David Chalmers: What is Consciousness?

00:00:00.000 | - Let's try to go to the very simplest question

00:00:04.840 | that you've answered many a time,

00:00:06.040 | but perhaps the simplest things can help us reveal,

00:00:09.500 | even in time, some new ideas.

00:00:12.600 | So what, in your view, is consciousness?

00:00:16.560 | What is qualia?

00:00:17.760 | What is the hard problem of consciousness?

00:00:21.640 | - Consciousness, I mean, the word is used many ways,

00:00:24.300 | but the kind of consciousness that I'm interested in

00:00:27.180 | is basically subjective experience.

00:00:30.960 | What it feels like from the inside to be a human being

00:00:35.340 | or any other conscious being.

00:00:37.100 | I mean, there's something it's like to be me.

00:00:39.960 | Right now, I have visual images that I'm experiencing.

00:00:44.460 | I'm hearing my voice.

00:00:46.560 | I've got maybe some emotional tone.

00:00:50.100 | I've got a stream of thoughts running through my head.

00:00:52.620 | These are all things that I experience

00:00:54.580 | from the first person point of view.

00:00:57.200 | I've sometimes called this the inner movie in the mind.

00:01:00.100 | It's not a perfect metaphor.

00:01:02.560 | It's not like a movie in every way,

00:01:05.180 | and it's very rich.

00:01:06.620 | But yeah, it's just direct, subjective experience.

00:01:10.340 | And I call that consciousness,

00:01:12.320 | or sometimes philosophers use the word qualia,

00:01:15.560 | which you suggested.

00:01:16.420 | People tend to use the word qualia

00:01:18.000 | for things like the qualities of things like colors,

00:01:21.380 | redness, the experience of redness

00:01:23.220 | versus the experience of greenness,

00:01:25.620 | the experience of one taste or one smell versus another,

00:01:29.780 | the experience of the quality of pain.

00:01:31.900 | And yeah, a lot of consciousness

00:01:33.660 | is the experience of those qualities.

00:01:37.980 | - Well, consciousness is bigger,

00:01:39.220 | the entirety of any kinds of experience.

00:01:42.020 | - Consciousness of thinking is not obviously qualia.

00:01:44.860 | It's not like specific qualities like redness or greenness.

00:01:47.420 | But still, I'm thinking about my hometown.

00:01:50.180 | I'm thinking about what I'm gonna do later on.

00:01:52.660 | Maybe there's still something running through my head,

00:01:55.140 | which is subjective experience.

00:01:57.300 | Maybe it goes beyond those qualities or qualia.

00:02:00.940 | Philosophers sometimes use the word

00:02:02.260 | phenomenal consciousness for consciousness in this sense.

00:02:05.660 | I mean, people also talk about access consciousness,

00:02:08.460 | being able to access information in your mind,

00:02:11.260 | reflective consciousness,

00:02:13.020 | being able to think about yourself.

00:02:14.900 | But it looks like the really mysterious one,

00:02:16.900 | the one that really gets people going

00:02:18.180 | is phenomenal consciousness.

00:02:19.820 | The fact that all this,

00:02:21.540 | the fact that there's subjective experience

00:02:23.660 | and all this feels like something at all.

00:02:26.060 | And then the hard problem is, how is it that,

00:02:29.820 | why is it that there is phenomenal consciousness at all?

00:02:32.460 | And how is it that physical processes in a brain

00:02:36.540 | could give you subjective experience?

00:02:40.340 | It looks like on the face of it,

00:02:42.620 | you'd have all this big, complicated physical system

00:02:44.860 | in a brain running

00:02:45.900 | without it giving subjective experience at all.

00:02:49.420 | And yet we do have subjective experience.

00:02:51.740 | So the hard problem is just explain that.

00:02:54.180 | - Explain how that comes about.

00:02:56.900 | We haven't been able to build machines

00:02:58.500 | where a red light goes on that says it's not conscious.

00:03:02.260 | So how do we actually create that?

00:03:06.660 | Or how do humans do it?

00:03:08.300 | And how do we ourselves do it?

00:03:09.860 | - We do every now and then create machines that can do this.

00:03:12.660 | We create babies that are conscious.

