[MUSIC PLAYING] DAVID CHALMERS:
Thanks for coming out. It's good to be here. As Eric said, I am a philosopher
thinking about consciousness. Coming from a background
in the sciences and math, it always struck me that the
most interesting and hardest unsolved problem
in the sciences was the problem of consciousness. And way back 25 years ago
when I was in grad school, it seemed to be the
best way to come at this from a big picture perspective
was to go into philosophy and think about the foundational
issues that arise in thinking about consciousness from any
number of different angles, including the angles
of neuroscience and psychology and AI. In this talk, I'm
going to present a slightly different
perspective on the problem after laying out some
background, the perspective of what I call the
meta-problem of consciousness. I always liked the idea
that you approach a problem by stepping one level up,
taking the metaperspective. I love this quote, "Anything
you can do, I can do meta." I have no idea what
the origins was. I like the fact
this is attributed to Rudolf Carnap, one of
my favorite philosophers. But anyone who
knows Carnap's work, it's completely
implausible he would ever say anything so frivolous. It's also being attributed
to my thesis advisor, Doug Hofstadter, author of
"Godel, Escher, Bach" and a big fan of
the metaperspective. But he assures me he
never said it either. But the metaperspective
on anything is stepping up a level. The meta-problem,
as I think about it, is it's called the
meta-problem because it's a problem about a problem. A metatheory is a
theory about a theory. Meta-problem is a
problem about a problem. In particular, it's the
problem of explaining why we think there is a
problem about consciousness. So there's a
first-order problem, the problem of consciousness. Today, I'm going to focus
on a problem about it. But I'll start by introducing
the first-order problem itself. The first-order problem is
what we call the hard problem of consciousness. It's the problem of explaining
why and how physical processes should give rise to
conscious experience. You've got all of these
neurons firing in your brain, bringing about all kinds
of sophisticated behavior. We can get it to be
[INAUDIBLE] explaining our various
responses, but there's this big question about how
it feels from the first person point of view. That's the subjective
experience. I like this illustration of the
hard problem of consciousness. It seems to show someone's
hair catching fire, but I guess it's a
metaphorical illustration of the subjective perspective. So the hard problem is
concerned with what philosophers call phenomenal consciousness. The word consciousness
is ambiguous 1,000 ways. But phenomenal
consciousness is what it's like to be a subject from
the first person point of view. So a system is
phenomenally conscious if there's something
it's like to be it. A mental state is
phenomenally conscious if there's something
it's like to be in it. So the thought is there
are some systems-- so there's something it's
like to be that system. There's something
it's like to be me. I presume there's something
it's like to be you. But presumably, there's nothing
it's like to be this lectern. As far as we know, the lectern
does not have a first person perspective. This phrase was made famous by
my colleague, Tom Nagel at NYU, who back in 1974 wrote an
article called "What Is It Like To Be A Bat?". And the general idea
was, well, it's very hard to know what it's like to be
a bat from the third person point of view, just looking
at it as a human who has different kinds of experience. But presumably, very
plausibly, there is something it's
like to be a bat. The bat is conscious. It's having subjective
experiences, just of a kind very different from ours. In human subjective
experience, consciousness divides into any number of
different kinds or aspects, like different tracks of the
inner movie of consciousness. We have visual experiences
like the experience of, say, these colors, blue and red and
green from the first person point of view and of depth. There are sensory experiences
like the experience of my voice, experiences
of taste and smell. They're experiences
of your body. Feeling pain or orgasms
or hunger or a tickle or something, they all have
some distinctive first person quality. Mental images like
recalled visual images, emotional experiences
like a experience of happiness or anger. And indeed, we all seem
to have this stream of a current thought
or at the very least, we're kind of chattering
away to ourselves and reflecting and deciding. All of these are aspects of
subjective experience, things we experience from the
first person point of view. And I think these
subjective experiences are, at least on
the face of it, data for the science of
consciousness to explain. These are just facts
about us that we're having these subjective experiences. If we ignore them,
we're ignoring the data. So if you catalog
the data that, say, the science of consciousness
needs to explain, there are certainly
facts about our behavior and how we respond
in situations. There are facts about
how our brain is working. There are also facts about
how subjective experiences, and on the face of
it, they're data. And it's these
data that pose what I call the hard problem
of consciousness. But this gets contrasted
with the easy problems, the so-called easy
problems of consciousness, which are the
problems of explaining behavioral and
cognitive functions. Objective things you can
measure from the third person point of view typically
tied to behavior. Perceptual discrimination
of a stimulus, I can discriminate two different
things in my environment. I can say, that's
red, and that's green. I can integrate the information
about the color and the shape. I can use it to
control my behavior. Walk towards the red one
rather than the green one. I can report it, say
that's red, and so on. Those are all data too
for science to explain. But we've got a bead on how
to explain though they don't seem to pose as big a problem. Why? We explain those easy
problems by finding a mechanism, typically a neural
or computational mechanism that performs the relevant
function to explain how it is that I get to say
there's a red thing over there or walk towards it. Well, you find the mechanisms
involving perceptual processes and action processes in my brain
that leads to that behavior. Find the right mechanism that
performs the function you've explained what needs
to be explained with the easy problems
of consciousness. But for the hard problem,
for subjective experience, it's just not clear that
this standard method works. It looks like explaining
all that behavior still leaves open a further question. Why does all that give
you subjective experience? Explain the reacting, the
responding, the controlling, the reporting, and so on. It still leaves
open the question, why is all that accompanied
by subjective experience. Why doesn't it go on in the
dark without consciousness, so to speak? There seems to be what the
philosopher Joe Levine has called a gap here,
an explanatory gap, between physical processes
and subjective experience. At least our standard
kinds of explanation, which work really well for
the easy problems of behavior and so on, don't obviously
give you a connection to the subjective
aspects of experience. And there's been a vast amount
of discussion of these things over-- I mean, well, for
centuries, really. But it's been
particularly active in recent decades,
philosophers, scientists, all kinds of different views. Philosophically, you can divide
approaches to the hard problem into at least two classes. One is an approach on
which consciousness is taken to be somehow
irreducible and primitive. We can't explain it in
more basic physical terms, so we take it as a
kind of primitive. And that might lead to dualist
theories of consciousness where consciousness is
somehow separate from and interacts with the brain. Recently very popular
has been the class of panpsychist theories
of consciousness. I know Galen Strawson was
here a while back talking. He very much favors
panpsychist theories where consciousness is
something basic in the universe underlying matter. And indeed, there are idealist
theories where consciousness underlies the whole universe. So these are all extremely
speculative but interesting views that I've explored myself. There are also a reductionist
theories of consciousness from functionalist approaches, where
consciousness is just basically taken to be a giant
algorithm or computation, biological approaches
to consciousness-- my colleague Ned Block
was here, I know, talking about
neurobiology-based approaches, where it's not the
algorithm that matters, but the biology it's
implemented in-- and indeed, the kind
of quantum approaches that people like Roger
Penrose and Stuart Hameroff have made famous. I think there's interesting
things to say about all of these approaches. I think that right
now, at least, most of the reductionist
