#124 — In Search of Reality
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Summary
Sean Carroll is a theoretical physicist from Caltech and Harvard who has worked on the foundations of quantum mechanics for some time. He s focused on the emergence of complexity and the arrow of time, and has been awarded prizes of many sorts from NASA, the National Science Foundation, the Sloan Foundation, and other societies. He is also a consultant for film and television, and he has written a fascinating book, The Big Picture: On the Origins of Life, Meaning, and the Universe Itself. It s not for sale here, but I highly recommend you get it. Please welcome Sean Carroll to The Making Sense Podcast. This is more than the usual podcast. This is an experiment in conversation, and there are so much we agree about. But there are places where we have probably been talking past one another, and I want us to sneak up on our differences, and use our differences as the basis for a conversation. We don t run ads on the podcast, and therefore, it s made possible entirely through the support of our subscribers, so if you enjoy what we re doing here, please consider becoming a supporter of what we're doing here! you'll get access to access full episodes of the podcast and access to all the great episodes of Making Sense, as well as access to our most popular podcasts and books. And as you might expect, this is a podcast that's made possible by you, the listener-submitted listeners. Thanks for listening to the Making Sense podcast. . Sam Harris - Sam Harris, PhD - PhD - MAKING MESING MINDING Sense and a great podcast by The New York Times bestselling author of The New Yorker and the New York Review of Science and The New Republic by The Astronomy Project by John Grady, and a fellow Making Sense by the New Yorker, in the making sense podcast by the Los Angeles Review, in this episode of The Huffington Post, in this podcast, in which you can be reached at making sense of it all. and on the internet, and much more. , , in the podcast by at the New Statesman, at to help spread the word about it. by , on , and , to (and & out there is here, to be or so much more! and so on
Transcript
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So this is my event with Sean Carroll, the physicist from Caltech that we recorded in Portland.
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And, as you might expect, we range over many topics, both of scientific interest and topics
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And people seem to like it in the room, and I hope you like it wherever you are.
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And now, without further delay, I bring you Sean Carroll.
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So I'm going to jump right into this, because we have a great guest.
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My guest tonight is a theoretical physicist from Caltech.
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He has worked on the foundations of quantum mechanics for some time.
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He's focused on the emergence of complexity and the arrow of time.
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He's been awarded prizes of many sorts, from NASA and the National Science Foundation, the
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He is also a consultant for film and television, and he has written a fascinating book, which
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unfortunately is not for sale here, but I highly recommend you get it.
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It's called The Big Picture on the Origins of Life, Meaning, and the Universe Itself.
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Can I just say, these are the most comfortable seats I've ever sat in on a stage.
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Like, every time I see pictures of you at the podcast, you have these wonderful overstuffed...
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Strangely, I have very little control over what chairs actually arrive here.
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But it seems to work out, at least in this universe.
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There's some of the universe where we're both being tortured.
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I don't know if you've been following along low these many years, but Sean and I have had
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a slightly prickly relationship online, and we've had disagreements in the past that I really
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There's so much we agree about in terms of just the importance of getting our hands around
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a realistic picture of what's going on in the world and using science as the basis for
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But there are places where I think we have probably been talking past one another.
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And I want to use your book as the template for that.
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And again, your book is a fascinating look at, as advertised, the big picture.
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Let's start with this notion of what you call poetic naturalism.
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Naturalism is just the idea that there's only one world, the natural world, the world that
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we learn about by doing science, the world that obeys rules and does its thing.
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So in other words, it's kind of defined in opposition to whatever might be not naturalism.
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If you believe that there were extra spirits or a realm of divinity or anything like that,
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But rather than just saying there is something you could imagine called God and that God doesn't
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exist, it's a positive statement about what does exist, the natural world that we can
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And then the poetic is the idea that there are many ways of talking about that natural world,
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which both means that there are different scientific ways.
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We can analyze it at the most comprehensive, fundamental level of particle physics and general
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There are more emergent levels that are still nevertheless scientific and descriptive, biology
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And then there are levels where we might actually get more poetic, which involve aesthetics or
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judgments or values, where I would argue the descriptions are not fixed by the facts of the universe
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I think the difference between us, if there is one in the end, is in what we will ascribe
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It's either naturalist or not to talk about values and meaning and the good life.
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So you certainly are a fan of the concept of the unity of knowledge.
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You don't think that there's a disjunction between levels.
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So if we're talking about physics, everything above that as an emergent property is beholden
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And it doesn't make sense to talk about cocktail parties and stock markets in terms of atoms
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I mean, certainly at the level of scientific description of what happens in the universe.
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The big thing that I try to push in the book is that there are these higher levels of emergent
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descriptions, but they better be compatible with the lower levels.
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And in particular, I'm not a fan of what even some of my scientific colleagues called
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The idea that somehow the shape of a macroscopic thing or the purpose of a macroscopic thing
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can feed back and change the behavior at the microscopic level in a way that you wouldn't
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have known about if you were just doing the microscopic level.
