Dwarkesh Podcast - Matjaž Leonardis - Science, Identity, and Probability

Episode Date: August 22, 2020

Matjaž Leonardis has co-written a paper with David Deutsch about the Popper-Miller Theorem. In this episode, we talk about that as well as the dangers of the scientific identity, the nature of scientific progress, and advice for young people who want to be polymaths.  Watch on YouTube. Listen on Apple Podcasts, Spotify, or any other podcast platform.Podcast website here.Follow Matjaž's excellent Twitter. Follow me on Twitter for updates on future episodes! Get full access to Dwarkesh Podcast at www.dwarkesh.com/subscribe

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The newest post I have out is titled if prediction markets or policies were legal, based on Robin Hansen's idea of a futurearchy. In fact, I just interviewed him for a podcast, so expect that in the next week. Okay. Today I have the pleasure speaking with Machos Leonardis. Machos is co-wrote in a paper with David Deutsch about the Palmer-Miller theorem, and we get into that, as well as the dangers of the scientific identity, the nature of scientific progress, advice to young people who want to be polymats. Machos is one such, as you will see. He's a fascinating person that have had to

the pleasure of getting to know. He has a broad range of interesting ideas, which we get into. So without further ado, here's Machos Leonardo artist. Okay, Mahjazz. You have court written a paper with David Deutsch about base theorem. But before we get into that, let's talk about the big picture questions. Science. What is it? And is it somewhat of a, is it somewhat of a confusion to even talk about it distinctly from other disciplines? Well, so my view on that subject is that, A lot of talk about science ends up being quite counterproductive. I'm not saying that there is no such thing as science, but I definitely think that people identify with science too much.

They wonder whether what they are doing is science. They think they are scientists and wonder what is it that they should do in their capacity as scientists. and I think that often has a counterproductive effect on on on basically what they do. Now, one interesting thing to note is that, is that, you know, the name scientist is actually an early 90th century invention. It was traced back to, I think, to professors that I think Trinity College in Cambridge. And it's, and, you know, people were able to do science before that quite well. And so one of the problems that I see, I guess, in that, in that respect is just that people perhaps think about, you know, what is a scientist and, sorry, who is a scientist and what is science a bit too much.

But I don't know the history here. The people not consider themselves natural philosophers before then? There is definitely been sort of names for this role. the, so one way to sort of think about it is that people, people have always thought about the natural world, though, right? So people have always, you know, try to understand, you know, how, you know, how machines work, how nature works, how sort of everything does. And they often did that without, you know, ever becoming conscious of the idea that they were doing anything special or that they are playing a special role by doing so. And, you know, they were able to sort of do it just fine. And one of the things that, you know, at some point that obviously changed, you know, this sort of idea that one is engaged in some sort of a special activity when one is trying to understand nature. And, you know, there being kind of a special social role for that. Like all of that obviously have to develop.

But it does seem to be the case that you can reach a better understanding of the natural world without it. Hmm. Let me ask you this question. Sorry. Sorry, go ahead. And therefore there is a question about, you know, whether it is actually helpful. Okay, well, if the identity of scientists is not that useful, then why do we have universities that we consider it to be special places? And we employ people with tax dollars to do special things. I mean, clearly they're not being construction or, you know, building archers or something like that.

So, so, like, there is an activity, i.e. trying to. to understand a natural world that seems to work better when it is supported sort of both kind of, that it is institutionally and culturally supported. So it is useful to have institutions that keep all the relevant books at the same place and kind of get some of the same people at the same place that sort of organize events and sort of where people

can kind of meet each other. And I think that that, you know, So I'm not disputing that there is an activity that is sort of worthy of being supported, but whether that sort of particular way of looking at that activity is the right one is less clear. Okay, so you do identify there's a special role for universities, and they're doing a distinctive activity. Well, if it's not science they're doing, how would you describe what the thing they're doing is? right so so well okay so so perhaps to illustrate this right one um needn't needn't think of this