approaches leave a gap. But the non-reductionist
approaches have other problems in
seeing how it all works. Today, I'm going to take a
different kind of approach, this approach through
the meta-problem. One way to motivate this is to-- I often get asked, well,
you're a philosopher. It's fine. You get to think about these
things like the hard problem of consciousness. How can I, as a scientist or an
engineer or an AI researcher-- how can I do something
to contribute, to help get this at this hard
problem of consciousness? Is this just a problem
for philosophy? For me to work on it
as a AI researcher, I need something I
can operationalize, something I can work
with and try to program. And as it stands,
it's just not clear how to do that with
the hard problem. If you're a
neuroscientist, there are some things you can do. You can work with humans
and look at their brains and look for the neural
correlates of consciousness, the bits of the brain that go
along with being conscious. Because at least
with humans, we can take as a plausible
background assumption that the system is conscious. For AI, we can't even do that. We don't know which AI systems
we're working with that are conscious. We need some
operational criteria. In AI, we mostly work on
modeling things like behavior and objective functioning. For consciousness, those
are the easy problems. So how does someone coming
from this perspective make a connection to the hard
problem of consciousness? Well, one approach is to
work on certain problems among the easy problems
of behavior that shed particular light
on the hard problem. And that's going to be the
approach that I look at today. So the key idea
here is there are certain behavioral
functions that seem to have a
particularly close relation to the hard problem
of consciousness. In particular, we say
things about consciousness. We make what philosophers
call phenomenal reports, verbal reports of
conscious experiences. So I'll say things
like, I'm conscious, I'm feeling pain
right now, and so on. Maybe the consciousness
and the pain are subjective experiences. But the reports, the
utterances, I am conscious, well that's a bit of behavior. In principle, explaining those
is among the easy problems. It's objectively
measurable response. We can find a mechanism in
the brain that produces it. And among our
phenomenal reports, there's the special class
we can call the problem reports, reports expressing
our sense that consciousness poses a problem. Now admittedly, not everyone
makes these reports. But they seem to be fairly
widespread, especially among philosophers and
scientists thinking about these things. But furthermore, it's a
sense that it's fairly easy to find a very wide
class of people who think about consciousness. People say things like, there
is a problem of consciousness, a hard problem. On the face of it,
explaining behavior doesn't explain consciousness. Consciousness
seems non-physical. How would you ever explain the
subjective experience of red and so on? It's an objective
fact about us-- at least about some of us-- that we make those reports. And that's a fact
about human behavior. So the meta-problem
of consciousness then, at a second approximation,
is roughly the problem of explaining these
problem reports, explaining, you might say, the
conviction that we're conscious and that consciousness
is puzzling. And what's nice about this is
that although the hard problem is this airy fairy problem
about subjective experience that's hard to pin
down, this is a puzzle ultimately about behavior. So this is an easy
problem, one that ought to be open to those
standard methods of explanation in the cognitive
and brain sciences. So there's a research program. There's a research program here. So I like to think
of the meta-problem as something we
could play that role. I talked about earlier,
if you're an AI researcher thinking about this,
the meta-problem is an easy problem, a
problem about behavior, that's closely tied
to the hard problem. So it's something we might
be able to make some progress on using standard methods
of thinking about algorithms and computations or
thinking about brain processes and
behavior while still shedding some light,
at least indirectly, on the hard problem. It's more tractable
than the hard problem. But solving it ought to shed
light on the hard problem. And today, I'm just going to
kind of lay out the research program and talk about some ways
in which it might potentially shed some light. This is interesting
to a philosopher because it looks like
an instance of what people sometimes call
genealogical analysis. It goes back to
Friedrich Nietzsche on the genealogy of morals. Instead of thinking
about what's good or bad, let's look at where our
sense of good or bad came from, the genealogy of it
all in evolution or in culture or in religion. And people think a
genealogical approach to God, instead of thinking
about does God exist or not, let's look at where our
belief in God came from. Maybe there's some
evolutionary reason for why people believe in God. This often leads, not
always, but often leads to a kind of debunking of our
beliefs about those domains. Explain why we believe in
God in evolutionary terms, no need for the God
hypothesis anymore. Explain how moral beliefs and
evolutionary terms, maybe no need to take morality
quite so seriously. So some people, at least, are
inclined to take an approach like this with
consciousness too. If you think about the
meta-problem explaining our beliefs about
consciousness, that might ultimately debunk our
beliefs about consciousness. This leads to a philosophical
view, which has recently attracted a lot of interest,
a philosophical view called illusionism, which is
the view that consciousness itself is an illusion. Or maybe that the problem of
consciousness is an illusion. Explain the illusion, and
we dissolve the problem. I take that in terms
of the meta-problem, that view roughly comes
to solve the meta-problem. It will dissolve
the hard problem. Explain why it is that
we say all these things about consciousness, why we
say, I am conscious, why we say, consciousness is puzzling. If you can explain all
that in algorithmic terms, then you'll remove
the underlying problem because you'll have
explained why we're puzzled in the first place. Actually, walking
over here today, I noticed that just a
couple of blocks away, we have the Museum
of Illusions, so I'm going to check
that out later on. But if illusionism
is right, added to all those
perceptual illusions is going to be the problem
of consciousness itself. It's roughly an
illusion thrown up by having a weird
kind of self model with a certain kind
of algorithm that attributes to ourselves special
properties that we don't have. So one line on the meta-problem
is the illusionist line. Solve the meta-problem, you'll
get to treat consciousness as an illusion. That's actually a view
that has many antecedents in the history of philosophy,
one way or another. Even Immanuel Kant and his
great critique of pure reason had a section where he talked
about the self or the soul as a transcendental illusion. We seem to have this
indivisible soul. But that's the kind
of illusion thrown out by our cognitive processes. The Australian
philosophers, Ullin Place and David Armstrong,
had versions of this that I might
touch on a bit later. Daniel Dennett, a leading
reductionist thinker about consciousness
has been pushing for the last couple
of decades the idea that consciousness involves a
certain kind of user illusion. And most recently, the British
philosopher, Keith Frankish, has been really
pushing illusionism as a theory of consciousness. He has a book centering
around a paper by Keith Frankish on illusionism
as a theory of consciousness that I recommend to you. So one way to go
with the meta-problem is the direction of illusionism. But one nice thing
about-- many people find illusionism
completely unbelievable. They find, how could it be that
consciousness is an illusion? Look, we just have these
subjective experiences. It's a data about our nature. And I confess, I've got some
sympathy with that reaction. So I'm not an
illusionist myself. I'm a realist
about consciousness in the philosopher's sense,
where a realist about something is someone who believes
that thing is real. I think consciousness is real. I think it's not an illusion. I think that solving
the meta-problem does not dissolve
the hard problem. But the nice thing about the
meta-problem is you can proceed on it-- to some extent, at least
in initial neutrality-- on that question, is
consciousness real or is it an illusion. It's a basic problem about
our objective functioning in these reports. What explains those? There's a neutral
research program here that both realists,
illusionists, people of all kinds of
different views of consciousness can explain. And then we can
come back and look at the philosophical
consequences. So I'm not an illusionist. I think consciousness is real. I've got to say, I do feel