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I think that it really is reductionistic in that sense.
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Now, in practice, when we do biology or chemistry or psychology, there is a non-reductionist element
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in the sense that as a practical matter, the way to learn new things about biology is not
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We can discover regularities at the higher levels that we don't need to know about what's
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going on at the lower levels to discover them, but they still better be compatible with them.
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So let's revisit that notion of downward causation because it has never made sense to me either.
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So the idea is that you have emergent properties like minds and consciousness or just the macro
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So you have collections of atoms that at some higher level have even temperatures in emergent
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I mean, one atom doesn't have a temperature, but you get collections together and then their
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But this notion that a higher level phenomenon can then, by virtue of its existing at the higher
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level, come down and have causal properties with respect to the lower level.
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So how is it that people are endorsing that idea?
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Because we have scientists who are talking in those terms.
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You've come to the wrong place because it's one of those ideas I've tried to understand.
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There's a lot of smart people who believe this is a very important part of how we describe
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I've never even been able to understand what they're saying, really, I think.
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You would like to understand something well enough to be able to give a good defense of
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it yourself before you said it was wrong, which I don't think I can do.
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But the example on the level of basic physics that is sometimes given is the formation of
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You know, snowflakes have this six-fold symmetry and they're all different and they have this
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And people say, you know, at some level it's water molecules sticking together.
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But to understand what any one individual water molecule is doing, you need to understand
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But if that's the example, it's just manifestly wrong.
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Like, if you really knew what every water molecule was doing, that's all you would need
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There's the famous thought experiment of Laplace's demon.
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Pierre-Simon Laplace back in circa the year 1800 said, if there were a vast intelligence that
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knew literally everything about the universe, the position, the velocity of every particle
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of matter in the cosmos, and knew all laws of physics, and had infinite computing power,
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that intelligence could predict the past and retrodict the, sorry, predict the future
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So that's what we're imagining when we pretend to be fundamental physicists.
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If we were Laplace's demon, would you need to know that the water molecule was part of
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But of course, the real, the hidden agenda there is they want to use it to talk about
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They want to say that somehow the fact that we are conscious changes how even our cells
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or atoms behave in a way that we wouldn't have guessed from reductionistic principles,
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Yeah, well, the problem there is, and this is a genuine mystery as to why consciousness
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would have evolved if it's an evolved property of creatures like ourselves, is that if consciousness
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is just arising by virtue of some micro constituent phenomenon, so we have some level of information
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processing by, in our case, you know, neurophysiology, if it is effective, if consciousness is doing
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something, if there are certain mental operations that can't be done but for the fact that there's
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something that it's like to be doing those things, it still must be effective by virtue of its
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micro-level properties at the level of the brain.
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I mean, it is neurons affecting neurons and their future states.
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Otherwise, you're talking about some magical influence.
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Well, that's right, and so there's a tension here, right?
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There's a tension between, on the part of many people, there's a reluctance to think that what it is like
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to be something, the hard problem of consciousness, can be explained simply as an emergent
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phenomena on the basis of what our atoms and molecules are doing.
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But at the same time, there are subsets of these people who are very much in favor of science
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and know that the atoms and molecules are doing something and they have their own laws of physics,
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so they're forced ultimately to panpsychism, to the idea that there is not just a physical property
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of every particle of matter in the universe, but there are mental properties as well.
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And the mental properties aren't very efficacious in doing anything when it's just an atom or two,
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but when it comes together to make a whole person, then the mental properties come together to give
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us consciousness. Just saying it out loud makes me think, how could anyone ever believe that?
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But it is a surprisingly popular position in some circles.
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Well, but it's also hard to see how the universe would be different if that were so.
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I mean, I wouldn't expect this comfy chair to behave differently than it's behaving if there
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was something that it was like to be an electron, say.
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I mean, if electrons buzz with some interior dimension of subjectivity, it's not like they're
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thinking thoughts or forming behavioral plans or feeling themselves to be in relationship.
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Yeah. I mean, to be as fair as I can, it's not very conscious, the chair. It's just a
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little bit conscious. That's even, you know, an electron, David Chalmers would say, is maybe
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And I think, you know, and it gets into, I don't know how much you want to discuss it, but then,
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of course, there's the famous philosophical zombie thought experiment. Can you imagine
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something that acts like a person but has no inner sensations, does not know what it is
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like to be a person, but acts exactly like a person would act? And to me, the answer is
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no. That's not even conceivable. Because if you asked a zombie, what are you feeling right
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now? It would say it's feeling something, because otherwise you'd be acting differently,
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So why is the zombie lying to you all the time about feeling something inside? How do
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So I actually just don't think that's possible. And I think that ultimately the attempts to
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wriggle around basing reality in stuff obeying the laws of physics don't quite hold together.