00:03:16.540 | They've got these brains.

00:03:17.500 | - As best as we can tell.

00:03:18.340 | - And that does produce consciousness.

00:03:19.380 | But even though we can create it,

00:03:21.620 | we still don't understand why it happens.

00:03:23.820 | Maybe eventually we'll be able to create machines,

00:03:26.380 | which as a matter of fact, AI machines,

00:03:28.780 | which as a matter of fact are conscious.

00:03:31.220 | But that won't necessarily make the hard problem go away

00:03:34.700 | any more than it does with babies.

00:03:36.420 | 'Cause we still wanna know how and why is it

00:03:38.420 | that these processes give you consciousness?

00:03:40.420 | - You know, you just made me realize for a second,

00:03:43.100 | maybe it's a totally dumb realization,

00:03:48.060 | but nevertheless, that it's a useful way to think about

00:03:52.780 | the creation of consciousness is looking at a baby.

00:03:56.660 | So that there's a certain point

00:03:58.460 | at which that baby is not conscious.

00:04:01.840 | The baby starts from maybe, I don't know,

00:04:08.060 | from a few cells, right?

00:04:10.500 | There's a certain point at which it becomes,

00:04:12.700 | consciousness arrives, it's conscious.

00:04:15.860 | Of course we can't know exactly that line,

00:04:17.820 | but it's a useful idea that we do create consciousness.

00:04:21.960 | Again, a really dumb thing for me to say,

00:04:25.500 | but not until now did I realize

00:04:27.940 | we do engineer consciousness.

00:04:30.580 | We get to watch the process happen.

00:04:33.180 | We don't know which point it happens or where it is,

00:04:37.140 | but we do see the birth of consciousness.

00:04:40.140 | - Yeah, I mean, there's a question of course,

00:04:42.020 | is whether babies are conscious when they're born.

00:04:45.940 | And it used to be, it seems,

00:04:47.260 | at least some people thought they weren't,

00:04:49.180 | which is why they didn't give anesthetics

00:04:51.460 | to newborn babies when they circumcised them.

00:04:54.100 | And so now people think, oh, that's incredibly cruel.

00:04:57.540 | Of course babies feel pain.

00:04:59.700 | And now the dominant view is that babies can feel pain.

00:05:03.060 | Actually, my partner, Claudia,

00:05:05.180 | works on this whole issue of whether there's consciousness

00:05:08.440 | in babies and of what kind.

00:05:10.620 | And she certainly thinks that newborn babies

00:05:14.180 | can come into the world with some degree of consciousness.

00:05:16.420 | Of course, then you can just extend the question

00:05:17.820 | backwards to fetuses,

00:05:19.060 | and suddenly you're into politically controversial--

00:05:21.460 | - Exactly. - Territory.

00:05:23.100 | But the question also arises in the animal kingdom.

00:05:27.820 | Where does consciousness start or stop?

00:05:29.600 | Is there a line in the animal kingdom

00:05:32.100 | where the first conscious organisms are?

00:05:35.680 | It's interesting, over time,

00:05:37.880 | people are becoming more and more liberal

00:05:39.220 | about ascribing consciousness to animals.

00:05:42.060 | People used to think,

00:05:43.340 | maybe only mammals could be conscious.

00:05:45.500 | Now most people seem to think, sure, fish are conscious.

00:05:48.400 | They can feel pain.

00:05:49.740 | And now we're arguing over insects.

00:05:51.940 | You'll find people out there who say,

00:05:53.180 | plants have some degree of consciousness.

00:05:56.580 | So who knows where it's gonna end?

00:05:58.820 | The far end of this chain is the view

00:06:00.340 | that every physical system

00:06:02.180 | has some degree of consciousness.

00:06:04.300 | Philosophers call that panpsychism.

00:06:06.540 | I take that view.

00:06:09.300 | - I mean, that's a fascinating way to view reality.

00:06:11.920 | So if you could talk about,

00:06:13.820 | if you can linger on panpsychism for a little bit,

00:06:17.500 | what does it mean?

00:06:19.380 | So it's not just plants are conscious.

00:06:21.940 | I mean, it's that consciousness

00:06:23.460 | is a fundamental fabric of reality.