activity in a unified way so for example like imagine that we had an institution and in this institution there would be you know somebody who was interested in you know liquid helium and he would be writing about it and talking with all the people that were interested in it and then you would have another person and that person would be you know interested in in you know the way star swarm and their evolution and that person would be sort of you know again writing about this talking with other people about it and you know you could have so on for just a bunch of other things now you can easily have an institution that would be sort of supporting all of these people in that in that endeavor but you know that you know but now for example if one if one order to just kind of stop

there right it's it's not possible yet at that stage you know to sort of say okay well well all of these people are engaged in this, you know, unified activity, you know, called science and, oh, are some of them really doing it or not, right? Everybody is just, it's just, you know, one person is doing this, one person is doing that, you know, one person is doing the third thing. So perhaps, I mean, an interesting, right, comparison might be, for kind of the particular review that I have, it's just like, you know, like, like people have this idea of an entrepreneur, right? Well, you know, in a certain sense, you know, and all of these entrepreneurs are kind of trying to construct different companies, right? But nobody is kind of asking the question, well, you know,

is any one of these people actually entrepreneuring, right? That is not a conversation that ever arises. So it is in that sense that I think that you can have an institution that supports that activity, but you don't need to like understand it in this particular way that that science is often understood. And so what's counterproductive about the current understanding of science and scientists? Right. So, so one problem with this idea is that the idea of sort of science and scientists comes with this idea that there is this particular method. In other words, that, that, you know, one, that one is somehow doing something more other than just being engaged you know, with a particular problem or question and pursuing it, you know, wherever it might lead. There is this idea that there is a specific method that one ought to use to think about this particular question

rather than just, you know, where sort of the question naturally leads you. And I think that that this attitude or this idea can often stop people from doing sensible things that would otherwise, that, you know, that would help. with sort of pursuing their problem, right? So, you know, the thinking is that you need to pursue the various questions with a specific method as opposed to just where kind of the logic of the problem itself leads you. And I'm not saying that this actually affects everybody or that this is a sort of an across-the-board thing, but it is sort of an argument that often features. The current conception of this, therefore, you know, as I said sort of before, kind of allows you

to make criticism of somebody, you know, you can say, well, are they really doing this thing or not, which is not a thing you could really do, you know, where it just, were people just sort of thinking about specific issues and what they did was understood in that way. And in general, I do think that like making, making, you know, becoming conscious of what one is doing and, you know, kind of being, and sort of classifying it or telling you, yourself the story about it is one thing that is known, you know, in several other fields to sometimes lead to problems, you know, hence the term self-consciousness and it being sort of productive, it being deemed counterproductive in many areas. But let me make the counter argument.

There is a specific method, or at least a family of methods, right? We have Popper, we have, you know, falsifiability, testability. And, you know, we privileged these over other methods we could be using, like myth-making and so on. So what's wrong with somebody, understanding their position and institution as to understand the world through a specific family of methods. Well, I would perhaps, funny you mentioned Popper there, because I would actually dispute that premise. He wrote this, I mean, there is, I think, a very nice set of undergraduate lectures that has been recorded from him, where he says that he was, I think, a professor of scientific method at the London School of Economics or something like that. And he says in that lecture that he is

a professor of a subject that he thinks does not exist. But his student Firearmint, I think, actually wrote a book against method, which is sort of yet another kind of philosopher of science arguing against that idea. And now it is true that there are certain, I guess, patterns of thought that are more conducive to under, that seem to at least be more conducive to understanding the natural world than others. But I think that that is still like, like, what patterns work, you know, how one thinks about them and so on. All of these things are kind of more of a great mystery than an exact science, to put it like that. So then, to paraphrase you, let me just see if I'm understanding you correctly.

