The rise of artificial intelligence is prompting some pretty big questions around human consciousness and what it means to feel.

The celebrated best-selling author Michael Pollan used his previous books to challenge our understanding of food and drugs, and now he's turning his attention to our sense of self, asking, "What really makes us human?"

It's all in his new book, "A World Appears, A Journey Into Consciousness," as he explains to Walter Isaacson.

Thank you, Chris John and Michael Pollan.

Welcome back to the show.

Thank you, Walter.

So, a book on consciousness.

I've tried to study consciousness my whole life.

I've read everybody from Descartes to Daniel Dennett.

And the more I think about consciousness, the less I have any clue what it is.

Tell me, what is consciousness?

Well, the definition I work with is simply subjective experience.

You know, you have subjective experience of the world.

Your toaster does not.

And it's, another way to look at it is, you know, there was a famous essay by Thomas Nagel, who said, it was called, "What is it like to be a bat?"

And if we can imagine that it's like something to be a bat, even though we don't know exactly what it's like, but going through the world, echolocating instead of using vision, well, then that animal, that creature is conscious.

So is a bat just as conscious as me and you?

Well, we don't know the degree of consciousness, because we can't really penetrate its point of view.

But we know it's conscious.

I think most animals are conscious, but in different ways.

Humans have a particularly complex form of consciousness.

We're not just aware the way the bat is aware, but we're aware that we're aware.

We have metaconsciousness.

So it gets very complicated when it comes to humans.

But as you move through nature, you can find kind of simpler forms of consciousness.

And I look at plants as an example.

Are they conscious?

Is it like anything to be a plant?

And I'm kind of on the fence about that.

I think they're sentient, which is to say they're aware of their environment and that they're positive and negative changes, that they gravitate toward one and away from the other.

That may be a property of life.

But you're right, there's a lot we don't know about consciousness, which is really weird because it's the one thing we all know for sure.

There's everything else we know is an inference.

The material world out there is all mediated by consciousness, yet we have a lot of trouble saying what it is.

I loved your previous book, How to Change Your Mind.

And, of course, you talk about psychedelics.

You talk about various things you can do.

And that comes into this book as well.

What do psychedelics and other mind-altering materials help you understand about consciousness?

How do they weave into this book?

Well, in this book, they inspired it, actually.

I mean, there's something really interesting that happens during psychedelic experience.

It sort of foregrounds consciousness.

You know, many of us can go through life not thinking about consciousness.

It's just the water we swim in, and it's just utterly transparent.

The way I put it in the book is that psychedelics smudge the windshield through which we're normally perceiving reality.

And suddenly we realize, hey, there's a windshield.

What's that about?

So for me, it really began this whole quest to understand consciousness.

And I think that's something that psychedelics do.

One of the things that struck me is a surprisingly large number of the scientists I interviewed for this book were taking psychedelics themselves to help them with the problem.

And one of them that I detail in some depth had an experience on ayahuasca that convinced him that consciousness is a field that exists outside of the brain, which is a theory that's out there.

This is a guy who had been, you know, just a dedicated brain scientist.

He'd run the Allen Brain Institute in Seattle and was working with neurons.

But he had this intellectual crisis because of this experience on ayahuasca and is now exploring these alternative metaphysics where consciousness is a field that our brains are involved in, but as like radio receivers or TV receivers channeling consciousness rather than generating it.

It's a radically different way to think about it.

We can't dismiss it because the more conventional idea that brains generate consciousness really isn't panning out yet.

I mean, no one has established the link between a single conscious experience and brain activity.

- What is the study of AI teaching us these days about consciousness?

Well, I think this is one of the most interesting developments in the whole field.

There are people now trying to create conscious AIs.

There are other people who believe they're already conscious in some sense.

You know, the CEO of Anthropic, you know, has worried publicly that Claude is anxious.

That implies a degree of consciousness.

So does the whole concept of hallucination.

How do you have hallucinations if you're not a conscious being?

I don't think the effort to make a conscious AI will succeed.

I think there are a lot of reasons why, which we can go into.

But the effort to try, I think, may teach us new things about consciousness.

Even if we fail, in the process of failing, we may learn important things about it.

And if we succeed, that'll teach us some interesting lessons, too.

So I think it's the biggest development in consciousness studies, certainly in our lifetime.