00:06:26.340 | What does that mean to you?

00:06:28.340 | How are we supposed to think about that?

00:06:30.620 | - Well, we're used to the idea

00:06:31.880 | that some things in the world are fundamental, right?

00:06:35.620 | In physics. - Like what?

00:06:36.460 | - We take things like space or time or space-time,

00:06:39.760 | mass, charge as fundamental properties of the universe.

00:06:44.060 | You don't reduce them to something simpler.

00:06:46.380 | You take those for granted.

00:06:47.880 | You've got some laws that connect them.

00:06:51.060 | Here is how mass and space and time evolve.

00:06:54.740 | Theories like relativity or quantum mechanics

00:06:57.540 | or some future theory that will unify them both.

00:07:00.900 | But everyone says you gotta take some things as fundamental.

00:07:03.460 | And if you can't explain one thing

00:07:05.540 | in terms of the previous fundamental things,

00:07:08.060 | you have to expand.

00:07:09.220 | Maybe something like this happened with Maxwell.

00:07:12.600 | He ended up with fundamental principles

00:07:15.140 | of electromagnetism and took charge as fundamental

00:07:18.460 | 'cause it turned out that was the best way to explain it.

00:07:21.060 | So I at least take seriously the possibility

00:07:23.800 | something like that could happen with consciousness.

00:07:27.040 | Take it as a fundamental property like space, time, and mass

00:07:31.080 | and instead of trying to explain consciousness

00:07:34.100 | wholly in terms of the evolution of space, time,

00:07:37.980 | and mass and so on, take it as a primitive

00:07:40.980 | and then connect it to everything else

00:07:43.980 | by some fundamental laws.

00:07:45.700 | There's this basic problem that the physics we have now

00:07:49.580 | looks great for solving the easy problems of consciousness

00:07:52.820 | which are all about behavior.

00:07:54.260 | They give us a complicated structure and dynamics.

00:07:58.460 | They tell us how things are gonna behave,

00:08:00.620 | what kind of observable behavior they'll produce

00:08:04.140 | which is great for the problems of explaining how we walk

00:08:07.380 | and how we talk and so on.

00:08:09.540 | Those are the easy problems of consciousness

00:08:11.580 | but the hard problem was this problem

00:08:13.500 | about subjective experience just doesn't look

00:08:16.300 | like that kind of problem about structure, dynamics,

00:08:18.540 | how things behave.

00:08:19.740 | So it's hard to see how existing physics

00:08:22.260 | is gonna give you a full explanation of that.

00:08:25.620 | - Certainly trying to get a physics view of consciousness,

00:08:28.940 | yes, there has to be a connecting point

00:08:31.900 | and it could be at the very axiomatic,

00:08:33.540 | at the very beginning level.

00:08:35.060 | But I mean, first of all,

00:08:39.100 | there's a crazy idea that sort of everything

00:08:44.100 | has properties of consciousness.

00:08:46.700 | At that point, the word consciousness

00:08:51.040 | is already beyond the reach of our current understanding,

00:08:53.940 | like far because it's so far from,

00:08:56.740 | at least for me, maybe you can correct me,

00:08:59.700 | as far from the experience and the experiences

00:09:02.940 | that we have, that I have as a human being.

00:09:06.220 | To say that everything is conscious,

00:09:08.420 | that means that basically another way to put that,

00:09:13.420 | if that's true, then we understand almost nothing

00:09:17.780 | about that fundamental aspect of the world.

00:09:21.060 | - How do you feel about saying an ant is conscious?

00:09:23.700 | Do you get the same reaction to that

00:09:24.980 | or is that something you can understand?

00:09:26.700 | - I can understand ant, I can't understand an atom.

00:09:31.140 | - A plant? - A particle.

00:09:33.060 | Plant, so I'm comfortable with living things on Earth

00:09:37.620 | being conscious because there's some kind of agency

00:09:41.740 | where they're similar size to me

00:09:46.140 | and they can be born and they can die

00:09:51.740 | and that is understandable intuitively.

00:09:55.340 | Of course, you anthropomorphize,

00:09:57.660 | you put yourself in the place of the plant.

00:10:00.500 | But I can understand it.

