- Let's try to go to the very simplest question that you've answered many a time, but perhaps the simplest things can help us reveal, even in time, some new ideas. So what, in your view, is consciousness? What is qualia? What is the hard problem of consciousness? - Consciousness, I mean, the word is used many ways, but the kind of consciousness that I'm interested in is basically subjective experience.

What it feels like from the inside to be a human being or any other conscious being. I mean, there's something it's like to be me. Right now, I have visual images that I'm experiencing. I'm hearing my voice. I've got maybe some emotional tone. I've got a stream of thoughts running through my head.

These are all things that I experience from the first person point of view. I've sometimes called this the inner movie in the mind. It's not a perfect metaphor. It's not like a movie in every way, and it's very rich. But yeah, it's just direct, subjective experience. And I call that consciousness, or sometimes philosophers use the word qualia, which you suggested.

People tend to use the word qualia for things like the qualities of things like colors, redness, the experience of redness versus the experience of greenness, the experience of one taste or one smell versus another, the experience of the quality of pain. And yeah, a lot of consciousness is the experience of those qualities.

- Well, consciousness is bigger, the entirety of any kinds of experience. - Consciousness of thinking is not obviously qualia. It's not like specific qualities like redness or greenness. But still, I'm thinking about my hometown. I'm thinking about what I'm gonna do later on. Maybe there's still something running through my head, which is subjective experience.

Maybe it goes beyond those qualities or qualia. Philosophers sometimes use the word phenomenal consciousness for consciousness in this sense. I mean, people also talk about access consciousness, being able to access information in your mind, reflective consciousness, being able to think about yourself. But it looks like the really mysterious one, the one that really gets people going is phenomenal consciousness.

The fact that all this, the fact that there's subjective experience and all this feels like something at all. And then the hard problem is, how is it that, why is it that there is phenomenal consciousness at all? And how is it that physical processes in a brain could give you subjective experience?

It looks like on the face of it, you'd have all this big, complicated physical system in a brain running without it giving subjective experience at all. And yet we do have subjective experience. So the hard problem is just explain that. - Explain how that comes about. We haven't been able to build machines where a red light goes on that says it's not conscious.

So how do we actually create that? Or how do humans do it? And how do we ourselves do it? - We do every now and then create machines that can do this. We create babies that are conscious. They've got these brains. - As best as we can tell. - And that does produce consciousness.

But even though we can create it, we still don't understand why it happens. Maybe eventually we'll be able to create machines, which as a matter of fact, AI machines, which as a matter of fact are conscious. But that won't necessarily make the hard problem go away any more than it does with babies.

'Cause we still wanna know how and why is it that these processes give you consciousness? - You know, you just made me realize for a second, maybe it's a totally dumb realization, but nevertheless, that it's a useful way to think about the creation of consciousness is looking at a baby.

So that there's a certain point at which that baby is not conscious. The baby starts from maybe, I don't know, from a few cells, right? There's a certain point at which it becomes, consciousness arrives, it's conscious. Of course we can't know exactly that line, but it's a useful idea that we do create consciousness.

Again, a really dumb thing for me to say, but not until now did I realize we do engineer consciousness. We get to watch the process happen. We don't know which point it happens or where it is, but we do see the birth of consciousness. - Yeah, I mean, there's a question of course, is whether babies are conscious when they're born.

And it used to be, it seems, at least some people thought they weren't, which is why they didn't give anesthetics to newborn babies when they circumcised them. And so now people think, oh, that's incredibly cruel. Of course babies feel pain. And now the dominant view is that babies can feel pain.

Actually, my partner, Claudia, works on this whole issue of whether there's consciousness in babies and of what kind. And she certainly thinks that newborn babies can come into the world with some degree of consciousness. Of course, then you can just extend the question backwards to fetuses, and suddenly you're into politically controversial-- - Exactly.

- Territory. But the question also arises in the animal kingdom. Where does consciousness start or stop? Is there a line in the animal kingdom where the first conscious organisms are? It's interesting, over time, people are becoming more and more liberal about ascribing consciousness to animals. People used to think, maybe only mammals could be conscious.

Now most people seem to think, sure, fish are conscious. They can feel pain. And now we're arguing over insects. You'll find people out there who say, plants have some degree of consciousness. So who knows where it's gonna end? The far end of this chain is the view that every physical system has some degree of consciousness.

Philosophers call that panpsychism. I take that view. - I mean, that's a fascinating way to view reality. So if you could talk about, if you can linger on panpsychism for a little bit, what does it mean? So it's not just plants are conscious. I mean, it's that consciousness is a fundamental fabric of reality.

