Michael Pollan: ‘Consciousness is really under siege’

Author Michael Pollan has tackled plants, food and psychedelics in bestselling books including The Omnivore’s Dilemma and How to Change Your Mind. Now, he has taken on the thorny problem of consciousness. In his latest book A World Appears: A journey into consciousness, Pollan charts the work of scientists and philosophers, weaving in literary perspectives along the way. He spoke to New Scientist about the value of writing a book where you know less at the end than before you started.

Olivia Goldhill: Let’s start with a deceptively tricky question: how do you define consciousness?

Michael Pollan: The simplest way is to define it as subjective experience. We have subjective experience; toasters do not. You could even take off the “subjective” because having experience implies being aware that you’re having experience.

Another definition I like comes from philosopher Thomas Nagel, who wrote a famous 1974 essay, “What is it like to be a bat?”. Bats are very different than we are, but nevertheless we can imagine it’s like something to be them. That’s a question to ask of any species or individual: if it’s like something to be you, then you’re conscious.

The cortex is the newest, most evolutionarily recent part of the brain and, for a long time, it was assumed that consciousness must be in the cortex. But I was sold on the idea that consciousness begins with feelings, not thoughts. I was persuaded by the work done by Antonio DaMasio and Mark Solms and Anil Seth that consciousness begins with feelings, like hunger or itchiness, and therefore begins in the upper brainstem. That has huge implications. It tells us that consciousness is an embodied phenomenon. You need a body that, like ours, is vulnerable and has feelings that have survival value.

You write about how much we don’t know about consciousness, and how science has struggled to make progress. Do we need a whole new form of science?

We’ve organised the physical sciences in such a way that they limit themselves to objective, third-person, quantifiable things, and consciousness is a first-person, qualitative thing. This goes back to Galileo – he suggested a division where we leave subjective, qualitative things to the church. It’s not as if Galileo didn’t believe in subjective or qualitative things. He did. He just said it’s too risky, we don’t want to piss off the church any more than we already have. This kind of science has come down to us, and there’s reason to doubt whether those tools are adequate.

You also have to study consciousness from inside consciousness. A book that had a big influence on me, The Blind Spot, points out that science itself is a manifestation of human consciousness. The problems we choose to work on, the way we measure things… these are all products of human consciousness.

We might need a different kind of science. Certainly, we need a kind of science that figures out a way to bring the first-person perspective in. There is one attempt to do that in consciousness studies with integrated information theory, which begins with subjective experience as defined according to five axioms, and then goes looking for the kind of structure that would foster that kind of experience. I didn’t find it very persuasive, but it’s an interesting attempt.

You describe plants having memory and intelligence, and it sounds like you’re open to plant consciousness.

I’ve drawn a distinction between sentience and consciousness. Sentience is the ability to sense your environment, but also to recognise the valence of changes, whether they’re good or bad for you, and react accordingly. So it’s a very basic kind of awareness, and it doesn’t have self-awareness. I think plants have that.

I spent a lot of time exploring the field of “plant neurobiology”, as it’s called in a joking way. There are some remarkable findings. Plants have about 20 senses. We only have five or six. They can navigate a maze. If you play the sound of a caterpillar chomping on a leaf, the plant will react and send toxins to its leaf. They send signals to surrounding plants when there’s a predator. They will share soil with a related plant, but not with an unrelated plant – so they’re recognising their kin and themselves.

And the spookiest of all is that they respond to the same anaesthetics we do. If you give the Venus flytrap an anaesthetic, the same ones that work on us, it won’t react [to nearby flies].

The question then comes up: what has the plant lost when it’s under anaesthesia? Some would say consciousness. Certainly its sense of awareness – it’s no longer aware that there’s a fly crossing its threshold. So I find that very suggestive.

People might be relieved that you seem pretty confident artificial intelligence won’t be conscious.

