Rationally speaking, is a presentation of New York City skeptics dedicated to promoting critical thinking, skeptical inquiry and science education. For more information, please visit us at NYC Skeptic's Doug. Welcome to rationally speaking in the podcast, where we explore the borderlands between reason and nonsense, I am your host, Massimo Puchi, and with me, as always, is my co-host, Julia Gillard. Julia, what are we going to talk about today?

Masimo with us today via Skype coming in from the UK is James Lieberman, who is a professor of philosophy at the University of Bristol. James is primarily focused on the philosophy of science and has written a great introductory textbook called Understanding Philosophy of Science.

But he's also written, which I actually happen to use in my classes and philosophy of science. That's right. It is very good. That's great. We're not going to talk too much about that today, though. We're going to be focusing on another one of James's recent books, which is actually about metaphysics and its relationship to science. It's called Everything Must Go Metaphysics. Naturalist. James, welcome. It's great to have you here.

Hello. It's great to be here. That book is co-written with Don Ross, of course.

Yes. And I notice you also have a couple of other sort of part time collaborators on the book, which is David's spirit and John Collier, right?

That's right. So this book tells us in sort of broad terms, how did this come about? This book is about, as you said, the relationship between metaphysics and science. Now, some scientists would say there is no such thing as metaphysics anymore. It's all science. And some metaphysicians would say metaphysics. There's very little to do with science. I'm guessing you fall somewhere in between.

Well, we have a definition of metaphysics in the book, which is the attempt to unify the science is to say something about the world in the light of all the sciences that we have. And that is not a project which is part of any particular science. Are those scientists engaged in that project when they think about the wider significance of their theories or how their theories relate to other theories and so on? So I think the scientists are wrong to think that there is no such thing as metaphysics.

I mean, that there is a genuine project there. And I think the metaphysicians are wrong to think that metaphysics has got nothing to do with science, if that's what they think, which which, of course, lots of them don't think is right, but they certainly do.

Would you mind giving an example of one or two questions that a physics professor might work on?

Well, the kinds of things that matter. Physics professors work on issues about the nature of space and time. The nature of properties are causation, laws of nature and so on. Obviously, I mean, my choice of topics reflects my interest in philosophy of science is all those topics are also topics in philosophy of science. But the kind of not distinctively naturalistic metaphysical questions I have in mind are issues that are discussed a lot on your blog, I notice, such as what's the relationship between biology and physics?

Can there really be causation in the special sciences if everything's really physical in some sense and so on? And those questions have been discussed by people interested in the scientific worldview for a long time, Rutherford famously said, in science there's physics and there's stamp collecting. What he meant by that was that all the other sciences are somehow involved in a kind of pragmatic keeping track of of things. That's where the real work is being done by physical. And that's a view with which I don't agree.

But I think that view is a challenge for anyone who who wants to take seriously the evidence we have for some kind of physicalism. And that evidence is the unification of science, the at the great success of applying knowledge of more fundamental sciences to emerging science. So, for example, we just wouldn't have a subject like molecular biology unless that project was successful.

Right. So successful independently of fundamental physics, you mean. Yeah. I mean, what I'm saying is that the project of of gaining insight into emergent sciences from more fundamental sciences has been successful. So famous people will say that Pasteur established that biological processes are really, in some sense, chemical processes right now so that our listeners have an idea of the big picture.

I want to go back straight to the very title of your book, which should be pronounced. The first two words should be pronounced separate, right. Everything must go. What do you mean by that?

Well, you know, it's partly the. The title, it is because it sounded good and was catchy. Yes, there is a point behind it, which is that we we set ourselves against a particularly dominant way of thinking about the nature of reality, which crudely put, is to is to think of reality as decomposing into some fundamental set of little things. Right. With their own intrinsic properties and then spatiotemporal relations among them, giving rise to everything else, like, oh, I'm sorry, by decomposing into little pieces.

You mean like quarks or some other kind of object, if you like.

So so sometimes forces to talk about the fundamental building blocks of matter, whatever that talk about it.

And and one part of the book, chapter three of the book, although it really is informing us right from the start, is an argument, an extended argument to say that physics has to be fundamental. The most fundamental physics has taught us about picture. The world is untenable. So I have in mind the idea that really fundamental particles are fundamental as particles. They are to be understood as emergent phenomena that arise because of the underlying behaviour of some kind of field, which is very difficult to to to conceptualize.

And also the ordinary quantum mechanics, rather than quantum field theory describes particles as in such a way that they don't seem to behave like individual classical objects would be for statistics. And likewise, general relativity teaches us that spacetime points are not individual entities between which relations are, but rather there is a structure to spacetime which has to be understood kind of holistically. At least it can't be broken down to a structure of relations between individual points which which come first.

So the physics behind this, as you and Dunross point out in the book, has to do with concepts that have been surfacing, even even the consciousness of the general public over the last few decades, like none locality and entanglements and things like that.

Right. So you're talking about the fact that essentially all the current and fundamental theories in physics don't really deal with what is in the book you describe as micro things in micro banking's. Exactly right.

Exactly. So but we also think that liberating oneself from the idea that we need to find some fundamental set of individuals is important for all the sciences, too. So as you may be aware, I'm sure you are aware there's a debate about individuality in biology. Right. And philosophers are often inclined to take that kind of the individual organism as a prime example of what they mean by an individual, even though we know that that the kinds of organisms that we that we form our intuitions in dealing with and that that we see around us, let's say puppy dogs and other human beings and.

