book called Madness and Modernism about this topic, showing how things you find in schizophrenia are now happening, and are being portrayed in our culture.

It’s not that we’ve all got schizophrenia — of course we haven’t — but what I think is that we’re all neglecting the right hemisphere. Schizophrenia is a case in which the left hemisphere has gone into overdrive, and the right hemisphere has been wound down or is not really being listened to, and this leads to delusions and hallucinations. I think we are now in a world which is fully deluded. We’re all fairly reasonable people, but now it’s quite common to hear people say — and for them to go completely unchallenged — things that everybody knows are completely impossible. They don’t have any science behind them. There are aspects of our culture that have become very vociferous and very irrational, and very dogmatic and very hubristic. “This is right, and anyone who says otherwise is wrong.” That’s the way the left hemisphere likes to be. Cut and dried, black and white. But the right hemisphere sees nuances, gradation: there’s good and bad in almost everything.

FS: Do you think we have ever been in a moment as left-hemisphere-dominated as we are now?

IM: No, I think this is hitherto unseen.

FS: Do you think technology has something to do with that?

IM: Definitely. I’d like to make a distinction, by the way, between what I would call a rationalistic approach and being reasonable. Being reasonable was something I remember from when I was growing up. There were reasonable people and they were admired. The idea of education was to make you reasonable. But now, that has been supplanted by something quite different: a rationalising framework such as a computer could follow. So we’ve been pushed by the increasing sophistication of machines — the intoxicating feeling that we have power over the world —  into viewing the world in this reductionist, materialist way. And the trouble with power is that it’s only as good as the wisdom of the person who wields it. And I don’t notice that we’re getting wiser. In fact, I think that would be an understatement. So it’s rather like putting machine guns in the hands of toddlers and then hoping there’s going to be a happy outcome.

FS: So we’re not living in an age of reason, after all?

IM: We’re living in an age of rationalising and reductionism in which everything can be taken apart. I suppose there was an almost equivalent period — it was very short lived — of Puritanism, when it was absolutely not tolerated for you to disagree with a certain way of thinking — which was, in fact, a very dogmatic, reduced, abstracted way of thinking. But I think at that point, we hadn’t reached the stage that we’re at now. Because at that time in history, people lived close to nature. Most people belonged to an inherited culture, a coherent culture. Art had not been turned into something conceptual, but was visceral and moving. Religion had not been presented as something that only a fool or an infant would believe. These are all very arrogant positions that we now hold.

We know that some things are key to human flourishing: proximity to nature; a culture; some sense of something beyond this realm. They make people healthier, both physically and mentally. We’ve done away with that and now all we’re left with is public debate.

FS: Those people who do dissent in this rationalist framework are often demonised as kooks. It’s a very heretical thought: that they may actually be the wiser ones in our society. How can we distinguish between those alternative voices that are actually wise, versus the ones that are kooks?

IM: Just having a differing point of view doesn’t mean you’re necessarily wise. You could be kooky. But nonetheless, I think those who are wise do have a position very different from the one that is now instilled in us in schools and through the media and so forth — which is, in fact, a very impoverished vision of life. It’s lost all its beauty, its richness, its complexity and become very simple, sterile, repellent. And so, I think, if we could begin to suspend our judgments, we’d be making steps forward.

I would say that a civilisation cannot thrive if differing points of view cannot be heard. Hannah Arendt, one of the greatest philosophers of the last 100 years, who was herself a German Jew and experienced Nazism, said that: “Once something can’t be said, you’re already in a tyranny.” So, it is indisputable that we are all now living, in Britain, in 2023, in a tyranny, because there are people who say, “You can’t say these things and there will be terrible consequences if you do.”

FS: You’re a big advocate of science, but you’ve written that you feel as if it’s taking a wrong turn. When does science become scientism?

IM: When it quite simply says that science can answer all of our questions — even though science is only supposed to admit things which can be proved to be the case, and it cannot be proved that science can answer all our questions. So it’s not a scientific assumption, it’s an assumption of faith. Scientism is a faith. Much as there are religious fundamentalists, which I very much regret, there are fundamentalist atheists, who I regret just as much. I think a reasonable person is somebody who has an open mind. It’s rather like a figure of fun in earlier philosophy called Simplices, who wants to learn to swim. And so, he just sits on the bank, and he reads about how to swim, but in fact, you can’t learn how to swim until you get into the water.