I’m talking about artificial intelligence on the immediate horizon – large language models and the other forms of AI projected within 10 years. Computers can simulate thought, but cannot simulate real feelings. A feeling is more than simply information, it has this qualitative dimension. Feelings are rooted in a body that has a vulnerability.

I profile someone in the book, Kingson Man, who’s trying to make a computer that would be vulnerable. He’s upholstering the thing with this tearable skin that will have sensors in it. I asked him: “Do you think those feelings will be real?” And he wasn’t sure.

How much did your earlier work, on plants and psychedelics, end up informing your investigation?

Oh, profoundly. My interest in plants goes back to my first book, and I wanted to work on plants because I love plants. I really care about whether they’re sentient or not. But there was also a psychedelic experience that informed that quest, of being in my garden in Connecticut, and having this distinct sense that the plants were conscious. It was particularly this group of plume poppies that were as tall as I was, and they were returning my gaze, and they had this total benevolence toward me.

There’s always a question: what do you do with a psychedelic insight? Does it have any value? I wasn’t sure. I read William James on mystical experiences and he said you treat it as a hypothesis, which means you look for other ways of knowing that might validate or invalidate it. That sent me down this path.

Christof Koch has a psychedelic experience in my book, a radical one, where he saw consciousness outside of the brain. This is someone who’d assumed the brain was at the centre of things. I asked why he changed his mind and he said, “nothing that I’ve experienced is as real as that”. So, psychedelics found their way into this book, and I was surprised how many scientists are working with psychedelics and finding them helpful in various ways.

In the larger sense, psychedelics made me wonder about consciousness. Psychedelics have a way of smudging the windshield of experience. Suddenly, you realise that the world is being mediated by something. And that’s consciousness. Once you realise that, it’s hard to think about anything else. It becomes kind of an obsession.

I love the bit in your book where you have your thoughts tracked by psychologist Russell Hurlburt, though you seem to not welcome his view that you don’t have many.

I feel a lot of my thoughts are not articulated, but they could be with just a little bit of work. James calls it premonitions – that you’re on the verge of something, and sometimes I go to the trouble to translate it and sometimes I don’t.

But what Hurlburt was saying about me was that there’s nothing going on. We argued a lot because I could not disentangle my thought at any one moment from the context. He took this to mean that there was a great hollowness I was backfilling with contextual stuff. I ruminate, and when I meditate, there’s plenty of thoughts going on. So I reacted a little defensively. But it was interesting.

He’s been doing the same experiment for 50 years, and he’s learned there are real distinctions between the way people think. We assume this word “thought” describes the same phenomenon for all, but it doesn’t. There are people who think in fully formed words, people who think in images, people who think in what he calls “unsymbolised thoughts”. The percentage of verbal thinkers is much lower than we assume.

Can thinking about consciousness both heighten our awareness and take us away from consciousness?

Alison Gopnik talks about spotlight consciousness [narrow, intense focus] versus lantern consciousness [general, exploratory awareness], and I was really going down the spotlight route. As I grew increasingly frustrated about finding a solution to this problem [of consciousness], my wife, who’s an artist, said that not knowing is a wonderful thing – sitting with uncertainty is really valuable. My first reaction was “yeah, yeah, yeah – I’m a journalist, I need an answer”.

But when I met Joan Halifax, the Zen teacher at the end of the book, and spent time in a cave, I realised she was right and there was another way to think about it. There was the problem of consciousness, but there was also the experience of it. And focusing on the problem got in the way of the experience.

We can be more conscious, and there’s some urgency to that, in that consciousness is really under siege. [It] is very precious. It’s this private space where we can think anything we want, and we’re giving it away to companies. We need to defend it. Even though you’ll know less about the science of consciousness than when you started this book, you’re going to learn something else that I think is even more important.

If understanding consciousness is potentially impossible, what is the value of this quest?

The quest is everything you learn along the way. When I read James especially, I do have this sense of awe at how complex this laboratory of our own minds is. You come away with a deeper appreciation for something you may have taken for granted. That’s what I’m hoping – that the book makes you more conscious than you were before you started.