It's that scientists should consider certain methods better than others, but they shouldn't identify themselves with some of them. Well, I mean, okay, that's, I'm not sure if that is sort of paraphrasing it exactly as I see it, because it's, like, it is very unclear if one is ever using a method. because, you know, like, like people, people, as I said at the beginning, people have been thinking about the natural world without being conscious of it in any way. And, you know, it is, it is, you know, like thoughts are constantly arising in the mind, right? And it's, it's, it's, it often feels like a bit of a stretch to say that, you know, all these different thoughts one is having, are arising as a result of a method, as opposed to just, just arising. There is a certain level of ambiguity that I think sometimes occurs there. So people have been trying to solve problems for a long time, but only recently, I would argue that only recently for maybe like the past 500 years,

they've been very productive in understanding the natural world. And it does seem to be because of a family of methods, right? So doesn't the case of the success of the Enlightenment lend credence to the idea that certain methods are to be privileged and are more productive? Well, I do not exactly have a view on that, on that subject. For example, there, to be honest, I just sort of don't know. I kind of have various passing thoughts on that issue. But, I mean, for example, there is this sort of question,

there is this sort of narrative about the importance of the Enlightenment. And it's not exactly obvious if that, to me, if that narrative is in fact true, or if that narrative is more of a fiction. And, you know, there are strong proponents for one of that positions and there are strong proponents for the other. And what are they have in common, ironically, is that I think that they both sort of agree

that there was something very important about the Enlightenment. Because there is perhaps yet another third explanation where, you know, it was, you know, all of this had nothing to do to do with anything else. maybe it was just, you know, economic progress that allowed for, you know, like all this thought to be produced at the time. Like, it's very, very difficult to sort of figure out exactly how causality works with most of these things. But to this idea that it was due to a change in method. I mean, like, well, that's, like, a lot of people at the time had that idea, but a lot of people

kind of subsequently criticized that idea by sort of pointing out, well, I don't know, maybe something did change in the way we thought about things, but nobody can really understand that change, right? Because a huge part of that idea was that, you know, what is that, is that, is that, what was this idea of reason, really, that somehow or other reason is the way to, to understand the natural world. And what, for example, Hume and other skeptics subsequently pointed out is just that, well, like, like this, like, this can't possibly really work as, as, you know, you guys are imagining it. Because, for example, I mean, as Hume pointed out,

this is kind of the famous problem of induction, you know, there is no way to kind of proceed logically, i.e. by reason, from experience to, you know, the celebrated, you know, general theories of the Enlightenment, such as Newton's theory and such like. And so I do not know what opinion exactly I have on that issue, but these are some of my thoughts. Yeah, that was a very interesting answer.

Speaking of induction, let's get into the paper you co-wrote with David that's coming out soon. So do you want to describe it? Oh, sure. So we wrote a paper on something called the Popper-Miller theorem. Popper-Miller theorem was a theorem that Popper, that we previously mentioned in this podcast, and David Miller, basically, they published a short letter in nature in 1983, where they presented this very kind of short paradox where they basically claimed that that the way they explained it was the idea that probabilistic support is not inductive.

That is quite vague and this was conceded by many people kind of subsequently. But the basic idea is something like, so basically, there is this idea that somehow, and this idea is very much a part of common sense and was a part of various attempts to build an inductive logic at the time, which is simply this idea that evidence somehow confers support on general theories. And figuring out the right model of that support, of how this sort of support works, you know, has been kind of one of the challenges that people have basically been trying to figure out at the time. And one of the ideas was that basically probability is, you know, probability was considered as one of such possible sort of support measures. And basically,

what their theorem aimed to show was that this probabilistic support that evidence sort of confers in theories, i.e., you know, a piece of evidence comes in and the probability of a particular theory increases by 10%, that that 10% increase contrarily be understood as in any way being due to that evidence conferring some kind of inductive support on that theory. And the way they made the argument is that they basically said, they basically identified. They basically identified two propositions, they said, look, this theory relative to this evidence, like really, this first propositions is a kind of a, the deductive part of the theory relative to the evidence, and this other part of the theory is the inductive part of the theory relative to the evidence, and they

showed that the evidence always decreases the probability of this inductive part. Now, there was sort of two, I think, there was a lot of kind of subsequent commentary on this, on this result. And the main, the main, sort of, the main points that people kind of made were, well, you know, the main points of the dispute were, well, in what sense is this proposition that they said was the inductive part? In what sense does it kind of capture, you know, all of a, you know, all of this theory that goes beyond the evidence, as they put it. And then the other issue was, was just, you know, because there is this sort of vague notion of, of, you know, inductive support and what exactly that means. And so that was kind of another.

