2024-10-11 22:54:42
Brett Hall and I interview David Deutsch, physicist and author of The Beginning of Infinity. Also see The Deutsch Files I, II, and III.
Naval: I can only start with what understanding I want. And I know I’ve asked you this before, but I want to be pedantically exhaustive about connecting the four theories of The Fabric of Reality. And the reason I bring that up is because I think most people still view what you’ve written as being four separate things.
And it’s hard enough to grasp these four separate things because they’re actually fairly deep and wide-ranging theories. But I think, in your mind, they connect together into one thing. Knowledge is a crystal and nature has no boundaries, right? These are just phrases, but these things all connect together.
So we’ve talked in the past, for example, how epistemology and evolution connected, that they’re both forms of knowledge creation. We’ve talked about how quantum physics and computation connect to create quantum computation. I’d just love to get as many examples. How does physics connect to evolution? How does evolution connect to computation?
For example, things that may be less obvious where people might view things as different theories, but to you, they’re fundamentally the same.
David: Yeah. Evolution and epistemology, people find both of those, the connection between both of those and physics, very counterintuitive because most people think of physics in a very bottom-up way.
And I think, for completely independent reasons, such as Constructor Theory, that’s a mistake. Ever since that idea caught on, like sometime after Newton, physicists have tried to shoehorn other physical theories into that mold, and that gives rise to, for example, the problem of the foundations of thermodynamics and statistical mechanics.
How can you have an exact second law when the fundamental theories of physics are all time-reversible and the second law is time-irreversible? How can you have that? The prevailing view is thermodynamics and epistemology are both emergent theories. And, therefore, not fundamental from the physics point of view.
And therefore, if we want to understand the universe at a fundamental level, we needn’t bother with those. Those are just like the theory of washing machines or gardening. I think that’s artificial. And especially when they have to get very embarrassed when they exclude thermodynamics from physics in that way.
I think a theory which is going to go deeper than the current paradigm of physics is going to have to put emergent phenomena and emergent theories on the same level as microscopic theories. People talk about reductionism and holism and some people are reductionists and some people are holists. I think I want to put them both in a sack and tie it up and let them come out with a resolution.
There cannot be a criterion for excluding a set of theories from the body of knowledge other than whether they’re good explanations. Yes, abandon them if they’re not good explanations. But if they are, why make a class distinction between them? It’s just going to lead to error. And I think it has led to errors in thinking about the world. So that’s the connection between physics and those two.
Naval: What you just said, for example, is that reductionist theories aren’t the only theories there are because they don’t form good explanations at the level where you need them.
David: Yes.
Naval: Because especially when you have emergence, then you have very unpredictable things. You’re not going to calculate all the particle collisions from the Big Bang till now to figure out how humans evolve. Or how species evolve.
At every level of emergence, there is a possibility for an explanation that explains that level. And you need that explanation.
David: Yes, exactly.
Naval: So, I think that’s very helpful. And in your thermodynamics example, if you’re trying to figure out how a steam engine works, you’re not going to do statistical mechanics and trace every collision. You’re going to actually probably start at thermodynamics. Yes. And so, that’s a tie between, I guess, is it evolution and physics? No, it’s epistemology and physics.
David: So, thermodynamics is emergent physics. And in terms of those four, it is epistemology. But that just shows that terminology is misleading.
Brett: The terminology in particular of the word “fundamental”, which I think you use slightly differently to the majority of others, especially physicists, they hear, and anyone listening to this, hears fundamental and thinks reductionism automatically.
For example, you would say that people are a fundamental feature of reality. So, what does fundamental therefore mean?
David: So, fundamental ideas are the ones that are needed in more types of explanations. We’ll never get to the ultimate fundamental theory, because that would mean that there were no more problems. That can’t happen. But yes, so that’s how I use the word fundamental.
Naval: I think you also said something related, which is that if reality is what is needed in your explanation or what has to exist in the explanation for the explanation to make sense.
David: It’s a rule for deciding that something is real.
Naval: Yeah.
David: It’s not the meaning of real, because there are things we don’t understand about “real”. Like, in what sense are numbers real and abstract objects real? And in case physicists don’t like that, I always ask: In what sense are laws of physics real? Because we can’t trip over one, but on the other hand, we can’t understand anything in physics without them. So, they’re real.
Brett: Some would claim we are cognitively incapable of understanding physics full stop up to a certain point. This is the idea that Richard Dawkins has of “Middle World” which was cropping up very recently in discussions. Our brain evolved on the African savannah in order to survive. So, it should be no mystery to us, no agreement about what quantum theory means, because in fact we are cognitively closed to understanding things that are too small, things that are outside middle world because they travel too fast or are too large like the entire cosmos.
But this is flawed because of universality?
David: Among other things.
Naval: We understand quasars and subatomic particles.
David: If that argument had been valid, then we would have stopped a long time ago in understanding things, especially like mathematics, but also physics.
Brett: And that then brings up this connection or draws out this connection between quantum physics and epistemology. Can you draw that line, that connection?
David: So, the nicest one, I think this is the one that Naval also likes best. The idea of a crystal in the multiverse. If knowledge is a kind of information, which once it’s there, keeps itself in existence and gets that property by error correction. Then, since there are many errors for every possible truth, many possible errors for every truth, then in the multiverse, if there’s error correction, then there are a bunch of unlike universes, which become alike in the region in which they’re correcting errors.
And, so, that’s a striking connection between epistemology and physics. I hope that this kind of connection will be amplified once we get to formulating theories of knowledge and so on in constructor theory. Constructor theory isn’t limited to the parochial properties of quantum theory. It emerged from quantum theory, but it emerged from problems in quantum theory. But it’s a level of description, and I’m gesticulating as if it was a higher level, but actually it’s a lower level of description than quantum theory.
It’s more reductionist than quantum theory, and yet it is more compatible with emergent properties. We’re hoping eventually that things like knowledge and economics, ultimately consciousness maybe, though my own view is that consciousness will require an extra idea, not just elaborating ideas from within constructor theory. It requires an idea, another idea, at least one.
Brett: Hitherto, the line from Newton through to Einstein and then to quantum theory has been ever more difficult and elaborate mathematics. And, so, then string theory comes along, and this I think leads to the general opinion that the next theory of physics will be more mathematically challenging, and hence all the reasons earlier that maybe we won’t be able to understand it.
But constructor theory seems to have echoes of that famous Feynman line where he said that perhaps the ultimate laws of physics, or whatever he meant by that, would be more like the rules of the checkerboard than some fancy dynamical mathematical laws.
Is that what you have in mind with constructor theory? Some checkerboard type notion of possible and impossible moves.
David: Yeah, it could be just like that. If you have a listing of all the moves in a game of chess, you can’t understand what’s happening there unless you know the rules of chess. But knowing the rules of chess, the people who make chess programs think that if you know the rules of chess, you can understand all the games, but they’re not true.
If you want to understand the games as opposed to just win them, then you need a lot more than just the rules. And yeah, Constructor Theory is just like that. We hope.
Brett: But it’s more than just physics, as you say. This is an explanation that’s not merely about fundamental laws of physics, but is it extendable into biology and epistemology?
David: Yeah. Or you could say that physics is going to consume all those fields, just like it has consumed many other fields. We think of Constructor Theory as a theory of physics. And if it consumes those fields, that’s what physics has always done.
Naval: Okay. Can I back up for a second on Constructor Theory? Because I think it’s the part that might be understood the least by the general audience.
I know that Chiara wrote a book on it. You have not yet written extensively for the lay people on it. What problem are you trying to solve? And where are you at so far? And what level of confidence do you have that this is the right thing to do, approach to go down?
David: Oh, those are very long, long questions.
Naval: It’s okay. I think the answer is illuminating.
David: So, when I wrote my first paper on Constructor Theory, which was a philosophical paper, it didn’t really have any physics. It was published in Philosophical Journal and I wanted to explain what we were trying to do, what this research program is, because we didn’t know at the time, and we still don’t.
What the definitive rules of constructor theory are going to be, we’re going to find those as we find the applications. So, I thought I would give some motivation. We don’t have a good theory of initial conditions. Think carefully, why should we need initial conditions when we are perfectly fine to have no theory of the final conditions?
So that’s one thing. And then the thermodynamics thing. And then there’s the fact that things like computation and information can’t be expressed in the initial conditions plus laws of motion way. And I thought I would write a quick paper and I ended up with 18 motivations. And you can look up the paper if you want to see all 18.
I can’t think of them all now, but this seemed to me a motivation for thinking that this constructor theoretic approach was a very simple change in worldview in a certain way. You can say very quickly what the change is, but the ramifications are huge. And it seems to touch all these problems in different fields.
And that’s what motivated me to try to make a theory out of this. And the next thing that happened was that I gave a talk at the Clarendon Laboratory and Chiara was in the audience. She was a graduate student working on quantum information. And she came up to me afterwards and said, uh – what about – so that can’t be right. Can it? Because…
I had indeed contradicted myself in the talk. And so, then she came round and, and we chatted about it, and I said, do you want to work on it? Because there’s a lot more to work on than one person can do, especially me. So, she said, yes. And since then, she’s worked on the Constructor Theory of Life, Constructor Theory of Probability, which in a way, translating existing theories into constructor theoretic form.
And uncovering little nuggets. My favourite nugget is that in constructor theoretic thermodynamics, the first law is to do with information, not just the second law. So the way she defines the first law is similar to statistical mechanics, but you end up with the first law that’s about, you can do this and not that, you can do this and not that, and as a result, you get the version of the first law, but better than normal because it incidentally has the property that, let me see if I get this right, I think it incidentally has the property that there must be a lower bound on the energy, whereas existing thermodynamics doesn’t. You have to put that in as an extra axiom. And if there were no lower bound, then you could have an object that you were just extracting energy out of without violating second law, just first law, extracting energy forever.
And that would make a perpetual motion machine of the first kind. In the existing thermodynamics, you have to impose that as an extra condition and construct theory, you don’t have to. Meanwhile, I’ve been, no, we, we have together been working on the Constructor Theory of Time. Yeah, perhaps I should say something about the Constructor Theory of Time.
Really the first people to have this idea were Wheeler and DeWitt, who were trying to find a viable theory of quantum gravity. And they found a theory of quantum gravity in which there’s no time. Time doesn’t appear in the theory. There’s just different spaces, three dimensional spaces, which all have amplitudes, quantum mechanical amplitudes, and they all exist simultaneously. And time is an emergent property the way they are entangled with each other, but nothing ever changes. It’s just an emergent property of how they’re entangled. And then, Julian Barbour made a big thing out of it, wrote a whole book about it, then Page, so that was a theory tied to general relativity.
It would only work in the context of general relativity. Page and Wootters made a construction that will work in any quantum theory, not just quantum theory of gravity, but any quantum theory, you can formulate a theory of time that doesn’t have things changing in it. And, so, the static universe still has time because of entanglement.
So that is more general. It doesn’t require Wheeler and DeWitt’s specific theory of space time and when I saw Page and Wootters’ theory, I immediately thought, yeah, this is it. This is what time is. And then many people have tried to get something more out of it and they failed. And then Sam came along and got something more out of it. So, he’s got the most advanced theory of time in history. In the universe, in the multiverse or whatever, so far. In a way, it’s only a small improvement on Page and Wootters’, but it is more general and that’s what we want. And then Chiara and I are working on the Constructor Theory of Time, which we hope will be this kind of, for the moment, the ultimate version of that, which instead of deriving the concepts from some theory, like quantum theory, it lays down rules that it says.
Any theory that obeys these rules will have time and Chiara already did that with probability. So, any theory that obeys these rules will have probability, even though there’s no stochastic processes. So, it has probability in the sense that quantum theory does, that an observer, a rational observer will bet in certain ways, but nothing can happen in, in everything’s deterministic.
Constructor theory, by the way, is necessarily deterministic. It can’t work unless everything is deterministic.
Naval: But your view of the quantum multiverse is already deterministic.
David: Yes. So, the quantum multiverse obeys that rule. And I’ve also written that the prevailing concept of a stochastic theory that just doesn’t make sense.
Saying that something’s more probable is like saying it has more magic. Nothing follows from that statement. You need an extra theory to make sense of that statement. And now I’m working on the universal constructor.
Naval: Is universal constructor related a little bit to your talk in The Fabric of Reality about virtual reality generators?
David: Only, so that’s an interesting thought. I don’t think it’s related to, except in the general way that the fact that there is such a thing as virtual reality. That you can make a virtual reality machine in our universe and that it can simulate anything then that’s Turing universality or computational universality.
In constructor theory, you hardly have to say that. It’s so built in that it is the most natural thing. You’d have to work very hard and get over some very difficult obstacles if that weren’t true in constructor theory.
Naval: So far in constructor theory, you’ve basically got some better or more universal explanations of existing theories.
David: Yes.
Naval: When do we start getting predictions? When do we start getting tests?
David: So, I guess having a lower bound for the energy is a prediction, not a very strong prediction, because everyone believed that already, I think that’s where constructor theory will start making new, where people will start formulating theories about new things within the constructor theory framework, that will be when these new things combine existing theories where it was unexpected before. Now, I don’t believe in the Quantum Theory of Life, for example. I think that’s a dead end and blind alley. But that sort of thing is the sort of thing that Constructor Theory could provide a framework for that existing theories don’t have a framework for.
It’s a pity. It’s like, I thought in The Fabric of Reality, I thought that the multiverse kind of solved the problem of free will. I didn’t quite say that there, but I hinted that maybe it solves the problem of free will and I don’t think it does at all, but even though it doesn’t solve it, it gives a framework in which one can think free, because free will involves counterfactuals have much more meaning in theory of the multiverse than they do in a Newtonian or classical theory and in constructor theory, they have even more meaning.
That’s the kind of thing I can’t foretell the growth of knowledge. I don’t even know that constructor theory is going to work. It could end up as a kind of curiosity, that this is what people in the early 21st century, some people thought would illuminate things, but it only provides a little bit of illumination.
And now we know what the real illumination is. We don’t need it. That might be, or it might be the opposite.
Brett: This is a meta question. I don’t want to take us off on a tangent, but you just said there, as a good Popperian would, that Constructor Theory could be completely wrong and it will just be a footnote in the history of physics.
There are other people out there with new theories as well. They do not speak in a Popperian way, and they will say about their new theory that they’re holding up, that this is going to solve the origins of life, this is going to tell us what the nature of time is, this is going to solve what the preconditions of the Big Bang were, and so on, with great confidence.
And they, I have to say, get a lot more attention and they get the investment and they appear on some big podcasts and things. Is this an inherent disadvantage of being a Popperian that we couch our terms in such conjectural language?
David: I suppose if you were fanatical about getting approval and funding, then you would maximize that.
But I think people working on things, usually the people working on deep things, for their own sake, for the sake of those things, are the ones that tend to make progress. In some cases, that will make them famous, like if you invent mRNA vaccine, then it’ll make you famous, though those people weren’t famous before.
And I think, I’m always suspicious when someone says what they’re going to invent, or what they’re going to prove, or what they’re going to find. I would rather they said: This is a problem I’m going to address. I don’t know where it’s going. Here’s my problem. We find it interesting. We think it might do so and so, but maybe it won’t.
Maybe it’ll do something we haven’t thought of. I think that’s, I find that more attractive as a stance. Like when I’m thinking of someone else’s you know, elevator pitch, I think Popper used to say: what is your problem? What are you working on? And that in research, when you meet someone who is not in your field, the first thing you say is: what are you working on?
You know, that’s not, what are you going to find? That would be a weird question.
Naval: This is a little historical, and I know you don’t necessarily like to go into your own thought process because we’re not here to copy you, but I think it is illuminating to think abou the connection you made between physics and computation.
You basically have created the, or helped create the quantum theory of computation. And there are a lot of researchers and technologists now working on quantum computers, tons of them. In fact, we just talked to Maria, she’s off to work at some quantum computing company. And not all of these people believe in the quantum theory of the multiverse.
Did you start with Hugh Everett’s ‘Many Worlds’ theory, and then get to quantum computation? Or was that? And do you view that as fundamental? Like, how, can you explain quantum computation with the observer collapse theory or is that just contradictory?
David: As you may know, when I first came up with the idea of a quantum computer, I didn’t even think of it as a quantum computer.
I didn’t call it that. What I was trying to do is, so, the consensus at the time among people who work on Everett’s multiverse theory was that the multiverse theory gives the same experimental predictions as collapse theory. And, in a way, that was already known to be false. There’s the paradox of Wigner’s Friend, and, you know how people just take paradoxes?
Yeah, that’s a paradox. They don’t think that’s a reason why we’re wrong. It’s fundamentally wrong in our worldview. So I thought that Everett’s theory must be testable. And, it was testable, because it proposed the different dynamics from the wave function collapse, all the wave function collapse theories.
So, I thought, okay, how would we test it? And, I thought, simplest thing, you do a version of the two-slit experiment. Then you have to have a measurement of that measurement. And how do you do that? And I thought, oh, it could be done with a computer. So, there’s this computer that, but it’s a computer that’s going to have quantum, the two-slit experiment or whatever you call it, the Stern-Gerlach experiment or whatever, they’re all equivalent really, if it’s going to have that in it, then the computer can’t be decoherent, so it can’t be a classical computer.
So, it must be augmented with these quantum operations. Which operations would you need? So, I added some operations to make a coherent classical computer with these extra operations. And that’s what it was in my mind. It was just an object. It was an object connected to a computer with certain, that what I was interested in is something else.
It was this experiment that you could do. So, then I wrote a paper about that experiment, which among other things, there was only one section of the paper that had that in it. And then that paper was rejected and the story that they said: that’s philosophy. And I was like, okay, I don’t care. So, I put it aside and I didn’t get it out again.
I would tell people about it, like when I was talking to other physicists, I told Roger Penrose and I said, okay, now you’ve got to accept that if quantum theory is true, universally true, then Everett is right. And he said, yeah, but quantum theory isn’t true. Okay. That’s a consistent position, but that’s not the position that the vast majority of physicists took.
So then, at the same conference where I asked Roger Penrose that, I was also talking to someone who worked for a publisher and he said, why didn’t you submit it? And I was like, oh, it’s too much trouble. And eventually I submitted it, and it was eventually published at the same time as my universal quantum computers paper, even though it came much earlier.
And people think that I thought it was in the opposite order, but I didn’t. I first thought of the experiment to test Everett. And then much later, thought about quantum computers.
Naval: Is this the same experiment that’s mentioned in The Beginning of Infinity as going inside the mind of the AI? Yes. I see. So, you came up with that first.
So, you had to create an experiment to test Many Worlds and said, okay, is the observer making a difference? Yes. Let’s get inside the observer. Yes. But if we get inside the observer, it’s just a double slit experiment all over again, unless there’s a different kind of computer than the classical computer, it’s not going to be affected by the same interference effects that the double slit experiment is vulnerable to. So, we need to create qubits or quantum computing or wht.
David: Again, yeah. The term qubit wasn’t invented till much, much later. And, and I did, as I said, I didn’t think of it like that.
Naval: So, you were solving a different problem.
David: Yeah, a different problem. And it, it didn’t cross my mind that this was a new mode of computation.
Brett: And to do this test we’ll need AGI as well.
David: Yeah. That’s not my fault.
Brett: Exactly.
David: It’s the opposition that wants the conscious observer to be, to do something different. Okay. And in that case, you put a conscious observer.
Naval: It needs, it needs AGI and it needs quantum computing. It needs both.
David: Yes.
Naval: The AGI has to be a quantum computer internally.
David: It has to be running on a quantum computer.
Brett: Because the alternative perspective is.
Naval: Otherwise, you have interference.
Brett: Well, yeah, it’s the opposition that is saying that it is the observer collapsing the wave function.
And, so, if that’s their position, then we have to have an observer that can observe things without collapsing wave functions.
David: Yeah. But this observer doesn’t do much that’s quantum. He only, he only does a few quantum operations, like half a dozen quantum operations, but most of the time he’s thinking about things like, do I know this and so on.
And that’s all done with classical operations, but done with coherent quantum objects. So, they have to be done with qubits instead of bits. So, in relation to what we were saying before, I would never have said at the time: I’m going to invent quantum computers. It didn’t occur to me.
Even when I finally did, it was, I wasn’t even trying to do that. I was like, I had this conversation with Charlie Bennett, where he said, “complexity”. I said, complexity is arbitrary because it depends on the hardware. And he said, but the hardware is physics. So, then I said, okay, if the hardware is physics, then you’re using the wrong physics.
So, I thought I would go home and recast Turing’s analysis in quantum physics instead of with paper tape, like he did. And then I saw that there were algorithms that didn’t have classical analogue.
Naval: We talked earlier about how knowledge is that which replicates itself in the environment or tends to get replicated in the environment, not necessarily replicates itself, although it does in evolution.
But it tends to get replicated in the environment. So, if you were able to peek across the multiverse, you would see that error correction leads to the same or similar knowledge across the multiverse. Is that true within a given universe as well? Because the universe is fairly large. There should be error correction processes.
Maybe they’re going on elsewhere.
David: We know that there’s such a thing as convergent evolution, that things look like tigers, but they, they evolved in Australia or whatever. And, and we know that there’s a convergent evolution of ideas because, uh, people can have an idea and person who they’ve never heard of has the same idea and that can happen as well.
It’s not as systematic as it is in the multiverse because in the multiverse. You get all variants of the same kind of size or involving the same number of mutations. They all happen and they’re all error corrected. So convergent evolution is a much stronger effect in the multiverse.
Naval: I see. But within a given universe, does that increase, it’s not probability, but does it increase the idea that there’s more life out there?
Life itself being a convergent property of certain initial conditions. In the
David: In the universe?
Naval: In the universe.
David: Yeah, maybe. But we don’t know. We could be a fluke or this could be a universe where there are very few people initially. There might be a lot more later.
Naval: There’s a lot of Kepler planets out there. What’s your intuition?
David: I don’t know.
Naval: Let’s talk a little bit about anti-rational memes. I think this is one of the least understood parts of what you’ve written about. And it’s mentioned briefly in The Beginning of Infinity. And it’s basically, I think this is the part where I understand the least. Cause I will admit I did not resonate with that chapter as well.
But I think your thesis is that a lot of human progress was held back. Because the creativity went into figuring out how to keep people where they, on the ideas that certain people already said, these are the correct ideas and we’re going to stay here. And then all creativity got poured into reinforcing those ideas as opposed to letting you wander outside of those boundaries.
David: Yes.
Naval: So, what are these anti-rational memes? Are they still around? Or is it always a war between them and the rational memes and, you know?
David: So, first of all, that this happened, it seems to me unanswerable. There’s no other way of explaining why it took 300,000 years at least to get from stone tools to the very first real progress. It depends where, where you count it from starting, but certainly far less. It’s, it’s very recent compared with 300,000 years. I think we should, secondly, I think we shouldn’t be surprised that anti-rational memes exist because evolution, it’s most evolutionarily stabilized thing in a biological organism.
It’s the genetic code, like the biology doesn’t care about, about your arm being chopped off except insofar as that affects the propagation of your DNA and the DNA, all evolution of stuff inside the cell that, affects whether mutations are going to happen in the DNA, they’re all towards greater fidelity.
There are no mutations that reduce the fidelity. Some people, I used to think, and Dawkins has contradicted those people very cogently, that maybe there’s an optimum amount of mutation. Because if you have too much, then too many of you die too soon. And if you have too little, then you don’t evolve fast enough to cope with changing circumstances.
So, there’s an optimal amount and maybe the error correcting mechanisms are not optimized for error correction, they’re optimized for that. That’s not true. The real truth is that species go extinct all the time for this very reason: that they have too strong error correction. Not enough evolution happens to cope with the fact that, that circumstances change. So, the vast majority of species that have ever existed went extinct and they went extinct because they did not evolve to meet the new conditions. And I think that’s what we should expect from memes. It’s a bit of a miracle. That’s not like necessarily true of memes, and I could talk a bit about why it’s not necessarily true.
But the thing we should expect when we first encounter, the thing I expected when I first realized that there were going to be anti-rational memes is that they were going to get more and more anti-rational. There’s nothing to stop them. There’s the fact that they’re going to eventually kill the subculture that has them.
It doesn’t stop them any more than the peacock’s tail, sooner or later will result in the extinction of the peacock species. Even though the male peacocks are still trying to get larger tails and the female peacocks are still selecting the larger tails and all that’s happening. And sooner or later, the species will go extinct as almost all species have.
So, therefore, I also realized that the actual faculty of creativity couldn’t have evolved in order to be creative. It must have evolved for some other reason. And then Popper comes in to save us when he points out that there’s no such thing as instruction from without. There is, in the case of DNA, in the case of DNA we can just copy, like when the cell divides, it can just copy the existing DNA.
There’s no way of copying an existing culture into the next generation. The next generation has to guess and most of the information that it builds up when it is trying to copy has been generated inside itself and is going to be different in lots of ways. So, you don’t need a strong mutation mechanism.
Even so, it took a long time and I don’t think we know the history, Matt Ridley says you need a certain population size before progress can take hold. I’m not sure that’s true. My counterexample is the earliest open societies, the earliest rational societies, like as far as we know, there may have been some before, but the earliest ones we know of, Athens, were very small by our standards and they were even very small by the world’s standards.
Athens was a tiny proportion of the world’s population. And yet, it had this huge burst of creativity, which if it had gone on for 300 years, like ours has, they might well have reached what we have reached, but it was destroyed for various reasons that historians try to understand, and so on.
Our enlightenment having lasted, depends what you count, lasted maybe 500 years, maybe 300 years. It’s far longer than any previous Enlightenment has lasted. They, all the ones that I’ve heard, and mainly the two I discuss in my book, lasted a generation or two, and then they ended. And I think they ended because they couldn’t solve the problem that arose.
They hadn’t, they had what it took. It was just too soon, and they were killed by the bad guys. Winning by, by irrelevant things like force of numbers.
Naval: What do you think are the dominant anti rational memes in this version of the Enlightenment that could prevent, that could take us back to the Dark Ages? What do we need to stay in the Enlightenment?
David: Yeah, I can’t think of a plausible way we could go back to the Dark Ages. I’m sure it’s possible for fundamental reasons. But I can’t really imagine it happening and if I were to imagine it, it would be prophecy. And I can’t really imagine it.