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Yeah. Well, I think you and I are on the same page as far as consciousness still being
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fundamentally mysterious. Depends on how you're leading the word mysterious there.
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Well, it's just like we don't know at what level it arises in the physics of things.
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Sure. My message throughout the book, and more broadly, is the subtitle of my book is
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On the Nature of Life, Meaning, and the Universe Itself. And even though we're not selling the
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books here, you can still buy them on Amazon from your phone right now. But if you do, you
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will not learn the origin of life, the origin of the universe, or the meaning of life. The
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point is that I argue that we can talk about these things in a framework given to us by
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naturalism. I don't give you the answers. The answers are still things we're looking
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for. That's how science works. I think they will someday be found. And I think there will
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ultimately be a naturalistic, physicalistic grounding for whatever it is we find them.
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In other words, there's no reason on the basis of what we currently know about the universe
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to put large credence in the idea that there's something beyond the physical world.
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How do you think about possibility as a physicist? So we live in a world where certain things
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happen, and certain things which we can imagine happening, which seem compatible with the way
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things might have happened, don't seem to happen. If your answer to this is some many worlds
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version of QM, I'm interested in that. But how do you map this claim that something might
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have happened but didn't happen onto naturalism as a physicist?
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Well, I think that there's two levels to that, as it were. We could go into, again, at whatever level
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detail you want, to the many worlds version of quantum mechanics, which is the one that I think
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is probably right. We don't know for sure. And in that version, when you specifically have a quantum
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mechanical measurement performed, so you have some quantum mechanical system, some other system that
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interacts with it, obeying the laws of physics, becomes entangled, and that's what we call a
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measurement. The universe, as it is described by the quantum state, branches into multiple possible
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but equally real different universes, one in which the spin was up, one in which the spin was down.
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I have an app on my iPhone that will do this, that will actually branch the wave function of the
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universe. Yes. So if you don't know what to do, if you're like, should I have Chinese food for
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dinner? Should I have pizza? You can have one universe each, right? So that doesn't mean that
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everything happens. It means that everything that is compatible with the laws of quantum mechanics
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happens with some non-zero probability, okay? So it is a feature of the world that there were
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relatively few branches of the wave function of the universe in the past, and there are relatively
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more in the future. So possibilities proliferate as time goes on. Now there's also an entirely
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different discussion about the emergent levels of description, which are not comprehensive,
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where in some sense you're ignoring certain facts that are true about the universe. When we discuss the air
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in this room as a fluid with a temperature, a pressure, etc., we can make enormously successful
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predictions about how the air in this room will behave just on the basis of its fluid properties. And
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that's kind of miraculous because the total information about the air would be what Laplace's
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demon would have, right? The position and the velocity of every single molecule as well as its rotation and so
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forth. And miraculously, we don't need that information. We can do with much less information
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and still make wonderfully precise predictions, but not perfectly precise predictions. So because of
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that missing information, there's another sense of possibility that comes in, just the possibility
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based on ignorance, that you make predictions on the basis of incomplete data, they're going to be
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But when you're talking about something that happens or not, what sense can be made of the claim
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that something else might have happened in that case? In the many worlds version, everything that
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can happen is happening, right? So in some sense, there is only the actual. Most of it's not in this
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universe, but it's still happening. So there was some possibility that I might have picked this up and
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put it down and then picked it up again and put it down and did that 75 times to the consternation
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of everyone in the room. Hopefully the probability is low, but yes.
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But if there's a non-zero possibility of that, that happened somewhere, right?
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And every other conceivable adumbration of that. So I was singing the Star Spangled Banner at one point
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when I was doing that. It gets worse than that, yeah, but yes.
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I go, well, if you've heard me sing, you know, it doesn't get much worse than that.
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But this is supposed to be science, right? But this sounds like the strangest
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and least believable idea on offer. So how is it that science, after centuries of being
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apparently rigorous and parsimonious and hardheaded, finally disgorges a picture of reality which seems
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to be the least believable thing anyone's ever thought of?
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You've come to the right place. You all have come to the right place.
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So let me just remember that there's this entirely different notion of possibility that we should get
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to, which is what could have happened given what we know, given that what we know wasn't everything.
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What we're talking about here with the many worlds interpretation is we know everything.
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Let's let us know everything. Let's let us know the complete quantum state of the universe.
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And if you believe this story, then there's these multiple branchings and everything that had a
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non-zero chance of happening actually does come true just in different universes for all intents and
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purposes. And if I can rephrase the question you're asking, why in the world would anyone believe that, right?
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So the answer is that it is the simplest, purest, most parsimonious way of making sense of the data.
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And to bolster that claim, to sort of see why you would get there, you have to know just a little
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bit about quantum mechanics. So think about what quantum mechanics says is that there's a difference between
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what is, how we talk about the world, how we attach mathematically rigorous quantifications of the
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state of the world to actualities, versus what the world looks like when we look at it, okay?