What does that mean to you? How are we supposed to think about that? - Well, we're used to the idea that some things in the world are fundamental, right? In physics. - Like what? - We take things like space or time or space-time, mass, charge as fundamental properties of the universe.

You don't reduce them to something simpler. You take those for granted. You've got some laws that connect them. Here is how mass and space and time evolve. Theories like relativity or quantum mechanics or some future theory that will unify them both. But everyone says you gotta take some things as fundamental.

And if you can't explain one thing in terms of the previous fundamental things, you have to expand. Maybe something like this happened with Maxwell. He ended up with fundamental principles of electromagnetism and took charge as fundamental 'cause it turned out that was the best way to explain it. So I at least take seriously the possibility something like that could happen with consciousness.

Take it as a fundamental property like space, time, and mass and instead of trying to explain consciousness wholly in terms of the evolution of space, time, and mass and so on, take it as a primitive and then connect it to everything else by some fundamental laws. There's this basic problem that the physics we have now looks great for solving the easy problems of consciousness which are all about behavior.

They give us a complicated structure and dynamics. They tell us how things are gonna behave, what kind of observable behavior they'll produce which is great for the problems of explaining how we walk and how we talk and so on. Those are the easy problems of consciousness but the hard problem was this problem about subjective experience just doesn't look like that kind of problem about structure, dynamics, how things behave.

So it's hard to see how existing physics is gonna give you a full explanation of that. - Certainly trying to get a physics view of consciousness, yes, there has to be a connecting point and it could be at the very axiomatic, at the very beginning level. But I mean, first of all, there's a crazy idea that sort of everything has properties of consciousness.

At that point, the word consciousness is already beyond the reach of our current understanding, like far because it's so far from, at least for me, maybe you can correct me, as far from the experience and the experiences that we have, that I have as a human being. To say that everything is conscious, that means that basically another way to put that, if that's true, then we understand almost nothing about that fundamental aspect of the world.

- How do you feel about saying an ant is conscious? Do you get the same reaction to that or is that something you can understand? - I can understand ant, I can't understand an atom. - A plant? - A particle. Plant, so I'm comfortable with living things on Earth being conscious because there's some kind of agency where they're similar size to me and they can be born and they can die and that is understandable intuitively.

Of course, you anthropomorphize, you put yourself in the place of the plant. But I can understand it. I mean, I'm not like, I don't believe actually that plants are conscious or that plants suffer, but I can understand that kind of belief, that kind of idea. - How do you feel about robots?

Like the kind of robots we have now? If I told you like that a Roomba had some degree of consciousness or some deep neural network? - I could understand that a Roomba has consciousness. I just had spent all day at iRobot. And I mean, I personally love robots and have a deep connection with robots.

So I can, I also probably anthropomorphize them. There's something about the physical object. So there's a difference than a neural network, a neural network running a software. To me, the physical object, something about the human experience allows me to really see that physical object as an entity. And if it moves and moves in a way that it, there's a, like I didn't program it, where it feels that it's acting based on its own perception and yes, self-awareness and consciousness, even if it's a Roomba, then you start to assign it some agency, some consciousness.

So, but to say that panpsychism, that consciousness is a fundamental property of reality is a much bigger statement. That it's like turtles all the way. It's like every, it doesn't end. The whole thing is, so like how, I know it's full of mystery, but if you can linger on it, like how would it, how do you think about reality if consciousness is a fundamental part of its fabric?

- The way you get there is from thinking, can we explain consciousness given the existing fundamentals? And then if you can't, as at least right now it looks like, then you've got to add something. It doesn't follow that you have to add consciousness. Here's another interesting possibility is, well, we'll add something else.

Let's call it proto-consciousness or X. And then it turns out space, time, mass, plus X will somehow collectively give you the possibility for consciousness. Why don't rule out that view? Either I call that pan-proto-psychism 'cause maybe there's some other property, proto-consciousness at the bottom level. And if you can't imagine there's actually genuine consciousness at the bottom level, I think we should be open to the idea there's this other thing X.

Maybe we can't imagine that somehow gives you consciousness. But if we are playing along with the idea that there really is genuine consciousness at the bottom level, of course, this is going to be way out and speculative, but at least in, say, if it was classical physics, then you'd end up saying, well, every little atom, with a bunch of particles in space-time, each of these particles has some kind of consciousness whose structure mirrors maybe their physical properties, like its mass, its charge, its velocity, and so on.

The structure of its consciousness would roughly correspond to that. And the physical interactions between particles. There's this old worry about physics. I mentioned this before in this issue about the manifest image. We don't really find out about the intrinsic nature of things. Physics tells us about how a particle relates to other particles and interacts.