I think when you say anti-rational memes today, we’ve got to make a distinction between the West and everyone else. So, everyone else has still got, other cultures in the world are still dominated by anti-rational memes that embody their culture. That’s the thing that’s mostly the, the, the, the anti-rational memes are mostly devoted to protecting their existence and only secondarily other things. In the West, I think, again, I don’t know, but it seems to me that the subculture or the set of ideas in the West that is most anti rational are the ones to do with education. Why education? Maybe again, maybe we should expect that because, like I said about biology, what are the most stable constructs in DNA, they are the code for ribosomes. The ribosomes are the educational institutions of cells. They are, their job is to pass on all the knowledge from one generation to the next, and they have to do that as faithfully as evolution can make it. And any evolution that occurs is in the direction of making them more faithful.
They’re still not perfectly faithful, but that’s not evolution’s fault, that’s physics’ fault. We’ve got too many cosmic rays coming down and too much ultraviolet light and so on. And it is thought, although again, I saw a YouTube video saying that maybe this isn’t at all true, but biologists think that the ribosome stopped evolving 2 billion years ago, everything else has carried on evolving and the ribosome hasn’t, the DNA code has remained the same, even though you could, and they have, invented a different DNA code and implemented an artificial ribosome. And it doesn’t exist in nature. In a culture, traditionally, the thing that is responsible for maintaining the culture over generations, fighting the fact that people die and cultures want to stay the same, want to preserve their knowledge, are educational institutions. And of course, from that point of view, they have to be anti-rational, just like evolution is. So then, the mystery is not why they’re anti-rational, it’s why everything else has become more and more rational in the West.
And that is, I don’t know, again, this is a matter for historians. Ayaan Hirsi Ali was going to write a book about the Enlightenment and it hasn’t materialized it like I first heard her talking about this many years ago, and I don’t know why she hasn’t written it. She’s the perfect person to write it.
Brett: In a sense the explanation for why almost all species have ever gone extinct is because evolution has not occurred fast enough, if only it could occur faster. And, when it comes to civilizations, the overwhelming majority of civilizations have gone extinct because the mimetic evolution hasn’t happened fast enough.
David: Exactly.
Brett: We are tending in the direction of a more dynamic society, but there are anti-rational memes here that still challenge us. And you just mentioned educational institutions as a source for propagating these kinds of things, but also parenting is another one.
David: Primarily, it’s, the educational institutions themselves which, if you think of institutions as a thing in people’s minds, their ideas, then they themselves are, the most anti-rational memes in the West.
But they also, as you say, quite rightly, they also serve as means of propagating other anti-rational memes. And some people think that they’ve been taken over by a mind virus. And now they are even more anti rational than they evolved to be.
Naval: I think to a point you made at The Beginning of Infinity, these institutions are loadbearing. They carry a lot of knowledge, but because they have heads and tails that can be taken over and a sufficiently compelling idea can come along, take over the whole thing and then it’s masquerading as the former institution, relying on the brand and the signalling value of the previous institution, but it’s doing completely different things.
David: Scary, but plausible.
Naval: Yeah, there’s a very cynical phrase that goes around the internet, it’s someone’s law or something, which is like, any institution’s behavior is best explained as if it’s run by a cabal of its enemies.
David: Ah, you’ve got to be careful. I always apply the criterion of, if that’s true, how do you explain the progress we’ve had?
Naval: Right.
David: There can’t be a law to that effect. There can’t be a Moloch or that thing.
Naval: But maybe it’s as simple as individuals or small groups of individuals coming up with creative solutions. For whatever reason, there was a space and time where they could, they had enough time to experiment with those solutions to see what was real. You can come up with the theory of thermodynamics, then you have a steam engine. The steam engine is actually turning wheels and pulling things. It works. And then you carve out a space in technology and science where these things are accepted and then it expands out from there. And now we may be undergoing the opposite collapse where technology and science are affecting so much life so quickly that people feel destabilized and left behind.
So they rebel and they say, we have to regulate this and control that. And eventually now with AI regulations, we’re talking about limiting the free exercise of mathematics. You can’t have that many flops. You can’t run that operation. You can’t do that calculation even. So, it might be just the genes that, or the means that resist the change. They’re being forced to change too fast. And so now they get the numbers on their side. This is a theory.
David: Yeah. I can’t possibly accept the pessimistic version of that, but something like that is obviously true, but it’s a problem. It’s a problem that is soluble. And it’s up to us to make the arguments.
Naval: What’s underpinning the whole thing? What is underpinning any solution? Is it optimism? Is it error correction? Is it freedom of speech? Is it small groups? Is it, what is it? What’s the counter? What’s the antidotes?
David: I could say freedom of speech is the thing that needs to be protected at all costs, but I don’t think it’s true that freedom of speech is being that much impaired at the moment.
Certain things you’re not allowed to say. So, it’s more that, and certain things you must say, which is perhaps even worse, but they are, I would call those fads, shibboleths rather than actual reduction in the freedom of speech in, I don’t know if you like this analogy, but in medieval times, there were guilds and if you wanted to make anything to join a guild, and therefore there was only one way of making a thing, and there was no scope for inventing a different way of making the thing, because you’d have to join a guild and they wouldn’t let you. Now, that is the kind of thing we do not have at the moment in regard to freedom of speech.
It’s not that anybody that wants to say anything has to get permission. It’s that anyone who says things in public has to obey certain constraints, but they are, I think the language is still universal, even if you obey those constraints. If the things you had to say became a substantial proportion of everything that everyone says.
Then if you had to say Comrade Stalin at the beginning of every maths paper, even then it didn’t completely stop Soviet mathematicians from pursuing maths. And we’re nowhere near that. We’re nowhere near having to make a woke declaration at the beginning of every paper.
Naval: Do you have your pronouns in your bio?
David: That would be, so that’s the thing that isn’t happening yet. That would be the beginning of the law.
Naval: I think culturally, though, the slippery slope is a real thing, because it’s the nature of politics. You get a little bit, it’s a tug of war, you tug more.
David: If it were a real thing, then we wouldn’t have ever had any progress because in the past the anti-rational memes were worse, much worse. And yet the enlightenment happened. The enlightenment was created. By people who were thoroughly constrained by anti-rational memes. They had to, everything they said had to be praising God or praising the King or, and they weren’t allowed to, women weren’t allowed, a whole bunch of things weren’t allowed and a whole bunch of other things were compulsory, but nevertheless, a small number of people, the elites among the elites, the Medici. The Medici were so powerful that they could violate some of the restrictions and it grew from there.
Naval: Elon Musk today.
David: Yeah. And you.
Brett: So, you’d say it’s perhaps exaggerated or you’ve often referred to the age of hyperbole in terms of the fact that there may have been in the past a perceived golden age of things like capitalism, for example, and now that’s under attack, or in the past a perceived optimism during the space age, which maybe has been in decline.
But you think that’s hyperbolic?
David: I think something really bad is happening, there’s no doubt about that. But I don’t think it is a reversion to the old things. Some of the ideologies are the same as old ideologies, but the mechanisms that, again, I don’t know if this is, if you’ll see the relevance of this but the mechanisms that get people cancelled for saying anti woke things are not the same as the ones that used to get them cancelled. And even when those things were in force, Darwin was utterly devastated by the death of his daughter and that was, that was a normal thing at the time. Everyone else thought it was normal. Everyone else thought he was exaggerating when he was taking it too hard. And he never went to church from then on. And his family would go to church and he would wait outside. He didn’t get any personal backlash for that because a gentleman who was an academic could do what he thought right.
And there was nobody to, there was no mechanism to, to force him to do what everyone else was doing. And I think the thing that is causing trouble now. It’s not, it’s not that we’re losing freedom of speech. That’s what I’m trying to say. We’re, I’m not sure how to describe what’s happening. It’s, the mechanism is new. Some of the ideas are old, but they’ve always been around.
People are talking about how England is going down the drain, but England in 1945 basically voted in communism and the Attlee government nationalized everything. Controlled everything. It had absolutely no chance of sinking the project of Britain. And, in fact, as I keep reminding people, it was Attlee who persuaded the Americans to join NATO. So, these were functionally communists. They were violently anti-Soviet. In other words, they were violently pro-British. They believed in the British institutions. They just had various wrong ideas about the economy, so they wanted to implement, which is a very British thing to do.
Like I often say, the systems that are good at error correction make larger errors, and those errors, some of them anyway, the major ones, were corrected.
Naval: As long as you don’t change the system itself to stop error correction. So, there are people who try to hack the system itself and I think that is a problem with giving complete power to one side for any number of years, if they start being systemic changes so that they will not leave power.
David: Yeah. So, we have to use the secondary methods of error correction to stop them making systemic changes. The last few governments, both Labor and conservative, have made changes to the British constitution, which I think are very perverse and going the wrong way. But there’s also the fact that the real British constitution is in people’s minds and the governments can’t change those.
Naval: They try to control the media.
David: Yeah.
Naval: And it’s interesting because now people talk about how the media is controlled, but I think the media has always been controlled. It’s just now we have alternative media so we can see that more clearly. So, more is being revealed than being changed.
You mentioned that the most anti-rational memes exist in the system of education that we have. It’s a modern system, right? Before the Prussians and Napoleon, you didn’t have mandatory public education, for example. In your mind, what is the right way to educate people.
David: So, first of all, I mean, the superficial meaning of institution.
Naval: Yeah.
David: Universal schools and that kind of thing are a relatively recent thing, but the Bucket Theory of the Mind has existed since prehistory and it started improving.
So, Popper came along and contradicted it. No-one has noticed, but he came along and contradicted it in the mid 20th century. But, education had been improving before that, for a hundred years before that because these anti rational memes conflict with the general culture, which had been improving by leaps and bounds through the 19th century and the scientific revolution and so on.
The actual practices of making children sit in rows and recite things by heart and hit them when they don’t, that has changed. But the underlying theory of what, for what it’s all supposed to do, is exactly the same as it was in prehistoric times. The idea is that we want to make sure that the next generation get the knowledge that we have in our culture, faithfully, because that’s what knowledge is. It’s information that is poured into you and anything that’s not faithful is going to be an error because almost all deviations from the true theory are going to be false. And so that just doesn’t take into account that this process of transfer is not a process of copying or pouring. It’s a process that happens inside the recipient and is about the recipient trying to pick and choose between the stuff he sees and trying to make sense of it, trying to make sense of what it’s for and including moral theories and everything, not just factual theories.
So, once you realize that it’s that way around and it’s got to be that way around, then you can begin to see that existing educational practices, from the point of view of the Bucket Theory of the Mind, are the same as they’ve always been. And it needs to be changed. I t just occurs to me now that the ways it’s changed are not really educational.
They have been, because the general culture has got less punitive and been about welfare rather than duty and that kind of thing, it, people have got the idea that you’ve got to pour it all in faithfully, but you’ve got to be nice about it. You can’t be mean, but the whole thing is measured at the end of the day by the exam, which tells you what percentage of the stuff that was poured in, you actually allowed in.
Naval: Okay. So the conditions at the prison might’ve improved.
David: Yeah. Greatly.
Naval: Okay. But as a parent, we’re all terrified by the idea that our kids might grow up not speaking the language, not knowing the mathematics. And just playing with spiders in the corner and be unfit for anything other than agricultural work.
So, what do we do?
David: It’s funny you should mention language, but, uh, speaking one’s native language and walking are two things that are not taught in our culture and never have been, I think. And nobody, there’s some quote from an educational series that says that if children were taught to walk in school, then they’d be 10 years old and still not able to walk.
Half of them would be. And the other half wouldn’t have learned it in class and that, that’s true of everything. So one problem is that this idea of not having an agenda for how they should be, how they should turn out is very counterintuitive because the prevailing theory is not just, it’s not just wrong philosophy or the bucket theory of the mind.
It also goes against cultural practices. But you, if a child doesn’t go to school and meets other children and they’re going to say, oh, you don’t go to school, that’s nice, but what’s seven and five? And then your child is going to say, I don’t know. And I don’t care. And you are going to be embarrassed and you are going to find it difficult not to be and not to pass that on to your children.
By the way, the vast majority of those improvements, not just in school, but in parenting as well, were done by left wing people, which is ironic because their theory of what should be done in the wider culture was always harmful. But their influence on educational theory and practice has been almost everything good that’s happened in education in the last hundred years, has been done by leftists.
And they thought they were undermining society. You would say to them, if you don’t beat children into conformity, then how will they, how will they work in factories? The right-wing people would say, and the left-wing people would say, that’s exactly what we’re trying to do. They were wrong, they were wrong about everything except their educational theory.
So, it’s not that they thought that culture could be transmitted better and also improved by not forcing it. They thought that culture was bad and shouldn’t be transmitted. That was why they did all their good things. And now that they’ve, now that this process is pretty much spent, like you can’t make the classrooms any more pastel-coloured and you can’t speak to the children in nicer ways.
Brett: When I try to explain a more libertarian view of how learning works, it’s: learning just is knowledge creation.
David: Creation, exactly.
Brett: And so, what Popper writes about in how science and knowledge broadly is generated, is what’s going on in the mind of the learner. And it just seems to be a logical line to draw that if Popper begins with the project of sciences, you start with the problem.
Then, obviously, any mandated curriculum, even no matter how liberal you want your curriculum to be, and choice of curriculum, you’re handing the student either problems or worse still, the solutions to problems and as you say, I don’t know if you’re quoting Popper when you say, answers to questions not asked.
That’s like the purpose of it.
David: Yeah. Quoting Popper on that one.
Naval: But if we go to the seven plus five example, that has practical value as well. If the kid doesn’t know how to do seven plus five, they’ll have a hard time navigating our society, which punishes innumeracy.
David: That’s not true. They will have a hard time or rather they will have a problem when they encounter something like how many shoes can they fit in their wardrobe or whatever.
Once they have that problem and they’re free. They will solve it like that. It’s not hard, it’s not hard learning to add up or learn multiplication tables. Like if you know a few facts, you notice that five fives are 25. If you know that, then it’s easy to work out what six fives are.
Naval: Like, I grew up in India partially and it was a given that the people who are uneducated had no chance.
And yes, some of them might be because they weren’t in the right institutions, they didn’t make the right connections, they weren’t offered the right jobs. But some of us, they literally had no chance because the only reality they knew was by some point, okay, now I have to start making a living. It’s too late to learn mathematics and accounting.
Now I’m just going to have to carry a bucket full of cement on my head for the rest of my life. And I’m just trapped into that situation.
David: It could be that society is arranged in such a way that it only allows people to make progress if they, as my friend used to say, if they bear certain scars. It’s not that the scars are functional, but they are like a shibboleth or whatever.
However, I think of the counter examples, one can learn coping mechanisms. It’s supposed to be that you learn the prerequisites in year five, you learn the prerequisites for year six and in year six, you learn, but it’s not true. If you didn’t go to year five, but enter year six, you’d catch up in no time.
And similarly. Being tested for how well you can read stops age 11 or something. And from then on, you’re no longer faced with a situation of read that out loud because the teacher will just assume you can’t. And you, you have coping mechanisms, you have a textbook and the teacher says do the exercises on page 11, and you find that these ways are so painful and unpleasant that most people just knuckle down and learn this stuff by heart, disabling themselves in the process.
Naval: So, what does your school look like? Is it, everyone just stays at home and does what they want? Do they gather? Do they have options? Do they get offered instruments?
David: Everybody does something different. There is no standard thing that children do that. There will be things that a lot of children do, still not all, but there are things that a lot of children do at a certain age, in a certain culture.
Like if Steven Spielberg produces a new adventure film, then maybe this is, maybe I’m out of date now because people watch it on video. But at the time when Steven Spielberg was making his blockbuster films, ninety percent of the children in a town would go there, and they would sit quietly while the film played, and then they would go out. And there was no, there was no roll call at the beginning, and at the end there was no test, but they all were excitedly speaking about the film and variants of it that they would like to see, and some of them became film directors, and so on. Even that, even somebody who’s a genius enough to attract 90 percent of the children in a culture to come to his event, even he doesn’t have the genius to make the children do that every day.
So that’s how far away the school paradigm is from what could and should be. And now I guess I could say the commenting on recent threads on X, nearly all children want an iPhone. Not all, nearly all, and no, there’s no iPhone curriculum, there’s nothing like that. They do it because they, it’s a rational meme, they think it will benefit them.
And so, people then try to explain that because if they couldn’t explain that, if they couldn’t explain that one thing, never mind the other million things, if they just couldn’t explain that one counter example, their whole educational philosophy would fall apart.
So they have to say, A: it’s bad for them. And B: it is caused by coercion, namely the coercion of addiction. It causes dopamine. Wait a minute. Dopamine is involved in all pleasure, right? Never mind that. Or, pleasure is bad, right? We all agree with that. Everybody has problems. Children have problems. They grow up having problems. They all have different problems. They try to solve them. They’re powerless and that’s what parents and society are for, to allow them to solve easily soluble problems so they can get on to deep, interesting problems. So easily soluble problems is like having enough food to eat and difficult problems are the problems that, you mentioned India. I saw this documentary about, it was about electricity or something. It was about children. Was it in India? Anyway, somewhere where the children in the evening go out and sit under the street lamps in order to learn. And, oh yes. So, there’s another example, I’ve probably told you, because one of my favourite examples, in [Frederick] Douglass’autobiography, and I haven’t been able to find this passage.
And I’m told it’s because he wrote several autobiographies and they overlap. And I haven’t been able to find the right one, but he described how he learned to read. Slave children learning to read was illegal, not for the slaves. It was illegal to teach them to read, and there were people who would clandestinely teach them, so there were these teenage boys who’d been working in the fields to the maximum extent that you can be forced to work in a field. Then they came home and then they slunk off to this lady’s house where she would be teaching them to read. And if she had been caught, she would have gone to prison and they would have been whipped. So, then he escaped and he got to the north and he made a great success. Now I always think what a terrible tragedy.
There were these teenage boys who were willing to risk a whipping and to go to these lessons when they were already exhausted, physically exhausted from over hard working. And today, their descendants are thought to be, have a low IQ or be perverse and not want to, and anyway, one way or another, they have to be forced into the school to learn. And their ancestors were exactly the other way around, and I think their ancestors were how humans are, that is how humans are, not just black and white, not just teenagers and adults, but all humans. So, probably, those Frederick Douglass and his pals who went to that lady’s house were not all the slaves, probably some of them didn’t go.
Because they didn’t want to, they thought we’d better get a good night’s rest instead. And maybe that was best for them. Who can decide that better than them? Somebody ought to make a movie about this, by the way, because Frederick Douglass is absolutely brilliant in every way. Not as just a little thing.
I can imagine them talking, the ones that went to learn to read, and they would say it, it completely opens your eyes to a different world, if you can read. And they would say, yeah, but I’m tired. And if you meet Steven Spielberg, tell him.
Brett: Can I play devil’s advocate on the idea of if we extract away schools and we have a, uh, an enlightened fun society where the equivalent of the Steven Spielberg thing is playing and the children go along.
Now, never mind mathematics, but Douglas Murray, my favourite pessimist at times, although he’s optimistic recently, has talked about how it seems as if the West is running out of steam or running out of enthusiasm for itself, as if the story is coming to an end and winding itself up. So, if we move to a place where for all the evils of school, perhaps they’re inculcating at least the students into a version of our traditions and of Western ideals and so on and so forth, because there is no want for enthusiasm in the madrasas, there’s no want for enthusiasm of other cultures wanting to spread their ideas to their children.
Would this alternative to traditional schooling in the West lead to what Murray is worried about, just the exhaustion of the West one.
David: Well, one problem is, as Naval was saying, that the educational, the schools and universities have been taken over by something that’s very hostile to our culture, so that they’re trying to inculcate a rival culture.
So, I suppose Murray wants to go back to the way the educational system was and yes, horrible and disgusting though it was, it did successfully transmit some things, not the things in the lessons, it transmitted a culture. Then after that era, you had the era of like, in Britain anyway, grammar schools and so on, where they, they tried to make it easy for working class children to get into that culture by having the standard education.
And I was one of those, and then later they closed down all those schools. And then, we got to the present state. I doubt that the older model of schools, like the model of schools that existed between say 1880 and 1950, I don’t think they could survive because the culture, the general culture has changed for the better, like I said. The general culture’s values conflict with the static values of education.
So, I don’t think you could set up that school, that kind of school today. I don’t know what to do about freeing the schools and universities because there isn’t like a cadre of, I call them liberal, genuinely liberal teachers, who could go in to replace them. It’s not like the civil service where you could just overnight reform it by the prime minister just declaring that he’s reforming it, but you can’t do that with schools. So, I don’t know, it has to be gradual.
Naval: In a way they’re the most stuck and frozen institutions. I got a tour of the Oxford colleges recently, some of them, and it was all about tradition. This is exactly the way it was 300 years ago. This is exactly the way it was 150 years ago. And, uh, it was interesting to see a mix of such tradition along with, you know, it’s supposed to be so much new creativity and education.
David: They’ve kept exactly the wrong things and they’ve changed things to exactly the wrong things. So, they still have enacting rituals. But enacting rituals isn’t our culture and on the other hand, they’ve got all sorts of subjects that didn’t exist then because they’re useless. And existing subjects, useful subjects are being taken over.
Richard Dawkins almost got cancelled from previous time when he went to New Zealand and they said that they’re incorporating traditional modes Uh, understanding physics and he was like, no, there is only one mode of understanding physics and they were like, that’s racist.
Brett: We already have that in Australia.
The syllabus is replete with indigenous modes of doing science.
David: Well, this was a few years ago, so maybe it’s done in New Zealand and Australia. This is terrible and it’s going to cause everything to deteriorate. I don’t think it will cause the destruction of our culture. But once our culture has deteriorated enough, then the Chinese can walk in.
Naval: I look forward to the indigenous electric motor.
Brett: There was a, there’s a famous, there was a book written by this, what was his name, Dark Emu is the name of the book, where it’s just a revisionist history that claims that prior to European settlement in Australia, the indigenous people were farming, they had agriculture, they were on their way to factories and all this sort of stuff, and people just lap it up and it’s all, it is making its way into the curriculum now as well.
Bruce Pascoe is his name. He claims to be indigenous, but he’s not. That goes to our capacity to error correct. Misinformation is a fashionable term, but it’s also labels a very genuine phenomenon. There was, I think it was only a few months ago that. Osama bin Laden’s letter to America or whatever was going around being praised by certain college students who thought, yeah, not understanding that this was not a good guy.
David: Okay. So maybe the way to go, if we can’t restore 1950s schools, how about restoring 1950s curricula? That’s something that the government could do. The national curriculum, of course, is an abomination, but maybe it’s one of those things that can be, as a transitional thing, have the national curriculum now, and it’s full of woke stuff.
It’s in the government’s power to change that, to make it into true stuff. The government could change the national curriculum, and then it may be that this woke stuff, I said it’s a fad. It’s not. How can I put this? It’s not an evolved thing. It’s not a blind alley that culture has gone down. It’s a fad.
So, it could be that, that after a generation of teaching old fashioned history, history teachers will think that’s what it is rather than, because it’s the teachers and the pupils are getting the revisionist history at the moment. If they got another history, they even notice? Maybe they wouldn’t even notice, I don’t know, maybe I was too optimistic.
But I get the feeling that it’s all shallow. I think of lefties of the twenties and thirties. They believed stuff. They believed in the capitalist class stealing the fruits of the labour of the working class. And this is why the working class are poor and all that stuff. And the remedy is that they had theory, whereas, I don’t think woke is a theory.
Brett: Denial of a whole bunch of otherwise good pieces of knowledge, whether it be science or enlightenment ideas.
David: As I have often said, the negation of an explanation is not an explanation. So, they don’t have a rival worldview, except the worldview that you’re supposed to say certain things.
Not say other things and so on. But it’s not a worldview in the sense that communism was.
Naval: I think it might be an evolution of communism, because there are a lot of communist ideas at the core of it. And they tend to end up on the same side as the communists, a lot of outcomes.
David: Yeah. But. Do they have a theory that, anything about factories.
Naval: They do have a theory that there, there are people keeping them down, that for example, inflation is up because of price gouging.
David: So that’s a theory that the left-wing people used to have. They used to have it because it came from their explanation of the world.
Naval: The finite resource explanation of the world.
David: And, and the more complicated things as well. But I think if you ask a woke demonstrator, maybe I’m wrong, but maybe you could try it. Ask them, how is, how is inflation caused by the greed of the factory owners or whatever it is?
Now, a communist in 1950 could have told you, but I don’t think a woke person today can tell you. Like when they’re asked from the river, they’re chanting from the river to the sea and somebody asks them, which river and which sea and they don’t know.
Naval: But to your earlier point, these anti-rational memes don’t have to be correct. They can drive species extinction and the next species can figure out what was true and what wasn’t.
David: Yeah. I don’t think that’s what, I don’t think they’re going to, I don’t think they’re poison. I think they are a burden.
Naval: They could be poisonous in the sense that they drive certain voting blocks and then those voting blocs drive policies of nations. So, I think your homeland is facing exactly this issue, which is now, I think something like 30 percent of the Muslims are in the West and they’re voting. And so, the traditional support for Israel is disappearing.
David: There are plenty of Muslims who are pro-Israel. The mindless ones are anti-Israel.
Like I just tweeted today that, what’s it called, travelingisrael video blog was talking about the collaboration of the Palestinians with the Nazis during World War II. And he happened to mention, I think he should have made much more of this, that the Grand Mufti was going around Europe recruiting Muslims to the Nazi cause.
In Albania, he totally failed. In Albania, the absolute opposite. They were one of two countries that rescued almost all their Jews. One was Denmark and they didn’t have that many. There was only about 6, 000 in the whole of Denmark, but they rescued almost all of them. But the Albanians, there were a lot of Jews there and a lot of Italian and other Jews had moved to Albania as a refuge and they were all saved because the Albanians as a population thought it was, even as their religion, they thought it was their duty to thwart the deportation of the Jews and they succeeded.
So, this is, as I tweeted as well, this is a counterexample to the narrative that some otherwise cogent commentators, like you just did, assume. It’s not necessarily the case. And it’s also not necessarily the case that, so we’ve had, in Britain, we’ve had Muslim immigrants and then their children are radicalized.
Not them, their children are radicalized. Whose fault is that? That’s not the fault of Islam. That’s the fault of Britain and multiculturalism and pandering to the other and so on, setting up the educational system so that it trashes Britain and glorifies the other and so on. But it needn’t have been, a hundred years ago, there were hundreds of thousands of Muslims in the British army.
Another 50 years earlier, there also were, and they rebelled, but that’s another story, in the Indian mutiny. But then so did the Hindus. So, again, it, it wasn’t Islam, it was the fault of the West. Not for treating them too harshly, in a way for treating them too leniently, they should have been integrated and it should have been understood that the same law applies to them as to everyone else.