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And looking at it isn't anything weird about consciousness or human brain or anything like
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that. A video camera or a rock can look at things just as well. So that's just any version of quantum
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mechanics. Any version of quantum mechanics says we describe the world differently when we are and
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are not looking at it. So how do you make the most parsimonious sense of that? We say that if you have
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an electron, for example, a little particle that is spinning, and if you measure it whether it's
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spinning, given some axis, is it spinning clockwise or counterclockwise? So it's the only possibility.
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It's one of the wonderful simplifications of quantum mechanics. It's never in between. If you measure
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it a certain way, it's clockwise or counterclockwise, that's it. Various reasons why, which we could go
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into, convince us that when we're not looking at it, the right way to talk about the electron is as
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a superposition of spinning clockwise and spinning counterclockwise. So it's not that we don't know,
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it's that it's in some sense doing both with sort of different amounts of admixture clockwise and
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counterclockwise. And then when you look at it, you only ever see it do one or the other, okay?
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So the question is what happened when we looked at it to make it go away? Well, we have an equation,
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right, the Schrodinger equation, which tells us what happened. And what the equation tells us is that
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before you looked at it, there was an electron that was in some mixture of clockwise and counterclockwise,
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and there was you, and you hadn't looked at it yet. And after you looked at it, there were two things.
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There was the electron was spinning clockwise, and you saw it spinning clockwise, and there was the
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electron was spinning counterclockwise, and you saw it spinning counterclockwise. That is the straightforward,
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unambiguous result of the equation. The question is, what do you do about that? And from 1920s to the 1950s,
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the answer was you panic. And you say, well, I only saw it spin counterclockwise or clockwise. So the
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other possibility magically disappears. And this is called the Copenhagen interpretation of quantum
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mechanics. And I'm being very unfair to it, but we're among friends. So it was in 1957 that a smart
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graduate student named Hugh Everett said, I have a better idea. Rather than magically getting rid of it,
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let's just admit that it's there, because that's what the equation says. What would be wrong with
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that? And people say, well, we only see one or the other. And Everett said, yeah, but now there's two
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of you. There's one that saw one, and one that saw the other one. And they kicked him out of the field.
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He left physics entirely, because they wouldn't talk to him anymore. But this is the birth of what
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we call the many worlds interpretation. In this universe, they kicked him out. In this universe,
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we kicked him out. Yeah, he's the king of physics and some other branch of the wave function.
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But the point is that it is in terms of ideas and mathematical concepts,
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you cannot get simpler and more parsimonious than the many worlds interpretation.
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In terms of universes, it's messy. But how should we judge it? I would go on the basis of concepts,
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not on the basis of universes. Right. So I want to bring in this notion of time,
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because you've focused on the arrow of time and why time seems to be as strange a phenomenon as it
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is. But there's this notion of a block universe that you don't hear much about now, which is the
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notion that the future and the past equally exist in some kind of atemporal space. It's like we're all
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living in a novel, and we're living on page 45 now, but page 95 exists just as much as the page
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we're on and could be visited, presumably. Just wait. Exactly, yeah. Is the block universe a retired
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concept, or are we still thinking in terms of the block universe? No, it's the conventional wisdom.
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It is, okay. But taken as a block, there is no such thing as process, or an event, or causality,
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isn't it? There's just this overarching pattern that is the block, right? Well, there are events.
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There are events scattered through the block. It's a different way of thinking. It's counterintuitive.
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But it's like a giant noun rather than a giant verb. If you think in terms of time and events and
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process, you're thinking in terms of a verb. Verbs are relative. And this is actually,
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it's closely related. Everett's PhD thesis was called the relative state version of quantum
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mechanics for kind of this kind of reason. Now is just a way of talking about my relationship to
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other moments of time that are equally real. They don't exist now, but they exist in the sort of
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whole four-dimensional block version universe of reality. And the only reason to do this is because,
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again, it's the simplest, most straightforward reading of the equations. The equations that we,
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as far as we best know them right now, of fundamental physics, don't distinguish
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between yesterday, today, and tomorrow. They're just different numbers on a line.
