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  • Right now

  • you have a movie playing inside your head.

  • It's an amazing multi-track movie.

  • It has 3D vision and surround sound

  • for what you're seeing and hearing right now,

  • but that's just the start of it.

  • Your movie has smell and taste and touch.

  • It has a sense of your body,

  • pain, hunger, orgasms.

  • It has emotions,

  • anger and happiness.

  • It has memories, like scenes from your childhood

  • playing before you.

  • And it has this constant voiceover narrative

  • in your stream of conscious thinking.

  • At the heart of this movie is you

  • experiencing all this directly.

  • This movie is your stream of consciousness,

  • the subject of experience

  • of the mind and the world.

  • Consciousness is one of the fundamental facts

  • of human existence.

  • Each of us is conscious.

  • We all have our own inner movie,

  • you and you and you.

  • There's nothing we know about more directly.

  • At least, I know about my consciousness directly.

  • I can't be certain that you guys are conscious.

  • Consciousness also is what makes life worth living.

  • If we weren't conscious, nothing in our lives

  • would have meaning or value.

  • But at the same time, it's the most

  • mysterious phenomenon in the universe.

  • Why are we conscious?

  • Why do we have these inner movies?

  • Why aren't we just robots

  • who process all this input,

  • produce all that output,

  • without experiencing the inner movie at all?

  • Right now, nobody knows the answers

  • to those questions.

  • I'm going to suggest that to integrate consciousness

  • into science, some radical ideas may be needed.

  • Some people say a science of consciousness

  • is impossible.

  • Science, by its nature, is objective.

  • Consciousness, by its nature, is subjective.

  • So there can never be a science of consciousness.

  • For much of the 20th century, that view held sway.

  • Psychologists studied behavior objectively,

  • neuroscientists studied the brain objectively,

  • and nobody even mentioned consciousness.

  • Even 30 years ago, when TED got started,

  • there was very little scientific work

  • on consciousness.

  • Now, about 20 years ago,

  • all that began to change.

  • Neuroscientists like Francis Crick

  • and physicists like Roger Penrose

  • said now is the time for science

  • to attack consciousness.

  • And since then, there's been a real explosion,

  • a flowering of scientific work

  • on consciousness.

  • And this work has been wonderful. It's been great.

  • But it also has some fundamental

  • limitations so far.

  • The centerpiece

  • of the science of consciousness in recent years

  • has been the search for correlations,

  • correlations between certain areas of the brain

  • and certain states of consciousness.

  • We saw some of this kind of work

  • from Nancy Kanwisher and the wonderful work

  • she presented just a few minutes ago.

  • Now we understand much better, for example,

  • the kinds of brain areas that go along with

  • the conscious experience of seeing faces

  • or of feeling pain

  • or of feeling happy.

  • But this is still a science of correlations.

  • It's not a science of explanations.

  • We know that these brain areas

  • go along with certain kinds of conscious experience,

  • but we don't know why they do.

  • I like to put this by saying

  • that this kind of work from neuroscience

  • is answering some of the questions

  • we want answered about consciousness,

  • the questions about what certain brain areas do

  • and what they correlate with.

  • But in a certain sense, those are the easy problems.

  • No knock on the neuroscientists.

  • There are no truly easy problems with consciousness.

  • But it doesn't address the real mystery

  • at the core of this subject:

  • why is it that all that physical processing in a brain

  • should be accompanied by consciousness at all?

  • Why is there this inner subjective movie?

  • Right now, we don't really have a bead on that.

  • And you might say,

  • let's just give neuroscience a few years.

  • It'll turn out to be another emergent phenomenon

  • like traffic jams, like hurricanes,

  • like life, and we'll figure it out.

  • The classical cases of emergence

  • are all cases of emergent behavior,

  • how a traffic jam behaves,

  • how a hurricane functions,

  • how a living organism reproduces

  • and adapts and metabolizes,

  • all questions about objective functioning.

  • You could apply that to the human brain

  • in explaining some of the behaviors

  • and the functions of the human brain

  • as emergent phenomena:

  • how we walk, how we talk, how we play chess,

  • all these questions about behavior.

  • But when it comes to consciousness,

  • questions about behavior

  • are among the easy problems.

  • When it comes to the hard problem,

  • that's the question of why is it

  • that all this behavior

  • is accompanied by subjective experience?

  • And here, the standard paradigm

  • of emergence,

  • even the standard paradigms of neuroscience,

  • don't really, so far, have that much to say.