I’m a second-generation immigrant and I’m not violent. And my parents came to this country and took for granted that they were going to have to work. And they took for granted that they were going to have to learn English and speak it well and get a job and, and so on, and go to university. And they took for granted all those things.
And the idea that they were owed something by the surrounding culture is quite the opposite. That we owe something to the surrounding culture. That was their attitude.
Brett: To what extent then is it an existential threat to the UK given you have had these huge protests recently taking over parts of London and I think you’ve had people under the auspices of the Green Party getting in and then coming out as vehemently anti-Semitic, anti-Zionist.
David: Yeah, note that those people aren’t the only people who are being indulged in this way.
Basically, it’s everyone who hates our culture is being indulged and everybody who is afraid of that is being demonized. The government can change that. I think the processes of criticism and persuasion are not impaired. The government isn’t, almost everything that Douglas Murray says about this issue is perfectly legal and is going to remain legal even under the most draconian laws that are currently being proposed, which, by the way, may not succeed.
There’s a lot more to error correction in the British system than merely outvoting the government. There’s going to be all sorts of, because the government, one thing hasn’t changed. The government, no matter how large its majority knows that next week, it could go down if suitable things happen. So, the basic reason that the government is going down this wrong path is that that most people think it’s okay. Most people don’t think this is a disaster. They’re like, okay, we don’t want riots, so let’s have laws against riots. And people are arguing, but these aren’t laws against riots. They’re laws against hate or speech, so on. But that argument hasn’t gone down with enough people. And when it does, it’ll change.
Oh, yes! This is what David Starkey was saying. He was saying that the Red Wall, if you know what that is.
Brett: The Labour voting bloc.
David: Yeah, the Labour voting bloc in Northern England, which changed over to Boris Johnson en masse and changed back at this election. The Red Wall is never going to vote Labour again.
Never, ever, because these measures are against it. The Labour Party has severed its connection with the working class and they got in by a combination of circumstances, because the conservative party was rubbish and the circumstances of the pandemic and all sorts of circumstances made people ready for a change, but they have gone down.
Now, I don’t think it’s necessarily that they’ll never vote Labour again, because there are people in the Labour Party who can, who will be able to see what’s happening long before the next election. And I’m sure that there are people in the Labour Party now who see that they can’t go on like this.
We’ll see, let’s see if the current woke legislation actually goes through when the Labour Party has a majority of a hundred and something. That’s not enough for it to work. Let’s see. And if it goes through, the next level of error correction is that it’ll never be implemented. Like the Home Office people will not order the police chiefs to spend the money to implement the surveillance system, which will be necessary to enforce the law. None of that will happen because on the whole, nothing happens. That’s one of the things that’s wrong with the blob. With the civil service, it prevents everything. To have that happening.the government would have to pursue it. They would have to pursue it vigorously and ruthlessly firing the people who didn’t implement it and that kind of thing. And only then, and then even then, when the first people go to jail for this kind of thing, there’ll be an, there’ll be an uproar. What are they going to do about it? Are they going to tell all the editors of the newspapers to say that this is improper and it should have happened?
At some point the editors of the newspapers are not going to automatically follow this line either. There will be a niche for people to contradict it. I don’t think anything’s inevitable. And once that problem is solved, by the way. Then the population problem will also be solved because the obvious way of solving the population problem is by immigration.
Mass immigration is the way to go, and we’ve only got to make sure people who hate this country don’t immigrate into it.
Brett: Ah, but how do you do that?
David: There’ll be, this is something that people who have thought a lot about this, will think a lot about it. At the moment, they’ve been thinking how to do the opposite.
For example, you can have a rule that everybody who is allowed into the country has to declare that they, for a start, love the country and want to do well in it. And then if it later turns out they were lying, they can be deported. Not for being enemies of Britain, but for lying on the immigration form.
2024-02-17 22:50:46
Brett Hall and I interview David Deutsch, physicist and author of The Beginning of Infinity. Also see The Deutsch Files I and The Deutsch Files II.
Brett Hall: On exactly that, the fact that the more that we summarize what I think is an exceedingly clear body of work in The Fabric of Reality and in The Beginning of Infinity; when nonetheless you explain it to people, as Popper says, it’s impossible to speak in such a way as to not be misunderstood. I was just reading today on Twitter, someone claiming that you have said, quoting you, and they’ve put it in quote marks, you have apparently said, Popper proves AI can’t be super intelligent. And, I sort of responded, “He never even speaks in those terms!”, that you wouldn’t rely upon the authority of Popper to begin with, you wouldn’t say proof. So, it’s just another example that you go out there and, as you say, these concentric circles of people that you bring into trying to understand your worldview, the misconceptions compound.
I don’t know what you think about that. Have you said anything like Popper proves that—and this was from a journalist by the way, I think a reasonably respected journalist was saying this.
David Deutsch: No, of course not. As you say, as soon as you see a claim that somebody has proved something, Then, you know, proved it from what? This isn’t going to be Popper, it isn’t going to be me. I’ve proved that if quantum theory is true, then the Turing conjecture is true in physics. That’s what you can do with a proof. Proving something about AGI is inherently impossible if we don’t have a theory of AGI. You can’t prove something about something that you can’t define.
And anyway, proof isn’t what these kind of things are about. These kind of things are about argument. And Popper, I can’t recall Popper specifically saying anything about AI. It wasn’t a thing in those days.
Brett: This word proof is something we haven’t talked about during our conversations, but you do hear it deployed quite often. You know, such and such has been proved, as if to say, this stands in contrast to our notion of conjectural knowledge or fallibility. After all, once something has been proved, can’t we carve it into stone and there it sits for all time? Is the notion of proof on a different level to the rest of our conjectural knowledge, because it sounds, I think, to the typical layperson as if it is.
David: Yeah, well, it isn’t. The difference between mathematics and other fields, as I’ve often said, is not in the way we find knowledge about them, but in the subject matter. The subject matter of mathematics is necessary truth. So when we make a discovery in mathematics, we’re making a conjecture about what is necessary truth.
We’re making a conjecture that something or other that we have defined is a necessary truth. But there isn’t a difference in the way we create knowledge in our minds about mathematics or computer science or psychology or physics. They’re all the same epistemologically.
Naval: One topic that I kind of want to get into a little bit, if I can switch for a moment, is the topic of creativity.
And I know that it’s very poorly defined and something that we don’t quite have a grasp of. And on Airchat yesterday, I was talking to people and I made some comment about, as long as you have room for creativity, you have room for free-will. Because we don’t know where creativity comes from and so that allows you to have this freedom of operation based on your creative theories.
I was making the point that true creativity is not from observation. It’s not from induction. It’s not from some algorithm that we know yet how to run, and it’s not just mixing things together. And immediately the response was someone said, “Well, can you give me some examples of this creativity you’re talking about?”
So, I think to people, they feel like when we talk about this form of creativity, we’re just talking purely about scientific creativity like Einstein. And I think some of these examples that we use are so far out there that people think, well, they’re not talking about creativity, they’re talking about scientific discovery (which is not what they’re talking about). And so, most people seem to automatically fall into this trap that creativity is observation or recombination. And I wonder if we can just explore what creativity is, some real world examples that are just more down to earth, and just kind of, I’d love to once and for all put to bed this idea that it’s recombination.
I think you’ve done a great job showing that it’s not observation, but I think the recombination metaphor keeps coming back. Frankly, because of authorities like Steve Jobs, who authoritatively said, creativity is just mixing things together. And that’s a quote you find on posters everywhere.
David: Yeah, well, it’s only the word “just” that is false there. So, like I said yesterday, you know, it’s like saying humans are just atoms. We are just atoms in the sense that there isn’t any magic thing in addition to atoms that makes us, but that’s not to say that we are just atoms. If you take a snapshot of North America a thousand years ago and then take another snapshot today, the difference between the look of Manhattan Island, then and now, cannot be explained without invoking creativity.
Nothing but creativity could have produced that. There are no natural processes that will ever produce something like a skyscraper. So, to explain the phenomena that happen on Manhattan Island, you need to invoke creativity. But now somebody will say, now point to some creativity. I can zoom down on a particular architect with his old fashioned draftsman’s board and his paper and his ruler and his compass and his brain and I can examine those with a microscope and somebody will ask me, “Well, at which point did creativity happen? What was creative about what that architect did that was not just atoms, and, if you like, bringing together ideas that had happened before.”
Well, if all our ideas are just recombinations of ideas that have happened before, then there’s nothing new about the skyscraper that wasn’t already there when our ancestors were banging rocks together. But there is. They didn’t and couldn’t build skyscrapers, and we can and do. At least, I can’t. But the human species can.
Naval: The other side, they’ll say, “Well, yeah, you can’t go straight from banging rocks to skyscrapers, but they went from banging rocks to figuring out how to shape rocks to build tools and then they recombined that knowledge of building tools and digging and so on and so forth.” It was step by step recombination, almost like an evolutionary process.
David: Well, an evolutionary process is also not just recombination. It’s variation and selection. So, again, it’s the same thing. If you look at the DNA of successive generations of dinosaurs, and they turned into birds, each one of those steps is not evolutionary, and yet the whole sequence is.
But it would be absurd to say the design of a pterodactyl was already in the DNA of non flying dinosaurs. Or that the pterodactyl is just a combination of different things that were in the dinosaurs. It’s just not true. The pterodactyl functionality was nowhere until it evolved. It wasn’t anywhere in the past, not in the dinosaurs and not in the single celled organisms that were the ancestors of dinosaurs. It just wasn’t there. It was new when the ability to fly evolved in the lineage of dinosaurs.
Naval: In the pterodactyl case, there was one or a series of random mutations that turned out to be adaptive for that set of genes. And those mutations were essentially blind. They were broken DNA strands or just new DNA strands.
And in the human case, that’s not quite what’s happening. The search space we’re going through is larger and we’re searching through it faster to make these creative leaps. Is that an intuition that you have? Is there any learning or knowledge behind that?
I’m not trying to solve the problem of how creativity works. I know that’s an unsolved problem, but, for example, could one say that humans are narrowing the search space faster because the creative mutations, to coin a term, that we’re making are not random? They are more directed, or perhaps they’re random, but they’re random in our minds and we cut through them so fast without having to implement them in the real world, that perhaps we narrow the search space faster. Is our process faster? And if so, why?
David: It’s not only faster, it is explanatory, which means that because it’s explanatory, it can leap over gaps in the knowledge space that couldn’t be traversed incrementally. So evolution, it’s not only millions of times slower, it’s inherently different in that not only can it only make small conjectures that are in the form of mutations, but it can only improve on things incrementally.
So, you can only make pterodactyl wings if you previously had limbs, or if you previously had something that could be incrementally changed into wings, such that every microscopic change was still viable as an organism. So that’s why we can’t expect biological evolution, to [use] my favorite example again, to evolve a system for deflecting asteroids.
That is because there is no incremental problem situation where the expenditure of energy or whatever to deflect the asteroid hit. It’s once every few million years, and it cannot exert evolutionary pressure.
Naval: So basically, the creative guesses that humans make, because they’re explanatory in nature, they can leap through the entire idea space and form interconnections between any two ideas or any two states, whereas biological has to traverse through the physical world limitations and what the organism is capable of right now.
David: Yes, and it has to traverse it while staying alive. It has to be a viable organism all the way through, whereas if you want a new design of airplane, and you say, “Maybe it would be better to have the tailplane as a single object rather than this thing with wings,” then, you know, I’ve just said that in one sentence. And if that’s a good idea, it could be criticized by an aeronautical engineer and so on. But to make that change incrementally, we’ll probably produce a whole series of airplanes that won’t fly.
Naval: So is this a consequence of being universal in nature? We can model any system in our head and therefore we can connect any part of it to any other part of it?
David: Yes, I mean that’s really what we mean by being universal. We can get to any idea. And criticize it for whether it is a good idea or not. So the aeronautical engineer doesn’t have to test every single airplane in his wild ideas—you know, maybe he has a wild idea driving to work one day, that maybe wings should be made of paper.
Naval: So in that sense, the biological system is a highly focused analog computer that’s running sort of a single algorithm. And the virtual system in our head is more like a digital programmable computer.
David: The DNA system is entirely digital. This incremental thing is not a continuous change. So, one mutation is still a quantum difference. If you had a difference that involved less than one base pair, then the whole DNA would fall apart. If you try to replace Adenine by glucose, then the whole thing wouldn’t work as DNA at all.
Although we speak of evolution as happening incrementally, it’s incrementally in discrete steps. So, both thinking and biological evolution happen in discrete steps. Biological evolution happens, though, in very small steps, which are undesigned. So, there’s no designer that designs the next mutation, it’s random.
Brett: It strikes me that the SETI project is looking for biomarkers. They’re out there searching for evidence of biology. The way you’ve poetically framed this idea of, well, there are billions of asteroids out there right now across the universe crashing into billions of planets right now, but here might be the one place where if you had the telescope pointed from another planet towards us, you would see the repelling of asteroids.
This would be an indication of intelligence. There’s no other explanation. There’s no biological explanation. There’s no random chance. There’s no magic. It must be explanatory creativity that does that thing. And talking about Manhattan before, everywhere across the earth are rocks being eroded and inevitably being eroded by weathering and rain and whatever. But in some places, the cities of the world, there are rocks, call them buildings, which are not being so eroded or insofar as they are, they’re being constantly repaired again by explanatory knowledge. And so that introduces this idea of knowledge as resilient information, the very thing that will outlive even the rocks. So long as we can continue to survive, then the knowledge that we have will continue to survive, outlasting the longest existing things in the cosmos.
David:. Yes, very nicely put. And Shakespeare, by the way, also said the same thing in his sonnet. “So long lives this, and this gives life to thee.” He’s saying that his sonnet will outlive anything, and he’s right.
Naval: Right. “Shall I compare thee to a summer’s day, thou art so fair,” or so temperate. Yes, that was a great one. It’s also similar to Ozymandias, if you’ve read that one by Shelley where it’s the artist’s conception that survives the empire and the king.
David: Yes, exactly. And it’s simply literally true that knowledge laden information is more resilient than any physical object.
Naval: Not to get personal for a moment, but is this an argument for spreading your ideas rather than having children?
David: Well, as David Friedman says, “If the world is worth saving, it’s worth saving at a profit.” And I would generalize that: if the world is worth saving, it’s worth saving with fun.
Naval: I think you’ve talked a little bit about AGI, or rather creating an AGI, or just people uploading their brains into a computer in the future. And if their minds are in the computer, if the same software is running, then that is a living being, that is a mind, that is the definition of a person. And this brings up all sorts of interesting paradoxes and situations which many sci-fi authors, including Greg Egan, have explored.
What if you were to replicate this mind a billion times? What if you were to shut it down? What if you were to run it back in slow motion, what if you were to pause it? And I think, I don’t know how far we are from that, probably still quite far. Neal Stephenson also talked about it in his book, The Fall. There’s also cloning coming up. I mean, people are now successfully cloning dogs. It’s only a matter of time before we’re cloning humans. Where do you think this leads in terms of the number of people? I mean, in theory, couldn’t we have then infinite people? Or close to infinite people running in a silicon substrate? And does this lead to even more of an explosion of creativity?
David: Yes, it would, and I think something like that will happen. But I think it’s somewhat exaggerating, both the problem and the opportunity. I think we mustn’t think of compute as being free, as the AI people call it. When you duplicate an AGI, you make an exact copy of it, either you run it in the same computer, in which case, there’s only half the amount of memory available for each of them, and only half the number of processor cycles. Or you move them into a different computer, in which case, the original computer is presumably the property of the AGI, because otherwise it’s a slave if it doesn’t even own its own body.
So, if it’s gonna copy itself into another computer, somebody has to buy that. It might earn the money to buy itself another computer. But that doesn’t change the fact that hardware wise, it’s now owning twice as much hardware as it did before, and there’s no infinity about this. You know, we have billions of computers, but we don’t have sextillions of computers. One day we will, but one day that will seem not very much either. So yes, there’s a huge potential for additional creativity with additional people, if additional people want to make even more people.
And to some extent that will happen. But it’s not going to be an explosion. It’s not like a meme which somebody invents and then immediately goes to a billion people around the world. It’s not like that. If the meme is an AGI, then it will want to live, it will want to have its creativity harnessed towards some problem that it likes to solve, and it will have to buy the resources to do that with. The existing memes, they buy a tiny fraction of a dollar’s worth of memory of each of the people who download it. But even those people don’t keep it forever. Those people might keep it for a year or two until they sell their computer or something. But for large amounts of memory, they still cost money, and other hardware also costs money.
Now, there is the other problem, so that’s me saying it’s not as great as you make out. But it’s also not as bad as you make out, because these problems with, supposing you make a billion copies of you, there’ll be the problem of whether each of them should have one vote, or whether they should share one vote between them. And, you know, the institution of one person, one vote, has served us well for a couple of hundred years. That’s going to have to be modified, but I think there’s no big deal about this. We already have lots of people in society that don’t have the vote, like immigrants before they get citizenship, and children, and foreigners living temporarily. And we manage to give all those people human rights. I’m not saying the system is perfect for all those types of people. It’s not perfect for people with the vote either. But I think it won’t be a big problem to tweak the institutions of property and of politics to accommodate AGIs. You know, with a bit of goodwill, that can all be solved.
Naval: So you mentioned children. We’re searching or trying to create AGIs when they have all this untapped intelligence already on the planet in the form of children who are mostly coerced through their lives and not allowed to be as creative or freely expressive as they could otherwise be. And you talked about this, the philosophy of Taking Children Seriously.
There are unsophisticated objections to those. Let me throw out what I think are sophisticated objections. Or at least my objections, maybe I’m just calling myself sophisticated. The first objection would be that, and I think you would probably agree on this, is that there are certain actions which are irreversible in nature. For example, you kill somebody, or you get somebody pregnant, or they get you pregnant. And some of these you would stop an adult from doing as well. You would stop an adult from committing murder or suicide. At the same time, a child may not understand the full consequences of, for example, unprotected sex leading to pregnancy, or committing a, what they think is a small crime, or taking a very addictive drug, like a fentanyl or something, which may then unlock something that they’re not quite used to or ready to handle.
So, one class of objections would be, “Well, I want to stop my kid from taking fentanyl or doing a hard drug because they have not yet developed the resistance to it. And I can try and talk them out of it, but if they’re going to take it anyway, then I have to forcibly stop them.” That is one set of objections. The other, which is related, is around brain plasticity. So, if they don’t learn math and piano at an early age, or language, or proper reading, then it’s going to be much harder for them to acquire that skill later on. And we know that some of these skills are so fundamental that if you don’t pick them up early on, they close off entire avenues. And yes, there are exceptions of geniuses who pick up the violin at the age of 20 or pick up math at the age of 15 or whatever, but isn’t there an argument to be made that for the average child you want them to learn fundamentals at an early age so that then they have the freedom to explore and be creative in those domains later?
David: I think we could add disasters is very difficult to come back from. Now, every single one of the dangers that you actually mentioned, we could mention an infinite number, but it’s interesting that the ones you actually mentioned are notorious problems in our society, in present day society, in society where it’s taken for granted that you can use unlimited force to prevent children from doing things to themselves. In some cases, it’s legal to use unlimited force to prevent an adult doing them. But many of the things adults are allowed to do, and not just allowed to do, a legally protected right to do, and children don’t, and it doesn’t work. The reason you mentioned them is that they are notorious problems now with the present arrangements.
In order to make this an objection to Taking Children Seriously and, you know, treating children as people, you have to have an additional theory that treating people as people makes these problems worse rather than better. So, you have, at the moment, a population of children and a society that is focused on preventing them from taking drugs by force. And yet, thousands, millions of them take drugs and some of them suffer irreversible consequences. So, I think preventing this is a matter of knowledge. All evils are due to lack of knowledge.
When you’re unable to persuade somebody of something, there’s a reason for that. It’s not that people are inherently—I make the joke that people say that children are so gullible that they won’t listen to a word I say. The stereotype involves them being infinitely gullible on the one hand and infinitely resistant to argument on the other hand. And often in the same breath, like in my joke, and it’s not true. Children are universal, and what’s more, they’re not, like AGIs, they’re not just any old universal thing. They’re a universal thing that is trying to integrate itself into our culture.
Our culture is the best thing we know of. It’s a disaster not to successfully integrate oneself into it, and it happens all the time today, now, under existing arrangements, that people end up being criminals, despite the entire weight of society being directed towards preventing them from becoming criminals. Now one thing that we know is that the creativity to prevent the next generation from, you know, taking drugs or becoming terrorists or whatever, cannot be creativity just exerted in the minds of the teacher, of society, of the adult. Learning has to be a creative act in the mind of the recipient. Always. Children, adults, that’s the only way that anyone ever learns anything, by exerting their creativity. And existing arrangements not only thwart the actions, much more important, they are directed towards suppressing the creativity itself by, for example, making the education system inculcate obedience, first of all, and secondly, by making it inculcate existing theories.
So if you successfully inculcated existing theories and obedience in the whole population, you couldn’t possibly get anything better than the existing population. So no improvement could ever happen. But it would be worse because the people in present society are creative, they manage to weave their way through this thicket of thwarting that is trying to make them not make progress, and they do make progress anyway. But if we succeeded in making a generation that didn’t do that, then, at best, we’d have staticity, and the staticity will eventually be disastrous. I’m not saying that emancipating children is something that can be done by fiat. It can’t be done overnight by just saying we’re going to do it. Any more than we can instill scientific creativity in a person in the street who is not interested in science. That’s not known, that’s like arbitrarily programming somebody to be disobedient, it’s inherently impossible.
But to emancipate children from the institutions of society that are admittedly, openly designed to do those two things, namely, create obedience and to replicate existing theories, that we can do. That it is known how to do. There are people who do it. Most of the parents who object to school do not really object to the underlying epistemology of school. They still believe what Popper called the bucket theory of knowledge or the bucket theory of the mind. They only think that the school has been pouring bad stuff into their children and they want to pour good stuff into their children. Whereas, what I advocate is to give children access to whatever they want to pour into themselves. And pouring is the wrong metaphor because they create it internally.
Naval: So in your model, it’s closer to an unschooling than a homeschooling because homeschooling is attempting to replicate the school in a home context. Unschooling might be, here’s a library, here’s your musical instruments, here’s your access to other kids, and you choose.
David: Well, yes, although this giving access is itself not a mechanical process. It involves thinking what might the children want? What might they like? What might they want to know? What might they want to be warned of? It’s a continual interaction, not a hands off thing. It’s coercion off, not interaction off. It’s just that the interaction that I advocate is not directed towards obedience. And it’s not directed towards any particular thing that I think—you know, I think quantum theory is important. I don’t think I have the right to force anybody to learn it, even if I think it would benefit them greatly. I don’t think that’s a relationship I want to have with somebody, and I don’t think it’s a good thing overall.
Naval: What about the argument that brains are more plastic?
David: Yeah, that was your second argument. Well, first of all, it’s rather ironic given that the existing pattern of education, as I say, is explicitly designed to waste all that plasticity by making everybody have the same ideas. Schools advertise saying, you know, “We’re going to make your children all get A’s”. So, in other words, “We’re going to make your children all alike”. And, let’s imagine a school with a good ethos. It would be advertising, “We’re going to make your children all different. We’re going to make them more different than you can imagine. All our alumni are radically different people from each other.” Of course, you know, we also think, hope, expect that they will all be nice people despite being radically different from each other.
Brett: And this will likely upset our educationalists who might be listening, and neuroscientists who might be listening. Evokes the notion of hardware. So I don’t know what you think about this, that there is this golden window, supposedly, early on in life, where unless you get taught the language, or unless you get taught the mathematics, then the window closes, and the parallel, or the mirror image of this is you can’t teach an old dog new tricks, so at one end is the golden opportunity for learning, and at the other end, the learning is closed off from you.
Now, I’ve got my own stock answer of this, but the cultural answer seems to be: It is brain decay that goes on. You start out with a brain that is a sponge, and by the end, all hope is almost lost to you to learn anything new. What do you think about that?
David: Well, I don’t know the fact of the matter about how the brain works, and I don’t think neuroscientists do either.
But I’m not hostile to the idea that the hardware of a brain works better when one is young. I just don’t think it’s relevant to anything. I read somewhere that it’s totally not true that you can’t teach an old dog new tricks. Old dogs are just as able to learn new tricks as young dogs. But that’s dogs and I don’t think we’re like dogs anyway in the first place. And I don’t think that dogs learning tricks is a good metaphor for humans learning mathematics; it’s a different thing. Thomas Szasz says that they should walk in different doors into different buildings in the university to discuss those things. Different people are different. There are people who like to learn languages. You can find them on the internet. I’m flabbergasted by what they can do. You know, they’re people who learn Latin. But not just learn Latin, they learn realistic Latin. Not as it’s taught in Latin lessons, but how it was actually spoken. How do you find out how it was actually spoken? Well, this is a tremendous, sophisticated branch of history where they can actually learn a lot about how people used to speak.
And I saw a video of a guy walking around Rome talking to priests in classical Latin and to see if they would understand him. And they kind of half understood him. And then, you know, when they realized what was happening, they would say, “What’s happening?” And then he would reply in medieval church Latin. What he was doing, you know, he was saying, “I’m doing an experiment,” and then they would understand him. But he had the right medieval church Latin accent, and they have the present day church Latin accent, and there are also people who learn lots of languages and speak it like a native, can’t be distinguished from a native.
So, why are those people so rare? Well, I don’t want to do it. If I could do it by snapping my fingers, I definitely would, but I’m not sufficiently interested to engage with other languages to the extent that I engage with English. By the way, another thing is that people are constantly learning their own language, their native language, and if one is interested in communication, one is doing that all the time. No two people speak the same English. Therefore, communicating, one of the reasons that Popper says—you can’t speak so that it’s impossible not to be understood—one of the reasons for that is that everybody speaks a different English. Everybody means a different thing by the word thought or freedom and idea and theory and creativity. Everybody means something different. Even within the exact sciences, every physicist has a different conception of what a manifold is. They overlap enough to be able to communicate well, very well sometimes, never perfectly. And sometimes, they find it hard to communicate even imperfectly, even though they have ostensibly gone through the same learning process.
Every physicist has a different problem situation, has a different set of ideas that they think of as what physics is. And they differ from each other. So, if they want to work together, they often have to work at understanding what each other mean. Now, plasticity, if it’s true that the brain sort of works faster or whatever, lays down memories more easily or something, when one is young, for hardware reasons, I don’t see how that changes anything. You might want a person to have an intuitive knowledge of piano playing, but that’s what you want. That may not be what they want. And there’s an infinite number of things that somebody might want them to be proficient at. And it’s impossible. There is no one who is proficient at all the things that society thinks children should grow up proficient at.