the temptation of illusionism. I find it really intriguing and
in some ways attractive view. It's just fundamentally
unbelievable. Nevertheless, I think
that the meta-problem should be a tractable problem. Solving it, at the
very least, will shed much light on the hard
problem of consciousness even if it doesn't solve it. If you can explain
our conviction that we're conscious,
somehow the source, the roots of our conviction
that we are conscious, must have something to do
with consciousness especially if consciousness is real. So I think it's very
much a good research program for people to explain. So then I'll move on
now to just outlining the research program a little
bit more and then talk a bit about potential
solutions and on impact on theories of consciousness
before wrapping up with a little bit more
about illusionism. So this meta-problem, which
I've been pushing recently, opens up a tractable
empirical research program for everyone, reductionists,
non-reductionists, illusionists, non-illusionists. We can try to solve
it and then think about the philosophical
consequences. Now what is the meta-problem? Well, the way I'm
going to put it is it's the problem of topic-neutrally
explaining problem intuitions or else explaining why
that can't be done. And I'll unpack all the
pieces of that right now. First, starting with
problem intuitions. What are problem intuitions? Well, there are
the things we say. There are things we think I say. Consciousness seems irreducible. I might think consciousness
is irreducible. People might be disposed,
have a tendency to say or think those things. Problem intuitions all take
to be roughly, that tendency. We have dispositions to say
and think certain things about consciousness. What are the core
problem intuitions? Well, I think they
break down into a number of different kinds. There is the intuition that
consciousness is non-physical. We might think of that as
a metaphysical intuition about the nature
of consciousness. There are intuitions
about explanation. Consciousness is
hard to explain, explaining behavior doesn't
explain consciousness. There are intuitions about
knowledge of consciousness. Some of you may know the famous
thought experiment of Mary in the black and
white room who knows all about the objective
nature of color vision and so on, but still doesn't
know what it's like to see red. She sees red for the first time. She learns something new. That's an intuition about
knowledge of consciousness. There are what philosophers call
modal intuitions about what's possible or imaginable. One famous case is
the case of a zombie, a creature who is physically
identical to you and me but not conscious. Or maybe an AI system, which is
functionally identical to you and me, but not conscious. That at least seems
conceivable to many people. So this is the
philosophical zombie. Unlike the zombies and movies,
which have weird behaviors and go after brains and so
on, the philosophical zombie is a creature that seems,
at least behaviorally, may be physically like
a normal human, but doesn't have any
conscious experiences. All the physical states,
none of the mental states. And it seems to many people
that's at least conceivable. We're not zombies. I don't think anyone
here is a zombie-- I hope. But nonetheless, it seems that
we can make sense of the idea. And one way to pose
the hard problem is, why are we not zombies. So this imagined
ability of zombies is one of the intuitions
that gets the problem going. And then you can go on
and catalog more and more intuitions about the
distribution of conscious, maybe the intuition that
robots won't be conscious. That's an optional one, I think. Or consciousness matters
morally in certain ways, and the list goes on. So I think there is an
interdisciplinary research program here of working on those
intuitions about consciousness and trying to explain them. Experimental psychology and
experimental philosophy-- a newly active area-- can study people's intuitions
about consciousness. We can work on models of these
things, computational models or neurobiological models, of
these intuitions and reports. And indeed, I think
there's a lot of room for philosophical analysis. And there's just starting
to be a program of people doing these things
in all these fields. I mean, it is an
empirical question, how widely these
intuitions are shared. You might be sitting
there thinking, come on, I don't have of
these intuitions. Maybe this is just you. My sense is-- from the
psychological study to date-- it seems that some of these
intuitions about consciousness are at least very widely
shared, at least as dispositions or intuitions, although they are
often overridden on reflection. But the current data on
this is somewhat limited. Although there is a lot of
empirical work on intuitions about the mind concerning
things like belief, like when do kids get the
idea that your beliefs about the world can
be false, concerning the way your self
persists through time-- could you exist after
the death of your body-- where consciousness
is concerned, there's work on the
distribution of consciousness. Could a robot be conscious? Could a group be conscious? Here's a book by Paul
Bloom, "Decartes' Baby" that catalogs a lot of
this interesting work, making the case that many
children are intuitive dualists. Thinks they're
naturally inclined to think there's something
non-physical about the mind. So far, most of
this work has not been so much on these
core problem intuitions about consciousness,
but there's work developing in this direction. Sara Gottlieb and Tania Lombrozo
have a very recent article called "Can Science
Explain The Human Mind" on people's
judgments about when various mental phenomena
are hard to explain. And they seem to find that
yes, subjective experience and things to which people have
privileged first person access seem to pose the
problem big time. So there's the beginning
of a research program here. I think there's
room for a lot more. The topic neutrality part-- when I say we're looking for
a topic neutral explanation of problem intuitions,
that's roughly to say an explanation that
doesn't mention consciousness itself. It's put in neutral terms. It's neutral on the
existence of consciousness. The most obvious one
would be something like an algorithmic explanation. Now here is the algorithm
the brain is executing that generates our conviction
that we're conscious and our reports
about consciousness. There may be some time between
an algorithm and consciousness, but to specify
the algorithm, you don't need to make claims
about consciousness. So the algorithmic version
of the meta-problem is roughly find the algorithm
that generates our problem intuition. So that's, I think, in
principle a research program that maybe an AI
researchers in combination with psychologists-- the psychologist could help
isolate data about the way that the human beings are
doing it, how these things are generated in humans. And the AI researcher
can try and see about implementing that
algorithm in machines and see what results. And I'll talk about a
little bit of research in this direction
in just a moment. OK now I want to say something
about potential solutions to the problem. Like I said, this is a
big research program. I don't claim to have the
solution to the meta-problem. I've got some ideas, but I'm
not going to try and lay out a major solution. So here are a few
things, which I think might be part of a
solution to the problem, many of which have
got antecedents here and there in scientific
and philosophical discussion. Some promising ideas include
retrospective models, phenomenal concepts,
introspective opacity, the sense of acquaintance. Let me just say something
about a few of these. One starting idea
that almost anyone is going to have here is
somehow models of ourselves are playing a central role here. Human beings have models of
the world, naive physics, naive psychology, models of
other people, and so on. We also have models
of ourselves. It makes sense for us to
have models of ourselves and our own mental processes. This is something that the
psychologist Michael Graziano has written a lot on. We have internal models of
our own cognitive processes, including those tied
to consciousness. And somehow something about
our introspective models explains our sense, A, that we
are conscious and B, that this is distinctively problematic. And I think anyone thinking
about the meta-problem, this has got to be at
least the first step. We have these
introspective models. If you were an illusionist,
they'll be false models. If you're a realist, they
needn't be false models. But at the very least,
these introspective models are involved, which is fine. But the devil's in the details. How do they work to
generate this problem? A number of
philosophers have argued we have special concepts
of consciousness, introspective concepts of these
special subjective states. People call these phenomenal
concepts, concepts of phenomenal consciousness. And one thing that's