  • Now, I'm a scientific materialist at heart.

  • I want a scientific theory of consciousness

  • that works,

  • and for a long time, I banged my head

  • against the wall

  • looking for a theory of consciousness

  • in purely physical terms

  • that would work.

  • But I eventually came to the conclusion

  • that that just didn't work for systematic reasons.

  • It's a long story,

  • but the core idea is just that what you get

  • from purely reductionist explanations

  • in physical terms, in brain-based terms,

  • is stories about the functioning of a system,

  • its structure, its dynamics,

  • the behavior it produces,

  • great for solving the easy problems

  • how we behave, how we function

  • but when it comes to subjective experience

  • why does all this feel like something from the inside? —

  • that's something fundamentally new,

  • and it's always a further question.

  • So I think we're at a kind of impasse here.

  • We've got this wonderful, great chain of explanation,

  • we're used to it, where physics explains chemistry,

  • chemistry explains biology,

  • biology explains parts of psychology.

  • But consciousness

  • doesn't seem to fit into this picture.

  • On the one hand, it's a datum

  • that we're conscious.

  • On the other hand, we don't know how

  • to accommodate it into our scientific view of the world.

  • So I think consciousness right now

  • is a kind of anomaly,

  • one that we need to integrate

  • into our view of the world, but we don't yet see how.

  • Faced with an anomaly like this,

  • radical ideas may be needed,

  • and I think that we may need one or two ideas

  • that initially seem crazy

  • before we can come to grips with consciousness

  • scientifically.

  • Now, there are a few candidates

  • for what those crazy ideas might be.

  • My friend Dan Dennett, who's here today, has one.

  • His crazy idea is that there is no hard problem

  • of consciousness.

  • The whole idea of the inner subjective movie

  • involves a kind of illusion or confusion.

  • Actually, all we've got to do is explain

  • the objective functions, the behaviors of the brain,

  • and then we've explained everything

  • that needs to be explained.

  • Well I say, more power to him.

  • That's the kind of radical idea

  • that we need to explore

  • if you want to have a purely reductionist

  • brain-based theory of consciousness.

  • At the same time, for me and for many other people,

  • that view is a bit too close to simply

  • denying the datum of consciousness

  • to be satisfactory.

  • So I go in a different direction.

  • In the time remaining,

  • I want to explore two crazy ideas

  • that I think may have some promise.

  • The first crazy idea

  • is that consciousness is fundamental.

  • Physicists sometimes take some aspects of the universe

  • as fundamental building blocks:

  • space and time and mass.

  • They postulate fundamental laws governing them,

  • like the laws of gravity or of quantum mechanics.

  • These fundamental properties and laws

  • aren't explained in terms of anything more basic.

  • Rather, they're taken as primitive,

  • and you build up the world from there.

  • Now sometimes, the list of fundamentals expands.

  • In the 19th century, Maxwell figured out

  • that you can't explain electromagnetic phenomena

  • in terms of the existing fundamentals

  • space, time, mass, Newton's laws

  • so he postulated fundamental laws

  • of electromagnetism

  • and postulated electric charge

  • as a fundamental element

  • that those laws govern.

  • I think that's the situation we're in

  • with consciousness.

  • If you can't explain consciousness

  • in terms of the existing fundamentals

  • space, time, mass, charge

  • then as a matter of logic, you need to expand the list.

  • The natural thing to do is to postulate

  • consciousness itself as something fundamental,

  • a fundamental building block of nature.

  • This doesn't mean you suddenly can't do science with it.

  • This opens up the way for you to do science with it.

  • What we then need is to study

  • the fundamental laws governing consciousness,

  • the laws that connect consciousness

  • to other fundamentals: space, time, mass,

  • physical processes.

  • Physicists sometimes say

  • that we want fundamental laws so simple

  • that we could write them on the front of a t-shirt.

  • Well I think something like that is the situation

  • we're in with consciousness.

  • We want to find fundamental laws so simple

  • we could write them on the front of a t-shirt.

  • We don't know what those laws are yet,

  • but that's what we're after.

  • The second crazy idea

  • is that consciousness might be universal.

  • Every system might have some degree

  • of consciousness.

  • This view is sometimes called panpsychism:

  • pan for all, psych for mind,

  • every system is conscious,

  • not just humans, dogs, mice, flies,

  • but even Rob Knight's microbes,

  • elementary particles.

  • Even a photon has some degree of consciousness.

  • The idea is not that photons are intelligent

  • or thinking.