I think there are good scientists — and there are now, at last, good life scientists: biologists who are being imaginative and talking in a holistic way. They’ve got a long way to go to catch up with physics: I find that the scientists who are most interested in my work are actually physicists. Because these two different hemispheres are rather like the differences between the wave and the particle: the one is specifiable here, exactly at this moment in time, and the other is actually existent over a broader area and is not certainly specified.

FS: You had an appendix in the first volume, entitled “Why we should be sceptical of public science”. Tell us about that.

IM: Public science is not the same as science. Public science is run by administrators. And they have various bees in their bonnet — about how we should all do this and that in order to be healthy. Usually, when you come to examine the science, it’s much more complicated than that.

There’s also a problem with peer review. Peer review is the basic idea of science — you send it to another scientist. What do they think about it? There are all kinds of pitfalls in this. It can be corrupted. In order to have a career as a scientist you have to have published, but one of the problems for many scientists is finding anyone who’s willing to publish what they’ve done. And there are now journals, a lot of them based in China, that will basically publish anything as long as you pay them. You’d be very credulous to believe that everything that is said to be science is science.

So, I’m not attacking science, I’m just saying that science is not immune from all the problems that go with being a human being. It’s practised by humans, with all their greed, their ambition, their competitiveness. And so it’s a minefield — you have to use your discrimination. When people say something, look it up.

FS: The world you describe has gone very wrong. But do you have hope that this can be fixed, that this civilisation can be righted? Or do you think now is the time just to withdraw and hope for the best?

IM: I think it is extremely unlikely that this civilisation will survive, but most civilisations have not lasted for more than a few 100 years. I think life will go on, but it won’t be life as we know it. None of us is going to live forever. We’re all only here for a while and we enjoy the gift we’ve been given. And then the world moves on and something else will come and they will have their gifts and their problems.

Trust is crucial here. You can’t trust when you’re in a virtual sphere of billions of people. Trust is the most important thing for civilisation. If we can trust one another, we can honourably work together with much simpler needs, closer to the earth — not the extravagant and fantasy lives that we now lead.

What can we do now? We can begin the work of limiting the damage we do to nature. I think we also need to reestablish some sense of who we are and what we’re doing here. Although we’ve got all this power, and machines that can “think”, they can’t think at all, they can only process information extremely rapidly. We’re not really wise.

One of my answers, when people say, “What should we do?”, is pray. And by that, I don’t mean, as Heidegger said, “Only God can save us now.” I don’t mean that God will suddenly come down with his divine hand, sort everything out, and it’ll all be okay. That’s not going to happen. What I mean is that we adopt a different, less arrogant, less hubristic attitude to the world; that we have some humility; that we re-kindle in ourselves a sense of awe and wonder, in this beautiful world, and with it bring some compassion to our relations with other people. Not shouting them down, vilifying them, telling them they’re frightful, but reasonably talking and saying, “Okay, you disagree with me. I’m interested, explain your point of view.” What we mustn’t do is follow the strident shrieking voices, whatever they may be saying.

FS: That is a wonderful moment to take some questions.

Question One: Is there a difference between the male and female brain?

IM: Yes. This question always comes up. And the trouble is that, to answer it in a sensitive way, I’d have to spend quite a lot of time answering it. To put it very simply: I think it’s certainly not true that the right hemisphere is somehow female, and the left hemisphere male. If anything, it’s the opposite. For example, what’s established beyond doubt is women’s excellence lies in skills that are often linguistic. Whereas men may be much less linguistic, but more able to manipulate things in space. That is a right hemisphere property largely, and linguistic fluency is largely a left hemisphere property.

In utero, it is testosterone that causes the right hemisphere to expand. Women’s hemispheres are more similar to one another. I think it’s pretty indisputable that male brains are more specialised, the left and right. Whereas in female brains, there’s more overlap between the left and right. So there’s more of the right about the left and more of the left about the right than there is in a man. And this means that if a woman has a stroke on one side, she’s more likely to be able to recover using the other hemisphere than a man. Neither is better. It’s just different ways of being.

Question Two: I’m thinking about how we’re moving towards the left. Do you think that it has anything to do with language and speech? In a podcast with Sam Harris, you were saying speech comes from the left side of the brain. And so speech inherently has to be limiting; it has to break things down in order to communicate.

IM: Yes, undoubtedly one of the big developments of the human brain is language and speech. And 97% of speech, in most right handers, is in the left hemisphere. In the case of left handers, it’s 60% in the left hemisphere, 40% in the right, but I don’t think we should get over-excited about that. The point that you’re making, I think, is that the business of being able to articulate something in language requires a certain degree of analysis and categorisation, and that the really important things in life don’t lend themselves to this process — the divine, love, music, all these things I keep coming back to. These things are enormously limited if I’m trying to do them in language, unless that language is poetry.