special is these concepts are somehow independent
of our physical concepts. They explain we've got one
set of physical concepts for modeling the external world. We've got one set of
introspective concepts from modeling our own mind. And these concepts,
just by virtue of the way they're
designed, are somewhat independent of each other. And that partly explains
why consciousness seems to be independent of the
physical world intuitively. So maybe that independence
of phenomenal concepts could go some distance to
explaining our problem reports. So I think there's got to be
something to this as well. At the same time, I don't
this goes nearly far enough because we have concepts
of many aspects of the mind, not just of the subjective
experiential past but things we believe and things we desire. And so when I believe that
Paris is the capital of France, that's part of my
internal self model. But that doesn't seem to
generate the hard problem in nearly the same way in which
the experience of red does. So a lot more needs to
be said about what's going on in cases like
having the experience of red and having the sense that
that generates a gap. So it doesn't generalize to
everything about the mind. Some people have
thought that what we might call introspective
opacity plays a role, that when we introspect
what's going on in our minds, we don't have access to the
underlying physical states. We don't see the
neurons in our brains. We don't see that
consciousness is physical. So we see it as non-physical. Most recently, the
physicist Max Tegmark has argued in this direction,
saying somehow consciousness is substrate-independent. We don't see the substrate. So then we think maybe it can
float free of the substrate. Armstrong made an analogy
with the case of someone in a circus where-- the headless person illusion
where someone's there with a veil across their head,
and you don't see their head. So you see them
as having no head. Here is a 19th century booth
at a circus, so-called headless woman. There's a veil over her head. You don't see the
head so somehow, it looks-- at least for a
moment-- like the person doesn't have a head. So Armstrong says maybe that's
how it is with consciousness. You don't see it as physical,
so you see it as non-physical. But still the question comes up,
how do we make this inference. There's something that's
special goes on in cases like color and taste and so on. The color experience seems to
attribute primitive properties to objects like
redness, greenness, and so on, when, in fact, in
the external world at the very least, they have complex
reducible properties. Somehow, our internal
models of color treat colors like red and green as if
they are primitive things. It turns out to be useful to
have these models of things. We treat certain
things as primitive, even though they're reducible. And it sure seems that
when we experience colors, we experience greenness
as a primitive quality even though it may be a
very, very complex reducible property. That's something about
our model of colors. The philosopher
Wolfgang Schwartz tried to make an analogy with
sensor variables in image processing. You've got some visual senses
and a camera or something you need to process the image. Well, you've got
some sensor variables to represent the sensory inputs
that the various sensors are getting. And you might treat them
as a primitive dimension because that's the most
useful way to treat them. You don't treat them as certain
amounts of lights or photons firing. You don't need to
know about that. You use these sensor
variables and treat them as a primitive dimension. And all that will play into
a model of these things as primitive, maybe
taking that idea and extending it
to introspection. These conscious
states are somehow like sensor variables in
our model of the mind. And somehow, these
internal models give us the sense
of being acquainted with primitive
concrete qualities and of our awareness of them. This is still just laying out. I don't think this
is still yet actually explaining a whole lot. But it's laying out--
it's narrowing down what it is that
we need to explain to solve the meta-problem. But just to put the
pieces together, here's a little summary. One thing I like about this
summary is you can read it in either an illusionist
tone of voice, as an account of the
illusion of consciousness-- so this is how false
introspective models work-- or in a realist tone
of voice, as an account of our true correct
models of consciousness. But we can set it out in a way
which is neutral on the two and then try and
figure out later whether these
models are correct, as the realist
says, or incorrect, as the illusionist says. We have introspective
models deploying introspective concepts
of our internal states that are largely independent
of our physical concepts. These concepts are
introspectively opaque, not revealing any of the
underlying mechanisms. Our perceptual
models perceptually attribute primitive perceptual
qualities to the world. And our introspective
models attribute primitive mental relations
to those qualities. These models produce the
sense of acquaintance, both with those qualities
and with our awareness of those qualities. Like I said, this is not a
solution to the meta-problem, but it's trying, at
least, to pin down some parts of the roots
of those intuitions and to narrow down what
needs to be explained. To go further,
you want, I think, to test these explanations,
both with psychological studies to see if this is
plausibly what's going on in humans-- this
is the kind of thing which is the basis of our intuitions--
and computational models to see if, for example, we
could program this kind of thing into an AI system and see
if it can generate somehow qualitatively similar
reports and intuitions. You might think that last thing
is a bit far fetched right now, but I know of at least one
instance of this research program, which has been put
into play by Luke Muehlhauser and [INAUDIBLE] two researchers
at Open Philanthropy very interested in AI
and consciousness. They actually built--
they took some ideas about the meta-problem
from something I'd written about it
and from something that the philosopher Francois
Kammerer had written about it. A couple of basic ideas about
where problem intuitions might come from. And they tried to build them
into a computational model. They built a little
software agent, which had certain axioms about
colors and how they work. There's the red and there's
green and certain axioms about their own subjective
experiences of colors. And then they combined it
with a little theorem prover. And they saw what did this
little software agent come up with. And it came up with
claims like, hey, well, my experiences of
color are distinct from any physical state, and so on. OK they cut a few corners. This is not a yet truly a
convincing sophisticated model of everything going
on in the human mind. But it shows that there's
a research program here of trying to find
the algorithmic basis of these states. And I think as more
sophisticated models develop, we might be able to use
these to kind of provide a way in for AI researchers
in thinking about this topic. Of course, there
is the question, you model all this stuff
better and better in a machine, then is the machine actually
going to be conscious or is it just
going to have found self models that replicate
what's going on in humans. So some people have proposed an
artificial consciousness test. Aaron Sloman, Susan
Schneider, Ed Turner have suggested somehow
that if a machine seems to be puzzled about
consciousness in roughly the ways that we are,
maybe that's actually a sign that it's conscious. So if a machine
actually looks to us as if it's puzzled by
consciousness, is that a sign of consciousness? These people-- this is
suggested as a kind of Turing test for machine consciousness. Find machines which are
conscious like we are. Of course, the
opposing point of view is going to be no, the machine
is not actually conscious. It's just like machine that
studied up for the Turing test by reading the talk
like a human book. It's like, damn,
do I really need to convince those
humans that I'm conscious by replicating all
those ill-conceived confusions about consciousness. Well I guess I can
do it if I need to. Anyway, I'm not going to
settle this question here. But I do think
that if we somehow find machines being puzzled,
it won't surprise me that once we actually have
serious AI systems, which engagement in natural language
and modeling of themselves and the world, they might well
find themselves saying things like, yeah, I know
in principle I'm just a set of silicon circuits,
but I feel like so much more. I think that might tell us
something about consciousness. Let me just say a little
bit about theories of consciousness. I do think a solution
to the meta-problem and a solution to
the hard problem ought to be closely connected. The illusionist has
solved the meta-problem. You'll dissolve
the hard problem. But even if you're