00:10:04.180 | I mean, I'm not like, I don't believe actually

00:10:08.540 | that plants are conscious or that plants suffer,

00:10:10.580 | but I can understand that kind of belief,

00:10:12.820 | that kind of idea.

00:10:13.900 | - How do you feel about robots?

00:10:15.900 | Like the kind of robots we have now?

00:10:17.700 | If I told you like that a Roomba

00:10:19.820 | had some degree of consciousness

00:10:21.420 | or some deep neural network?

00:10:27.060 | - I could understand that a Roomba has consciousness.

00:10:29.380 | I just had spent all day at iRobot.

00:10:31.580 | And I mean, I personally love robots

00:10:36.140 | and have a deep connection with robots.

00:10:37.900 | So I can, I also probably anthropomorphize them.

00:10:40.980 | There's something about the physical object.

00:10:44.820 | So there's a difference than a neural network,

00:10:47.740 | a neural network running a software.

00:10:49.900 | To me, the physical object,

00:10:51.980 | something about the human experience

00:10:53.620 | allows me to really see that physical object as an entity.

00:10:57.900 | And if it moves and moves in a way that it,

00:11:01.860 | there's a, like I didn't program it,

00:11:04.380 | where it feels that it's acting based on its own perception

00:11:10.340 | and yes, self-awareness and consciousness,

00:11:14.380 | even if it's a Roomba,

00:11:16.400 | then you start to assign it some agency, some consciousness.

00:11:21.400 | So, but to say that panpsychism,

00:11:24.740 | that consciousness is a fundamental property of reality

00:11:27.820 | is a much bigger statement.

00:11:32.300 | That it's like turtles all the way.

00:11:34.540 | It's like every, it doesn't end.

00:11:37.020 | The whole thing is, so like how,

00:11:39.300 | I know it's full of mystery,

00:11:41.060 | but if you can linger on it, like how would it,

00:11:46.940 | how do you think about reality

00:11:48.540 | if consciousness is a fundamental part of its fabric?

00:11:52.800 | - The way you get there is from thinking,

00:11:54.220 | can we explain consciousness

00:11:55.660 | given the existing fundamentals?

00:11:57.460 | And then if you can't, as at least right now it looks like,

00:12:02.060 | then you've got to add something.

00:12:03.240 | It doesn't follow that you have to add consciousness.

00:12:05.860 | Here's another interesting possibility is,

00:12:07.940 | well, we'll add something else.

00:12:08.940 | Let's call it proto-consciousness or X.

00:12:12.580 | And then it turns out space, time, mass, plus X

00:12:17.060 | will somehow collectively give you the possibility

00:12:19.860 | for consciousness.

00:12:21.140 | Why don't rule out that view?

00:12:22.700 | Either I call that pan-proto-psychism

00:12:25.700 | 'cause maybe there's some other property,

00:12:27.180 | proto-consciousness at the bottom level.

00:12:29.820 | And if you can't imagine

00:12:30.980 | there's actually genuine consciousness at the bottom level,

00:12:33.740 | I think we should be open to the idea

00:12:35.040 | there's this other thing X.

00:12:37.100 | Maybe we can't imagine that somehow gives you consciousness.

00:12:40.900 | But if we are playing along with the idea

00:12:43.300 | that there really is genuine consciousness

00:12:45.260 | at the bottom level, of course,

00:12:46.300 | this is going to be way out and speculative,

00:12:49.220 | but at least in, say, if it was classical physics,

00:12:52.980 | then you'd end up saying, well, every little atom,

00:12:56.220 | with a bunch of particles in space-time,

00:12:58.580 | each of these particles has some kind of consciousness

00:13:02.480 | whose structure mirrors maybe their physical properties,

00:13:05.500 | like its mass, its charge, its velocity, and so on.

00:13:10.020 | The structure of its consciousness

00:13:11.240 | would roughly correspond to that.

00:13:13.220 | And the physical interactions between particles.

00:13:16.940 | There's this old worry about physics.

00:13:19.180 | I mentioned this before

00:13:20.060 | in this issue about the manifest image.

00:13:22.060 | We don't really find out

00:13:23.020 | about the intrinsic nature of things.

00:13:25.500 | Physics tells us about how a particle relates

00:13:28.380 | to other particles and interacts.