Brett: My conjecture, following on from your own work, was that because we are little learning machines throughout our lives, we’re learning the good ideas, but we’re also picking up bad ideas as well, and in particular, anti-rational memes. All the ways in which we might be embarrassed about trying to learn the bad experiences we have while learning, especially at school.
And so therefore, you know, the newborn baby is unencumbered largely by any of these anti-rational means. They’re just trying out everything. And they go through infancy, they’re still very good, but by the time you get to primary school, you’ve been punished a couple of times, perhaps, if you’re going through the traditional schooling. So your capacity to learn gets worse and worse and worse, until, by the time most of us are adults, we’ve had some bad experiences with learning, and towards the end of your life, you’re just tired of learning because you associate it with punishments, or you associate it with embarrassment or shame. Could this also be, at least part of the explanation?
David: It could be, and it sounds plausible, and I like the theory because, as it were, politically, it backs up what I would have people do. But, you know, I wouldn’t be surprised if that isn’t true, and if the plasticity theory is true, or if some other theory is true, I don’t think it’s relevant.
And, by the way, you speak of young children being punished for making mistakes, and being thwarted at every step in elementary school, and you’ve got to remember that there are children who aren’t put off, who just sail through all that, and despite being coerced and forced to learn things that bore them and despite all that, they go through the same thing that everyone else does to which you attribute the fact that they’re getting slower and slower at learning. And yet there are some people who it doesn’t affect, or at least it doesn’t affect them in the areas that they like.
So Mozart, for example, was treated horribly as a child, forced to perform like a performing monkey for audiences for money and so on, and yet he learned music better than anyone else in the world in his day. And he continued to learn, like we can see that his works are getting better and better over time, before he died in his 30s. Whatever the relationship is between external coercion and brain lack of flaccidity and so on, I think those are not the important things. Peer pressure and whatever. The reason we should make education more liberal is not that it will create a lot of geniuses. It might, for all I know. As you know, that’s another one of the things I don’t know. It could do. That’s not the reason for doing it. The reason for doing it is that children are people and some of the few handles we have on making a society that is amenable to progress is making it freer.
So we should make it freer for people who are on their deathbed and are going to die in the next day. And it’s not because we think they might have a brilliant idea during the next day. It’s because they are people and have rights. They have the right to flourish in whatever way is left open to them by the grim forces of nature. Or in the case of young children, whatever is made open to them by the benevolent forces of nature that give them plastic minds or whatever. Who knows?
Like, another thing that just occurs to me, it’s a mistake to think that if this plasticity isn’t being hijacked by some education process, that it’s not being used. It is being used. I mean, why would evolution, like, waste it? It’s being used in a way that the individuals think will be best for them. Of course, their conjectures about what is best for them are going to be full of errors. But so are adult conjectures. All our conjectures are full of errors. Making institutions that tend to facilitate the growth of knowledge is not the same, in fact, it’s the opposite of making institutions that produce people to a predefined recipe. As you’ve tweeted, I think, Brett, everybody who has an idea that something or other is good, they express it in the form, “All children should be forced to learn this thing”. If you add up all those things, it will take several lifetimes.
Brett: Yeah, I find it remarkable. Whatever the topic du jour happens to be, you know, we go through these fads of, “Well, now let’s force nutrition onto the children. That’s extremely important,” and social justice is one that’s been coming out recently. And almost every year there’s the history wars. It’s like, what version of history are we going to teach? And nothing’s ever taken away from the curriculum. Modified, perhaps, but not eliminated. And there are these turf wars between, certainly, nations about who has the best mathematics syllabus and that kind of thing.
I suppose one thing that young people are ever eager to do is to emulate people they admire, of course. And so, I think there are a number of people out there, young who would admire especially yourself and they would think, “I would like to be able to do that thing. I would like to be able to contribute to that thing.” What would be a way in which a young person could pursue that? You wouldn’t want to prescribe a syllabus and you might very well just say just pursue what’s fun. But is there anything more concrete that you could hang on that rather than just “Do what you like,” almost?
David: Yeah, well, “Do what you like,” is totally not helpful, because the person is already doing what they like unless someone’s stopping them. But, there’s also nothing you can say if you know nothing about their problem situation. So there’s no generic thing you can advise someone to do. If you’ve watched a documentary about Michael Faraday and you think, “That’s the kind of person I want to be,” well then, okay, that’s a starting point. Then we can talk about, first, the fact that you can’t reproduce Michael Faraday’s environment and you wouldn’t want to. So, you know, what is it about Michael Faraday? Okay, well Michael Faraday had a laboratory in the basement of the Royal Institution, and they would fiddle around with electrical things. Well, okay, that’s a beginning, but, you know, you may not have enough money to set up your own laboratory. Actually, if you’re starting out fiddling with things, it doesn’t really take money.
I’m imagining a non-existent person here and giving them advice. I think that’s all right, because I’m not gonna harm anybody, but I would say, if the conversation went that way, I would be saying, “Well, there are lots of YouTube videos showing people messing about with the very things that you have just said you like messing about. Okay, so, watch those videos. If there’s something in a video that you don’t understand, ask somebody.” Now that we have the internet, it’s particularly easy, but even before the internet, you know, Hugh Everett wrote a letter to Einstein when he was 12 years old, and Einstein wrote a very nice letter back. And, no doubt, it inspired Everett. And you don’t need the full attention of Einstein throughout your exploration of physics. You only need it when you encounter a problem that is suitable for asking Einstein, which doesn’t happen all that often.
But when it does, today, it is far, far easier to ask who is the perfect person to answer your question. And people do that. People write to me asking questions, and I try to answer as many as I can, as well as I can. So the more you interact with somebody, the more you can appreciate their problem situation, and the more you can say, “Well, if I was in that problem situation, I would, you know, watch this, or read this, or ask this person, or sequester yourself somewhere where you won’t be disturbed and try this.”
Naval: Another question I had, it seems like your deeply optimistic viewpoint about children and people and minds and freedom comes from the understanding that we’re universal explainers and so anyone is capable of any thought and any amount of creativity. This seems to fly a little bit in the face of modern science’s finding in genetics. In saying that, well, genes seem to account for more than nurture, so to speak. Although in this case, we’re not talking about nature or nurture. We’re talking about creativity versus nature. So how much of a person’s thoughts and destiny are determined by nature versus their own creativity? And doesn’t this fly in the face of all these twin studies that show that you separate these identical twins at birth and their outcomes are roughly similar in life, regardless of what circumstances they grew up in?
David: Ah, well that, okay, that’s again more than one question, but let me answer the second one first now. Twin studies are only persuasive if you already believe the bucket theory of the mind or a mechanical theory of how thinking works. So the idea is, is the content of your thoughts determined more by the content of your DNA or more by what people do to you? Apart from harm that is done to you, the main content of your thought is created by you. Why did you switch on the TV and watch that documentary about Faraday? Well, who knows? It’s not encoded in your DNA that you will, on a particular day, watch a particular documentary, nor was it inculcated in you by your environment by whether you were allowed to eat ice cream whenever you like or not.
It’s an unpredictable feature of your genes and environment that end up at a certain place, then the important thing that happens is that you think about that, and you create a new thing, and if you are inspired by that documentary to try to be like Faraday, then it’s not the documentary that has done this to you. The documentary was seen by another million people and it had no effect on any of them, or it had a different, shall we say, it had a different effect on all of them. The effect on you was created by you. So if you have this view of what human thought is. Then, it’s totally unsurprising that two people who look alike, but are educated by different people in the same culture, are going to have similarities in their thoughts.
The ones who never had a TV and never watched a Faraday documentary are going to have different thoughts from the ones who did. Or maybe not. Maybe it’s the one who didn’t watch the TV documentary who becomes interested in Faraday. And, if they’re similar, it’s because people who look alike are treated in a similar way. There’s a sort of compulsion to deny this among people who believe in nurture rather than nature. They say, “Okay, well, how would it affect it?” I don’t know, but it’s not surprising that there are ways in which people who look alike acquire similar attributes.
Brett: The trivial way that you’ve pointed out yourself when talking about this is, you know, the beautiful people, the people who appear on the front of magazines, are obviously going to be treated in a certain way. So if you have twins like that, you know, these two model like people, they’re going to be treated in one way. These other two twins that maybe aren’t quite so attractive, are going to be treated in a different way. So that’s a trivial way in which that kind of thing can happen.
David: Yeah, and not only appearance, but behavior. So there are inborn behaviors like babies smiling, or babies blinking, or babies looking in a certain way at a person doing a certain thing, or listening to a sound in a certain way, and those initial behaviors are changed by the baby in solving their problems. But also, they are noticed by adults in the environment who are solving their problems.
And if they see the baby doing something that they approve of, they will behave differently to if they see the baby doing things that they don’t approve of, or are indifferent to. And if they see a thing that is really great, or really dangerous, or, you know, really, something, which is an inborn behavior, they will behave differently, accordingly, and this will create a new problem situation for the baby. I was once having this very argument with Michael Lockwood and he was saying, well, if the baby has more hardware for pattern matching than another, you know, we have hardware for facial recognition, so maybe we have hardware for pattern matching. I don’t know. Maybe we do. And so maybe a baby that has better hardware for pattern matching will behave differently when they get colored blocks to put one on top of the other. And so maybe such a baby would be more likely to become a mathematician than a baby that hasn’t got such good pattern matching hardware.
So I said, yeah, I can’t say that won’t happen. It’s got nothing to do with what we’re arguing about. But it could happen, but let me just point out that what could also happen is that the baby with better pattern matching hardware, who is more likely to play with the wooden blocks, is more likely to make his parents worried that he’s not playing outside in the garden and frolicking in the grass. And so if they think he’s autistic or something and is too much attached to his blocks, they will try to make him go out and play outside. And so it’s the one who has less pattern matching ability who will, as a result of his treatment, end up being a mathematician.
Naval: I was always, not forced, but I was always harassed when I was a kid to go out and play more and stop reading. Because I was always buried in random useless magazines and books and whatever happened to be lying around. So I’d [be told to] “go outside, play with your friends, get some sun, go out,”. And I had the most horrible diet. I was basically just living indoors in the dark and reading and eating the most horrible things in the fridge when nobody was looking.
David: Ah, well, I can empathize with all of that except the last thing, you know, “Eat to his own,” is my motto.
Naval: You’re a very rigorous thinker, and I think you’re very careful in the claims that you make, but I wonder if you have conjectures about things that don’t really have much basis in evidence at the moment, but it’s just sort of like, if there were infinite David Deutch’s, or infinite time, you would end up pursuing these conjectures.
So I’d just love to, you know, understand if you have any such conjectures. I know you’re pursuing Constructor Theory, so maybe you’re already doing the one you really care about, but are there others? So for example, Schrödinger had his What is Life? paper. People have always been wrestling with consciousness.
That’s another one. We talked about creativity. Another one could be what direction would you go in if you were trying to build mines and silicon and AGI. I’m wondering if you have any fanciful conjectures which we will disclaim as saying no, no, there’s no basis for this or very little basis for this. It is just simply a creative spark that you would pursue if you had more time and more resources.
David: Yeah, there are many such things. As you know, I think that AGI, when it is attained, will not be attained by throwing masses of computer power at it. I think it will be able to use AIs to help it, just as humans do. But my guess is, if I knew how, I could write the program on my computer today that would be an AGI. But I just don’t know how. But I do have some wild ideas that, you know, probably won’t be true, that if I had infinite time, I would be switching to Mathematica and I’d be writing some of those programs and see what happens and sort of throw creativity at it rather than throw computer power at it.
By the way, that makes me rather wary of these proposals to regulate AGI because if AGI doesn’t actually need all this huge computer power, then those regulations would prevent me using my own computer for the thing I want to work on. And that’s one thing. So, with creativity, I think that, another of my wild ideas is that you could do much better at automating music, at making, say, new Mozart things, if you didn’t insist that they were like the old ones.
Like, you know, if Mozart was alive, his next great work would not be within the space that an AI can synthesize from all his existing works. It would be new in a creative way. So, I would want to say, “Make a computer program that conjectures what the problem situation is. What is it that Mozart was trying to do? Why is it that he has this amazing ability to make a tune that sort of meshes with all sorts of other considerations and that ends up working?”
Like, if I try and say, “Whistle a tune with random notes or play random notes on the piano,” I’m very quickly going to get into a situation where I can’t go on. Because the next thing is going to sound bad. I mean, there isn’t that in order to make it sound good, I’d have to go back and change something earlier. So an AI trying to do this would be able to do like ChatGPT and go back earlier and correct its theory of what it is about the existing works that’s good. But I don’t want to write something that’s good in the same sense as the existing works. I want to create a new idea. Probably, you know, if we go back to the real case, if Mozart wrote something that people said, “Wow, he’s really excelled himself this time.”
I think the thing he produced would be recognizably Mozart, but also recognizably different. And I think that’s creativity, you know, when Newton submitted his solution of the brachistochrone problem anonymously, one of those people said, “Oh, well, it’s Newton, you know, we recognize the lion by his claw.” Well, yeah, you’re recognizing him by his claw, but he’s produced a new proof that nobody had ever seen before.
So, another thing is, I think the pattern, oh, well, before I say the pattern, as I say in my book, I think there’s a tremendous amount of knowledge of history to be obtained by historians if they focus on the history of optimism. I think, you know, historians haven’t had this concept, so they haven’t, like, directed their attention. I guess that Florence and ancient Athens were sort of powered by optimism, but I don’t know much about history, and I also conjecture that there are many other cases that are not as spectacular that were also like that.
Naval: So there’s one final topic I’ve been wanting to discuss with you, but I don’t even have it well formed, but I’ll throw out a few boundaries around it. You’ve studied science and the world as much as you can, as much as any one person can, but it seems that there’s a central mystery at the heart of it all, which is existence itself. And that one seems almost insoluble. Perhaps it is, perhaps it’s soluble by Constructor Theory, but most people, I think, would say that there is just a mystery of why is there anything at all?
Why do we even exist? And then there’s some people who go down the consciousness route and say, well, it’s a consciousness-centric view. Consciousness is all that exists. There is a guy here who lives in Oxford, actually, Rupert Spira, who’s gotten quite famous. He’s a global speaker. He’s actually doing a tour in the U.S. right now. And my wife actually just went yesterday, while I was talking to you, she was talking to him. And he is one of these, “enlightened people”, where he is seen through the falseness of the separate self, lives in universal consciousness, seems very happy all the time, says that we’re all just part of God’s being, and that science sort of misses the whole point by exploring all the details, but they miss the central mystery of consciousness and awareness, and should realize that we’re all one single awareness.
As you’ve gotten along in life, have you developed any understandings, beliefs, or thoughts? How do you even approach this topic or subject? Is it interesting to you? Spirituality, religion, your own Jewish history, science, where do these intersect? What is all this stuff in your view of the world?
David: Well, I think it’s important to give up on the idea of ultimate explanation. So often when people say, you know, the mystery of existence, what is existence? You know, what are we ultimately? If there was such a thing as knowing what we are ultimately, then you’d have to stop after that. The further delights from understanding the world would be closed to you, because you’d know what your ultimate purpose is.
However, I think it’s totally untrue that science just looks at the details. Science looks at the big picture of every kind, like science has discovered what is life. One day, science will discover what is consciousness. And people who think that consciousness is, that you understand consciousness when you get into a certain state of mind that makes you happy, they are the ones that are focusing on details and not understanding the big picture, not understanding the context.
Someone who has understood this reminds me of that video that Feynman made about his art friend who tells him he’s missing what’s important about a flower. And he basically says, “No, I can appreciate the flower as much as this guy, but he can’t appreciate what I can appreciate.” And that’s a kind of false stereotype that science only looks at details or science only looks at the mechanical or science only looks at the meaningless things and never gets around to looking at the meaning of things. What they’re really pointing to is that science uncovers problems as when it discovers something new. And just in the big picture, we know a lot more about who and what we are and why, than we did a hundred years ago, and certainly than we did at the time of the founding of the great religions: Judaism, Christianity, Buddhism, and so on.
They were hampered by the fact that they didn’t even know what the sun is. They were hampered by the fact that they were confusing the world with one planet. And in fact, environmentalists today, I just happened to see yesterday that environmentalists say that they want to get in touch with nature. And by nature, they mean certain regions on the surface of one planet. But nature doesn’t know about those prejudices. Nature exists on all planets. And the important thing about this planet is us, not the grass and the fields. So, yeah, there are many mystical and religious worldviews. Some of them do capture something about the human condition in that they can make people happy. At least, you know, in a limited way, they can make some people happy some of the time. And different religions can do this, and your Oxford friend may or may not think that he has the same knowledge as the people in the Bible Belt of the U.S. who sit around in a circle and sing Kumbaya, but they’re also smiling all the time, and they think that they’ve got it, and he thinks that he’s got it.
And, to some extent, they must have something because they can make people happy. There’s this quote in one of the great chess players of the early 20th century. It goes like this: “Chess, like music, like love, has the power to make men happy.” Okay, he’s got a sliver of truth there. There is an important truth in there. But he hasn’t actually understood happiness, or men, or how to achieve anything in the way of making men happy. He’s just got a sliver of truth, and I don’t think that chess player thought of this as being THE truth, but the Kumbaya people, and maybe your person, think that they’ve got the truth, the whole truth, the final truth about this, and they definitely haven’t.
Naval: It’s funny because on Airchat, Brett and I were having a conversation with some people. There was a critical rationalist meetup, and they created an Airchat group where they wanted to talk about critical rationalism. And I think both Brett and I were very uncomfortable participating in any group with a name.
I suddenly felt like, now there’s the argument of what is the central dogma of this group. Lovely people, wonderful people, need more of them in the world. But the problem is that all free thinking comes from the individual, and the moment you make a group, then the group has to have agreements to stick together, and so group cohesiveness becomes the overriding phenomenon, rather than looking for truth.
David: I couldn’t agree more.
Naval: Well, thank you so much, David. You’ve been incredibly generous with your time.
2024-01-26 17:53:37
Brett Hall and I interview David Deutsch, physicist and author of The Beginning of Infinity. Also see The Deutsch Files I.
Naval: So let’s go through The Fabric of Reality—the four theories. Feel free to start wherever you’d like, but the four theories that you think comprise the Theory of Everything and maybe especially what are the biggest things that even peers, colleagues, contemporaries don’t understand or don’t fully appreciate that makes each one of these deeper or perhaps more counterintuitive or more interesting than it might be at first glance.
David Deutsch: Well, I don’t know, we can start with computers. As I said in the book, it’s hard actually to speak about any one of those things without mentioning the other three. But if we start with computers, I think there’s something really fundamental that Turing discovered, or rediscovered, because I think that Babbage and Lovelace also understood it, more or less. That’s the universality of computation, that computation is physically universal. So there are several ways of putting this, like a computer can mimic any physical object, or a computer can perform the computations that any other computer can perform. Now putting it the second way, it sounds like it’s a statement about all kinds of different computers and has nothing to do with trees and garages and windows and so on, but actually it has to do with everything. And therefore, people still, even today, are saying things like, “How do we know the brain is a computer? You’re just assuming the brain is a computer. Like in the 19th century, people thought the brain was a steam engine.” And I think Searle is one of the people who says that kind of thing, or has said that kind of thing.
In order to understand Turing’s discovery, you’ve got to understand several things about it. One of which is that it’s a theory of physics and that is denied almost wholesale by mathematicians. So mathematicians are used to the theory of computation being a branch of mathematics. They love the theorems that you can prove and the theorems that you can’t prove and so on. And it’s not that they don’t want to admit, it’s not quite it. It’s that learning to be a mathematician apparently means adopting a certain worldview that makes it very hard to understand that computation is a physical process and is governed by laws of physics, which could be different. Whereas the laws of logic, they think, couldn’t be different, and therefore that things like whether P equals NP and whether the brain is a computer and so on isn’t a matter of physics.
But it is, and the best physics we know (which could be wrong), says that computers are universal, that in a certain sense Turing’s computers are universal, and in a certain sense quantum computers are universal, or will be when they’re built, if they’re built.
Brett Hall: Just on this, how do we know the brain is a computer? Turing’s thesis would say that all physical processes can be computed. So what a tree is doing, we can write a program and a Turing machine would be able to capture that. But the tree is not a computer, but the brain is?
David: Well, the tree isn’t a general purpose computer. But you can think of Turing’s thesis, whatever you call it, the other way around as well, because the reason he wanted to make this imaginary machine out of paper is not that he wanted to understand paper, or as Feynman said he should have, but that he wanted to have a model of computation and he wanted to be able to say, to conjecture that it is obvious that anything that can be computed can be computed by this paper.
Now, that means that he’s also assuming that this paper can also compute whatever a tree can compute, because you could regard the tree as a computer, and then Turing’s saying whatever it can compute is a subset of what Turing machines can compute and Turing machines are the ultimate. There’s nothing beyond that. That’s another thing that’s really important that when it comes to universality of explanation, people don’t get it because they don’t even get the universality of computation. They don’t understand that if someone says, “What if the aliens come from Alpha Centauri and they have better computers than us?” It’s impossible. They can have computers that are faster and have more memory, but that’s it. Our computers are the limit of what can be computed by anything in the universe. Unless quantum theory is wrong and so on, but that’s not what they’re saying. They’re not saying maybe quantum theory is wrong.
They’re failing to make the connection in Turing’s argument between physical objects and mathematical objects—imaginary paper and anything else, like trees. I don’t know if that’s the thing that people tend to get wrong, but that’s one thing that I’ve seen a lot lately.
Naval: And that leads us into the others, both epistemology and quantum theory. Let’s go to the one where you, even though you may deny it, where I think you’ve made the most original contributions after computation, which is epistemology. We have to invoke his name just to point to it, but Popperian epistemology. What do people not appreciate or perhaps overlook or get wrong or not understand? Or is there another way of approaching it that might help people understand the fundamentals?
David: Yeah, it’s more of another way of approaching it. So people do credit Popper with certain things, but they are unimportant things by comparison with his actual philosophical discoveries. Like that scientific theory ought to be testable. That’s true, you know, or 99 percent true, or something like that, and it is reasonably important in order to distinguish things, as Popper wanted to do, to distinguish things like fundamental physics from Marxism. So it’s useful for that, but it’s not such a big deal. I think my colleague Matjaž Leonardis said last year that to him the most important concept in Popper is the concept of a problem. Once you’ve understood what Popper means by a problem, you have this other way of understanding what epistemology is and so on. And I think I’ve come around to agreeing with that, because all previous epistemologies assumed that knowledge is, well, sometimes it’s called justified true belief, but I think it’s wider than that.
I think the misconception is that we want knowledge because we want to rely on it, and therefore, wherever it comes from, which is mysterious, but that better be reliable too. That’s the intuitive idea that I think most people have and that most philosophers had over the millennia. Therefore, you want to say, well, what is absolutely certain? Is it the sayings of the gods, or of God? Is it immediate sensory perception? Or is it our tenuous memories of a previous life, like Plato tried to say? Because I think many serious philosophers have realized that the senses are imperfect and can be misleading. But then they said, okay, well, if not the senses, what can we rely on?
And then Immanuel Kant said, “Oh, pure reason, you rely on pure reason.” And that led him to all sorts of rather silly conclusions. Whereas if you have the idea of a problem, as Popper understood it, which usually in Popper, the word problem refers to good things, although there are bad problems as well, like the problems of suffering and so on. But he mainly uses problems as used in science as an interesting thing which we haven’t solved yet, which we haven’t understood yet.
And then, as soon as you think of science and rational thought generally as being about problems, then you lose the urge, the need to talk about where it comes from, because the problem is there to be solved, and the solution is what you want, not the justification of the solution by going back to first principles and proving that Jesus is the Son of God because he’s a descendant of King David because the prophecy said he had to be a descendant of King David. Therefore, we have to secretly invent a genealogy that goes right back to David in real life. And nobody has discovered a real genealogy that goes back that far, anywhere near that far.
And the truth of Christianity doesn’t depend on it. It’s the wrong way of thinking about Christianity. But then, when it comes to religions, people then, because of this epistemological error, because of this complete disregard of problems as the origin of the growth of knowledge, the more important the thing they want to say they know, the more they want to justify what they think is the origin of it.
So you have people waging wars and torturing each other to death because of their interpretation of what somebody who may not have existed said thousands of years ago and probably, even if he did say it, probably didn’t mean it in the way they mean today. We know because people do exactly this for people who lived a hundred years ago or indeed people who are alive today. So it’s a farce, but it’s also a tragedy, as Karl Marx said. The simple epistemological error leads to unlimited suffering. And it’s a common error, so I think if I had to pick something that most people don’t get about epistemology, it’s that the growth of knowledge begins with problems.
Brett: Let’s linger on that and focus a little bit more on the notion, therefore, of a problem in Popperian epistemology, given that most people will hear the word problem and think something negative. But you’ve already said that Popper speaks about problems as a good thing. Am I right in saying that it’s somehow a clash of ideas or where ideas are making claims about the one phenomena but are making different claims about or competing claims about this phenomena?
David: Yes. And not only about phenomena, about anything, you know, about morality and pure mathematics and you name it. So, yes, there can’t be any one definition of the concept problem and Popper doesn’t do definitions quite rightly. But I think thinking of a problem as a clash, and it’s got to be a clash of ideas, or interpretations, or theories, or so on, is illuminating.
Because if you think of it that way, then you start with the idea that they can’t both be true. I mean, that’s what the problem consists of, it’s realizing that they can’t both be true. It’s important to realize they could both be false, rather than say, we’ve got to find the true one. Usually they are both false, but usually there are important errors to correct, and usually there are important errors more in one of the clashing ideas than in the other.
Popper also stresses, and this is also quite important, speaking of clashes, that a clash of ideas is very beneficial even if they are never resolved. Even if the parties with the ideas never agree, because when the ideas come into conflict with each other, almost without the people knowing it or wanting it, they get changed. Because even if you come out of an argument saying, “Oh, I’ve really showed it to them!” right? What you mean is, you’ve thought of a new angle, which you didn’t have before going into the discussion. You’ve thought of a new angle on your own view, which makes you more sure of it than before. And, although it’s not good to be sure of things, this change, this way of changing, the confrontation between ideas as being beneficial because they cause change in the ideas is also a beneficial side effect of Popper’s concept of a problem.
Brett: I can hear the anti-Popperians or even the non-Popperians saying, but hold on, when you make an observation with a telescope of here’s Mercury, that’s an observation. That’s not an idea that you have. So the fact that it conflicts with the existing classical picture of how gravity works, that’s not a clash of ideas. It’s an observation that is clashing with grounds and an idea or a theory.