sorts of objections. And what, and I think that the conversation has in many ways sort of moved on from there. Um, but we sort of thought that that, that argument is sort of still interesting. We found sort of a couple of other ways of explaining it. Um, and, uh, I think they, you know, present kind of a very interesting challenge to this idea of, of, um, you know, sort of kind of trying to use Bayesian reasoning to, to either build an AI or, or for various other purposes. And we thought it would be sort of a very interesting thing to present. Okay. Did this serum fit a broader theme in Popper's work?

Well, it sort of did, right? So the basic idea that Popper had that I think kind of sort of came out, the theorem, I think, came out of kind of the same way of thinking about this, was basically just this idea that, so he was interested in the idea of logical content of a theory. There was this idea that just like you could have, you know, this probability measure that you assigns to theories, you can assign a content measure. So the idea is that some theories say more than others.

And the question was, can you construct a measure of that kind? And one of the interesting observations in thinking about that measure is simply the fact that the constraints or the rules it has to obey are exactly the same as the probability calculus, basically. So in a certain sense, you can always interpret some assignment of probabilities, right, as really being a kind of a statement of, as he put it, a degree of logical weakness. So, you know, if I say that one theory is more likely

than another theory, you know, there is always this perfectly consistent interpretation where what I'm actually just saying is that, you know, if I say that this theory is more likely than that theory, I can say this theory says less than this theory. That was kind of the idea of it. And basically, the reason therefore he, I think, kind of became skeptical of these probabilistic approaches to knowledge

is simply the fact that, it's simply the fact that as he saw it, and I think that there are some reasons to kind of think that this is in fact how people think, is that what people actually want, what they believe in, what they seek, are not kind of these sort of topology-like contentless, but likely theories, as it were, but kind of these incredibly informative and therefore, you know, informative, explanatory and therefore kind of less likely theories. And if you want an example of the fact that people do seem to think about that way, right, there is something known as the conjunction fallacy that would seem to sort of support that. So there is this famous experiment. I think it was popularized by Daniel Kahneman in his book, Thinking Fast and Slow,

which was, I think, the sort of case of Linda. So in this experiment, you're told about a woman, and you're given a bunch of information that we're kind of, you know, that are kind of stereotypically associated with being a feminist. And then the question is, well, is it more likely that Linda is, A, a banker, or B, a banker and a feminist? And a lot of people pick option B, even though the probability calculus kind of tells you that,

that, you know, option A has to be more likely, is not an option B. And so the question can be why that is. But I think that this tendency that he talked about sort of explains this phenomenon, right? The second fact explains the facts you were initially given, but option A, as I called, it doesn't. And I think that this is sort of a part of a general theme where people really do, you know, sort of look for, and as I said, believe in explanatory general theories not by by not this sort of content you know not not kind of the most likely theory I mean there are several European languages I think the the German German and Slovenian are the two that I know where I think that like if you were translated the word for probability into English

it would be something like believability and and I think that you know if you If you interpret probability in that way, sort of, I think that, you know, the believability of explanatory theories is always higher than the believability of these sort of less likely theories, and therefore believability isn't really probability. Okay. And can you explain why explanatory theories should be preferred? Well, I'm not saying that they should be. You know, I do like explanatory theories.