not an illusionist about consciousness, there
ought to be some link. So here's a thesis. Whatever explains consciousness
should also partly explain our judgments, now reports
about consciousness. The rationale here
is it would just be very strange if these
things were independent, if the basis of consciousness
played no role in our judgments about consciousness. So they can use this as a
way of evaluating or testing theories of consciousness. For theory of consciousness
says mechanism M is the basis of consciousness,
that M should also partly explain our judgments
about consciousness. Whatever the basis is ought
to explain the reports. And you can use this. You can bring this to bear
on various extant theories of consciousness. Here's one famous current
theory of consciousness, integrated information
theory developed by Giulio Tononi and colleagues
at the University of Wisconsin. Tononi says the basis
of consciousness is integrated information, a
certain kind of integration of information for
which to and he has a measure that he calls phi. Basically, when your phi is high
enough, you get consciousness. A consciousness is
high phi, and there's a mathematical definition. But I won't go into it here. But it's a really
interesting theory. So here's a-- basically
it analyzes a network property of systems of units. And it's got a
informational measure called phi that's supposed
to go with consciousness. Question, if
integrated information is the basis of
consciousness, It ought to explain problem
reports, at least in principle. Challenge, how does that work? And it's at least far
from obvious to me how integrated information will
explain the problem reports. It seems pretty
dissociated from them. On Tononi's view, you
can have simulations of systems with high
phi that have zero phi. They'll go about making
exactly the same reports but without
consciousness at all. So phi is at least
somewhat dissociable. You get systems with very high
phi, but no tendency to report. Maybe that's less worrying. Anyway, here's a
challenge for this theory, for other theories. Explain, not just how high
phi gives you consciousness, but how it plays a central
role in the algorithms that generate problem reports. Something similar goes
for many other theories, biological theories, quantum
theories, global workspace, and so on. But let me just wrap
up by saying something about the issue of
illusionism that I was talking about near the start. Again, you might be
inclined to think that this approach through
the meta-problem tends, at least very naturally,
to lead to illusionism. And I think it can be-- it
certainly provides, I think, some motivation for illusionism,
the view that consciousness doesn't exist, we
just think it does. On this view, again, a
solution to the meta-problem dissolves the hard problem. So here's one way of putting
the case for illusion. If there is a solution
to the meta-problem, then there is an explanation of
our beliefs about consciousness that's independent
of consciousness. There's an algorithm
that explains our beliefs about consciousness. It doesn't mention
consciousness. Arguably, it could be in
place without consciousness. Arguably, that
kind of explanation could debunk our beliefs about
consciousness the same way that perhaps explaining beliefs
about God in evolutionary terms might debunk belief in God. It certainly doesn't prove
that God doesn't exist. You might think that if you can
explain our beliefs in terms of evolution, it somehow
removes the justification or the rational basis
for those beliefs. So something like
that, I think, can be applied to consciousness too. And there's a lot to
be said about analyzing the extent to which this
might debunk the beliefs. On the other hand, the
case against illusionism is very, very strong
for many people. And the underlying worry is
that some of the illusionism is completely unbelievable. It's just a manifest
fact about ourselves that we have conscious
experience, we experience red, we feel pain, and so on. To deny those things
is to deny the data. No, the dielectric
here is complicated. The illusionist will come
back and say, yes, but I can explain why illusionism
is unbelievable. These models we have, these
self models of consciousness, are so strong that
they were just wired into us by evolution. They're not models
we can get rid of. So my view predicts that
my view is unbelievable. And the question is, what-- the dialectical situation
is complex and interesting. But maybe I could just wrap
up with two expressions of absurdity on either side of
this question, the illusionist and the anti-illusionist,
both finding absurdity in the other person's views. Here's Galen Strawson,
who was here. Galen's view is very much that
illusionism is totally absurd. In fact, he thinks it's
the most absurd view that anyone has ever held. There occurred in
the 20th century, the most remarkable episode
in the whole history of ideas, the whole history of human
thought, a number of thinkers denied the existence
of something we know with certainty
to exist, consciousness. He thinks this is just a sign
of incredible philosophical pathology. Here's the rationalist
philosopher, Eliezer Yudkowsky, and something he wrote a
few years ago on zombies and consciousness and
the epiphenomenalist view that consciousness plays
no causal role, where he was engaging some stuff I
wrote a couple of decades ago. He said, "this
zombie argument"-- the idea we can imagine zombies
physically like us but without consciousness-- "may be a
candidate for the most deranged idea in all of philosophy. The causally closed
cognitive system of trauma's internal narrative
is malfunctioning, in a way, not by necessity but just in
our own universe miraculously happens to be correct." And here he is expressing
this debunking idea that on this view,
there's an algorithm that generates these intuitions
about consciousness. And that's all physical. And there's also this further
layer of non-physical stuff. And just by massive coincidence,
the physical algorithm is a correct model of
the non-physical stuff. That's a form of debunking here. It would take a miracle for
this view to be correct. So I think both of
these views are onto-- these objections
are onto something. And to make progress
on this on either side, we need to find a way of
getting past these absurdities. You might say, well,
there's middle ground between very strong
illusionism and very strong epiphenomenalism. It tends to slide back
to the same problems. Other forms of
illusionism, weaker forms don't help much with
the hard problem. Other forms of realism
are still subject to this. It takes a miracle for this
view to be correct critique. So I think to get
beyond absurdity here, both sides need to
do something more. The illusionist needs to do more
to explain how having a mind could be like this, even
though it's not at all the way that it seems. They need to find some
way to recapture the data. Realists need to
explain how it is that these meta-problem
processes are not completely independent of consciousness. Realists need to explain
how meta-problem processes, the ones that generate
these intuitions and reports and convictions
about consciousness, are essentially grounded in
consciousness even if it's possible somehow for them or
conceivable for them to occur without consciousness. Anyway so that's just to
lay out a research program. I think a solution to
the meta-problem that meets these ambitions
might just possibly solve the hard problem
of consciousness or at the very least shed
significant light on it. In the meantime,
the meta-problem is a potentially tractable
research project for everyone, and might I recommend
to all of you. Thanks. [APPLAUSE] AUDIENCE: Yes, I
just want to say I think it's very interesting,
this concept of, we have these collection
of mental models and that this collection of
mental models is consciousness, basically. Consciousness defines
the collection of these mental
models that we have. And the problem
with consciousness is that we don't understand
the physical phenomenon that causes these mental
models or that stimulates these mental models. So we just have this belief
that it's ephemeral or not real or something like that. And if you take that view,
then what's interesting is that you could simulate
these mental models like robot could simulate
these mental models. And you could simulate
consciousness as well. And even if the underlying
physical phenomena that fuels these mental models
is different-- robots have different
sensors, et cetera-- you could still get the
same consciousness effect in both cases. DAVID CHALMERS: Yeah,
I think that's right. Or at the very least,
it looks like you ought to be able to get the same
models, at least, in a robot. If the models themselves are
something algorithmic and ought to be, you ought to
be able to design a robot that has, at the
very least, let's say, isomorphic models and some
sense that is conscious. Of course, it's a further
question-- at least by my [? lights-- ?]