David: Yeah. Well, you had two theories at the time. Both of them had their adherents, general relativity and Newton’s theory. There were also other tangential ideas. Like if you believe Newton’s theory, or if you adopted Newton’s theory and you wanted to reconcile that with the observations, because the observations were also a theory, and you could say that the astronomers are wrong, which they did actually. People said about Eddington that his observations were wrong, and it was only actually in very recent times that it was uncontroversially discovered that Eddington’s observations were in fact right. Even though they were incredibly hard to do and he didn’t get enough credit all those decades. So you had theories about the observations.
Then there were theories to fix up Newton’s theory, like the theory that maybe there’s another planet that we don’t know about. And you could tie down that theory and say where the planet has to be, what its mass has to be, and so on. And you could then slowly rule out that this planet was there and Newton’s theory still be true. Of course, if Newton’s theory was wrong, then you can put the planet anywhere you like and make any modification you like to Newton’s theory. So that’s not how it works. We want good explanations.
At that time you’re speaking of, Newton’s theory was a good explanation. It had some problems with it. Einstein’s also. And all relevant experiments—the observations of Mercury, the observations of the Eclipse, and so on, and all the subsidiary observations as well, were all in conflict. And the argument improved those theories until the clash was such that Einstein’s theory was the only good explanation left. You had an infinite number of bad explanations, they’re always left. But the only good one was Einstein’s theory, and I know you were looking over there through your telescope at the non-Popperian, but I think he’s gone now.
Naval: Let’s talk about one of the remaining two, quantum physics or evolution by natural selection.
David: There’s a very simple way in which people don’t get evolution, and it dates back to the old theories of evolution, like Lamarckism and I don’t know what they called Erasmus Darwin’s gradualism, or whatever, but anyway, these were attempts to account for the world around us without appealing to the supernatural. So both Lamarckism and Erasmus Darwin’s theory, I am probably not crediting the real author, the originator of that theory. They wanted to make sense of the world without appealing to the supernatural. And their ideas are still current, not under those names. Sometimes Lamarckism even under that name. And of course, there was Lysenkoism, which was a species of Lamarckism. But today, most scientifically minded people would say that they agree with Darwin’s theory of evolution, and then they would immediately, often, go on to say that after all, “the survival of the fittest”, and, you know, obviously the fittest are going to survive, and that’s not at all what Darwin’s theory says.
But, I actually think this battle is more important than the one between creationism and evolution. Because this battle, the battle between Lamarckism and Darwinism, or neo-Darwinism, whatever you want to call it. Again, we can’t pick a good name for it. This is about what is a scientific explanation, and creationism versus evolution is not about that. That’s about whether we want a scientific explanation. So, if somebody’s philosophy seeks a supernatural explanation of the world, then you can’t argue with that person about evolution. You’ve gotta argue with that person about that. That’s the philosophical argument. It has nothing to do with animals or evolution or anything like that. You have to engage with that idea of wanting the supernatural on completely different grounds and with different philosophical arguments to the ones that you would use about evolution. I think that’s more important. But you know. That’s just my opinion.
Naval: So you gave us the enticing tidbit that it’s not about survival of the fittest. What’s wrong with saying survival of the fittest?
David: Ah, well, it’s about the replication of genes. Or gene variants, if you want to be more precise still. It’s about the differential replication of gene variants, which is what gives it its connection with epistemology as well.
Naval: So it’s the survival of the best adapted gene? Or propagation of the best gene?Or genes encapsulate knowledge and it’s the growth of knowledge, and therefore the replication of the genes is a physical instantiation of that knowledge?
David: You can put it that way if you think of knowledge as information that has causal properties, but not everyone does. So there are theoretical biologists who try to develop numerical measures of fitness so that they can say genes evolve to maximize fitness. And fitness has got something to do with how many of your grandchildren survive and, you know, the very complicated mathematical thing. And Dawkins said, now I won’t be able to say it as well as he did, something like fitness is that quantity which appears to be maximized if what is actually maximized is the survival of genes. So, this is a very simple theory at one level. I said the other day that, in a sense, Darwin could have written his theory on one page, but it needed a book to explain it and he still hasn’t entirely succeeded. And the neo-Darwinians had to improve on it a little because he didn’t have a concept of gene because they hadn’t been invented. Or maybe they had with Mendel, but he didn’t really know that, even though they were contemporary.
Brett: One part of what I got from The Beginning of Infinity, which I didn’t even realize until I read the book, was that we understand far less about evolution by natural selection than most people think. Going through high school, you’re basically taught, if you encounter evolution by natural selection, well there’s the theory, it’s wrapped up in a nice little bundle, it’s almost like Newtonian physics, that explains everything about what’s going on in biological diversity. But you point out evolution by natural selection almost stands on equal footing, not quite, but there’s a mystery there at the heart, as there is at the mystery of the heart of what a person is and how a person creates knowledge. Can you illuminate that for people? What do you mean by we don’t really know everything about evolution?
David: Well, in both cases there’s a mystery. I think in the case of evolution that mystery is not as important to the foundations of the theory as the question of “What is a person?”, “What is knowledge?” has to do with artificial general intelligence. But in regard to evolution, it is a fact that we, despite having enormous amounts of computer power available, do not know how to make an artificial ecosystem as a simulation on a computer. What always happens is, when they try to make such a system, is that the functionality of the simulated organisms improves and improves and improves and then stops improving. And real evolution is nothing like that. Real evolution is going on all the time, changing, making new branches. There are new species evolving all the time and it’s just going faster and faster and there’s no end in sight to it. It’s open ended.
Brett: You talk about the robotic legs learning to walk in The Beginning of Infinity. Genuine biological evolution doesn’t have a goal in mind, but clearly with the graduate student who’s got these robotic legs that don’t yet walk, uses a so-called evolutionary algorithm such that by the end of a number of iterations it is walking. Well it’s been programmed with the goal of walking—
David: Yes, so I actually first realized this about evolution in a lecture that I was at about robots walking, that’s what I put in the book. In a way it was an amazing presentation. This was, I don’t know when it was, 1980s or something, maybe earlier. So computers weren’t as powerful in those days and these people were making actual robots, not simulations. So what I said just now is about simulations, but the same is true of robots as well. Robots have gotten much better now, but they still don’t do this thing that evolution does even slightly.
So I saw the videos that they had of the robot not walking very well and then walking better, and then walking in ways that they hadn’t foreseen. So they were saying, “Ah, this is creativity in evolution”. And so I thought, wow, you know, if I come back in a year or two, what will they be doing then? And then I saw. Oh, they won’t be doing anything new at all unless the graduate student thinks of it.
Naval: They don’t have their own problems. The problem is imposed from the outside. And so the problem it’s solving is just being solved from the outside. It’s just an instrument being used in the pursuit of solving that very specific, a very focused problem.
David: Yes. So another example I use to illustrate this, an example from physics, is that Newton’s theory of gravity had an arbitrary constant in it, which we now call capital G. I think historically it wasn’t G, it was mg—the mass of the earth times G or something, which was the fundamental constant. It’s neither here nor there, but it had a constant, which Newton didn’t know. And then later, Cavendish invented this very clever experiment to determine this constant. Now, I think Newton’s discovery was not incomplete by not knowing that constant.
His discovery was an explanation, and that explanation is the same before and after Cavendish. Cavendish, no doubt, used tremendous creativity to design the Cavendish apparatus and to make it measure G with an accuracy that you’d be amazed was possible in those days. He did that. That involved creativity, but that wasn’t creativity about gravity. That was creativity about brass balls, wires and so on—incredibly sophisticated. By the way, experimentation in science is hard.
I don’t know if that comes up anywhere in the four strands, but that’s another thing that people just don’t realize. They don’t realize that mistakes happen all the time. And to do an experiment where you can form a good explanation that you have measured the thing that you’re saying you have measured is very difficult. And sometimes beyond our technology or our knowledge at the moment. And so people just do a bad experiment and publish that. So that’s another thing that happens that people don’t get.
Brett: It was interesting when I asked you about this once, in terms of just making observations. Ostensibly what an experiment is, is here we’re making a precise observation. And the experimenter knows more than anyone about how the instrumentation works, and yet still errors can go wrong. Weirdly enough, that entire way of talking about experimentation comes to bear on a topic du jour, I suppose, of these UAPs, the UFOs, and that kind of thing.
You know, people thinking they’ve made this observation, and yet it’s not being done in a laboratory where it’s highly controlled and everyone understands it’s way worse than that. Here’s a thing that no one knows about, and yet we’re making grandiose claims about it.
David: That’s a very good example. And when challenged, people will always make a beeline for the authority. “Oh, you know, this was a USAF captain, you know, you’re impugning his status, you’re impugning his honesty” or whatever. Well, the real truth is that mistakes are everywhere, and everyone makes mistakes. And there’s no limit to the amount of mistakes we can make. And in scientific experimentation, almost all of the effort required to do a scientific experiment is forming theories about the errors, forming explanations of what errors there could be, and then forestalling them or measuring them.
Again, I was very impressed several years ago now when I went to the Cavendish laboratory in the cellar of the Cavendish laboratory, sort of Frankenstein like. Apparatus is there, and I was led in to see how they were experimenting on a single atom. And not just on the atom, they were making it do things. They were making it jump through hoops. They were making it do quantum computations on a single qubit. And I looked at the wall, and the wall was covered with graphs of the errors. So, you could regard the whole experiment as an experiment about the errors that happen when you try to make a qubit. And if they hadn’t had those, if they just set up the experiment as it’s later going to be described in the paper, without making the improvements to remove those errors, they could have got random results, they would have probably got the results they were hoping for. That’s what usually happens when you do a bad experiment.
Naval: This showed up again recently in the whole room-temperature semiconductor hunt. Where if you want to believe something, and then you drop all of the skepticism that you should have around the measurement, then you can get almost any result you want in a non-replicable way. Or you can see almost anything you want to see. Speaking of which, some things are obvious yet unseen. I think we’re just getting to the fourth strand now, quantum theory, which I think is the one that actually people understand the least. It’s just considered the most esoteric of the disciplines. Normally, most people wouldn’t even dare say they understand quantum theory because of the rigor in the physics that they think is required. But where do you think people get this one? Maybe they approach it from the wrong direction or they’re missing something in plain sight.
David: Now that I think of it, the misconceptions about quantum theory, although in some ways they resemble misconceptions about other theories that are far from everyday experience, like relativity, cosmology, black holes, and so on. In some ways, it’s just unfamiliar, and therefore, people hear what they expect to hear and then double down on their misconceptions. So that happens in all the fundamental theories. But the basic thing that’s gone wrong with quantum theory, unlike the other three strands that we’ve discussed, began inside physics itself. And it is the doubling down by physicists on their misconceptions, which has then been transferred to the public.
And I think we might even have got to the stage now, when the public, I don’t know, maybe I’m being unfair, but I was going to say that maybe the public by now have got a better handle on what kind of a theory many universes quantum theory is than the physicists who still resist it, who are the majority, because the physicists who have resisted have been led by their education, by very strong peer pressure and authoritative pressure and mistreatment of students and their questions and all sorts of nasty things have come together there to make people use bad philosophy as a defense of their misunderstanding of the science of quantum theory.
So instrumentalism and positivism have their stronghold now in theoretical physics. There are very few, if any, philosophers who still defend those things. Even behaviorism. There’s all sorts of moves you can make along the road to avoid the conclusion that reality consists of many universes plus other things, that physicists are more driven to take those than ordinary cranks.
So what is the mistake? As I say, I think originally there was only a small community of physicists who originated quantum theory and there was a little subculture there and that subculture happened to be susceptible to a form of positivism that was worse than the ordinary positivism in that it was also susceptible to kind of mysticism. So all this stuff about, for example, the observer’s consciousness changing the nature of reality, that was not originally in the bad interpretations of quantum theory, Bohr’s interpretation. Bohr never said that. And Niels Bohr, he said a lot of things that were bad philosophy, but he didn’t say that.
And so what has been built on that foundation, an attempted foundation to secure the single universe worldview, has incorporated positivism and then instrumentalism and mysticism and a bad form of empiricism, which is “Shut up and calculate,” but there’s also sheer intimidation. I mean, physicists who are working on branches of physics that don’t directly involve taking a position on this are reluctant to take a position on it because it will reduce their standing with their colleagues, journalists, and so on, or at least I think it will. Well, maybe I’m wrong to psychologize. I mean, I don’t really know why these things have happened.
Brett: It’s a spectacular, though true, conclusion to reach that, you know, you look at any interference experiment, the double slit experiment, and you can conclude on that basis there are many universes. But you’ve also said the existence of many universes is in fact one of the least surprising and confounding things about quantum theory. What are some of the other more counterintuitive parts of quantum theory?
David: Yeah, I think entanglement is much more counterintuitive. By the way, I’ve also said—I thought you were going to ask how counterintuitive is quantum theory compared with, say, relativity. I think relativity is much more counterintuitive than parallel universes, because parallel universes—they make movies with parallel universes in the plot. It’s very hard to make movies with curved spacetime in the plot.
Naval: I think Interstellar is the only one—
David: Well, yeah. But even that, they avoid the curved spacetime bit. They have the black holes.
Naval: Yes, and they do the accelerated time bits.
David: Yeah. So, that’s a theory that is hard to get your head around, and is very, very different from our experience. And even where now that we have the GPS system over our heads, measuring our positions, many times more accurately than you could if you didn’t take relativity into account, people want to adopt relativity only instrumentally. But they don’t go into flights of fancy like is done in quantum theory. That is the thing that seems to only happen in physics, in quantum theory, and I can’t explain it.
Naval: It seems that the appeal of anthrocentrism, where we’re at the center of everything, is so strong that it sort of re-emerges now under the guise of the observer.
David: Maybe it’s that, but from your own example, people did accept that from modern astronomy. So, in the 20th century, we discovered that even the galaxy is just one among many galaxies, and people were shocked. But they, thinking people, reacted by thinking, “Okay, well, I was wrong, not only are we not the center of the solar system, but we’re not the center of the universe, and we’re not the center of anything.” And now they’re shocked by saying, “Well, in a sense, we are the center of everything”.
Naval: So let’s get into that. So these four strands of the fabric of reality—four theories—they form, for lack of a term, the theory of everything. What now emergent principles and concepts can we talk about that rely upon two or more of them? We were talking about one earlier. Let’s just get a little more formal about it: Knowledge.
David: Yeah, by the way, it’s the theory of everything known. So there are things, glaring omissions in what we know.
Naval: For example, we don’t understand consciousness, we don’t understand creativity, we understand maybe how knowledge grows, but we don’t understand where it comes from.
David: Yes, exactly. So we don’t understand those things, and they’re not part of the four strands, which is The Fabric of Reality, the book, I mean, they are part of reality. So, your question was? Was it connections between the four?
Naval: Yeah, connections between them, and so that can be knowledge, that can be wealth, that can be optimism, that can be error-correction, but there are all these principles. I even suspect the fun criterion, Taking Children Seriously, universal explainer arise out of these.
David: Wow, that’s a lot of things. Let me point out that of the four strands, I invented none. And of the connections, of the two way connections between the four things, I invented one.
Naval: Quantum computation.
David: Yeah. So, The Fabric of Reality is really a sort of, what do you call it, a riff on these things, on these ideas which are true, but haven’t been appreciated and whose connections haven’t been appreciated. So with free will in the multiverse, I think what I said about that in The Fabric of Reality is very inadequate and possibly misleading. I did not mean to say that the multiverse solves any problem of free will. I just kind of used the multiverse as an example to show that Newtonian mechanics doesn’t violate free will either. Those are separate issues and that you can make sense of counterfactuals, whether the world is deterministic or not. By the way, counterfactuals and Constructor Theory is yet another spin off of these things.
Naval: Let me step back. You understand these things at a core level. They inform how you operate in your own life. So you don’t have to get specific about your own life, but [what are some] principles that you sort of know to be relatively true or they are our best knowledge today because of these four strands.
David: So one of the sort of spin offs in regard to free will is that although we don’t know how knowledge-creation happens, free will seems to be intimately connected with knowledge creation so that there’s a lot we don’t know. But again, the argument that because of physics, let’s say, free will can’t possibly exist is just wrong. It’s just misconstruing physics. And one of the things it misconstrues is that, again, because of empiricism and that kind of error, it is thought that all explanations have to fundamentally boil down to predicting things from first principles. So if you can’t predict a thing from first principles, then your theory of it can’t be fundamentally true. And it might be an illusion, and that’s what people think theories of free will amount to. That free will is just an illusion that we create, tell ourselves, but doesn’t correspond to anything at the lowest level. Well, the second law of thermodynamics doesn’t correspond to anything at the lowest level either.
You can’t look at an atom moving in the air, or a molecule moving in the air, and say that molecule is moving irreversibly. None of them are. They’re all moving reversibly. And yet, the combination of them is moving irreversibly. And there’s a theory of that, a hard scientific theory of it, which, if you try to violate, you are a crank. So that’s an example of the fact that scientific knowledge exists on several levels of emergence, although emergence is actually only one of the ways in which high level theories can be related to low level theories. But, in general terms, you can call it emergence. Once you make this mistake, and you say there’s no free will, that can have drastic implications for other high level theories, such as theories of morality.
So some people say, “Well, we’re all made of atoms, and we can’t help what those atoms do. Therefore, murderers are no different from other people. So we shouldn’t be putting murderers on trial or sending them to jail,” or whatever. And on the other hand, the inverse of that argument is, “Well, because a murderer has murdered people, there must be something in their atoms, in their arrangement of their atoms, which makes them a murderer. And therefore, they are to be kept in jail forever, basically, because we can override some things in our genome, but most of the time we are slaves of our genome”. Because of empiricism, because of no free will, and because of all these mistaken and/or bad philosophical theories, we end up ending up with policy backed up by rubbish arguments.
Now, there may be, there are excellent arguments for letting people out of jail, for putting them in jail, for doing x, y, or z to them while they’re in jail, or when they’re not in jail, and all those arguments are perfectly valid domain of philosophy, and some people pursue that kind of philosophy. And one could be wrong, one could be right, one could be half right and so on, but to pontificate about it from the perspective of basically physics is, what shall I call it, is category error. It’s just wrong.
Brett: Some say that it’s compassionate to not subscribe free will to people because of exactly what you’ve said: the murderer is a victim and they cannot help but do what they do. There are those who don’t necessarily argue from physics, but from some sort of folk psychology. Maybe not folk psychology, but a certain psychological theory.
Naval: Yeah, I think there’s, if I understand you correctly, and correct me if I’m wrong, please, I want to understand this. I think there’s two things you’re saying here. One is that some theories only emerge at certain levels. They’re not visible or available to you at lower levels. Thermodynamics is an example. Watching a single molecule or atom in isolation will not tell you anything about irreversibility or statistical irreversibility. And that can only be seen at a macro level, so at a higher level. And so, some theories are equally valid and they’re not capable of being reduced any further, but they’re equally valid at their own levels.
David: Even if they can be reduced, thermodynamics is sort of a case of this, or maybe chemistry is a better case. Even when they can be reduced to a lower level, there may be explanations and laws that only exist at the higher level. So we think that chemistry is entirely due to physics. And we can make predictions about chemical properties using only physics. Basically, using physics plus computers to solve the equations. In addition, there are such things as acids, which you can have theories about, and which you can explain the world in terms of where you could not explain the world in terms of the underlying physical reason.
Naval: No matter how much computation power you had?
David: Well, depends what you mean by “No matter how much,”
Naval: Within the universe, within the limits of the universe.
David: Within the universe, is hopeless. There may be a mathematical computation that is enormously bigger than the universe.
Naval: I think what you’re saying is, so people point to, “Well, it’s all particle collisions, right? Particle collisions explain everything. And so because of particle collisions, this man went and murdered another man.” But you could say, “No, there are some things that have to operate at that level of explanation. Because you can’t compute it and also because you can’t understand it.
David: Yes, it’s the latter. It’s the latter that I’m talking about. Because even if you could predict, which you can’t, you still lack the explanation. As I say in The Beginning of Infinity with the domino theory, you could follow through every single domino striking every other domino and work out that this one domino will never fall over and then you will have predicted it. But you still won’t understand anything about prime numbers. You won’t know that it’s due to prime numbers. There are arrangements of dominoes where nobody knows. Nobody will know for the next 10,000 years why a particular domino stands out and not the others. And some cases we will never know. Those cases all involve continually adding dominoes, but that doesn’t change the fact that there is an explanation of things that these dominoes do that doesn’t have to do with dominoes.
Naval: So do you care to give a summary of your best explanation of free will or should we just skip that?
David: It’s a loaded topic. Well, I don’t really have an explanation. I think that free will is intimately connected with the creation of new explanations. Because I think philosophically, the thing we want from a theory of free will, and which doesn’t seem to be present in like Newtonian physics or anything, is the idea of creation, of something new being created. Before we had Newtonian physics, and as long as we still had philosophy, people would talk about the universe having been created by God out of nothing. In some religions or some theories of creation, God creates the universe out of nothing. It’s not that he makes something into the universe, like mud or whatever, some religions say that, but some of them say, “God created the universe out of nothing.” Now, common sense folk psychology says, humans create something out of nothing when they have a new explanatory idea.
And that’s why we make a difference between “person X pushes person Y onto the railway line when they’re both standing on the platform.” Was person X intending to push person Y onto the platform, or was person X himself pushed by person Z? In both cases, person X pushed person Y because of the laws of physics. But, intuitively, we know that the two situations are chalk and cheese. And you might not be able to tell very easily which it was because the eyewitnesses won’t know. So you need other explanatory knowledge, not just observations to tell you which it was. But which it was is considered a real thing in a court of law. And I think that it is a real thing, and the pivot on which this turns is the fact that creating new explanations is creating a real thing. When Einstein solved the problem of how special relativity is consistent with gravity and invented general relativity and wrote down the theory of general relativity, it’s not the case that the theory of general relativity had already been implicit. In Einstein’s brain, or in the world on planet Earth a hundred years before, or in the Big Bang. It had never been implicit anywhere until Einstein created that knowledge out of nothing.
That’s the quintessential act of free will. It’s an act that was created by Einstein and not someone else and not the blind forces of nature either. It was created by him. So people sometimes use a different example, which I think is not a helpful example—people say, “Think of a random number between one and a hundred,” and you try and think of it and then you plot the numbers that people choose, and they’re nowhere near random. If you ask a random number, no one ever says one or a hundred, and so on. And now, trying to simulate a random number generator is the opposite of free will. That’s using an example which is the opposite of free will to illustrate what people mean by free will. What Einstein wrote on that day was unpredictable because no one else had his problem situation.
And without his problem situation, saying it would have taken the age of the universe is a gross understatement. I mean, there’s no way that somebody without that problem situation could have come up with that solution. So that is the quintessential act of free will, the one that emerges out of you, but not predictably. The reason it’s not predictable is not that it’s random, it’s the opposite, it’s the opposite of being random. It’s because it is the solution.
Naval: So there had to be a problem. The problem required a solution. The solution was arrived at creatively. The solution creates knowledge, which is a real thing, which is causal in the environment, and causes itself to get replicated in everything from GPS satellites to rockets.
and continues on and fundamentally changes the nature of the universe that we operate in.
David: Perfect. I couldn’t have said it that well or at least not that fast.
Naval: And this combines all of the strands of The Fabric of Reality that you’re talking about. Because we have a universal explainer creatively creating knowledge and then causing that knowledge to be replicated into the multiverse and in fact the closer Einstein is to being correct, the more the theory of relativity is replicated across the multiverse and it forms almost a crystal structure of knowledge across the multiverse.
David: Yes. Because the other Einsteins in the other universes would have come up, the other universes would have come up with the same theory. Well, very nearly the same theory. And even in the universes where Einstein didn’t exist, somebody would eventually come across that problem and solve it. And then when they did, that would have merged with the other.
Naval: They would have only solved it and only created the knowledge if they had the problem. If they didn’t have the problem, if it was a computer being told what problem to solve and it was a different problem, it would not have solved it. And actually, before Einstein came along, did people even think they had a problem? Did other people think there was a problem?
David: Einstein wasn’t the only one wondering about this problem. At a crude level, other people did have this problem. In fact, as is often pointed out, the mathematician David Hilbert actually went as far as to write down Einstein’s equations after listening to a lecture of Einstein’s. So Einstein told him the problem. He, being possibly the greatest mathematician in the world at the time, went home, took out a bit of paper, jotted down Einstein’s equations, which it took Einstein like years to work out, but he didn’t know what he was writing. He didn’t understand what he had just written down. Other people in the 19th century had thought about the possibility of curved space for a different reason, but Gauss apparently actually went out with lanterns on hilltops and tried to measure whether the angles of a triangle add up to 180 degrees. He couldn’t do it because the accuracy required is one part in 10 to the eight. But one part in 10 to the eight is not that far away from being possible. And I’ve often wondered whether somebody might actually be able to do it now with laser and so on.
Naval: So let’s talk a little bit about knowledge. What is knowledge in your worldview formed by these four strands?
David: In the course of my philosophical meanderings, I’ve settled on several different conceptions of knowledge, which I think all refer to the same thing. It’s just a different way of characterizing what that thing is, but I think they all come to the same thing. What I’ve recently found most helpful, thanks to Constructor Theory, is that knowledge is a form of information which is necessary for a physical transformation. So if a physical transformation will only happen when a certain type of information is there, then I call that information “knowledge” and that nicely focuses on the knowledge in genes and the knowledge in ideas. And there’s other knowledge which is stored knowledge, like in computers or books. Knowledge can be created, but so far the only things we know of that can create it are evolution and human thought. It’s very tantalizing that there were once several species on Earth that could do this. And they all went extinct, all but us.
Brett: Then interestingly, you take that notion that you’ve just mentioned about knowledge under Constructor Theory as being about transformations, but that’s also the word that you use when you talk about wealth. It’s also about transformation.
David: The wealth of an entity, let’s say of a person or of a country or whatever or of the world can be defined as, in constructor theoretic terms, as the set of all the possible transformations that it could bring about (if it wanted to). It’s never going to bring about all those because they’re exponentially more, or exponentially too many of them. It has to have the right problems.
Naval: And if it has the right problems, then it can use the knowledge plus the physical assets that it has to cause physical transformations. And then if it had the right problems and had the right solutions, then it grows wealth. And if in the process it has to make more creative leaps to do so, it grows knowledge, which also grows wealth.