I find them interesting to think about and kind of much more fun to engage with. I mean, I can give you his arguments for it. I'm not sure if I entirely agree with them. Actually, I'm more interested in where you might disagree. Where might I disagree? Well, so for example, he points, so there is this interesting question, right, of what exactly is the role of this universal theories? Like, why do we have them?

Why do we think about them? Why do we try to improve them and so on? And his argument was that people actually, his argument was actually quite psychological. It was that people seemed to have this need for regularity. And, you know, if you put them in an environment without regularity, people kind of go mad or, you know, at least, you know, kind of invent regularity out of thin air.

And I think that's a very interesting argument. And, you know, like, there is this interesting question of why, if this is true, I can't quite exactly see why this need for regularity exists. But it is, it is something that I think is a kind of worthy of exploration. On the other hand, I think that another thing that is great about explanatory theories is that, is that they allow. And I think that this was another point that he would make is that they sort of allow for progress, right? because it's only if you kind of create this universal explanatory theories and you go out there, you will eventually find that something about it doesn't quite work. So you will replace it with another and then another one after that.

But what is kind of happening in that process is that your kind of knowledge of the world is increasing in a way it wouldn't if you just accumulated experiences. Because if you were just accumulating experience, you might. never go out there and try, you know, things that your universal theory says you should do and therefore discovered it is false. And another thing that can happen in this process of, is that is that kind of various kinds of truth can accumulate in this, in this general theories that are not present just in the experience alone. And so I get, I'm not sure of this thing that I just said is his argument or something that, or not, but it is, I think, another reason why

planetary theories play such an interesting role in life in general. I completely agree with everything there, but you didn't explain where you disagree with Popper. Well, I mean, I said that, that, you know, it's somewhat unclear to me. This thing that I mentioned about the need for regularity. I'm not sure if it exists, it's plausible that it exists, but if it does, I don't quite understand how it works. So that's kind of that. Okay, let me ask about being polymathic. So this paper clearly pulls from a lot of disciplines,

and I think a lot of the work you do generally does. What advice do you have to a young person who's trying to be a polymath? Well, first of all, the first piece of advice that I would give is that you should never take advice from me. The second thing I would say, though, is it actually relates. So again, this sort of relates to just a particular problem that I think I, I think people are naturally interested in everything. And it is only through, again, it's actually very similar to the thing

we talked about at the beginning. I think that, I think that the same phenomenon that happens with the way people think about science sort of happens with learning. So, you know, people learn all their life. And in fact, people learn all the time. You interact with information all the time. It changes you. But you never think, you never consciously think of changing yourself by doing that or, you know,

trying to change. It's only in very special circumstances that, that you kind of try to think of yourself in that way. And I think a lot of what happens when one tries to do that is actually quite counterproductive. Like, for example, there are a lot of ideas that, that if you want to learn something, you can't just do it through osmosis.

You have to be very, very systematic about it. And I think that is basically completely false. I think that, and again, this sort of leads people in the sort of very, very counterproductive direction where they think they need to study the fundamentals of something. And then there are, first of all, they think they need to study a subject. Then you think, okay, first I need to study the fundamentals,

then the intermediate level, then the advanced levels, and all of these levels are fiction. There is sort of none of that there. And all of these ideas were actually developed to, they have always been developed to solve a particular problem or advance a particular need. And I think what is, you know,

if one wants to just have broad interests, I think the most important thing is to just, you know, pursue whatever you're interested in, not be afraid or think that you can't understand it. And paradoxically, not actually trying to achieve any particular change in yourself. but rather just sort of going going where the story goes. Reading history is perhaps perhaps sort of helpful because a lot of books are kind of written

with these ideas that I think are misconceptions in mind. But, you know, there is a substantial, but history often, history of things often gets around that because like, you know, as I said, like every single one, every single thing you see in a textbook wasn't written to be put in a textbook, wasn't developed so that somebody could learn it. It was created by somebody who was trying to do something or understand something. And it was useful in a particular context. And that's why people adopted it. And that's why it eventually ended up in that textbook. But what often happens is that then that context goes away and all that remains is a textbook. And so you are left with all of these