00:13:30.260 | It doesn't tell us about what the particle is in itself.

00:13:33.780 | That was Kant's thing in itself.

00:13:35.540 | So here's a view.

00:13:36.660 | The nature in itself of a particle is something mental.

00:13:41.780 | A particle is actually a little conscious subject

00:13:45.420 | with properties of its consciousness

00:13:48.260 | that correspond to its physical properties.

00:13:50.060 | The laws of physics are actually ultimately relating

00:13:53.540 | these properties of conscious subjects.

00:13:55.460 | So in this view, a Newtonian world

00:13:57.580 | actually would be a vast collection

00:13:59.100 | of little conscious subjects at the bottom level,

00:14:02.140 | way, way simpler than we are without free will

00:14:05.860 | or rationality or anything like that.

00:14:08.180 | But that's what the universe would be like.

00:14:09.700 | Now, of course, that's a vastly speculative view.

00:14:12.260 | No particular reason to think it's correct.

00:14:14.520 | Furthermore, non-Newtonian physics,

00:14:17.380 | say quantum mechanical wave function,

00:14:19.860 | suddenly it starts to look different.

00:14:21.020 | It's not a vast collection of conscious subjects.

00:14:23.500 | Maybe there's ultimately one big wave function

00:14:26.260 | for the whole universe corresponding to that.

00:14:28.580 | Might be something more like a single conscious mind

00:14:33.180 | whose structure corresponds to the structure

00:14:36.040 | of the wave function.

00:14:37.180 | People sometimes call this cosmopsychism.

00:14:40.060 | And now, of course, we're in the realm

00:14:41.780 | of extremely speculative philosophy.

00:14:44.100 | There's no direct evidence for this.

00:14:46.080 | But yeah, but if you want a picture

00:14:48.240 | of what that universe would be like,

00:14:50.220 | think yeah, giant cosmic mind with enough richness

00:14:53.620 | and structure among it to replicate

00:14:55.420 | all the structure of physics.

00:14:57.460 | - I think therefore I am at the level of particles

00:15:00.640 | and with quantum mechanics at the level

00:15:02.420 | of the wave function.

00:15:03.520 | It's kind of an exciting, beautiful possibility,

00:15:09.720 | of course, way out of reach of physics currently.

00:15:12.880 | It is interesting that some neuroscientists

00:15:15.980 | are beginning to take panpsychism seriously.

00:15:19.620 | You find consciousness even in very simple systems.

00:15:23.800 | So for example, the integrated information theory

00:15:26.500 | of consciousness, a lot of neuroscientists

00:15:28.300 | are taking it seriously.

00:15:29.140 | Actually, I just got this new book by Christoph Koch

00:15:31.940 | just came in, "The Feeling of Life Itself,"

00:15:34.620 | why consciousness is widespread but can't be computed.

00:15:38.140 | He basically endorses a panpsychist view

00:15:41.460 | where you get consciousness with the degree

00:15:43.760 | of information processing or integrated information

00:15:46.580 | processing in a system and even very, very simple systems

00:15:50.460 | like a couple of particles will have some degree of this.

00:15:53.680 | So he ends up with some degree of consciousness

00:15:56.180 | in all matter and the claim is that this theory

00:15:59.620 | can actually explain a bunch of stuff

00:16:01.460 | about the connection between the brain and consciousness.

00:16:04.520 | Now that's very controversial.

00:16:06.280 | I think it's very, very early days

00:16:07.840 | in the science of consciousness.

00:16:08.940 | - But it's interesting that it's not just philosophy

00:16:11.780 | that might lead you in this direction

00:16:13.620 | but there are ways of thinking quasi-scientifically

00:16:16.220 | that lead you there too.

00:16:17.420 | - But maybe it's different than panpsychism.

00:16:22.140 | What do you think?

00:16:22.980 | So Alan Watts has this quote that I'd like to ask you about.

00:16:27.820 | The quote is, "Through our eyes,

00:16:31.300 | "the universe is perceiving itself.

00:16:33.640 | "Through our ears, the universe is listening

00:16:35.500 | "to its harmonies.