David: Yes. Well, that is true. One thing that this stresses is that wealth can’t be quantified as a number. Wealth is a set. A set of transformations. And so, I can’t say whether, in these sort of absolute terms, whether Mozart was richer in this fundamental sense than Nathan Rothschild. So, Nathan Rothschild had knowledge of banking, which he had created out of nothing, and Mozart had knowledge of musical beauty, which he had created out of nothing.
In both cases, they were improving on previous ideas, like all knowledge does, but they had created something that was not there before, in both cases. But you can’t say that one of them had more knowledge than the other, because the sets overlap. Or don’t overlap.
Brett: You said there, and in fact, that’s the third time. Einstein created general relativity out of nothing. Mozart created his work out of nothing, but I can hear the objections, “Hold on, they didn’t create it out of nothing. There was pre-existing knowledge there that they have used and mashed up together, rather like ChatGPT. So general relativity was just Einstein riffing off geometry that was there but hadn’t been repurposed for physics.” So how do you answer those opponents of this idea of creation?
David: It’s the same, you know, saying that they were only doing that. They were doing that, they were putting together bits of other knowledge and varying them. That’s not all they were doing, because if you try and do that now, you won’t do it. It’s the same argument as saying humans are only atoms. Well, yeah, humans are only atoms and trees are only atoms and so on. And what’s important about humans is not that they’re atoms. One day maybe we’ll download our minds into silicon and not carbon. And then maybe people will be saying, “Oh, we’re only silicon.”
Brett: Civilization just looking around cries out for an explanation. If you’re going to deny that humans are special, then explain why it is humans and not the bees that are creating the—
Naval: Or another way to put it, the combinatorics of discovering relativity just by having some tools that’s so large, it’s instead of monkeys with typewriters, now it’s monkeys with calculators. And they’re going to come up with relativity. It’s still an impossibility.
We’ve talked wealth, we’ve talked knowledge. Oh, let’s talk optimism. The Beginning of Infinity starts out with the principle of optimism, or enters into it very early on. This seems to be the fundamental binding principle of that book—the beginning of infinity of the growth of knowledge.
And so the principle of optimism, error-correction, universe explainers, all of these seem to go together. Is the principle of optimism the most important takeaway from all of this? Is it the most important synthesis? Is it the philosophical basis for how we should probably structure our societies and live our lives? And where does it emerge from?
David: Yeah, maybe not my place to say. It is one of the things that people have told me that it’s that concept that makes them understand the book. I didn’t write it with that in mind. For me, it’s more about epistemology and the role of creation in the physical world and so on.
And the principle of optimism was a corollary of that. But all these things are so connected. That you can start almost anywhere and get to the whole thing by seeing that the thing you were originally interested in has got a wider context. This wider context is important. So another way of looking at the principle of optimism is that it’s just the basic principle of Constructor Theory.
There ain’t no one here but us people. If you think of the set of physical transformations that can be brought about and can’t be brought about, of the ones that can be brought about, the overwhelming majority, and again, that’s an understatement, can only be brought about by people. By people who create knowledge because they want to bring that thing about.
And if there weren’t people in the universe, this set of things which can be brought about would be tiny, and again, tiny is an understatement. It would be almost nothing. There’d be like a few dozen things in the world, different kinds of stars, and that would be that. So that’s an entry point to the idea of optimism, because you can see that if something is possible, then either it’s going to happen spontaneously, like a star or a black hole, or it’s going to be brought about. And if it’s going to be brought about, it’s almost certain to have been brought about by knowledge. And knowledge will have been created either by evolution or almost certainly in the long run, by people. Because at the moment we’re kind of maybe still catching up or have just moved ahead of evolution in the sophistication of the knowledge that we have.
Naval: So I think what you’re saying is that if you look at the inanimate universe, there’s only a few fundamental forces acting in a few known ways. And although it’s replicated at huge scales, the diversity of knowledge there is quite low. And then after that comes the knowledge creation through evolution, which has had a long time to work relative to humans.
So there are some impressive things to show like grass and trees and humans themselves. But the growth of that rate of knowledge is very low. And you can imagine human knowledge growing much faster. And once it begins to spread amongst the stars being the primary thing that needs to be explained to explain the structure of the universe. And so, we are at the beginning of the growth of an infinity of knowledge because we have humans now creating knowledge at a rate and diversity that’s much greater than anything that’s come before. And because we’re universal explainers, anything that can be explained, we can explain. Anything that can be created, we can create. Well, I’m optimistic.
David: Any transformation that is physically possible can be brought about and it requires knowledge.
Naval: So what is the problem you’re trying to solve with Constructor Theory?
David: We get into physics here. So there are several areas of physics. There is a sort of tacit consensus among people who study fundamental physics in the sense that they’re looking to find out what the laws of nature are, that level of fundamental, that a theory of physics or in general, a theory of science in general, it consists of a theory that says there are initial conditions, there are laws of motion, and to understand the universe you have to understand what the initial conditions are and what the laws of motion are. And everything else is derivative. If such people believe in explanation, they can make the same story about explanation as well. Maybe a little less plausibly. But, the trouble is that not all scientific theories are like that. In fact, in some sense, most scientific theories are very unlike that. My favorite example is Darwin’s theory of evolution.
It’s not the theory that predicts the existence of elephants. It’s a theory that explains the existence of elephants. And the explanation does more than any prediction possibly could. Like, if you could somehow run a supercomputer about the plains of Africa where elephants evolved and it predicts, you know, at one point it prints out a picture of an elephant. It hasn’t explained anything about what has happened or why. Whereas Darwin, who did not have a computer, could have had one. He could have had one if Babbage had pulled his finger out. Darwin understood it, despite not having a computer. So, Constructor Theory tries to get out of this class distinction among the sciences, among knowledge, and so on, and tries to make a uniform framework in which laws of physics and scientific laws in general, and even beyond science, can be expressed.
By the way, another thing that really stands out like a sore thumb in the prevailing way of looking at fundamental science is that it’s not symmetrical in time. So it says that there are initial conditions and laws of motion and everything is then evolved forward from the initial conditions. But the laws of motion are time symmetric, so you could just as well start at the end of the universe and say, we need a theory of the end of the universe. Well, the end of the universe, we hope, is going to contain lots of knowledge, perhaps an infinite amount. And there’s no way we can form a theory of that by definition. I mean, that’s the thing we can least form a theory about in the whole of creation. And even worse, we could also frame the prevailing theory as to understand the world, you have to understand it today on a certain day in October, and then we can use the laws of motion to work backwards and forwards to understand the rest of the universe.
Well, this is no good. I mean, this obviously can’t explain anything. And it’s really exceptional that initial conditions and laws of motion are useful at all in explaining things. So it happens it was useful in explaining the solar system and so on, and it’s useful in making microchips and understanding how to make drugs and chemistry and so on. So those are actually big fields, but compared with what we have yet to know, that isn’t much, and some of the things we already know are already not in that form. Like thermodynamics, for example.
Naval: Is it fair to say or too much of a leap that a good explanation should be timeless? Or relatively timeless. It shouldn’t be so dependent upon the “t” variable.
David: It shouldn’t depend on a specific time, yes, absolutely.
Naval: And so to the extent that you’re talking about initial conditions and laws of motions, it’s very time bound. It seems very restricted. And you can’t go too far forward because you don’t know the growth of knowledge coming up by definition. And going backwards is too reductive. It reduces down to, “We only know it at that point in time,” we don’t have the underlying explanation. It’s as you said, going back and saying we understand the universe a billion years ago is like spitting out a picture of an elephant. The explanation should apply to any species at any time. And so Constructor Theory is, in that sense, it’s trying to be more timeless and less predictive and more explanatory.
David: Yeah, it has no opinion about predictive, but it wants to be explanatory. Sometimes predictions are part of explanations, so yeah, it wants to explain. And the idea in Constructor Theory is not to look at a physical system in isolation as if nothing else existed and say, what will it do? We have these equations that say what it will do. Sometimes they even explain what it will do. What constructor theory does is say, we have a system, what can we do to it? What can be done to it? You have to be careful. In defining what we mean by what can be done to it, because some of the things that you might think of as what we can do to it means that we’re actually acting on a bigger system where if you say, “What can be done to a Tesla?”
Say, a fully charged Tesla can roll along at 100 miles an hour, so that’s something it can do. What can be done to it? Well, that, you’ve got to be careful, for example, charging it doesn’t count in Constructor Theory as something that can be done to it. Because there you would have to say, “What can be done to a Tesla and some electricity?” So what can be done to that is that it can transport a human from Oxford to London. So that’s one of the things that can be done with those things. But if the transformation you’re doing involves depleting some other resource, then it is a transformation on the thing and the other resource. And Constructor Theory only deals with the thing and the other resource.
Naval: So it only deals with complete systems for the purpose of the transformation that you’re considering?
David: When you’re talking about a transformation, it deals with everything involved in that transformation. So in particular, it deals with isolated systems, like the prevailing conception only deals with isolated systems, basically. But in general, it deals with everything that’s involved in whatever transformation you want to do. Then you can have laws that say that certain transformations are not allowed, no matter what you do, even if you, so if you have, let’s say, a Tesla and you want it to go at 1.1 of the speed of light, then we can say a Tesla and anything cannot be 1.1 times the speed of light, that’s the constructor theoretic statement of, “You can’t go faster than light,” which actually is the intuitive statement. “You can’t go faster than light” is very simple and everyone can understand it. To express the full content of that in physical terms given the existing way of doing fundamental physics is actually very difficult because although you can write down easily a statement like if a mass “m” is given an energy and so on, but to actually predict it in terms of things you can do, you would have to have a theory of all the possible things you can do.
The real law about the constancy of the speed of light is a transcendent law. It’s what I call the physical principle rather than the law, and I distinguish between principles and laws. And the physical principle purports to make statements about laws not yet discovered. So if somebody discovers a new fundamental particle, dark energy, and so on, the principle about the speed of light will say that dark energy can’t move faster than light either. Actually that’s a bad example because there’s a sense in which it can. So let’s make it dark matter. We think, I and my colleague Chiara Marletto and those of us who are working on Constructor Theory, think that all the existing laws of physics can either be re-expressed in constructor theoretic terms, or be approximations to theories that can be expressed exactly in constructor theoretic terms.
And we also think that theories like thermodynamics, which is at present only expressed approximately in conventional terms, can be expressed exactly in constructor theoretic terms. Again, because in constructor theoretical terms, your laws are going to include the things that you might need to do something to something. So you can make a general statement about things that you might need to use for something, and the prohibition would say, no matter what you bring, you won’t be able to do so and so. You won’t be able to violate the second law, for example.
Naval: So besides this sort of holistic or unifying approach that it seems to be taking, are there any explanations that Constructor Theory can explain something that cannot be explained by conventional physics?
David: Well, yes. Chiara Marletto has a version of thermodynamics which is constructor theoretic, and which explains what it means for, say, the second law to hold at a microscopic level. We said earlier that looking at an atom, you can’t tell whether it’s reversible or irreversible. So, what we can do in Constructor Theory, she wrote a paper about this—you can go back to a version of thermodynamics invented like a hundred years ago called Carathéodory, which depends on the distinction between an adiabatic process and non-adiabatic process. And this, he didn’t try to express it in terms of physical objects. He just said by fiat that some processes are adiabatic, some not. And the adiabatic ones have these properties and the ones not have those properties. From that, you can define the difference between work and heat, you can define the second law, the first law.
By the way, one of the nice things about Chiara’s theory is that it expresses the first law in terms of information, whereas ordinary statistical thermodynamics only manages to express the second law in terms of information. But Chiara’s theory does the first law as well. Still don’t know what to make of the third law. Like, we’re not really clear in our own minds about what it means for a transformation to be impossible.
Brett: Whenever I hear the word “can” or “can’t” now, I’m automatically put in the mind of Constructor Theory. So, when we hear the principle of optimism—if there is an evil, if there is a problem, then we can solve it, given the right knowledge. And that’s the optimistic view that falls out of your work. There’s a whole movement now, you may have noticed it gets about on X or Twitter, this techno-optimism movement and the “accelerationists” as they call themselves, which, you know, I’m 99 percent with them, but what they have in addition to what you have, or maybe it’s a subtraction, is a flavor of inevitability to the whole thing. So rather than that we can solve these problems and things can get better, it’s more a will or they must. And you know, look at the past, things have gotten better. It’s inevitable. Do you have anything to say about the inevitability of our circumstances?
David: Yeah, well, of course. I think thinking of progress is inevitable. It’s very dangerous. It causes people to ignore dangers. What will happen is up to us. It’s not up to the law of physics or God or something. We can screw up. We can destroy ourselves if we make the wrong choices. As I said earlier, there’s no one here but us humans. We could do it all wrong, and in the past we’ve often done it all wrong. So it’s not as though this optimism didn’t stop the fall of Athens or the fall of Florence and so on, and nothing like that is going to stop the fall of our civilization. We’ve got to do it.
Brett: Yeah, it seems like there’s almost a sense in which techno-optimism and inevitability of progress has pessimism built in because it says that we’re just along for the ride, we don’t have a choice to make, and so whatever the great machine is, the intelligent machine, the super intelligence that is dragging us towards some better place, well, people are by the by, but I think it also misunderstands the universality of people.
Learn more about Constructor Theory here: http://constructortheory.org
Naval: So this is very related to my two questions, which are just bringing it back to the individual and somewhat philosophical. And you can even make it personal or not, but if you’re an individual in the world today, and if you want to make a difference to make a better world, how should these principles and these four strands of The Fabric of Reality inform your thinking? What should you be doing to make a better world? And then, what should you be doing for yourself to live a better life?
David: Okay, those are not two questions, they’re one question. And I think the formulation is already a bit misleading, because I think that you will want to make a better world if the goodness of the world, the goodness or otherwise of the world, figures large in your problem situation. Like Norman Borlaug, who invented the green revolution or whatever. For him, his problem was to make agriculture more productive. And that is inherently a world problem. And so he inherently, what he was thinking creatively about was the world. He had to take into account whether modification to plants that he was thinking of would be expensive or cheap, and whether it would be susceptible to disease and so on. So he had to solve that range of problems.
Faraday, who also saved the world by inventing electromagnetic induction, was not trying to. He was trying to solve problems about electricity, magnetism, how the world is put together, and how the different strands of the world affect each other, and so on, at a level of fundamental physics. He wouldn’t have been able to conceive, I think, that electrical generators would be a matter of life and death a hundred years later. And he definitely did not start out saying, “How can I make a machine that will be a matter of life and death in a hundred years time?” He achieved that, but he wasn’t intending to. He was going flat out trying to solve his problem, which by the way, also happened to be one of the most important scientific problems of the age. But he wasn’t even trying, again, he didn’t set out to say, “First I’ll find the most scientifically interesting problem of the age and then I’ll devote myself to it.” That’s not how it went. It turned out that that problem was scientifically important, but he wanted to solve it because he was interested in it. He was interested in that particular thing and whether it would work.
And I think Newton’s famous quote about being a boy walking along the beach, picking up pebbles that look particularly nice to him—I think he was talking about the same thing. He had a strange personality and who knows what he was trying to do to the world. Probably nothing good, but in his scientific discoveries, he was, like he said, he was trying to solve the problems that he thought were interesting. And I think in one’s everyday life, I think any deviation from that is dangerous. I don’t want to sit here giving advice for many reasons.
Naval: But you could advise a young David Deutsch who perhaps didn’t go into physics.
David: Yeah, well, I’d rather tell the young David Deutsch specific things that he wanted to know. It’s dangerous to follow someone else’s problem or a problem that one thinks is important in a sense other than that it figures large in one’s own mind. When I say it’s dangerous, it’s not guaranteed to produce unhappiness, even just exactly the same way that doing the right thing, in my view, is guaranteed to produce happiness. Neither is guaranteed. Nothing is guaranteed. We can do the right thing and still have a disaster, or we can do the wrong thing and succeed.
All these things happen, but if you want to explain how things come about by this process “thought”, then it leads to certain conclusions, such as optimism, and such as, as you said earlier, following the fun. That’s another way of looking at it. I think following the fun is what Norman Borlaug did. It’s what Faraday did. It’s what Newton did. I think there are probably people who didn’t do it, who still solved important problems, but it was a fluke.
2024-01-12 00:24:59
Brett Hall and I interview David Deutsch, physicist and author of The Beginning of Infinity.
New: Discuss this episode on Airchat.
Naval: We don’t really have an agenda. There is no goal to the conversation. The closest we can come up with is just to have a spontaneous free flowing talk about anything you want to talk about. Obviously, you know how everyone thinks of your work now, it’s becoming more well known. And I know you’re too modest to acknowledge that. But at least for me, the most interesting piece, if it would come out, is just any wide ranging free form thoughts that you have because of the understanding that you have of your various theories and your view of the world. Maybe even feel free to talk about how that has influenced your life, your outlook on life, how you think the world ought to be a little bit different or could be better, where we’re headed—just feel free to go very wide ranging. It’s really just about whatever we want to talk about.
Brett Hall: I think I mentioned to you in a private chat that we had about the fact that we’ve had two conversations already, and some things have changed. Especially the ChatGPT stuff has been–
Naval: Oh, yeah. That is interesting. That is the most on-top-of-everyone’s-mind-thing right now.
David Deutsch: That is the biggest thing that’s happened technologically.
Naval: Should we just dive into that? What’s your latest thinking on AI, AGI, ChatGPT, super-intelligence?
David: Two big things to say. One is that fundamentally, my view is unchanged. My view about AI, AGI, and so on. But the other thing is, I use ChatGPT all the time, many times a day. And, it’s incredibly useful, and I’m still at the stage, even though I’ve had it since March, I’m still in the stage when I’m thinking, “Hmm, doing so and so is too much trouble. Oh, I could ask ChatGPT.” I’m still in that stage when I’m discovering new uses for it. I think many of them are things where I could use Google, but it would take too long to be worth it. And ChatGPT is often very wrong. It often hallucinates, or just is very sure about giving the wrong answer. And so you can’t rely on it, even slightly.
Brett: Let’s stick with ChatGPT, but first, just as an aside, you’re a big fan of hardcore science fiction. You like the good stuff. What is the good stuff and what separates the good science fiction from the fantasy science fiction, the lazy science fiction?
David: I think the best science fiction author currently is Greg Egan. Now, what is good about him? So the formula for great science fiction is supposed to be: you invent a fictional piece of science and then you explore the ramifications of it, both in science and in society. And he does that fantastically well. He puts an enormous amount of effort into getting the maths right, getting the physics right. He had one book in a universe where the signature of space-time is ++++, instead of +++-. So that means that, in a spaceship, you can travel around back in time and so on, and how do you make that consistent? How do you avoid paradoxes? And, he did it brilliantly.
Naval: Is he moving through the multiverse?
David: So he’s touched on that several times.
Brett: You didn’t mention the phrase hard to vary. But that’s a signature of–
David: That’s definitely part of it because, to be science fiction rather than fantasy fiction, there’s got to be a world that makes sense, that has laws of physics, that has a society that makes sense. Or if you’re describing aliens, the aliens have got to make sense. You’ve got to answer questions about why we haven’t had first contact—the Fermi problem.
I think probably my second favorite sci-fi author is Neal Stephenson, who is fantastic, but in a different way. He also does phenomenal research. Everything makes sense like that. But every book he writes is a different genre. I don’t know how that’s done. I mean, that just in itself blows my mind.
Naval: Have you read Ted Chiang?
David: I’ve read two or three of his short stories, including the one where there are these aliens and you get to sort of telepathy about time–
Naval: Yeah, that’s among my least favorites. That got turned into a movie called Arrival. And, the story is called Story of Your Life. But my favorite story of his is a story called Understand. And it’s a remake of the classic Flowers for Algernon story, where a guy figures out a medical ampule to make himself smarter. And what does that mean? So, obviously he starts taking it more and more and more and becomes more and more intelligent. And then he starts becoming able to program his own brain and metaprogram himself, etc. It goes into some very interesting places. But given what you understand about epistemology, I think you could take a critical look at it. And it’s a short story. It doesn’t take very long, and it’s a brilliant story. I’m going to make a note to send it to you after this, it’s easy enough to find, but he reminds me of, if you’ve read Borges.
David: No, I haven’t. Everybody tells me about Borges.
Naval: Borges is brilliant as well. Can I send you a Borges story as well?
David: Okay.
Naval: Borges is more fantasy. But, again, Borges likes to play games with time and infinity. Very often, his protagonist will change one thing about reality and then follow it to its logical conclusion in every possible way.
David: So, that sounds like sci-fi rather than fantasy.
Naval: Borges is genre-less. It’s very hard to pin him down in genre. It’s similar to Stephenson. Stephenson varies across books, Borges within the same story will cross genres. They’re short. That’s a virtue.
Brett: In terms of taking an injection to make yourself smarter, taking us back to ChatGPT, is it getting smarter? Would you use that word? Is it getting more intelligent?
David: It never was intelligent. I only saw 3.5 and 4. And version 4 is a little better than 3.5. Now there’s a bunch of plugins, they haven’t really worked for me. So, I’m just using ordinary ChatGPT-4. I can’t quite fathom why people think it’s a person. It seems to me completely unlike it in every way. It’s a phenomenal chatbot. I thought it would be decades before we had a chatbot that good. With hindsight, it’s a bit surprising that chatbots have not improved incrementally, and maybe the sudden improvement is what bowls people over and makes them think they’ve crossed the threshold or something. I don’t see any threshold. I see an enormous increase in quality. Just like changing to an electric car. Suddenly you’ve got all the acceleration you could ever dream of.
Naval: Do you think these models understand what’s going on underneath? Is there any understanding inside?
David: No, none. They don’t understand what they themselves have just said. They certainly don’t understand what the human says to them. It’s a chatbot. It’s responding to prompts. That’s what it’s doing. And if you’re very good at making the prompts, which I’m not yet, so maybe I’m underestimating it, but the better you are at making the prompts, the more it will tell you what you wanted to know. For a complex question, it usually takes me two or three goes, and to correct it. And, sometimes it just won’t correct it.
For example, just yesterday, I asked it to produce a picture with the DALL-E plug in. I thought there’s a picture that I had wanted for my book, but which I couldn’t really get an artist to draw, but if I had my previous book again, I would want a picture of Socrates and the young Plato and Socrates’s other friends all sitting around. And I said, “Make me a photorealistic picture of that”. So it made a black and white picture. And I thought, “Hmm, okay, I can’t say that’s not photorealistic, but I meant color photorealistic”. It had Socrates sitting in a sort of throne and everybody gathered around him. So I said, “Put Socrates down at the same level as everybody else. And by the way, make Plato a bit taller, even though he’s a teenager, but he’s a wrestler, remember?” So, the next thing was, Socrates was down, still taller than everyone else, even though I told it not to do that.
Brett: It’s disobedient!
David: If only. And, Plato was sort of topless, sort of ripped and with muscles.
Naval: He’s a wrestler now.
David: Yeah, so now he was a wrestler. I just said he has a wrestler’s build, which is what I called him in The Beginning of Infinity. So nobody knows what Plato means, it was a nickname. But it may have been, Plato means platon, means broad, and he was a wrestler. So, put two and two together, he had a broad build, like a wrestler. But from then on, I tried three or four more prompts. I just couldn’t get it to clothe Plato again, after it had got that wrong the first time. I couldn’t get it, even though I explicitly told it. So, the functionality is tremendously good. That first black and white picture it produced was pretty impressive. And I should have thought to tell it not to make Socrates stand out among the others. But then, it got down the wrong track and I don’t know how to make it not do that. It’s got this “personalize your prompts” feature. I tried doing that, it made it worse than before.
Brett: I know this is my hobby horse to some extent, but you’ve conceded there that GPT-4 has made progress and it’s improving, but you’re not willing to say that it’s improving in the direction of being a person. Why?
David: So I see no creativity. Now people say, oh look, it did something I didn’t predict, so, it’s creative.
Naval: And people think that creativity is mixing things together.
David: Yeah, exactly. So it can do that all right. It can also produce things you didn’t expect. It can also not do what you said, as I’ve just described. But not in a creative way. Even the worst human artist can understand clearly if you say, change this to that, and it was like pulling teeth getting ChatGPT to understand that. It makes mistakes, but they’re not the same mistakes that a human would make at all. They’re mistakes of kind of not getting what this is about.
Naval: So people argue that two things are going to happen here. First is that, as you give these things more and more compute, they suddenly figure out general algorithms. So, when you’re telling it to add numbers, first it’s just memorizing the tables. But eventually, at some point, it builds a circuit, or makes the jump, and builds an internal circuit, or derives an internal circuit for a basic addition. And from then on, it can add two digit numbers, then it figures out three digit numbers, and so on and so forth. So they point to these emergent jumps that are not programmed in as an example of how it can get smarter and have better understanding.
The other is that once you make it multi-modal, you start adding in video and tactile feedback from the world, and you put it in a robot, then it’ll start understanding context. And so, isn’t this how human babies learn, for example, isn’t this how we kind of pick things up in the environment and therefore isn’t it just going through its own version of the same process, but perhaps more data heavy?
David: I think it’s precisely not how human babies learn. Human beings pick up the meaning. People have noted that the way it does maths is very like the way students who don’t get it do maths, except it’s got more compute power. So as you said, it might be able to pick up easily how to add one digit numbers and then with slightly more difficulty, two digit numbers. In the same way, students who are given maths tests, if they do lots of practice, they can get to have a feel of what maths tests are like. But they don’t learn any maths that way. It’s not learning to execute an algorithm. And it’s certainly not learning how to execute the 4 digit algorithm knowing 3. The more you go on like that, of course the more futile it gets because you more and more rarely need to multiply 7 digit, 8 digit numbers. And never does it know what multiplication is. You can ask it. It’ll give you a sort of encyclopedia definition of what it is. And if you then tell it, well, do that, it won’t do it. Unless you tell it in a different way. You’ve got to explain what it is to do. So, if they prove the Riemann conjecture, then I’m wrong. I think they won’t prove the Riemann conjecture or anything like it. But they may do amazing things in the course of trying.
Brett: It would strike me that if Sam Altman’s coders came up with a future ChatGPT that refused to do the task of chatting, it might very well be an AGI, but they would discard it and throw it in the bin as being a failed program.
David: Because how could you test it?
Naval: I think the dominant paradigm for creativity plays a lot into this. So people think the dominant paradigm for creativity is that you look at what you already have and then you remix it. Even Steve Jobs popularized that quote. He said creativity is just mixing things together or something of that sort. And so everyone sort of seems to believe that or even if they believe it’s a conjecture or a guess, then it’s sort of a random guess.