I see poetry as a way of language undercutting itself — doing something that ordinary language can’t do. And the interesting thing about poetry is that it’s very much right hemisphere dependent, because it involves all these implicit things like metaphors and tone. The right hemisphere is much better at this; the left hemisphere can read a repair manual for a lawn mower. There’s a difference between certain kinds of language. But broadly speaking, yes, the advent of language, and particularly speech, favoured the left hemisphere over the right.

FS: And so the left-hemisphere-dominated culture will see a decline in literature, in poetry and imagery?

IM: And creativity in general, because it’s so dependent on the ability to hold many things together that may not look like they gel, rather than collapsing them into certainty. We know from accounts of creativity that the important thing is not to say, “Oh, I see what it is.” Because as soon as you’ve done that, you’ve plonked it into a left hemisphere box with a label on it. You have to resist that and allow the thing to come into being and then it will be a true poem, not just a piece of verse.

The postmodern thing is a disaster, it’s basically collapsing into: “There is nothing really there, we make it all up.” I accept that in intellectual history, there has been a shift away from a narrowly analytic way of thinking, but I’d say that’s only in pockets within academia. And what is much more common is this post-structuralist, post-modernist, anything goes attitude in which everything is equally true. Well, if everything is equally true, why don’t we all just cut our throats now?

I believe there is such a thing as a truer view, a truer pronouncement. But it’s not that there’s something out there that we have to get to by a chain of reasoning. It’s something that we have to feel our way towards and have a sense of, and then it comes more and more into being. There aren’t any rules for defining what exactly is true. You see, because we idolise rules and procedures, we think that if there aren’t rules and procedures for something, then it can’t be real. But all of the really real things are not susceptible to this proceduralisation.

One of the problems with universities now, as with schools, as with the medical profession, and with the whole of life, is the sudden explosion of bureaucratic procedures and thinking. There are manuals upon  manuals that you’re supposed to read and observe and follow. And then we’re surprised that professionals, who are skilled people who have learned things through experience, want to leave the profession because they’re effed off with the way in which they’re cheated by managers. I had a very, very distinguished colleague — a professor of neuro-psychiatry at the Maudsley — and he was queried by a manager about why he’d sent a patient for a scan. And he said, when I have to explain to a manager why I’ve sent a patient for a scan, it’s time for me to leave the profession. And he did.

Question Three: Could we say that we’re living in a world where the very reasons for doubting are doubted and there is this crusade for certitude?

IM: Absolutely. One of the first things that differentiates the hemispheres is that the left hemisphere has to have certainty. There’s a famous picture used by Wittgenstein, which is actually taken from a Victorian children’s comic, which shows either a duck or a rabbit depending on how you look at it. The right hemisphere is able to hold those two images together without collapsing them, but the left hemisphere is unable to. It’s either a duck or it’s a rabbit. It’s black and white, dogmatic thinking. Whereas the right hemisphere is the devil’s advocate. It was so called by V.S. Ramachandran, a very great neuroscientist. It’s the one that says, “Yeah, but maybe not.” And if only we had more of that voice, we wouldn’t be in the mess we’re in.

FS: The one area that we haven’t spent much time on is the sacred. Do you think this must be part of the story: that the need for certainty is also an insecurity because there is an absence which religion used to fill?

IM: I think to some extent, although I would say that any religion that peddled certainties was not a religion, properly speaking. It was a dogma or doctrine. Not that there’s no reality about it, but there is no single way of thinking about this or realising it or seeing it. Everybody has to make their own way there.

I wouldn’t like to say exactly what I believe in religious terms, but what I definitely believe is that all the great religions — and the great mystical traditions of Buddhism and Taoism — have central truths that they hold in common, and that these are a kind of wisdom that is not appreciated unless one is brought up in a tradition that helped one see them. And our tradition is dead against seeing them. It’s much simpler just to say, “Oh, it’s all nonsense, because I can’t see any of this. I can’t measure any of it.”  But I don’t think that is reasonable; I’d be much more cautious. I think I have had experience of such a realm — in my appreciation of the beauty of the world. It spoke to me and still speaks to me of something beyond this realm. When I first heard the great polyphony of Renaissance, I thought, yes, it can move the emotions, but it’s not primarily either intellectual or emotional. In fact, it’s spiritual.