whether then the robot will be conscious. And that was the
question I alluded to in talking about the
artificial consciousness test. But you might think that would
at least be very good evidence that the robot is conscious. If it's got a model of
consciousness just like ours, it seems very
plausible there ought to be a very strong link
between having a model like that and being conscious. I think probably something
like Ned Block-- who was here arguing against machine
consciousness-- would say, no, no, the model is not enough. The model has to be
built of the right stuff. So it's gotta be
built of biology. And so on. But at by my
[? light, ?] I think if I had found an AI system
that had a very serious version of our model of
consciousness, I'd take that as a very good reason
to believe it's conscious. AUDIENCE: In the
IIT theory, is there a estimate or plausible estimate
for what the value of phi is for people and
for other systems? DAVID CHALMERS: Basically, no. It's extremely hard to measure
in systems of any size at all. Because the way it's
defined, it involves taking a sum over every
possible partition of a system. It turns out A, it's hard
to measure in the brain because you've got to involve
the causal dependencies set between different
units on neurons. But even for a pure
algorithmic system, you've got a neural network
laid out in front of you. It's computationally
intractable to measure the fire of one of those once
I get to bigger than 15 units or so. So Tononi would like to say
this is an empirical theory and in principle
empirically testable. But there's the in principle. It's extremely difficult
to measure phi. Some people, Scott Aaronson
the computer scientist, has tried to put forward
counterexamples to the theory, which were basically
very, very simple systems like matrix
multipliers that multiply two large matrices. Turn out to have
enormous phi, phi as big as you like if the
matrices are big enough and therefore by Tononi's
theory will not just be conscious, but as
conscious as a human being. And Aaronson put this
forward as a reductio ad absurdum of the IIT theory. I think Tononi basically bit
the bullet and said, oh yeah, those matrix
multipliers are actually having some high degree
of consciousness. So I think IIT is probably
at least missing a few pieces if it's going to be developed. But it's a research program too. AUDIENCE: You mentioned belief
as an example of something where there's another
mental quality, but people don't seem to
have the same sense that it is very hard to explain. In fact, it almost
seems too easy where people-- like a
belief about something sort of feels like
just how things are. But you have to
reflect on a belief to notice it as a belief. Do you think there
is also or has there been research related
to this question into why is that different? It seems like another angle
of attack on this problem. It's just like, why doesn't this
generate the same hard problem. DAVID CHALMERS: Yeah. In terms-- I'm not
sure if there's been research from the
perspective of the meta-problem or of theory of mind. Certainly, people have thought,
in their own right, what is the difference in
belief and experience that makes them so different. This goes way back to
David Hume, a philosopher a few centuries ago who said
basically, perception is vivid. Impression of
impressions and ideas. And impressions like
experiencing colors are vivid in force and
vivacity, and ideas are merely a faint copy or something. But that's just the first order. And then there are
contemporary versions of this kind of thing, far more
sophisticated ways of saying a similar thing. But yeah, you could, in
principle, explore that through the meta-problem. Why does it seem to us that
perception is so much more vivid? What about our
models of the mind makes perception seem so
much more vivid than belief and makes beliefs seem
structural and empty whereas perception
is so full of light? But no, I don't
know of work on that from the meta-problem
perspective. Like I said, there's
not that much work on these introspective
models directly. There is work on theory
of mind about beliefs. Tends to be about
models of other people. It may be there's something
I could dig through in my literature on belief
that says something about that. It's a good place to push. AUDIENCE: Thanks. AUDIENCE: I wanted to
bring up Kurt Godel. You mentioned your advisor
wrote "Godel, Escher, Bach". There's something that
seems very like Godel-- Godelian or whatever about
this whole discussion in that-- so Godel showed that
given a set of axioms in mathematics,
that it would either be consistent or
complete but not both. And it seems like
when Daniel Dennett-- Daniel Dennett seems to have a
set of axioms where he cannot construct consciousness
from them. He seems to be very much
in this consistent camp, like he wants to have
a consistent framework but is OK with the
incompleteness. And I wonder if a
similar approach could be taken with
consciousness where we could, in fact,
prove that consciousness is independent of Daniel
Dennett's set of axioms, the same way they proved-- after Godel, they proved
the Continuum Hypothesis was independent of ZF set
theory, and then they added the axiom of choice,
made it ZFC set theory. So I wonder if we could show
that in Daniel Dennett's world, we are essentially zombies or
we are either zombies or not. It doesn't matter. Either statement could be true. And then find what is
the minimum axiom that has to be added to
Dennett's axioms in order to make
consciousness true. DAVID CHALMERS: Interesting. I thought for a
moment this was going to go in a different
direction and you were going to say Dennett is
consistent but incomplete. AUDIENCE: Yes. DAVID CHALMERS: He doesn't have
consciousness in his picture. I'm complete. I've got consciousness-- AUDIENCE: Yes. DAVID CHALMERS:
--but inconsistent. That's why I say all
these crazy theory. AUDIENCE: Right, yeah. DAVID CHALMERS: And you're
faced with the choice of not having consciousness and
being incomplete or having consciousness and somehow
getting this hard problem and being forced into, at
least, puzzles and paradoxes. But the way you put it
was friendlier to me. Yeah, certainly, Doug Hofstadter himself
has written a lot on analogies between
the Godelian paradoxes and the MindBody problem. And he thinks always
our self models are always doomed to be
incomplete in the Godelian way. He thinks that that might be
somehow part of the explanation of our puzzlement, at
least about consciousness. Someone like Roger
Penrose, of course, takes this much more
seriously literally. He thinks that the
computational aspects of computational
systems are always going to be limited in the Godel way. He thinks human beings
are not so limited. He thinks we've got mathematical
capacities to prove theorems, to see the truth of
certain mathematical claims that no formal system
could ever have. So he thinks that
we somehow go beyond the incomplete Godelian-- I don't know if he actually
thinks we're complete, but at least we're not
incomplete in the way that finite computational
systems are incomplete. And furthermore, he
thinks that extra thing that humans have is
tied to consciousness. I never quite saw
how that last step goes, even if we didn't have
these special non-algorithmic capacities to see the truth
of mathematical theorems, how would that be
tied to consciousness. But at the very least, there
are structural analogies to be drawn between
those two cases, about incompleteness
of certain theories. How literally we should
take the analogies, I'd have to think about it. AUDIENCE: Has there
been some consideration that the problem of
understanding consciousness inherently must be difficult
because we address the problem using consciousness? I'm reminded of the halting
problem in computer science where we say that
in the general case, a program cannot be written to