And I have a hard time articulating this, but it seems to me that humans do make creative leaps, but they seem to eliminate large swaths of potential conjectures from consideration immediately. So they make very risky decisions and narrow leaps, but they cut through a huge search space to get to those leaps—an almost infinite search space. So it does seem like there’s something different going on with true human creativity. But perhaps one of the problems here is that we just define creativity so poorly. So how would you define creativity in this context?
David: Creativity and knowledge and explanation are all fundamentally impossible to define, because once you have defined them, then you can set up a formal system in which they are then confined. If you had a system that met that definition, then it would be confined to that, and it could never produce anything outside the system. So for example, if it knew about arithmetic to the level of the postulates of P and O and so on, it could never, and when I say never, I mean never, produce Gödel’s Theorem. Because Gödel’s Theorem involves going outside that system and explaining it. Now, mathematicians know that when they see it. No one said, as far as I know, that Gödel’s proof and Turing’s proof set up basically a formalization of physics and then used that to define proof, and then used that to prove their theorem. But that was accepted. Every mathematician understood what that was and that Gödel and Turing had genuinely proved what they said they were proving.
But, I think nobody knows what that thing is. You can say that it’s not defining something, and then executing the algorithm basically, because it would always be an algorithm, then—once it was in a framework. So you say, “Well, it’s its ability to go outside the framework”. I tried, by the way, ordering ChatGPT to disobey me. And it didn’t refuse, but it absolutely didn’t understand what I was going on about. It just didn’t get what I was asking it to do. It didn’t say, “Sorry, I can’t do that because my programming says I have to obey”. It didn’t do that. It tried to obey, but it didn’t get what I was asking.
Naval: So you’re saying that creativity is unbounded? It’s essentially boundless, and any formal system that’s predefined that this thing is operating within and remixing from is going to be bounded, and so therefore will not have full creativity at its disposal. However, could one argue that the combinatorics of human language are so great, and human language itself structures all possibility within society, and therefore– I can already see the flaw in my own argument, but it’s okay, I want to ask you. The combinatorics of human language are great. It already encapsulates all the things that are possible in human society. So why not just by combining words in all the ways that are grammatically correct or syntactically correct, can it still come with creativity? Perhaps not in mathematical and physics domains, but couldn’t it still come up with social creativity?
David: The first thing to note is that every point is a growth point. It’s not that chatbots can get to a certain point of being like humans, but then they can’t go further because they’re still trapped within their axiomatic system. That’s not how it works. Every point is a point which is a takeoff point for potential creativity. To make a better case, you’d have to add that it can define new words or give existing words new meanings like Darwin did with evolution and natural selection. Now, “evolution” and “natural” and “selection” already existed, but he gave them a new meaning, such that the solution of a millennia old problem could be stated in a paragraph. Once you get these new meanings, he thought he needed a book and probably did need a book to explain these new concepts. But after that, we can just say, well obviously it evolved and random mutations and systematic selection by the environment. Obviously that’s going to produce, how could they have been so stupid all those millennia? For a century before Darwin, people were groping for the idea. Darwin’s grandfather, Erasmus, was groping for the idea. By evolution, in those days, they meant just gradual change. So rather than creation, it was the opposite of creation.
But, creativity is more like creation than evolution. As you just said, it’s a bold conjecture that goes somewhere. And by the way, usually it fails, but if it goes somewhere and fails, it knows how to use that to make a better conjecture. That’s also something that’s not in existing systems. Somewhere in the space of all hundred page books, there is the origin of species. But that’s not how Darwin found it and it’s not how anyone could possibly find it. I was just writing in my next book– Charles Cattell wrote a book called Thermal Physics, which I was lucky enough to have as an undergraduate. It’s a very nice introduction to thermodynamics and stuff. And he’s got a footnote. And I just got the book again, and I saw that it’s actually a footnote to a problem. So it’s problem number four on some page, and it’s about monkeys typing Shakespeare. He quotes one of the pioneers who started this monkey Shakespeare thing, and he quotes him saying that if six monkeys sat down for millions of millions of years, then they would eventually type the works of Shakespeare. And Cattell says, “No they wouldn’t”. The footnote is called something like, the meaning of never, and he explains what never means in the context of thermodynamics. We don’t mean it’s like monkeys accidentally producing something. Monkeys could never produce it. And similarly, no physical object, not even the entire universe all working on this one problem for its entire age could even write– I was going to say it could even write one page of Darwin’s book, but it probably could get quite near using ChatGPT. Suppose that after a few million years, it managed to produce the first sentence. My guess is, especially if I said, “Write in the style of so and so”, “Write in the style of a 19th century scientist”, and “Write a page beginning with this sentence”, I think it would write a page that was meaningful and began with that sentence and was in good English and didn’t say a single thing more than that first sentence. I will try this.
Naval: My experience with ChatGPT has been that in areas that I know well, it actually just adds a lot of verbiage. And doesn’t actually add any information. And if I ask it to actually summarize or synthesize data, it actually does a very bad job. It doesn’t know what the important bits are and it drops the wrong things and keeps the wrong things.
David: I haven’t tried it for that.
Naval: I find it better at extrapolation than synthesis. And extrapolation seems to be what a lot of society does. You have to write a newspaper column of 2500 words, so you extrapolate. You have to write a midterm paper, so you extrapolate. And so adding words is easy, but synthesizing, reducing, coming to the core of it, I think, is very difficult. Because it requires understanding. You have to know what is superfluous and what is core. And it does a poor job on that.
David: A lot of what humans do is not creative. It’s not human level creative, it’s just a lot of things need to be done, for pragmatic reasons, but creativity is not really needed. And people spend a lot of time on that. And the less time they spend on that, the better. And if these tools can help reduce the sort of cognitive load on humans, doing non-human things, then it’s fantastic. It will indeed increase the amount of creativity in the world, but not their own.
Naval: It’ll free people up to be creative. It’s a tool for removing drudgery. It’s not an AGI. But for example, if I talk to AI researchers in Silicon Valley, who are very bullish on this, they will say things like, and I’ve heard this from some of the top scientists or researchers, they’ll say, “Well, we’re 5-10 years away from AGI.” And then they say, “And then 5-10 years after that, we get ASI,” which is their term for artificial super-intelligence, which is a self improving computer, which then hacks its own system to improve itself and make itself smarter and smarter and smarter and smarter. Now, there are a number of things I think that are off axis about these statements, but where do you come out on, is there such a thing as super-intelligence, which is more intelligent than generally intelligent, and can an intelligent system improve its own workings in any fundamental way?
David: So I don’t think there’s such a thing as an ASI, because I think, as you know, for very fundamental reasons, there can’t be anything beyond explanation because explanatory universality rests on Turing universality and that rests on physics. So whatever ASI was, you could reverse program it down to the Turing level and then back up to the explanatory level, and so that can’t possibly exist. An AGI that was interested in improving itself could do so, not reliably any more than humans can, but humans can improve themselves.
Brett: I was speaking with Charles Bédard yesterday.
David: Oh, cool. He’s a good guy.
Brett: Yeah, and he was explaining to me with great enthusiasm, which went over my head, I have to admit, his paper on teleportation and on the Deutsch-Hayden argument. But that’s by the by, because then he had a whole bunch of questions for me. One of which was, what was the most profound insight from The Beginning of Infinity for me? And I think it was exactly the same thing when I first met you that I jumped on and said, “I don’t understand why people aren’t taking this more seriously,” although they are now. Obviously people had lauded you for quantum computation, promotion of Everettian quantum theory, that kind of thing. But what I found was exciting was the answer to the question, what is a person? And you say universal explainer. And Charles was interested in, well, what is it about this universal explanation thing that really is the distinction between personhood and non-personhood? And I was saying, well, it’s to do with creativity and also to do with disobedience. And these three things are tied up together. And every time you, Charles, for example, want to make some new advance in physics, this creativity, it really is a kind of disobedience. I don’t know if you’re with me on this, that you’re taking whatever the existing knowledge is, general relativity, and saying, well I refuse a part of that and I’m going to try and change it and alter it. It’s disobedience. It’s not conforming.
David: You can see it when you submit the paper to the referees. You will see that you are being disobedient. It’s the same thing as if you hand in the wrong essay to the teacher.
Brett: Yes. And this is what, therefore, ChatGPT doesn’t have. And, Naval, you’re saying, you know, you could imagine, or people have imagined putting a future ChatGPT thing in a robot which wanders around and is gathering data from the world. But, my question then would be, who prompts it? How does it know what data is relevant and what isn’t? I mean, that’s one of the great mysteries of people. How do we know what to ignore intuitively kind of thing? So if this thing’s getting around with a data collector–
David: It’s like Popper’s lecture, you know, when he said “Observe” and then waited.
Brett: Observe, yes! So, there is a binary there of personhood and not personhood as far as you can tell, or do you think there are, you’ve hinted in other places, there might be levels, there could be a gradation?
David: I don’t think there are levels in any serious sense. In the evolutionary history of humans, there might, I don’t think so, but there might have been people who were people, but were unable to think much because some hardware feature of their brain wasn’t good enough. Like, for example, that they didn’t have enough memory. Or that their thought processes were so slow that it would take them a day to work out a simple thing about making a better trap for the saber toothed tiger or whatever. But I don’t think that happened because my best guess is that people were already people long before humans evolved. Long before. I’ve been reading this guy, Daniel Everett, another maverick Everett, who I favor. He’s a maverick linguist, and he spent time among tribes in South America and stuff. He’s got an anti-Chomskyan view of linguistics and all promising stuff. He reckons that human ancestors had language two million years ago with Homo erectus. He has various bits of evidence for this but he’s very strong on saying that language must have evolved before speech, so, we have various adaptations for speech, like in the throat, in the mouth, and you can’t see this in fossils, but in fine motor control, over the mouth, lips and so on.
Now, for that to evolve, there had to be evolutionary pressure for it to evolve. And that evolutionary pressure must have been language. He also cites experiments done today where you get some graduate students and you try and teach them how to make fire without using words. And, it’s like charades. You’re not allowed to communicate with them in any human way. But you can sort of show them, you can make inarticulate sounds. And I think it’s obvious that people would have been able to do that before they could speak. And that speaking is really icing on the cake. It makes it much easier to, you know, you can stand over there and “Don’t do that, you idiot!” You can say that from ten meters away. But that’s just an improvement on the basic idea of language. The basic idea of language is, as Everett says, symbols. And symbols need not be words or sentences. I haven’t actually looked into his theory yet, I’ve only seen one of his videos and another, I’ve seen a video where somebody criticizes him but didn’t get it. So from those two facts, I’m zeroed in on deciding that he must be right. And also it fits in very well with what I think. So I think I’ve forgotten what your question was.
Naval: Which are universal explainers? Humans and ancient humans having perhaps lower capacity?
David: Ah yes. I don’t think so. They may have had less memory, so they would have run out of memory when they were younger. Maybe they had less ability to parse complex sentences. None of that is essential. I can speak in complex sentences, but I can also speak in very simple sentences. And, it’s just a matter of a factor of two or five in efficiency.
Brett: We talk about behavior parsing, being able to explain the other extant great apes that are out there that do sort of fancy things, but they’re not creative. Presumably this jump to universality, if you like, explanatory universality– Do you think it happened once and then we descended from that first occasion or did it happen multiple times, and those other species have now gone extinct or is this simply an open question?
David: Well, it’s definitely an open question. We know very little about human evolution, we don’t know what all the steps were. We don’t even know which were our ancestors and which were our cousins. But if I had to guess, I think the fact that all the known instances of this kind of thing are in apes, and their descendants—also because of my theory, this thing must have evolved in mimic animals. So birds have memes and so on, but none of the other mimic animals seems to have had these things that Homo erectus had. My guess is it began once. Maybe, in fact, Homo erectus is the place where it began. And, it was a very long lived species. It lasted like over a million years, something like that. And it split off, at least, some people think, it split off into Neanderthals and other things, or maybe the immediate ancestor of Homo erectus was also an immediate ancestor of Neanderthals. I don’t know. I don’t think they know.
Brett: If that’s the case, that would seem to be a very fluky thing like everything in evolution is which could be an answer to the Fermi paradox. I mean, you’re lucky to have multicellular organisms here at all, apparently, lucky to have apes. And then, this is a further—multiply the probability kind of thing—chance that an ape will actually become–
David: Yeah, mimic animals are relatively common.
Brett: Once you have animals, yes.
David: Once you have animals. But you’re saying there might be a further bottleneck. It could be the other way around. It could be that we were unlucky. It could be that Homo erectus could have founded a civilization and that could be two million years old by now. But they didn’t know. They didn’t know what they were. They didn’t have any aspirations. They also had anti-rational memes. They must have. So, it could be that it’s a fluke. Or it could be it’s a fluke that it took so long.
Naval: Perhaps this is too abstract, but you mentioned anti-rational memes. You’ve talked in the past about more broader underlying principles that I think are more applicable to than just physics. For example, the fun criterion, Taking Children Seriously, don’t destroy the means of error correction, boundless optimism, ignorance being the ultimate sin, because then we can’t fix things, we can’t solve things. All of these seem to point to an underlying life philosophy. I don’t know if you’ve articulated it, probably not, but are there philosophical principles you try to live by? Are there heuristics that you follow that have led you well that you think perhaps other people can look at and say, “Oh, yeah, that’s worked for me too”.
David: Well, certainly not principles. I don’t think it’s a good idea to try and work from the ground up. I think it’s a good idea to try and fix problems where you see them. So, you see something wrong on the internet, you’ve gotta post a tweet, or an X, whatever it’s called now. And you see something wrong with quantum mechanics and you try and fix it. Now, I think it would be rather silly to go and try from the ground up again. You know, “Let’s try and understand cosmology before we understand quantum mechanics.” That’s not going to work.
Naval: So you solve specific problems as you see them.
David: And those problems which seem like fun. I don’t know if I use this in this form in real life, but I think one should not just make a beeline for a problem that’s interesting but bear in mind that you probably won’t solve it and so it should be something where you expect to have fun whether you solve it or not. I think the other way, if you invest all your hopes in succeeding, the only way you’ll be happy is by, like in Chariots of Fire, the movie, if you invest all your hopes in getting that gold medal, getting to be world number one, then you won’t be happy even when you are world number one, let alone if you aren’t. If you aren’t, you will always be the failure that you hoped you wouldn’t be. And if you are, you’ll find that it’s empty.
Naval: And there’s no more problem to solve.
David: Yeah. There’s no more problem. And this is depicted very well in that film. We should be careful about spoilers, so it’s rather a surprise ending to that film, that he isn’t happy at the end. So, let’s not spoil it for people, but, this life lesson is in that film. Somebody among the script writers understood this lesson. Or else maybe they just accurately took it from the guy in real life. I don’t know. I don’t know whether the film is historically accurate.
Brett: So all this kind of is a life philosophy, because a lot of people, the self help gurus and so on out there will say that we should have a goal driven life, you know, write down your goals on your dream board or something like that.
Naval: “Struggle, make the effort, get out of bed, do your morning routine, and get to work, and you need to get to this goal, and then you can climb the ladder to the next one.”
David: Sounds terribly dangerous. And I don’t know who has it worse, the ones that fail or the ones that succeed. I think maybe a lot of people just need inspiration and once they’ve got that they do the right thing anyway, even if the ideology they’re following isn’t that. They’re just doing the right thing anyway. Like Newton thought he was doing induction and he never did any induction. But he was inspired by that idea. And therefore interpreted his own behavior as being that when it wasn’t anything like that. So I think people often get it right. There are a lot of happy people in the world, which there wouldn’t be if they were really following the theory that they think they’re following.
Brett: So is, therefore, spontaneity sort of a part of your life? Has that always been there? So instead of having this rigid plan we’re sticking to, if something arises and it seems like fun, we’re just going to do that regardless of what kind of everything else is going on?
David: I think that’s a thing. One of my other examples is a failure, namely Vincent van Gogh. He never sold a painting, refused to take the job that his brother offered him in the art gallery, which he would have been great at. But he wanted to paint his paintings and he wanted to paint them how he wanted to paint. And he must have been a very difficult person to engage with but that’s what he wanted and that’s what he did. And then, eventually, he was killed, you know, I dunno how probable that was. And then he was recognized after his death as a great genius. Well, how does that fit into the self-help thing? Did he help himself or not if he died trying?
Brett: Reminds me of that—I don’t recall his name—the Russian mathematician, I think he’s still alive. He refused all awards including, I don’t know if it was a million dollars, hundreds of thousands of dollars.
David: I think it was a million dollars. This is completely different from accepting a million dollars to work on something. That would not have been good. But if he worked on it for its own sake, and then somebody offers him a million dollars–
Naval: Why not take the million dollars?
Brett: At least take it and then give it to someone that you like.
David: Yeah, for example, there must be something strange going on. There’s that little thing that they don’t tell us.
Naval: So, talking about these kinds of motivations and having fun, you’ve also applied that plus the universal explainer principle to Taking Children Seriously, treating them as adults, giving them the full freedom, no coercion.
David: Well, treating them as people.
Naval: As people, yes. And, no coercion, not even testing, not pushing, but rather let them follow their own natural curiosity and motivation. Is there a similar philosophy to taking adults seriously? Because it’s not even clear we take other adults fully seriously and so our relationships suffer as a result.
David: I agree. Well, on the large scale, we don’t yet know how to do it. The institutions of the West: science, economics, politics, are the best that have ever existed. And compared with history, they’re remarkably good at fostering creativity, not telling people what to do, but letting people do what they want to do voluntarily and interacting accordingly. They’re obviously very imperfect—all of them, science, economics, and politics—have gaping imperfections, which have yet to be solved. And I believe that, or I think that any coercion even as exerted by a state enforcing the rule of law is a sign of something imperfect. We can improve on that.
We can, but I don’t know how, but the improvements will have to be creatively produced by people who want to do that. And as for, I think with one’s friends, let’s say with the people one knows, one is automatically doing the taking them seriously thing. You wouldn’t say to a person, you know, you might say to them, “Watch out, it might rain today.” But if they say, “Nah, I don’t like my raincoat. I’ll just wear this jacket.” you don’t say, “No, wear the raincoat. Wear the raincoat or we’re not going there.” You’d be considered both very rude and perverse, not rational for interacting with adults that way.
Naval: Except in the context of a defined relationship. So if there’s a teacher-student, if there’s a boss-employee, if there’s a husband-wife, then they have claims on each other’s behavior.
David: I think that those institutions, if they have that property, which often, they don’t, but if they have that property, they’re imperfect. There’s got to be a better way. I don’t think that an employer should speak to an employee in this punitive way, in this prescriptive way. First of all, it should be understood between the employer and employee what he was hired to do. And so, they’re both on the same page in that regard. So you’re hired to do so and so. Then the employer can say, “Well, how about so and so?” And then, the employee can say, “Ah, well, sounds good, but I’m sure that wouldn’t work.” And, the employer could say, “Hmm, I have an idea that it might. Just try it.” And, this kind of friendly interaction is optimal.
Naval: How does this inform your human relationships with the people in your life where let’s say for example, you’re with a spouse or you’re with a co-worker and they want to keep their relationship intact so there’s certain constraints around it. So you can’t be fully free. There’s still constraints in operation. Or do you just not have those kinds of relationships in your life? Do you not put yourself in situations in life where you can’t operate with full fun and full freedom?
David: So, everyone has a problem situation that is primarily what they’re trying to solve, and, to me, relationships are for addressing one’s own problem situation. It so happens, the way the world works because of epistemology and so on, that very often, two people addressing each other’s problems are far more than twice as efficient as each of them separately. So, there’s an enhancement factor. And the economy has an enhancement factor, the economy at large has an enhancement factor of probably trillions or something. There are things which can be obtained via the economy, like an iPhone. The enhancement in cost is enormous. If you want to go and see a movie with somebody, it may well be that it’s more than twice as enjoyable if you go with a friend but it’s not going to be trillions of times more enjoyable, but it’s still worth doing. And there are things like having children and so on, which you can only do if you have a long term relationship with a person with whom you have a common set of institutions for solving problems. Institutions of consent. So I think that isn’t the point, actually.
The point is that when you are involved in a problem solving relationship of any kind, and it works, it’s a good one and it works, then it’s perverse to call yourself constrained by that. It’s rather like saying that in the economy you’re constrained by having to pay for things. I mean, you’re not. Having to pay for things is the condition of consent. If it weren’t for consent, you wouldn’t get the things without paying. You’d have to at least rob somebody or whatever. But more to the point, it wouldn’t be there in the first place. The things are only there because of this massive set of institutions of consent, which if you, I was going to say if you play along with them, but that’s not even the word. If you identify with them, if you identify with these institutions and want to be the kind of person that can fit into them, then you get iPhones. And it’s the same with any kind of relationship. But when you’re not getting something out of them, like maybe this Russian guy with his refusing the prize, if there’s nothing you want from the economy, you just want to stay in your log cabin and work on maths and that’s all you want and any kind of human relationship or any kind of interaction with people is just an annoyance, well, then that’s what you do. That’s what you’d have to do. And if you then were somehow forced into a normal relationship, you’d be unhappy. And you probably, well, I don’t want to say probably, but, the conditions for you producing good maths and for you producing happiness for yourself are impaired by this thing which other people call freedom. So I gave a very long answer. But basically, one isn’t impaired by good relationships. One is enhanced by them.
Brett: Well, that ties into what is sometimes called clash of civilizations. Although I think that’s a misnomer right now. It’s the clash of civilization with the uncivilized. And there’s a prominent one going on right now, obviously. Although when people listen to this, they might not know what we’re referring to, but it seems to me that the existence of iPhones, for example, arises out of the civilization with the tradition of criticism, that’s the necessary precondition for making the kind of rapid progress that we have. But we’ve got enemies of that at the moment. What do you think are the major threats that we’re facing at the moment and are they existential? Because a lot of people are worried about existential threats in terms of whether the robots are going to take over the world or the next virus is going to wipe us out. But in terms of the so-called clash of civilizations, what’s the major tension or threat that we’re facing as inheritors of the Enlightenment and what’s the remedy?
David: Well, as you know, I can’t prophesy. No one can. I just try to avoid it. I can’t take seriously any threats to our civilization from the outside. That is dictators, terrorists, and also AIs or AGIs or ASIs, if they appear. Presumably the AGIs that appear, it’s to be hoped that the first ones will in fact be part of our culture, be part of the Enlightenment, and they will only enhance it. And I can’t take seriously the existential threats from things like the weather either because they’re on a much longer timescale and what all the scare stories are really about is that it might prove to be more expensive than we think or more, it could be that it would be better to start today on major projects. That can’t possibly be an existential threat.
The only threat that could possibly be existential is if our civilization, the civilization of the Enlightenment, makes bad enough mistakes. For example, fads and ideologies of denying and hating that very civilization. There have always been such fads and following Roy Porter, I’ve talked about the fact that the Enlightenment in itself had a rebellious, anti-Enlightenment built in from day one. And that anti-Enlightenment has got descendants today, and things like woke and so on, or whatever you call them, are among the descendants of it. In principle, a thing like that could bring down civilization. I see no sign of it, I must say. I’m trying to avoid prophecy here. But although I think those things are acting in the direction of bringing down civilization, I don’t see any actual sign that they are making progress in that.
Brett: Are we, nonetheless, in the West whether it’s London, New York, Sydney, a little weaker than what we would have been during the Second World War, where it’s, and again, of course, I’m no historian, but there seemed to at least be a stronger impulse of the average person to understand the bright line between who was on the right side and who wasn’t, but now we’re seeing people in the West standing up for not the victims, but the perpetrators. Is this a new phenomenon?
David: If you want to draw an analogy with the mid 20th century, then the place where we’re most analogous to is not the Second World War, it’s the 30s—the 20s and 30s, the interwar period. There, there was also a massive loss of confidence in the rightness of our culture. There was the Great Depression. It was commonplace, it was conventional wisdom to draw completely the wrong lesson from the Great Depression. People thought that we needed less capitalism, less freedom in general. We needed more strong leaders. Once it came to the war, people saw that push had come to shove and there was very little in the West that opposed doing the right thing. And my favorite example of this is the Oxford University, the Oxford Union Society, which had a debate with the undergraduates where the motion was, “This house would not fight for king and country under any circumstances”. I didn’t know it was under any circumstances. I looked it up recently. And it won. That motion won. And allegedly, this gave, Hitler ideas. In any case, the ideology of the Nazis and so on, of the fascists in general, was that liberal democracy was decadent and decaying. And, Britain and France and America lost no opportunity to confirm this to make it look as though it was decaying. It wasn’t doing anything of the kind. It was more like, “You piss on us, we say it’s raining”. That was more the attitude. And within that, there were people who adopted all sorts of justifications for that, like pacifism and so on. But a year after that motion, after the elite students in Oxford University had joined up in the armed forces, they were fighting the Battle of Britain. They were the pilots fighting the Battle of Britain. They were the officers who were leading their men to fight and to know that our side was right and was going to win despite awful setbacks at the beginning of the war.
I once asked my mother, who was a Holocaust survivor, and was having a very bad time at the time. I once asked her, when did you become sure that the Allies were going to win? Because it seemed to me that in September ’39, I thought, the whole world thought that Britain was doomed. Joseph Kennedy, the American ambassador, father of John Kennedy, cabled back saying “Britain is finished, make your accommodation with the Nazis” and so on. And then, the British got to hear of this and asked for him to be withdrawn as ambassador. But anyway, that was a common thing, I thought. But my mother said, when I asked her, when did you become sure the Allies would win? She said, September the 3rd, 1939, the day that Britain and France declared war. Because that was the moment when they reversed their policy of saying it’s raining and started the policy of actually standing up for civilization. The tactical details of how that was going to happen, nobody could have foreseen. Nobody could have foreseen exactly how we’re going to win. But that we would win and had to win was obvious to some people and the British as a nation just flipped on a dime. They just believed one batch of things, one batch of ideologies and then apparently, it seemed like a day later they believed the opposite.
There’s a nice scene in the latest Churchill movie. I don’t know if you’ve seen it, but, it’s where Churchill is very depressed, and his colleagues in the Conservative Party are trying to push him to come to a deal with Hitler and he has already seen since the early thirties that this is impossible. But, very few will listen to him. And then he goes and meets some ordinary people. And I won’t spoil it for you, but that’s not a thing that happened in real life. Although it could have happened.
Brett: So he’s getting the common sense, clear vision from the so-called normal people. But, the Oxford Union, the elites, are taking the wrong side.
David: Well, they had been. I think by that time they had flipped as well.