It doesn't tell us about what the particle is in itself. That was Kant's thing in itself. So here's a view. The nature in itself of a particle is something mental. A particle is actually a little conscious subject with properties of its consciousness that correspond to its physical properties. The laws of physics are actually ultimately relating these properties of conscious subjects.

So in this view, a Newtonian world actually would be a vast collection of little conscious subjects at the bottom level, way, way simpler than we are without free will or rationality or anything like that. But that's what the universe would be like. Now, of course, that's a vastly speculative view.

No particular reason to think it's correct. Furthermore, non-Newtonian physics, say quantum mechanical wave function, suddenly it starts to look different. It's not a vast collection of conscious subjects. Maybe there's ultimately one big wave function for the whole universe corresponding to that. Might be something more like a single conscious mind whose structure corresponds to the structure of the wave function.

People sometimes call this cosmopsychism. And now, of course, we're in the realm of extremely speculative philosophy. There's no direct evidence for this. But yeah, but if you want a picture of what that universe would be like, think yeah, giant cosmic mind with enough richness and structure among it to replicate all the structure of physics.

- I think therefore I am at the level of particles and with quantum mechanics at the level of the wave function. It's kind of an exciting, beautiful possibility, of course, way out of reach of physics currently. It is interesting that some neuroscientists are beginning to take panpsychism seriously. You find consciousness even in very simple systems.

So for example, the integrated information theory of consciousness, a lot of neuroscientists are taking it seriously. Actually, I just got this new book by Christoph Koch just came in, "The Feeling of Life Itself," why consciousness is widespread but can't be computed. He basically endorses a panpsychist view where you get consciousness with the degree of information processing or integrated information processing in a system and even very, very simple systems like a couple of particles will have some degree of this.

So he ends up with some degree of consciousness in all matter and the claim is that this theory can actually explain a bunch of stuff about the connection between the brain and consciousness. Now that's very controversial. I think it's very, very early days in the science of consciousness. - But it's interesting that it's not just philosophy that might lead you in this direction but there are ways of thinking quasi-scientifically that lead you there too.

- But maybe it's different than panpsychism. What do you think? So Alan Watts has this quote that I'd like to ask you about. The quote is, "Through our eyes, "the universe is perceiving itself. "Through our ears, the universe is listening "to its harmonies. "We are the witnesses to which the universe "becomes conscious of its glory, of its magnificence." So that's not panpsychism.

Do you think that we are essentially the tools, the senses the universe created to be conscious of itself? - It's an interesting idea. Of course, if you went for the giant cosmic mind view then the universe was conscious all along. It didn't need us. We were just little components of the universal consciousness.

Likewise, if you believe in panpsychism then there was some little degree of consciousness at the bottom level all along and we were just a more complex form of consciousness. So I think maybe the quote you mentioned works better. If you're not a panpsychist, you're not a cosmopsychist, you think consciousness just exists at this intermediate level.

And of course, that's the orthodox view. - That, you would say, is the common view? So is your own view of panpsychism a rarer view? - I think it's generally regarded, certainly, as a speculative view held by a fairly small minority of at least theorists, philosophers, most philosophers and most scientists who think about consciousness are not panpsychists.

There's been a bit of a movement in that direction the last 10 years or so. It seems to be quite popular, especially among the younger generation, but it's still very definitely a minority view. Many people think it's totally bat shit crazy to use the technical term. (laughing) - It's a philosophical term.

- Yeah, so the orthodox view, I think, is still consciousness is something that humans have and some good number of non-human animals have and maybe AIs might have one day, but it's restricted. On that view, then there was no consciousness at the start of the universe, there may be none at the end, but it is this thing which happened at some point in the history of the universe, consciousness developed.

And yes, that's a very amazing event on this view because many people are inclined to think consciousness is what somehow gives meaning to our lives. Without consciousness, there'd be no meaning, no true value, no good versus bad, and so on. So with the advent of consciousness, suddenly the universe went from meaningless to somehow meaningful.

Why did this happen? I guess the quote you mentioned was somehow, this was somehow destined to happen because the universe needed to have consciousness within it to have value and have meaning, and maybe you could combine that with a theistic view or a teleological view. The universe was inexorably evolving towards consciousness.

Actually, my colleague here at NYU, Tom Nagel, wrote a book called "Mind and Cosmos" a few years ago where he argued for this teleological view of evolution toward consciousness, saying this led to problems for Darwinism. It's got him on, you know, this was very, very controversial. Most people didn't agree.

I don't myself agree with this teleological view, but it is at least a beautiful speculative view of the cosmos.