tell whether another program will halt because what
if you ran it on itself. It can't be broad enough to
include its own execution. So I wonder if there
is a similar corollary in consciousness where
we use consciousness to think about consciousness
and so therefore, we may not have enough equipment
there to be able to unpack it. DAVID CHALMERS:
Yeah, it's tricky. People say it's like,
you use a ruler. To measure a ruler-- well, I can do this ruler to
measure many other things. But it can't measure itself. It's not [INAUDIBLE]. Well, on the other
hand, you can measure one ruler using another ruler. Maybe you can measure one
consciousness using another. The brain-- [INAUDIBLE] the
brain can't study the brain. But the brain actually
does a pretty good job of studying the brain. There are some self-referential
paradoxes there. And I think that,
again, is at the heart of Hofstadter's approach. But I think we'd have
to look for very, very specific conditions under which
systems can't study themselves. I did always like the idea that
if the mind was simple enough that we could understand
it, we would be too simple to understand the mind. So maybe something like that
could be true of consciousness. On the other hand,
I actually think that if you start thinking
that consciousness can go along with very simple systems,
I think at the very least, we ought to be able to study
consciousness in other systems simpler than ourselves. And boy, if I could solve the
hard problem even in dogs, I'd be satisfied. Yeah? AUDIENCE: Hey, so I have
a question about how the meta-problem research
program might proceed, sort of related to
the last question. So certainly things we believe
about our own consciousness, even if we all say them,
probably some of them are false. Our brain has a tendency to
hide what reality is like. If you look at
visual perception, there's what's called
lightness constancy. Our brain subtracts out the
lighting in the environments so we actually see more reliably
what the color of objects are. Like these viral examples
of the black and gold dress is an example of this. And when you're presented
with an explanation of it, it's like, huh? My brain does that? It's not something
we have access to. Or Yani Laurel-- DAVID CHALMERS:
Laurel Yani, yeah. AUDIENCE: --illusion
is another one where when you hear the
explanation, the scientists that understand it, our
own introspection doesn't include that. So how do you
proceed with trying to get at what
consciousness really is versus what our whatever
simplified or distorted view might be? DAVID CHALMERS: Yeah, I
think well one view here would be that we never have
access to the mechanisms that generate consciousness,
but we still have access to the
conscious states themselves. Actually, Karl Lashley
said this decades ago. He said no process of the
brain is ever conscious. The processes that get you to
the states are never conscious. The states they get
you to are conscious. So take your experience
of the dress. For me, it was white and gold. So I knew that. Each of us was
certain that I am-- I was certain that I was
experiencing white and gold. Maybe you were
certainly you were experiencing blue and black. AUDIENCE: I forget which it was. All I remember is I was right. [LAUGHTER] DAVID CHALMERS: You were
sure that, yeah, those idiots can't be looking at this right. I think the natural way to
describe this, at least, is that each of us
was certain what kind of conscious experience we were
having, but what we had no idea about was the mechanisms
by which we got there. So the mechanisms are
completely opaque. But the states themselves
were at least prima facie transparent. I think that would
be the standard view. Even a realist
about consciousness could go with that. They'd say we know
what conscious states where we know what
those conscious states are. We don't know the processes
by which they are generated. The illusionist, I think,
wants to go much further and say, well it seems
to you that you know what conscious state you're having. It seem to you that you're
experiencing yellow and gold. Sorry, yellow and
white, whatever it was. Gold and white. AUDIENCE: Black and
gold is what I remember. DAVID CHALMERS: No, black
and blue, I think, and-- AUDIENCE: Blue? DAVID CHALMERS:
--gold and white. It seems to you you're
experiencing gold and white. But, in fact, that too is
just something thrown up by another model. The yellow gold was
a perceptual model. Then there was an
introspective model that said you are experiencing
gold and white when maybe, in fact, you're just a zombie. Or who knows what's
actually going on in your conscious state. So the illusionist
view, I think, has to somehow take this further
and say, not just the processes that generate the
conscious states, but maybe the conscious states themselves
are somehow opaque to us. AUDIENCE: It feels
like some discussion of generality of a problem is
missing from this discussion. The matrix multiplier example
of having high phi is still-- it's not a general thing. Is there someone exploring
the space, the intersection of generality and complexity
that leads to consciousness as an emergent behavior? DAVID CHALMERS: When
you say generality, there's the idea that a theory
should be general, that it should apply to every system. You mean mechanisms? AUDIENCE: Generality
of the agent. If I can write an
arbitrarily complex program to play tic-tac-toe and all
it will ever be able to do is play tic-tac-toe,
it has no outputs to express anything else. DAVID CHALMERS: Yeah. So general in the sense
of AGI, artificial general intelligence. Some aspects of
consciousness seem to be domain general
like for example, maybe insofar as belief
and reasoning is conscious. Those are domain general. But much of perception doesn't
seem especially domain general. Right? Color is very domain. Taste is very domain specific. So it's still conscious. AUDIENCE: But if my agent can't
express problem statements, like if I don't give it an
output by which it can express problem statements,
you can never come to a conclusion
about its consciousness. DAVID CHALMERS: I'd like
to distinguish intelligence and consciousness
and even be able to-- even natural language and
being able to address a problem statement and analyze
a problem, that's already a very advanced
form of intelligence. I think it is very
plausible that a mouse has got some kind of consciousness,
even though it's got no ability to address problem statements,
and many of its capacities may be very specialized. It's still much more general
than a simple neural network that can only do one thing. A mouse can do many things. But I'm not sure that
I see an essential-- I certainly see a connection
between intelligence and generality. We want to say somehow a
high degree of generality is required for high intelligence. I'm not sure there's the same
connection for consciousness. I think consciousness can
be extremely domain-specific as a taste and maybe vision are. Or it can be domain-general. So maybe those two across
cut each other a bit. AUDIENCE: So it seems to me
like the meta-problem as it's formulated implies some
amount of separation or epiphenomenalism between
consciousness and brain states. And one thing that I
think underlies a lot of people's motivation
to do science is that it has causal import. Like predicting
behaviors is clearly a functionally
useful thing to do, and if you can predict
all of behavior without having to
explain consciousness, their motivation for
explaining consciousness sort of evaporates and it
feels like, yeah, well, what's the point of
even thinking about that because it's just not
going to do anything for me. What do you say to someone
when they say that to you? DAVID CHALMERS:
What is the thing that they said to me again? AUDIENCE: That maybe
consciousness exists, maybe it doesn't. But if I can explain
all of human behavior and all of the behavior