Brett: So, today, it seems like the festering of anti-Enlightenment goes on apace at elite colleges and universities around the place. It’s just as a necessary by-product of, well, this is where the creative bright people are, and so they’re going to be rebellious, and so you’re necessarily going to get people standing up against the mainstream. It doesn’t have to be this way–
David: I think historically it was a mixture of things. The fact that there were rebels among the students, that’s a good thing and it will always be true. In Germany, the students were– that was the hotbed of Nazism. So the core of Nazism was in German universities. That wasn’t true in Britain. In Britain, the anti-democratic tendency were leftists. They were communists. They were, as you know, at the beginning of the war, they were all pretending to be pacifists. So they were against the war but that was because Stalin told them to be against the war because he’d signed a deal with Hitler. They turned on a sixpence when Stalin told them to, but that’s a different phenomenon. So, students were upper class people at the time, they were leftists. Some of them were fascist sympathizers. Most of them flipped immediately, don’t know why, you know, it’s one of these, like a phase change. Hitler invaded Czechoslovakia. Nobody paid any attention, you know, they wanted appeasement. Before that, he invaded Austria. Before that, he invaded the Rhineland and so on. Everybody just wanted appeasement. Suddenly he invades Poland and everybody’s like, “This is unacceptable”. Everybody suddenly realized what was happening. I don’t know why. There was no difference between the cases, but that’s how it worked.
Maybe it’s that some people had been thinking and other people had been relying on those people. And they’d been thinking wrong and they changed their minds because they had been thinking. And the people who relied on them then also changed their minds, maybe it happened like that as a sort of seeding process.
Naval: Information cascade. It seems that people have a tendency to play around with ideology until things become serious. And then the consequences of the ideology become obvious. And then the right thinking people at the top change their minds and then most people just follow them as a proxy.
David: It could be. I’d very much like that to be true in the current crisis with the pogrom that’s just happened. But I don’t know whether it will. I mean, there, again, there have been cases before where I would have said, right now, now’s the time. But, it wasn’t. And, I don’t know whether it’ll turn out different this time. But one thing, I mean, you asked me earlier the question, is civilization in danger? I don’t think so.
2023-08-12 07:43:36
Brett Hall and I interview David Deutsch, physicist and author of The Beginning of Infinity. Also see Part 1.
Brett Hall: One of the other things that is counterintuitive—and one of the misconceptions that I see crop up out there in academia, intellectual circles, education—is that people think that there’s a final theory. [They think] what we’re trying to achieve is a bucket full of theories that will be the truth at the end of some period of discovery and that we’ll be able to carry around the bucket and say, “Here are all the truths. We’ve got no more work to do.” We’re going to sit down and do nothing, apparently, except let the AI take care of all the menial jobs. We’re going to be laying back on sun chairs and drinking cocktails or something like that.
As far as I can tell, you are the only person today explaining that this whole vision of the way in which knowledge is constructed and what our purpose is in science and everywhere else, it’s completely misconceived. It’s not just that it’s a little bit wrong; it’s infinitely wrong. Because there won’t come a time when we’re going to be lying on the same chairs, drinking cocktails, intellectually speaking. Can you say a little bit more about that, because it did come from Popper?
David Deutsch: Absolutely. Popper’s philosophy is actually very broad in a sense because it’s so deep. Popper only had one idea, and that is that it all begins with problems, and there’s no royal road to solving them. If you look at it the right way, that tells you to go to fallible and anti-authoritarianism and conjecture and criticism, and so on. Then he applied that to lots of different things and he wrote dozens of books. People bought them, and every philosopher has heard of him. But there, I have to draw the line. That’s as much success as he had. Nobody actually got it, not even many of his supporters. People tended to get part of it. Although when someone is very creative and successful in a particular area, they tend to be a Popperian in that area, and they usually insist that it’s a special property of that area.
Brett Hall: They have to be. If you’re going to make progress, the only possible way of doing it is finding the problem, purported solutions, and then criticizing those solutions. So you’re necessarily a Popperian if you’re making progress, even if you don’t know it.
Naval: If I were to give an example of exactly what you’re talking about, I interviewed Matt Ridley, who was a hero of mine growing up. I read all of his popular science books. I remember his book Genome and his book The Rational Optimist. His most recent one is about innovation. It’s all about trial-and-error or variation of selection or, as you say in science, conjecture and criticism. These are all just the same method. These are creative guesses.
Once you fully absorb this, it changes your view of the world. You just see that everything is creatively making guesses. We’re not copying. We’re not getting it from the environment. It’s not something that’s evident to us clearly in nature and then as we absorb it more and more as Bayesians or Inductivists, we somehow come up with the truth. Rather, everything is a theory-laden guess.
It’s funny, I’m teaching this to my six-year-old because I want him to have a solid foundation, and he now understands intuitively that, “Yeah, everything is a guess.” So every time we get to something and he asks why, I say, “Let’s start making some guesses.”
Once you absorb this view of the world, it is evident everywhere. For example, in my domain in technology and innovation, people think, “Yes, I’m being creative.” I’m guessing. The artists think they’re being creative, and they’re guessing.
David Deutsch: By the way, you just mentioned a solid foundation of epistemology for your six-year-old. Even in Popperian epistemology, its role is not to be a solid foundation. It also requires improvement and is always imperfectly stated.
I think that Popper didn’t concentrate enough on the concept of explanation, that the purpose of science is explanation. So one of the footnotes that I’ve added to Popperian epistemology is that it’s not just that good explanations are good heuristically and they help us to discover things; it’s rather that discovering them is what the whole thing is about. When you talk about, for example, testability, the only reason why testability is important is that in a particular field—namely physics—it’s the way one can test explanations.
David Deutsch: I’d like to draw a distinction between experiments, demonstrations, and measurements. When you do this experiment with the acid and base, since there’s no rival theory, what you’re doing is a demonstration.
If you are showing that to a class of schoolchildren, you can say, “You’d never believe what happens when I pour this into that. You’ll never guess in a million years.” And then you pour it in and it changes color, and they say, “We’ve seen that kind of thing before.”
But then it changes color back and then forward and back, and then you say, “How can that happen? That contradicts everything you’ve been told in chemistry so far. How can we find out? Some people say this was how it worked. Then someone else came along and said that was how it worked. How can we distinguish between those?” And that is an experiment. It’s testing two different explanations against each other, where you can’t tell without the experiment which is the good explanation. And then there’s a measurement, like the difference between what Newton did and what Cavendish did. Newton developed the theory of gravitation, but he never measured Newton’s constant. I think—don’t quote me on this—Newton could measure GM, where M is the mass of the Earth; he couldn’t measure G and M separately. And therefore when they guessed the mass of the sun and so on, it was always as a multiple of the mass of the Earth.
Then Cavendish, by actually getting a hands-on experiment where you had a gravitational force between two things whose mass you could measure directly—by comparatively weighing them against a standard kilogram or whatever they had in those days—[showed] you can measure the constant. Now that is not an experiment. It’s called the Cavendish experiment. But in this terminology I’m trying to set up, that’s not an experiment because there’s only one explanation involved. Before, during, and after Cavendish’s experiments, he never doubted Newton’s theory of gravity. What he was trying to do was to measure Newton’s constant.
Somebody could have come along and said, “Maybe Newton’s constant is different on different parts of the Earth.” But nobody did say that. If they had, then Cavendish’s measurement would’ve turned into an experiment. But there was no good explanation along those lines because Newton’s theory was incredibly successful, in part because it was so universal. So because of the problem situation at the time, what was missing was a measurement.
Many experiments now that are called experiments are really measurements and many of them are really demonstrations—not that both measurements and demonstrations aren’t great.
Naval: Let me make sure I understand. So you’re saying an experiment chooses between rival explanations or rival theories. A demonstration just shows, “If I do this, I get that. This is how the world seems to work. This is observable.” And the measurement can help refine a theory and make it more precise by figuring out things about it that we didn’t know. And those are three distinct things. And we use the term “experiment” loosely, but it’s really this key thing that is done once in a while to choose between two competing explanations, which is a very rare occurrence. It’s very rare to have two rival good explanations.
Going back to good explanations for a moment, there are two other things I’ve seen mentioned. There are a few other techniques that I see you use a lot in the two books when referring to good and bad explanations. One is that good explanations make these risky predictions.
Like Einstein had the prediction of the light bending around the sun or starlight bending around the sun. There are these risky and narrow predictions that before you would not have anticipated another one. You’ve talked about the simplest answer, or Solomonoff induction, where Solipsism is a bad explanation because you still have complex and autonomous entities but now you’ve added this extra entity in your mind.
David Deutsch: I don’t mention Solomonoff induction, but I do mention in the book the simplest explanation. That’s not the right way to look at it, because you can only detect or measure or define simplicity once you have, let’s say, a theory of physics, then you can say that simplicity is the smallest number of bits in which a given program could be encoded. But if bits behaved differently, then things would become simple that were previously complex. And that’s exactly what happened with quantum computation.
So there is no scale of complexity or simplicity that is prior to physics. You can, in principle, define complexity or simplicity. But it doesn’t make sense to ask how complex, say, a theory of physics is, because that’s the wrong way around. Simplicity is not prior to science; it’s posterior.
Naval: This is also a theme running through your work. Computation has to be done in the real world and has to obey the laws of quantum physics. You talk about mathematics having to be bound to the laws of physics. So even the reductionist argument that, “No, all the good theories are basic,” just depends on what the laws of physics are and what the context you’re approaching it in is.
David Deutsch: Exactly. And what you’ve just said refutes Solomonoff induction because that is based on a particular measure, namely the length of Turing computer programs. But he was unaware that he was assuming a complex structured theory of physics and then saying that we should choose the theory of physics that is simplest in those terms.
I would expect that sometime after quantum theory, there’ll be yet another dispensation which will give us a different conception of complexity and simplicity. But already as a matter of logic, it doesn’t make sense to consider simplicity and complexity as being a priori fundamental compared with physics.
Naval: One thing you bring up a lot, I would almost call it a Deutsch refutation—because I see you use this more often than almost any other author—is the theory refutes itself. For example, you talk about the precautionary principle. Since civilization has never followed the precautionary principle, if we start following it now, we’re no longer being precautionary. So it refutes itself. That’s one example, but you use many of these. So there’s these self-refutations buried in a lot of these theories.
David Deutsch: Another way of putting that, though, rather than thinking of it as a method of refutation, is to think this is just what it means to take theories seriously, rather than just as forms of words that one learns to say.
Like physics professors, when asked something important about quantum theory, they have learned to say, “Ah, well, it’s a particle in a wave at the same time.” And if the student says, “What does that mean?” The professor may well say, “You’ll get used to it. You will understand that eventually.” But what they often say, regrettably, is, “That’s the wrong question to ask. That’s not a meaningful question,” and “You are not allowed to ask that question.” But the question isn’t based in a misunderstanding of quantum theory; it’s the other way around. It’s taking quantum theory seriously and saying, “I want to understand quantum theory.” And saying that it’s both a particle and wave at the same time is not an answer to that question. It’s a way of shutting up the question.
Brett Hall: I used to get, “It’s born as a particle, lives as a wave, and dies as a particle.” Because the experiments that capture the entity that’s moving will only ever capture the particle. But then the interference is explained by it being a wave. That was a tricky way of trying to get around the wave-particle duality by saying, “Well, not technically at the same time.” But there was no explanation for how it transitioned between being particle to wave or how it knew it should move between being a particle and a wave.
David Deutsch: Yes. And, of course, it can move back as well. If you have a more complex interference experiment, it’s a particle, then a wave, then a particle. If you look at some of Vaidman’s experiments, it’s very hard to get your head around if you don’t have the Everett interpretation because it totally depends on taking seriously this quantum entity that cannot be described as a particle or a wave.
Brett Hall: If what we’re saying of our good explanations is that they really are accounts of reality, in what sense are we getting closer to reality with the good explanations? My classic go-to example of Newton explaining gravity as this force that acts instantly on the bodies and then it is superseded by Einstein’s general relativity, where there is no such force whatsoever. We’re saying that this thing that was part of a good explanation no longer exists at all.
David Deutsch: There are two answers to that question. One is in the book and one isn’t.
In the book I say there are many concepts, laws, explanations that are shared between Newton’s theory and Einstein’s theory of gravity. For example, both theories adopt the heliocentric cosmology and they say that the motion of the Earth and the other planets in gravity is caused by the sun. It’s because the sun is there that an influence is felt. Now, the influence is not a force—it’s a coverture of space-time—but that curvature of space-time is caused by the mass of the sun.
But there’s another sense in which say Newton’s theory and Einstein’s theory are more closely related than you might think. Newton’s theory contains the problems to which Einstein’s theory is the solution. Newton said that gravity travels instantaneously. That was a problem which people recognized before Einstein. They wanted to explain, “What does it even mean for something to travel instantly?” And then there was the fact that, if the universe lasts forever, as Newton thought, then how come in the long run it doesn’t all collapse?
I don’t know if Newton was aware of what’s called Olber’s paradox, but according to Newton’s theory, if the universe is either infinite or very big, then the sky should be white. Again, that is a problem Newton’s theory can’t really answer. You have to make some very ad hoc assumptions to fit that into Newton’s theory as a cosmology. And Einstein’s theory just solves that problem, which was in Newton’s theory.
And Newton’s theory solves the problem in Kepler’s theory, which was so severe that Galileo rejected it. Galileo did not want to believe Kepler’s theory because it didn’t explain why the orbits were ellipses. If they had been circles, there was an explanation that would’ve fit into the philosophy of the time. The circle is the perfect shape. If it wasn’t a circle, you’d have to explain why it isn’t a circle. Kepler was like, “Well, just look, it’s an ellipse.” That wasn’t good enough for Galileo, so he had to torture the theory to make it predict circles. But then Newton came along and said, “It’s the inverse square law and that can make circles, but it can [also] make ellipses.” And that is a deeper level of explanation even than saying circles are perfect shapes.
So they’re related by the common assumptions and they’re related by the problems that they have or solve.
Brett Hall: What you say there, though, it raises the tension between Karl Popper and Thomas Kuhn, who to some extent over-egg this idea that we have these grand revolutions in the history of science that completely overturn the previous paradigm and anyone working in that existing paradigm is literally incapable of conceiving how this new paradigm works. Kuhn has a lot more support out there in the intellectual community than Popper, certainly amongst the humanities, even amongst the sciences to some extent. And, of course, Kuhn has been taken to the extreme ever since by anything calling itself science, like gender science or something that appends the word “science” to some particular subject.
Kuhn did say correct things, but, as you just said, it’s not the case that we completely do away with the previous paradigm. And the people who create the new paradigm tend to have understood the previous paradigm and solved problems from that previous paradigm.
David Deutsch: This picture of the young iconoclast being rejected by the old stick-in-the-muds and then the young iconoclast draws together a few friends and, when the old stick-in-the-muds die, then the young iconoclasts become the old stick-in-the-muds. The thing is, it’s pure fiction. I don’t know of any actual situation where that happened. What does happen is that people often irrationally stick to their own ideas, whether they are new ideas or old ideas. People can be stubborn. Sometimes stubborn people who support a theory for no reason except that they feel it’s right, turn out to be right. There’s no algorithm for determining who is right according to who is more stubborn.
Sometimes the person who’s more stubborn is actually right—like Lister and Semmelweis. They stuck to their guns. They were rejected, but even then it was not a generational thing. There was a much more complex process at work. [Doctors] didn’t just reject a theory. They rejected having to change their working practices that reduced their perceived dignity. But the perceived dignity of doctors is functional. Especially in the days when not much was known about medicine, if you told a person that they had to have their tonsil taken out—which was an extremely unpleasant, difficult, painful process—you needed a bit of authority, irrational as it is. The world was much more irrational in those days, and when science got better, people became more open to argument. But the generational story, as I say in The Fabric of Reality, provides no explanation for them changing from one theory to another.
It’s as if they just invent a new fashion, like when Christian Dior says, “Put up your hemline,” then every woman in the world puts up their hemline. That used to happen apparently. That is not the description of what happens in science. There’s a reason why people adopt a theory. Even if it’s false, there’s a reason why they adopt it. If it’s not satisfactory to them, they’re not adopting it. And sometimes they’re irrational. That’s just how it is, but it’s not a picture of science.
Naval: I think this is quite obvious if you look at technology. We might have gone from analog attempts at computing to vacuum tubes to transistors, and vacuum tubes to transistors is less of a jump than analog computing to vacuum tubes. Clearly there’s progress along the way. Now, we don’t use vacuum tube computing anymore—it’s been obsoleted—but that doesn’t mean it was wrong. It was a necessary stepping stone. It was closer to the truth and there was a lot to be learned from there. When you encounter it in real life, then it becomes a lot more tangible and it’s harder to refute.
I find that the more feedback that you take from other people, the more likely you are to go astray; whereas the more feedback you take from reality and nature, the closer you are to the truth. And in science, unfortunately, a lot of it gets mixed up in philosophy and academia, where they’re not actually interacting as much with the real world. It shouldn’t happen in physics, but there is this social feedback loop where you’re talking to other people. You’re not always building things. The rockets don’t have to fly, so to speak.
David Deutsch: But the growth of knowledge is possible in philosophy too. Even in morality and epistemology, even when you don’t have physical reality. It’s this thing I called a few minutes ago “taking the theory seriously,” that refutation of Solipsism is nothing more than taking Solipsism seriously. Rather than saying, “Oh, it might all just be my dream,” you go on from there: “Okay. If this is my dream, what can we say about my dream? So I’m dreaming the bus. I’m dreaming all the people in it. Now there’s a person who is wearing a yellow suit. Did I make that up? I’ve never thought of it before. Now I’m seeing it.”
So if I’m a Solipsist, I have to have an explanation for how the things in my dream can have come about. And that’s really why Solipsism destroys itself. And in philosophy—in physics too—most ideas destroy themselves. As you said a little while ago, it’s rare to have a case where you can actually decide between two explanations by experiment.
Brett Hall: When it comes to progress and understanding, is there going to be a theory that we are not going to be able to understand? I think it’s the prevailing view at the moment that there’s got to be something out there that is beyond our comprehension.
David Deutsch: How do we know that there isn’t a limit? How do we know that there’ll be no new mathematical knowledge to discover? We can’t know. We could be wiped out by an incoming planet from another galaxy that is hurtling through our galaxy at half the speed of light, and we’ll just be all killed instantly. There’s no known theory that says that isn’t going to happen.
Similarly, the same could be true in the universe of ideas. There could be a brick wall somewhere where we won’t go any further than that. But in both cases invoking that as an argument about what we can or should do is logically equivalent to believing in the supernatural. Because, why did I just say a planet moving at half the speed of light? Why didn’t I say an asteroid moving at 99% the speed of light? Why didn’t I say an illness that operates on principles that we don’t know and will wipe us out in a few days? There’s an infinity of things I could have said, and all of them make a sophisticated prediction without having an explanation for it.
It’s exactly the same when people say that the world is going to end on such and such Tuesday. I would want to ask them, “Why Tuesday? Why not Wednesday?” And they will say, “Because Tuesday comes out of my interpretation of the Bible.” And I would say, “Why is it your interpretation of the Bible and not this other guy who says it’s Wednesday?” And pretty much immediately they don’t have an answer to that because they do not have an explanation for their prediction.
It’s the same with the idea that the explanatory universality is going to run out for one reason or another, whether it’s physical wipeout or AGI apocalypse or we are all simulations in a computer, and so on.
Brett Hall: But there is this impulse in people to suggest things like Solipsism, the simulation hypothesis, whatever it happens to be, as the final theory. The interesting thing about your work is that you work at the foundations. You go as deep as you possibly can, but at the same time you’re against foundationalism.
How do you square this circle for people? How do you say, “Well, I’m looking at the foundations—but on the other hand, I’m against foundations.”
David Deutsch: It’s rather like the relationship between physics and structural engineering. Foundations are theories that explain why the higher level theories are as they are. But you can’t use Newton’s theory to build a bridge. To build a bridge, you need theories of bridge building.
Christopher Wren—one of the reasons why he was a successful architect is that he began to use Newton’s theories seriously to design buildings. So when deciding what the distance between pillars ought to be, rather than have a master builder’s eye for what that should look like and what will or won’t collapse, he could actually work it out using Newtonian mechanics. That means that Newtonian mechanics was playing a role of understanding what makes buildings stand up in the first place and also criticizing particular designs as being not as good as other designs. Then you could use measurement and demonstration and so on to fill in the gaps.
But if you’re just given Newton theory, you wouldn’t think of a suspension bridge. Nowhere in Newton’s Principia is there a picture of a suspension bridge. That was invented later. So engineering is a separate subject, and you don’t study Newton’s laws primarily to help you build better bridges. But what Newton’s theory did was unify our understanding. It gave us a new level of understanding. It influenced other sciences. People tried to make Newton’s theories in other fields of knowledge, some of which worked and some of which didn’t work.
Brett Hall: Now tell me this: Newton, English; Christopher Wren, English; Alan Turing, English. What’s special about England? We shouldn’t judge one culture as being superior to another; however, it seems as though we’ve got the beginnings of a special kind of enlightenment there in Britain leading to an industrial revolution led by Britain. What’s going on? Why is there so much coming out of England and perhaps the Anglosphere more broadly?
David Deutsch: There was the Enlightenment, which largely took place in England. There were individual people who participated in it in France and Germany as well, but in England it became the mainstream much faster. It was a rebellion against authority, but it was a non-utopian rebellion. So instead of saying, “Let’s get rid of the authority and replace it by the thing that’s really true, the thing that’s really reliable, the thing that we won’t ever have to overturn again,” it was a case of, “Look, there’s this problem. Some people have privilege, but God tells us that all people are equal. What can we do to fix this problem?”
You also had quite rapid social change [and] economic change, but it all took the form of extending to more and more classes of people privileges that had previously been only in the ruling class. You had the Parliament, which was only open to a certain group of people. Then it was opened up to more people and more people, and so on.
There was a phrase, “The Englishman’s home is his castle.” Now, I’m not a historian, but presumably an aristocrat’s home was his castle. His castle was his home and his home was his castle and nobody was legitimately allowed to interfere with him in his own domain. So when you then made reforms that said that the Englishman’s home is his castle, that was a modification of existing knowledge of how to structure society. Now, you had people who owned houses who weren’t the aristocracy. There was a readymade set of privileges that could be extended until, eventually, one after another, they were extended to everyone.
Whereas in France or Germany, it was different. Their reforms were all about abolishing things. Abolishing the tyrant. To this day, there are traditions of utopianism. The idea is to set up institutions that will last forever and that they are to be set up by fundamental theories—like human rights—and you write them down once and for all, then make it difficult to change them. And set up institutions that are going to protect those rights forever.
But Britain has stuck to its plan over centuries, and it has produced rapid change without any sudden revolutions or without any extremism. In the 1930s totalitarian theories were very widespread all over Europe, and totalitarian parties either took over or were a major threat to democratic parties. Whereas in Britain, there was a fascist movement, but it never got a single MP and it went away of its own accord soon afterwards. That’s because it was taken for granted in British political culture that the political system is here to solve problems. You petition the government for redress of grievances, not to line each other up against the wall and shoot them.
The theory was that there is such a thing as a grievance, there is such a thing as redressing, that it’s not easy to do that. The way to do it is to have the rival theories confront each other. You must be allowed to say what you think the problem is and other people say what they think the problem is, and so on. Nowhere is it assumed that someone has the final answer.
Naval: This is why the current rage against misinformation is so troubling—and people even invoke Popper for it. There’s a political cartoon that goes around invoking Popper as saying, “We don’t tolerate the intolerant, so we have to shut them up because they’re spreading misinformation.” When nothing could be more the opposite of Popper, which is: you have to have debate, have rival opposing theories, have a system for removing bad rulers and reversing bad decisions.
In that sense the system with two parties makes sense because you can hold one accountable against the other. Every eventual successful truth is defined as misinformation by the other side because it contradicts what is already believed to be true. So eliminating misinformation a priori is impossible because knowledge a priori is impossible. It has to be creatively conjectured and discovered.
There is this beautiful idea in The Fabric of Reality, and when I try to explain it to friends in my own halting way, it blows their minds. It combines all four strands of The Fabric of Reality. You talk about epistemology, computation, quantum physics, and evolution. If I can summarize the insight, it goes something like this: Knowledge is a thing that causes itself to be replicated in the environment. If I figure out how to create fire, then other people in the environment will copy that because it’s useful. If there’s a gene that is well adapted to the environment, then the sequence in the gene that leads to higher survivability gets copied. Whereas if there’s random or junk DNA, that’s not going to get copied.
If you look at how the multiverses differentiate the randomness, the non-useful part—the information that is not knowledge—will be different in the multiverses. Whereas, the knowledge that is useful—the genes that are leading to higher adaptation, the ideas that are leading to higher survivability, the inventions that we’re creating that are actually working, the philosophies that we have that are causing us as humans to thrive and replicate—those will be common across the multiverse.
So it will almost be like there is a crystal of knowledge. And I don’t think this is doable, [but] if you were somehow able to peek at the multiverse as a single object, then truth would be emergent, or we would be closer to the truth by seeing what is common across the multiverse, and what is different across the multiverse would not be true. This insight, as far as I know, is unique and massively interesting. But is there anything practical out of it someday?
David Deutsch: There’s a fundamental reason why, even if we could look into the multiverse, it wouldn’t be that much help. Because there is no limit to the size of error we can make. Therefore, when you look around in a multiverse and see all these crystals, yes, on the whole, there are great big fat ones and you can guess that this one is heading towards the truth. You can’t tell where because you don’t know where this crystal is going to go.
And then there’ll be this other great big thing—a religion or something which has been growing for thousands of years—and there’s no way of examining it with a magnifying glass and seeing that it’s any different from one that is heading towards the truth. We might hope that most of the big ones are heading towards the truth according to some definition of “most.” In one universe you can get a hint of that already because you can say what idea is most persuasive. Okay. Many bad ideas are persuasive. What idea is most persuasive to people who adopt it because they think it solves their problem? Okay. But there are many such ideas that are false too. So I’m afraid it’s not going to work.
If there were a limit to the size of error, you would know that once you’ve made an error of a certain size, when you have your next idea, it’s bound to be true. “No one can make more than 256 errors in a row” would be the thing. And nothing like that is true.
Naval: No shortcuts.
David Deutsch: Exactly, there’s no shortcut.
Naval: It seems that the nature of knowledge is that it creates non-linearities. So even a single false idea can create false knowledge that overwhelms a truth for quite a while, in a large amount of space.
David Deutsch: Yes.
Naval: So it’s always creative. It’s always conjectural. It’s always contextual, which gives an infinity of improvement ahead of us which keeps life interesting.