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And both the block universe view and the many worlds view come from this philosophy that,
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you know, you mentioned before, you sort of gave the game away, that these pictures are very
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counterintuitive. And the philosophy is, well, sure, they're counterintuitive. Like,
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why should our intuitions, developed over some number of years of evolutionary time,
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teach us anything at all about relativity, cosmology, or quantum mechanics? Like,
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it would be very surprising if our best view of the fundamental nature of reality was not
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highly, highly counterintuitive. And in that situation, I would argue,
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the best thing we can do is take the equations seriously. And that leads us to the block universe
00:25:28.160
and to many worlds. Okay, so then why does time seem to flow the way it does? And how do you think
00:25:36.320
about the future being different from the past? Yeah, so that's a good question. We don't know the
00:25:42.320
entire answer to that. Half of the answer is the physical answer as to why the past seems different
00:25:50.800
from the future is because of entropy, right? Entropy is physicists' way of talking about the
00:25:55.920
messiness, the disorderliness, the disorganization of a physical system. And entropy tends to increase
00:26:02.640
in closed systems over time. So if you take cream and coffee, mix them together, they become higher
00:26:09.120
entropy as time goes on. It's very easy to mix them together. It's very hard to unmix them. If you
00:26:14.720
have cream mixed in with coffee, it'd be very, very difficult to lower their entropy. It can be done,
00:26:19.360
but only by increasing the entropy of the universe somewhere else. So the amazing thing is that this
00:26:26.560
simple definite feature of the universe, which is enshrined in the second law of thermodynamics,
00:26:31.520
entropy increases, we would claim that underlies every single difference that we notice between
00:26:39.040
the past and future. So the fact that we were born as little babies and will die as older people,
00:26:45.200
the fact that we remember what happened yesterday but do not remember tomorrow,
00:26:50.080
the fact that we have free will about making choices today that can affect what happens tomorrow,
00:26:54.880
the way that I put it sometimes is you all could choose right now to get up and leave, right? That is
00:27:01.680
something you could do because in some sense to you the future is open. You could not choose to not
00:27:07.600
have come here already. Where does that asymmetry come from? There's a long song and dance but
00:27:13.680
ultimately the answer is because entropy was lower in the past. How that works psychologically is more
00:27:20.400
of a neuroscience problem actually than a physics problem. We carry around in our brain little memories
00:27:26.320
of what just happened as well as little projections of what will happen and we're constantly updating these
00:27:32.240
things on the basis of new information and that gives us this sense of an impulse or a flow even
00:27:37.760
though all the, to a physicist, all of those moments of time are equally real. Right, so you mentioned
00:27:44.240
free will which is getting us closer to areas of interest and potential disagreement. Although I don't
00:27:50.320
think we, yes a little bit, but I actually don't think we disagree about the core claim which is the
00:27:59.280
the free will that most people think they have, this notion that you could have done otherwise.
00:28:05.440
Neither of us believe in that. There's the physics of things, if you could rewind the universe
00:28:12.000
to precisely the state it was in when everyone decided to come here, everyone would still decide
00:28:17.280
to come here helplessly a trillion times in a row, for better or worse. Yeah, they might be rethinking
00:28:23.440
it out. I would put a little footnote because whenever you say, could not have been different,
00:28:27.760
you have to say, given what? So if you were Laplace's demon, if you were, like you, like you correctly
00:28:35.120
said, if you absolutely knew everything about the physical state of the universe, then it would have
00:28:42.560
given the uncertainties due to quantum mechanics for putting that aside for a second. But otherwise,
00:28:47.200
yes, it would have, according to the laws of physics, played out in exactly the same way.
00:28:51.120
But as we footnoted before, there are other ways of describing the universe, emergent,
00:28:55.680
higher level ways where you're not Laplace's demon, where you can say, given what we actually
00:29:00.960
know about the physical situation at some earlier time, what could have happened? And there you still
00:29:06.720
might get some probability distribution over what could have happened, and the answers might have
00:29:10.320
been different. Well, so you're saying that it's a lack of information that carves out of space for free
00:29:17.520
will? Yeah, absolutely. So, but it's that a puppet is free as long as it can't see its strings. What
00:29:25.840
would it mean to actually see the proximate cause of the thing that is effective in each moment?
00:29:32.880
Well, I think that it would mean that you would have to be Laplace's demon, that you would really
00:29:36.320
have to. So the idea of these emergent theories is you throw away a lot of the information that Laplace's
00:29:44.240
demon would have, yet you still retain some of the predictive power. And in fact, like I really
00:29:49.520
like to emphasize, this is a very unusual, special, quasi-magical situation when that happens.
00:29:56.320
Typically in physics, if you give me some information about the air in this room, right,
00:30:00.720
if you give me the position and velocity of every molecule of air, and you pick out one molecule and
00:30:05.760
say, how is it going to move, right? So Laplace's demon has no trouble telling you exactly what it's going
00:30:10.640
to do. But if then you say, okay, I only tell you the position and velocity of half of the air molecules,
00:30:17.440
Laplace's demon has no idea where this one's going to go, because it's going to be hit by the ones you
00:30:22.400
don't know about. That's the generic case in physics. You throw away a little bit of the data,
00:30:27.680
you lose all predictive power. Emergence is this wonderful exception to that rule where you throw away
00:30:34.080
almost all of the data and keep an amazing amount of predictive power. So if you want to talk about
00:30:39.040
the motion of the earth around the sun, you don't need to talk about the position and velocity of
00:30:44.320
every atom in the earth, right? You just need to know the center of mass. And that is an enormous
00:30:49.520
saving of information, and you still get quite good predictive power. So when it comes to things like
00:30:56.880
human beings, the best emergent theory that we have necessarily has probabilities built into it. We
00:31:06.800
don't have a deterministic way of talking about human beings given the information we have about
00:31:11.840
them. That's why I would argue it's useful to talk about free will.