of the world in general without recourse
to such concepts, then I've done
everything that there is that's useful, like
explaining consciousness isn't a useful thing to do. And thus, I'm not interested
in this, and it may-- DAVID CHALMERS: I see. AUDIENCE: --as well not be real. DAVID CHALMERS: I think
epiphenomenalism could be true. I certainly don't have any
commitment to it, though. It's quite possible that
consciousness has a role to play in generating behavior
that we don't yet understand. And maybe thinking hard
about the meta-problem can help us get
clearer on those roles. I think if you've got any
sympathy to panpsychism, maybe consciousness
is intimately involved with how
physical processes get going in the first place. And there are people
who want to pursue interactionist ideas
where consciousness interacts with the brain. Or if you're a
reductionist, consciousness may be just a matter
of the right algorithm. In all those views,
consciousness may have some role to play. But just say it
turns out that you can explain all of behavior,
including these problems, without bringing
in consciousness. Does that mean that
consciousness is not something we should care about
and not something that matters? I don't think that would follow. Maybe it wouldn't matter for
certain engineering purposes, say you want to build
a useful system. But at least in my
view, consciousness is really the only
thing that matters. It's the thing that
makes life worth living. It's what gives our lives
meaning and value and so on. So it might turn out
that consciousness is not that useful for
explaining other stuff. But if it's the source
of intrinsic significance in the world, then
understanding consciousness would still be absolutely
essential to understanding ourselves. Furthermore, if it comes
to developing other systems like AI systems or dealing with
non-human animals and so on, we absolutely want to know. We need to know whether they're
conscious because if they're conscious, they presumably
have moral status. If they can suffer, then it's
very bad to mistreat them. If they're not conscious,
then you might-- I think it's very plausible--
treat non-conscious systems, we can treat how we like. And it doesn't really
matter morally. So the question of whether an
AI system is conscious or not is going to be absolutely vital
for how we interact with it and how we build our society. That's not a question of
engineering usefulness. It's a question of
connecting with our most fundamental values. AUDIENCE: Yeah, I
completely agree. I just-- I haven't
found that formulation to be very convincing
to others necessarily. AUDIENCE: Hi, thanks
so much for coming and chatting with us today. I'm really interested in
some of your earlier work, the extended mind
[? distributed ?] cognition. And you're at a company
speaking with a bunch of people who do an incredibly
cognitively demanding task. DAVID CHALMERS: Yeah. AUDIENCE: Most of the literature
that I've read on this topic uses relatively
simple examples saying like it's difficult
to think just inside your head on these
relatively simple things. And if you take a look at
the programs that we build, on a mundane day-to-day basis,
they're millions of lines long. I've read people in
the past say something like the Boeing 777 was
the most complicated thing that human beings have ever
made, and I think most of us would look at that and
say, we got that beat. The things that large
internet companies do, the size, the complexity
of that is staggering. And yet if we close our
eyes, everyone in here is going to say, I'm going
to have difficulty writing a 10 line program in my head. So I've just sort
of, as an open, I'd be very interested in
hearing your thoughts about how the activity of programming
connects to the extended mind ideas. DAVID CHALMERS: Yeah,
so this, I guess, is a reference to
something that I got started in
about 20 years ago with my colleague, Andy Clark. We wrote an article called
"The Extended Mind" about how processes in the mind can
extend outside the brain when we become
coupled to our tools. And actually, our
central example back then in the mid-90s was a
notebook, someone writing stuff in a notebook. And even then, we knew
about the internet, and we had some
internet examples. I guess this company
didn't exist yet in '95. But now, of course,
our minds have just become more and more extended. And smartphones came
along a few years later, and everyone is coupled
very, very closely to their phones and their other
devices that couple of them very, very closely
to the internet. Now it's suddenly the case
that a whole lot of my memory is now offloaded onto the
servers of your company somewhere or other, whether
it's in the mail systems or navigation mapping
systems or other systems. Yeah, most of my navigation
has been offloaded to maps. And much of my memory
[INAUDIBLE] has been offloaded. Well, maybe that's in my phone. But other bits of my memory are
offloaded into my file system on some cloud service. So certainly, yeah,
vast amounts of my mind are now existing in the cloud. And if I were somehow to lose
access to those completely, then I'd lose an awful
lot of my capacities. So I think now we are now
extending into the cloud thanks to you guys and others. The question's specifically
about programming. Programming is a kind of active
interaction with our devices. I mean, I think
programming is something that takes a little bit longer. It's a longer timescale so the
core cases of the extended mind involve automatic use
of our devices, which are always ready to hand. We can use them to
get information, to act in the moment,
which is the kind of thing that the brain does. So insofar as programming
is a slower process-- and I remember from
my programming days, all the endless hours
of debugging and so on-- then it's at least going
to be a slower timescale for the extended mind. But still, Feynman talked
about writing this way. Someone looked at Feynman's
work and a bunch of notes he had about a physics
problem he was thinking about. And someone said to
him, oh it's nice you have this record of your work. And Feynman said, that's
not a record of my work. That's the work. That is the thinking. I was writing it down and so on. I think, at least
my recollection from my programming days,
is that when you're actually writing a program, it's not like
you just do a bunch of thinking and then code your thoughts. The programming is to some
very considerable extent your thinking. So is that the sort
of thing you're-- AUDIENCE: Yes, absolutely. [INTERPOSING VOICES] If we, I
think as people that program, start to reflect on what we do,
and very few of us actually-- if you're the tech
lead of a system, maybe you've got
it in your head. But you would agree that most
of the people on the team who have come more
recently only have a chunk of it in their head. And yet, they're somehow
still able to contribute. DAVID CHALMERS: Oh, yeah. This is now
distributed cognition. The extended mind,
the extended cognition starts with an individual and
then extends their capacities out using their tools or their
devices or even other people. So maybe my partner
serves as my memory, but it's still centered
on an individual. But then there's the
closely related case of distributed
cognition, where you have a team of people who are
doing something and making joint decisions and carrying out
joint actions in an absolutely seamless way. And I take it at a
company like this, there are going to be
any number of instances of distributed cognition. I don't know whether
the company as a whole has one giant
Google mind or maybe there's just a near infinite
number of separate Google minds for all the individual
teams and divisions. But I think probably some
anthropologist has already done a definitive
analysis of distributed cognition in this company. But if they haven't,
they certainly need to. AUDIENCE: Thank you. [APPLAUSE]