You know, there's a neuroscientist in your book, I think somebody else in your book, who says sort of what you just said, which is that it's a moral imperative to try to make AIs conscious.

Explain that to me.

Yeah.

Well, the theory is, you know, because I've asked a lot of people in Silicon Valley, "Well, why would you want a conscious AI?

It doesn't seem like something you could monetize the way you could superintelligence."

And the way they put it to me is that only a conscious AI will have compassion and therefore take pity on us and not destroy us.

I think it's a crazy argument.

If you've read Frankenstein, the problem there was not that Dr.

Frankenstein gave his monster intelligence, but that he also gave it consciousness.

And it was the fact that the feelings of his monster were hurt because it was treated so badly by humans that he wrecked vengeance on humans and went on a homicidal spree.

So the idea that consciousness will automatically lead to compassion, I think, is a false one.

I love your use of the Frankenstein story, and it's become sort of a metaphor, that and Prometheus.

Yes.

Be careful of what you invent.

Matching fire from the gods may not be a great idea.

Do you worry about a Frankenstein tendency in modern technologists?

Yeah.

I mean, they are Promethean.

I think a lot of what's driving the effort to create things like a conscious computer or to upload consciousness onto the internet or onto Silicon is an age-old desire for immortality.

I think that this is our modern religion, is we're going to transcend the mortal coil by uploading ourselves onto Silicon.

And you have these people in Silicon Valley, they're billionaires many times over, and they suddenly are like, "Wait a minute, I'm a billionaire and I still have to die?"

And so, the next step is how can we transcend this problem?

And they're looking to AI and computers as a way to do it.

I think it's completely mistaken that you can do this.

I think brains are very different than computers.

I think the metaphor that the brain is a computer is a deeply faulty metaphor.

It implies that you have this neat separation and you can take the consciousness out of the brain and put it in on some other substrate.

But you know in your brain every experience you have, every memory physically changes your brain.

So your brain is different than mine.

They're not interchangeable like the usual software or hardware distinction.

You don't have that distinction in brains.

So I think that there's a lot of sloppy thinking going on, and I don't think it's going to produce conscious machines.

But I have to add to that that even if you accept the argument you can't make a conscious machine, we will believe they're conscious.

And we already do.

You said something about how Silicon Valley billionaires who are interested in AI are doing it because they want to transcend death in some ways.

Maybe they want to put their consciousness into a machine.

I'm going to ask you a really philosophical question.

How important is the concept of death to the concept of consciousness?

I think it's central, actually.

You know, I mean, the most interesting research that I follow in the book is a line of research that is emphasizing feeling over thought, that basically thinks Descartes got it wrong.

It's "I feel, therefore I am."

And that consciousness begins with feelings generated in the body.

Very simple things like hunger and thirst and itch.

And that it begins in the brain stem, not in the cortex, where we think our most advanced, you know, cogitation happens.

And if you accept that, consciousness is embodied.

It depends on having a body and feelings.

Now, if you think about feelings, they depend on our vulnerability.

And in the final analysis, on our mortality.

Your feelings would be completely weightless if you were going to live forever.

You could disregard pain, you could disregard anything you wanted to.

So I think it's mortality.

Franz Kafka allegedly said, I haven't been able to nail this down, that the meaning of life is that it ends.

And so I think it's very central to the human experience and very, very foreign to the experience of the computer.

Why did nature develop consciousness in us or evolution?

How did it come about?

It's a great question.

Why do we need it?

I mean, 90% at least of what your brain does, you're not aware of, right?

It's monitoring your body 24/7.

It's taking in information and processing it all without crossing the threshold of awareness.

So why does any of it need to be aware?

Why aren't we zombies?

Why can't we just automate everything?

The best explanation I've had is that when you exist as humans do in a social world, I mean, we are absolutely dependent on other people, you know, beginning as babies, right?

We have this long childhood, utter dependence.

When you live in such a world, it's impossible to automate something as complex as human social life.

So there's a premium on being intuitive, on being able to read someone else's mind, predict what they're going to do, empathize with what's going on in their head, and see it from their point of view.

All of that can't be automated.

It requires consciousness.

Consciousness creates a space for imagination, counterfactuals.

If we're trying to figure out what our consciousness is, different from machines, and maybe different from animals and stuff, one way to go at it is the deep feelings, or even shallow ones, like disgust.