00:31:15.120
Well, the thing is, but adding probability to it or chance or randomness doesn't give people the
00:31:22.320
freedom they think they have either. So if I told you that you might have done differently had
00:31:27.040
someone roll the dice in your head and it would have produced a different synaptic outcome. That's
00:31:35.600
not what people feel they have as the authors of their actions. So the libertarian sense is there's
00:31:41.440
no upstream proximate cause of my decision, but for me making the decision. The fact that it gets made by
00:31:48.800
a deterministic universe or deterministic universe plus probabilities that I didn't
00:31:55.840
have a hand in either, that isn't the feeling that gets carried forward in consciousness in each
00:32:00.480
moment. Yeah, so I don't want to get too bogged down in this because this is the sort of the
00:32:04.480
definitional morass that becomes less interesting. So I think people think different things about what
00:32:11.600
they have in terms of free will. Neither one of us believes in libertarian free will in any possible
00:32:17.200
sense. If you were Laplace's demon, you would be determined a hundred percent. The way that I like
00:32:22.240
to put it is, if you didn't believe that, if you believe that even if we knew everything about your
00:32:28.400
atoms and molecules, there's still something extra that makes me able to affect my motions
00:32:33.840
open and over and above that, then here's a simple experiment. Jump out of the window of a tall
00:32:39.440
building and use your free will to change the motion of your center of mass. No one thinks they can do
00:32:45.280
that, right? They think they can use their libertarian free will to change their hands,
00:32:49.120
but not their center of mass. But the truth is you don't even have to engage any kind of suicidal
00:32:53.440
experiment like that. You can just, I mean, I invite you all to just try not to hear the sound of my
00:32:58.560
voice right now. Use your free will not to hear me say these words. Use your free will not to understand
00:33:06.400
them. You know, like you speak English, you're helplessly decoding the meaning of these sounds.
00:33:11.440
There's not a person in this room who can stop doing this right now, right? So that if your freedom
00:33:17.360
doesn't extend to even that. Sure. That's right. Happily, no one has taken me up on the dare that I
00:33:23.520
have suggested to them. But there are other aspects to free will. And this is why I don't even like
00:33:30.320
using the term free will. As a compatibilist, I'm sort of regretful that free will is the label that has
00:33:36.800
been given to the thing we argue about. Because neither you nor I nor Daniel Dennett or any of
00:33:42.000
our friends at this level think that there is some magical spark that lets us overcome the law of
00:33:46.800
physics, right? The question is, is there a, the question to me is, can we describe, what is the
00:33:54.000
best possible way we have of describing how human beings behave? That's the question. As far as I can tell,
00:34:00.720
the best emergent effective theory we have of human beings is one that inevitably involves them being
00:34:07.120
agents that make choices. Certainly, I think, and we can argue about this too, if we want to discuss
00:34:13.120
things in a vocabulary of morals and oughts and responsibilities, we need to imagine that human
00:34:19.920
beings make choices. And also empirically, I think that when I go to the restaurant, I do make choices.
00:34:26.080
So if someday we come up with a better description, a description of human beings that,
00:34:32.560
given the same data we have about them, lets us describe what they will do with better accuracy,
00:34:38.480
then I will totally give up on any connection or commitment I have to the idea of free will.
00:34:43.200
I just don't see that theory yet. Practically speaking, it's not that the best way to order food
00:34:49.680
in a restaurant will be to scan your brain to figure out what you're going to order. It would be,
00:34:54.240
the easier thing is just to order. But the order still comes from somewhere which we know that if
00:34:59.840
we were paying attention to what's happening at the level of the brain, it is happening there and
00:35:04.800
is determining the choice you make even while you still think you're making up your mind, the you,
00:35:10.640
the conscious witness of your experience. And we know that's the case. And that is undermining of
00:35:17.280
what people feel they have. And the reason why I think this is important and not just
00:35:22.640
a merely academic conversation is that I think this does begin to have ethical implications
00:35:28.560
when you think about the possibility of just understanding the human mind more and more
00:35:32.960
deeply. So we have this category of human misbehavior that we call evil now. So there's evil people in the
00:35:38.480
world that they do terrible things that we have to figure out some way to prevent. But the physicist
00:35:46.320
in you must see them, I presume, on some level as malfunctioning robots, right? I mean, they're part of
00:35:53.440
this concatenation of events that's ultimately describable in terms of physics. And if there was some
00:36:00.960
way of understanding evil at the level of the brain, there would be a more complete description of it there.