00:16:36.960 | "We are the witnesses to which the universe

00:16:38.900 | "becomes conscious of its glory, of its magnificence."

00:16:42.460 | So that's not panpsychism.

00:16:45.740 | Do you think that we are essentially the tools,

00:16:50.740 | the senses the universe created to be conscious of itself?

00:16:56.420 | - It's an interesting idea.

00:16:58.540 | Of course, if you went for the giant cosmic mind view

00:17:01.500 | then the universe was conscious all along.

00:17:04.340 | It didn't need us.

00:17:05.180 | We were just little components

00:17:06.200 | of the universal consciousness.

00:17:09.120 | Likewise, if you believe in panpsychism

00:17:11.760 | then there was some little degree of consciousness

00:17:13.800 | at the bottom level all along

00:17:15.640 | and we were just a more complex form of consciousness.

00:17:19.240 | So I think maybe the quote you mentioned works better.

00:17:23.020 | If you're not a panpsychist, you're not a cosmopsychist,

00:17:26.080 | you think consciousness just exists

00:17:28.160 | at this intermediate level.

00:17:30.280 | And of course, that's the orthodox view.

00:17:33.260 | - That, you would say, is the common view?

00:17:35.600 | So is your own view of panpsychism a rarer view?

00:17:40.600 | - I think it's generally regarded, certainly,

00:17:43.080 | as a speculative view held by a fairly small minority

00:17:47.400 | of at least theorists, philosophers,

00:17:49.720 | most philosophers and most scientists

00:17:52.160 | who think about consciousness are not panpsychists.

00:17:55.560 | There's been a bit of a movement in that direction

00:17:57.160 | the last 10 years or so.

00:17:58.840 | It seems to be quite popular,

00:17:59.920 | especially among the younger generation,

00:18:02.520 | but it's still very definitely a minority view.

00:18:04.880 | Many people think it's totally bat shit crazy

00:18:08.060 | to use the technical term.

00:18:09.260 | (laughing)

00:18:11.240 | - It's a philosophical term.

00:18:12.080 | - Yeah, so the orthodox view, I think, is still

00:18:13.760 | consciousness is something that humans have

00:18:16.100 | and some good number of non-human animals have

00:18:19.960 | and maybe AIs might have one day, but it's restricted.

00:18:23.660 | On that view, then there was no consciousness

00:18:25.360 | at the start of the universe, there may be none at the end,

00:18:28.160 | but it is this thing which happened at some point

00:18:30.860 | in the history of the universe, consciousness developed.

00:18:34.120 | And yes, that's a very amazing event on this view

00:18:38.400 | because many people are inclined to think

00:18:40.520 | consciousness is what somehow gives meaning to our lives.

00:18:44.120 | Without consciousness, there'd be no meaning,

00:18:46.680 | no true value, no good versus bad, and so on.

00:18:50.680 | So with the advent of consciousness,

00:18:53.120 | suddenly the universe went from meaningless

00:18:56.920 | to somehow meaningful.

00:18:59.680 | Why did this happen?

00:19:00.760 | I guess the quote you mentioned was somehow,

00:19:03.120 | this was somehow destined to happen

00:19:05.280 | because the universe needed to have consciousness within it

00:19:08.760 | to have value and have meaning, and maybe you could combine

00:19:12.040 | that with a theistic view or a teleological view.

00:19:15.560 | The universe was inexorably evolving towards consciousness.

00:19:19.360 | Actually, my colleague here at NYU, Tom Nagel,

00:19:22.360 | wrote a book called "Mind and Cosmos" a few years ago

00:19:25.160 | where he argued for this teleological view

00:19:27.000 | of evolution toward consciousness,

00:19:29.960 | saying this led to problems for Darwinism.

00:19:33.560 | It's got him on, you know, this was very, very controversial.

00:19:36.040 | Most people didn't agree.

00:19:37.560 | I don't myself agree with this teleological view,

00:19:41.000 | but it is at least a beautiful speculative view

00:19:45.000 | of the cosmos.

00:19:46.760 | [ Silence ]

00:19:52.840 | [ Silence ]

00:19:58.840 | [ Silence ]

00:20:04.840 | [BLANK_AUDIO]

David Chalmers: What is Consciousness? | AI Podcast Clips

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