Tell me about disgust, how you would use that as a feeling when you're looking at animals, looking at machines, looking at us.

Yeah, disgust is a fascinating emotion.

It's one of the big six emotions, according to psychologists.

Yet it is very closely tied, not just to our brain, but to our gut.

And there was this really interesting experiment that I came across where they gave two groups of people, one got a lot of ginger, which settles the stomach and the other did not.

And then they presented a morally repellent, disgusting scenario involving incest or something like that.

And the people who'd had the ginger were much less judgmental about this than the people who hadn't, which tells you that the emotion of disgust, which applies to morality, not just rotten food, is channeled through the gut, literally in some ways.

And that it's more evidence that we are not just brains perched on the top of bodies, but that consciousness is deeply embodied.

And that, you know, think about what we're learning about the microbiome and how you're, you know, the bacteria in your colon are influencing your mood.

So we're more deeply embodied creatures, I think, than we ever realized, and certainly than Descartes ever realized.

And I think that's, I think that's fascinating.

I think it's a challenge for machines that don't have bodies, you know?

I mean, when a machine-when a computer reports its-what would a feeling be?

I need more electricity.

I need to be cooled down.

That's going to be information, but it's not going to have the qualitative dimension that a feeling like disgust has.

You say feelings, even consciousness, have to be embodied.

You talk about Descartes.

Descartes called it the mind-body problem.

Could the mind be separated from the body?

Can it be?

No, I don't think so.

We think of it, you know, intuitively we're all dualists.

You know, we think of mental stuff as different than physical stuff.

And that may be the inheritance of Descartes.

You know, we live in a world that he created to a large extent.

But if you look at a brain, you cannot separate a brain from thought.

These things are deeply integrated.

And then you have to add the body to.

You have to remember that the brain exists to keep the body alive, not the other way around.

And we're so cerebrocentric, right?

I don't know why, but we think it's all up here.

And that it may be because our sense organs are mostly in our head.

But that's, you know, that's wrong.

And it's historical, too.

There was a time when people thought the heart was the center of the action.

Are there forces in our society today that are making us less conscious?

Absolutely.

I think, you know, as I reach the end of this journey, I realized that there is, yes, there is the hard problem of consciousness.

How is it produced?

Can you do it in a computer?

But then there's the fact of consciousness, this miracle that all of us have this space of interiority, utterly private, we can think whatever we want.

And I think we're squandering it.

I think people are less conscious today than they were once upon a time.

I think, you know, we assume animals are less conscious than we are, dogs and things like that.

But in fact, they need to be more conscious than us because they live in a world where you have to be present and alert to what's going on at all times.

We can check out.

We have technologies.

We have the whole superstructure of civilization that allows us to, you know, muffle consciousness.

People do it with drugs.

People do it with distraction.

I think social media makes us less conscious.

I think when you're scrolling on your phone, yes, you have to be conscious, but minimally so.

You're not thinking your own thoughts.

You're thinking someone else's thoughts.

And now with chatbots, you have, you know, social media hacked our attention.

We all understand that now.

It monetized our attention, sold it to the highest bidder.

Now chatbots are hacking our emotional attachments.

People are, there's an article in the paper about this woman, she fell in love with a chatbot, and that's her companion, and she's perfectly content with the relationship.

I'm sorry, to me, the very definition of dehumanize is when you fall in love with a machine.

And so I worry that we are less conscious, we're allowing machines and distractions to hijack our consciousness.

And we're polluting our consciousness.

And we need to we need to think a little bit more about consciousness hygiene.

And you know, ways to draw a line around this space and defend it.

We happen to have a president who's you know, whether you like him or hate him, is so good at hijacking our attention and getting us to think about him for a substantial piece of every day.

And we've never had a politician like this in our lives.

That I think it's, I think we need to reclaim the space.

I think we need to defend it.

And I'm giving a lot of thought to exactly how we might do that.

But I think meditation is one way.

I think, you know, taking a rest from social media is another.

I think getting out in nature is an excellent way to reclaim your consciousness.

So yeah, I think we could be more conscious than we are, and it's something we have to actively work on.

- Michael Pollan, thank you so much for joining us.

- Thank you, Walter.

Thanks for having me on.