irrelevant-seeming information that was actually relevant to somebody at some point. point, but it's no longer relevant to anybody that reads it, or at least not immediately relevant to how they approach. So that are some of my basic thoughts on like what I sometimes see kind of go weird, but I think that people, you know, polymath is not something you learn to be, it's something you unlearn to be, as some people would put it. Awesome. That's very liberating advice, but let me ask you this. Should you just, should a young person just be focused on learning where they find it interesting? Or as you mentioned,

like people are trying to find solutions of the problem situations they're in, should they be purposefully trying to identify problem situations in existing knowledge? Yeah, so I think that when it comes to that, I think my impression at least is that the most important thing is to connect

with other people or groups of people that are doing something. because there you will, you know, again, find, find something that you can contribute to as well as, you know, sort of get support for doing so and so on. I think that that is sort of very much an unsolved problem as a thing to kind of do at scale. As I think we talked about at some point, like there is this idea that you would create a kind of a, there is often this idea that one could easily create kind of a list of all unsolved problems in a given field and just put it on the internet.

And many people kind of think, well, this seems so simple. Like, why doesn't anybody ever do that? And I think that is that it's actually incredibly difficult to do. I think that the kinds of information that you would have to put online is just incredibly, it's very, very unclear how one does that. And the key thing is that, is that the key thing to realize is that, well, first of all, that, there really is no such thing as a, as an unsolved problem, I think, as conventionally understood. There are just a bunch of people and, you know, like one can form a view that, that creating something would be valuable to them. It often won't be valuable to everybody.

It will only be valuable to a subsection of those people. and those people might not actually know in advance that that's what they would want. And for that reason, it's actually quite difficult to sort of put, you know, that seems to be a kind of, that is kind of, it's a difficult thing to kind of put online for that reason. And, yeah. Oh, interesting. So, but if you're a young person who needs to connect to people who are solving the right problems or about to solve the right problem. problems, but you yourself don't know what the right problems are because you haven't connected to them yet. I mean, how do you solve that circle? Right. So I think that that is sort of quite a

challenge. And as I said, I think I'm terrible at this. There are people who I think are sort of, because I think, you know, it is very much the case, as you sort of say, that the whole thing has a bit of a sort of a chicken and egg problem to it, right? Because the whole idea is, well, you can't really contribute anything valuable because you don't know. anything about you know what these people's lives are like what you can contribute to it and on the other hand it's kind of difficult to join the conversation because you don't have anything get to contribute to it right and so the the there are these sort of all kinds of idiosyncratic ways that that I think

this sort of happens and gets solved but there isn't anything as it's not an impossible problem to solve but but it does require I think quite a bit of an experimentation I don't think I'm the best at this by any stretch, but these are, I guess, are just some general thoughts in that. So then young people connecting to mentors who are solving the right problems, is this very hard? Is this impossible almost? I actually, no, I don't think so at all. I think that the main problem is just that it is somewhat idiosyncratic, right? So you cannot just sort of give a, give a universal answer.

But I think that it's definitely not the case that the, the, the, the, it's definitely not the case that the world is hostile to it. I think people are very sympathetic to attempts to do that. You know, and, you know, as I'm, as basically you illustrate, I think a lot of, a lot of that is very, very possible. There's tremendous goodwill for young people out there. So that's, yeah, I have sort of the same impression. And so, so, so, so yeah, I don't want to, like, I think, I think one of the worst things, perhaps, perhaps the reason I sort of bring this stuff, just because I think people often just lack awareness of this. They kind of lack the awareness of the fact that that is kind of the main challenge,

or at least a thing that we all to do. And yeah, I guess for that, for that reason, I think it is sort of worth mentioned. On that hopeful and optimistic note, Mastras, thank you for reading on the show. This is very fascinating. Thanks. Thanks for having me. It's been a pleasure.