00:36:06.240
And if there were a way to remedy it, right? If there were a cure for evil, if there were a pill
00:36:12.800
that could cure a psychopathy, say. I mean, just take one band on the spectrum of evil. So we have
00:36:17.760
these people who we diagnose with psychopathy. And we sort of dimly understand anomalies in the brain
00:36:25.920
that correlate with that condition, conditions of low empathy and all the rest, and a disposition to use
00:36:32.240
instrumental violence. If we understood that perfectly and could intrude in the brain in a way
00:36:37.200
that was harmless and just change them. And so every time you gave a psychopath this pill,
00:36:42.240
he promptly apologized for everything he had done and said, I'm such a relief. I was such a bad person.
00:36:48.160
And now I'm just horrified and thank you for this cure. And then he lived every day of his life as
00:36:54.000
morally healthy as any normal person. We would cease to have this category of evil. We would just cure
00:37:00.400
people. And so we certainly wouldn't have a retributive justice system that punished people
00:37:06.560
because they were the true deserving authors of their actions who deserved to suffer for all that
00:37:11.840
they had done. On some level, we would recognize them to be casualties of bad biology, which we now
00:37:17.200
have a remedy for. Short of getting that remedy, the door is already open to viewing even evil people
00:37:24.480
as on some basic level, unlucky inheritors of bad biology or a bad mixture of biology and environment,
00:37:32.240
or just whatever concatenation of causes makes them how they are.
00:37:36.320
Yeah. So, I mean, there's a lot going on there. I think that I completely agree that thinking
00:37:43.200
clearly and scientifically about where people's motivations and the causality behind their actions
00:37:50.320
come from will have enormous repercussions for how we think about responsibility, how we do criminal
00:37:58.240
justice, how we do morals and ethics more generally, right? And I think that advances in neuroscience and
00:38:06.560
psychotherapy of various ways or alterations to the brain could very well have these enormous
00:38:13.680
ethical implications, which I don't have strong feelings about what they are, but I totally agree that
00:38:18.480
we should start thinking about them and that's very important. I don't really think that it gets at
00:38:24.560
the point that I wanted to make about how we think about the effective theory of human beings as
00:38:32.240
emergent phenomena. I think that if you imagine, I think that what you're doing by imagining looking into
00:38:40.400
the brain and seeing what someone is going to do and saying that changes our understanding of their
00:38:47.360
responsibility for their own actions, to me, that's fine, but you're not changing our best theory of
00:38:55.440
human beings. You just have a theory of a lower level. You know, Plato would have said that there
00:39:00.720
is something called the platonic form of a chair, and this chair participates in that form. And today,
00:39:07.520
we know that's not true. The chair is made of atoms, okay? It's a particular shape of atoms. But we don't say,
00:39:13.200
therefore, there is not a chair, right? Therefore, the chair went away. There's a description of the
00:39:18.560
chair as a chair, the level that we describe it as chairs, and there's another level below where we
00:39:23.040
describe it as a collection of atoms. I see no incompatibility with saying that there is a way of
00:39:28.400
describing human beings, which is the best way we have given the data and information we have about
00:39:33.920
human beings in our everyday lives, which describes them as agents capable of making choices. And also,
00:39:42.000
that if we knew more about the microprocesses in their brain, we would use a different vocabulary
00:39:47.600
Right. You don't see an ethical implication to the recognition that if you were exactly
00:39:56.960
in the place of the person who's behaving badly, you would be that person behaving badly. So, I mean,
00:40:02.320
you're lucky not to be Saddam Hussein or some bad person. If you had his brain and his life
00:40:08.000
circumstance, you would be precisely that person. That there are no degrees of freedom,
00:40:13.120
apart from whatever randomness you want to throw into the system, to avoid being that person.
00:40:18.320
Yeah, I think that those sentences literally do not make sense. The sentence is,
00:40:26.480
Well, no, I understand that, yeah, something gets lost there because there's no you carried
00:40:33.280
Yes. Well, do you feel you can take credit for being who you are?
00:40:55.440
Well, no, because, see, this is the problem I have in these conversations, because my experience
00:41:00.720
is actually compatible with what we're calling determinism or determinism plus randomness.
00:41:05.760
So, like, I, when I look at how decisions get made, I experience a fundamental mystery
00:41:13.040
in each moment around just what becomes effective. So, the decision to, you know,
00:41:19.280
I see a list of topics here that I can choose, right? Now, if I skip over one and go to the next
00:41:25.440
one, that, quote, decision is always mysterious on some level. It's like, I can have some story,
00:41:32.640
you know, post-hoc story about why I did it in that case. But that always strikes me as post-hoc.
00:41:39.440
And even if the story is accurate, even if I said, oh, we don't need to talk about that,
00:41:45.680
because I talked about that on my last podcast, the fact that that memory arose in that moment
00:41:51.840
is mysterious. The fact that it was effective in the way that it was is mysterious. The fact
00:41:56.320
that it didn't have the opposite effect is mysterious. It could have just, I could have said,
00:42:00.320
oh, well, I talked about that in my last podcast, but Sean's the perfect person for me to bounce
00:42:04.560
that off of. So, everything there is compatible with determinism. So, in this case, I do actually
00:42:09.600
feel like it's possible to see the strings. Then the puppetry is no longer an affront to our
00:42:16.560
subjectivity. It's just, it actually is bringing our subjectivity more in line with what we have every
00:42:22.160
reason to believe that data are. Right. So, the way I would disagree with this analysis,
00:42:27.440
I think it's, I think that what you're saying is related, although at the end of the day,
00:42:32.400
different to an argument that John Searle gave in favor of free will. The argument, it was just a
00:42:41.440
joke. It was literally, he was supposed to be a joke. And he said, look, if I really didn't believe
00:42:45.360
in free will when I went to a restaurant and the waiter says, what would you like to eat? All I should
00:42:49.920
ever say is, just give me whatever the laws of physics determined I will have. Right. And of course,
00:42:55.720
no one does that. And Searle concludes from that, we must have free will because, you know, we don't
00:43:00.040
really act like that. But I think that that's a misunderstanding in the sense that it's a mixing
00:43:04.180
of levels. I think that what you're, the tension that you're pointing at comes from, on the one hand,
00:43:10.300
we have this way of talking about human beings as agents making choices. At the other hand, we also
00:43:15.520
have a different, slightly lower level description of brains. And there are different parts of the brain,
00:43:21.700
and they're talking to each other, and there are subconscious things going on. And we have
00:43:25.540
histories that, you know, led us to certain places that we didn't control. And all of that is also
00:43:31.160
true. But it's compatible in my mind with the existence of another layer where we can talk about
00:43:37.440
human beings as people making choices. It's just that it's a different way of talking about the
00:43:42.240
same stuff. It's not incompatible ways. Yeah. So I fully agree that we can talk in a conventional
00:43:47.380
sense about choices. And the proximate cause of doing something is rather often choosing to do
00:43:54.340
that thing. But if you actually drill down on what a choice is, you are once again laid bare to this
00:44:00.580
stream of causes, which you, the witness of each conscious moment, haven't authored.
00:44:07.600
Well, right up until that last clause, I was going to totally agree and say we should declare victory.
00:44:12.460
But the, the, uh, I think that the, up until that last clause, I thought the thing that you were
00:44:18.320
laying out, uh, that there are two different ways of talking about human beings.
00:44:22.720
Well, I guess my question is, do you feel that your experience is compatible? Let's just say that
00:44:27.980
determinism is true and provably so, so that, you know, we could have the people in, in, with the
00:44:35.140
right scanners backstage actually anticipating everything we're going to say before we say it. So we could
00:44:41.180
see a printout of everything we said here before it could possibly have been recorded, say, or
00:44:45.940
there's some way of proving to us that we are mere puppets. Is your conscious experience compatible
00:44:50.880
with that fact or not? Okay. So that's not an affront to the fact that everything you said
00:44:56.940
tonight could have been predicted. Absolutely. It's fine. It, but that, that maps onto your experience.
00:45:02.140
It could have been predicted by the imaginary Laplace's demon in the back room. It couldn't
00:45:05.420
have been predicted by me. Yes. And so, so, so, so, I mean, and I think, I think it was Max Planck who
00:45:11.160
had that construal of free will. That it's basically, it's just, it's not a claim about the physics of
00:45:16.400
things. It's a claim about the psychology of being a person. The fact that you have incomplete
00:45:20.360
information about what you are going to do always makes it seem like you are the free author of your
00:45:26.780
thoughts and actions. It's a psychological claim about what it's like to have incomplete
00:45:31.820
information about your own physics. Well, we're getting very, very narrow here, but it's not
00:45:36.020
quite, to me, a psychological claim. It is, again, a claim about what is the best way of talking about
00:45:43.540
human beings at this level of description. And the way that it sounds wrong is when you use words that
00:45:51.500
should only be used in the vocabulary of human beings making choices like you or yourself, and you
00:45:59.900
translate them down into the layer that is more imaginary, where we have a lot more data, where
00:46:05.260
you say, you are the author of all these influences, or, you know, how could you be affecting all these
00:46:11.060
things that you didn't even know were happening? But you're not allowed to talk that way. You're
00:46:14.940
allowed to talk about you as a person talking to other people making choices, or you're allowed to
00:46:19.940
talk about brains being influenced by things, but not both at the same time. And you don't see a way in
00:46:24.380
which those two levels will come into tension when we have a greater understanding and more
00:46:31.240
predictive power of the base level. I mean, it is just a thought experiment to think of Laplace's
00:46:38.500
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