Relatively discreet plant life forms are the exception, and for most of life, it's very contentious how exactly individual individuality comes about and what it means and what the status of something as a biological individual is.

So, for example, a lot of recent discussion about ourselves as human beings, or are we better thought of as colonies than as individuals from the biological point of view?

Well, what given the role that the bacteria in our guts play and so on, but when it comes to bacteria themselves or various kinds of plants or creatures like Portuguese Munawar, then their individuality is is really problematic. And likewise, we know that the idea that psychology is all about the fundamental individual, the self has been really dismissed by lots of recent advances in psychology. They think of the human mind as much more complicated as not resolving into a fundamental individual or its properties.

And economics would be another example where the economic agents need to be and probably often aren't best identified with individual human beings. They're a kind of abstraction which which is useful for the purpose of theorizing. And that's really the view of our book. It's not that we shouldn't talk about things, but rather that we should regard singlehood as a scale relative matter such that in particular theories at particular scales for particular purposes, there's a well-defined set of individuals. But we shouldn't think of that metaphysically being some fundamental set of individuals which which make up the world.

And James, do you think that physicists like, at least when you were applying this principle to physics, it sounded to my not particularly physics informed brain like something that physicists would have to already be aware of if they're doing physics correctly.

So are you are you explaining physics to the public or are you explaining physics to physicists?

That's a very good question. I think that physicists are aware of this, and I think that sometimes they slip into thinking of of particles naively as particles. But I would say I mean, depends what physicists you're talking about, really, but the theoretical physicists in general, I would say, are well aware of this. I mean, you think of the recent discovery of the Higgs boson, what anyone would say if if asked to be precise, is that what's really been verified is the existence of the Higgs field, that the Higgs boson is the first excitation state of that field.

And, you know, talk of particles being discovered is is good for public consumption. But really, the true story is much more subtle.

Well, this goes back in some sense to the whole problem that as characterized to some extent, 20th century physics in terms of especially physicists trying to make the rest of us understand what the hell they're talking about. You know, when people think when physicists talk about, oh, well, light is is behaves, both is a particle.

And as a way, for instance, right now, that's that's a classic from the early part of the 20th century.

And well, the the normal none, particularly physically oriented person would say, well, what do you mean, is it a particle or is a wave? And then you have to start retreating into. Well, it's something that behaves as under certain conditions, which sounds to me like what you're saying. Right. So you're saying for certain.

Right. But I wouldn't call it retreating. I mean, I would expect it to we need to be more positive about it. And people look, there's no reason why reality should fundamentally be a way that we can visualize or grasp an intuition. Right. And the experience of physics, as it has been to it's become more and more mathematical. And so most, I think, would say, look, you can only go so far in our explanations before we just show you the mathematics and say this is how it goes.

This is how it behaves. So, yes, it behaves a bit like a particle, behaves a bit like a wave. And both of those ways of thinking are useful for thinking about about particles for some purposes. But neither of them should be regarded as an insight into the ultimate nature of particles.

Now. I think it's really tricky because we're always tempted to say, yeah, but what is the ultimate nature of politics? And I want to argue that we really have to accept that the ultimate nature is revealed by a mathematical description of not is not translatable into a description in terms of the in terms of ordinary language.

Now, I want to go back in a minute to the mathematical description part, because that's where I think things get for me very interesting and at the same time very, very tricky. But so let's break it there for a second. Just to clarify even further what what you guys are proposing here. One of the examples that I found that I ran in the book that that really brought it home for me. And in fact, I wrote about it in the blog post that there were sort of proprietory to this podcast.

Was the one the classic example of, oh, this table is not really a physical object. It's not really a table. It's made it's really made of whatever atoms, quarks, protons, etc..

And you guys, if I understand you correctly present is in this example. I said, no, no, no, wait a minute.

The correct way to think about it is that at the level of perception of patterns of the world that, say, a human being operates and there really is a table, it does make sense to call that the pattern a table because it is stable enough in space and time at the level of observation and interaction of human beings that you really ought to talk about a table. And in fact, even if you go down to the quantum level, to the atomic level, you can't say that the table is really made of protons, works or whatever, because those themselves are, in fact patterns that instantiate, you know, a more fundamental understanding of reality, which is in turn not made of things.

Did I get that right?

But that's that's absolutely right. And I would I would say it doesn't just go for tables, but it goes for other things that are interested in, like molecules or intermediate entities between between tables and fundamental physical entities. So what it means to say there's really a table is, well, you you will be predictively an explanatory successfully in your dealings with the world by taking that to be a enduring physical object with a certain mass and certain dimensions. And that that will enable you to keep track of the phenomena and make predictions and so on.

And that's the kind of scale of description that we're interested in now. At the more fundamental scale of description, I would say not only is that the alleged particles are themselves made of something else, but I would say rather at the fund that the more fundamental level the table doesn't really exist. Its boundaries give out. Right. It's not useful to track it as a table over the nano second scale, right? Well, in the same way that really, you know, as a relatively enduring object is still absolute.

Use this to track phenomena and the cosmological time scale, thinking about things like tables, because they're completely ephemeral from that perspective. So it's going the other way around, basically going from from a table scale to a cosmic scale. It doesn't it also doesn't make any sense to talk about.

Table geology are often called spontaneous when they take about a million years to happen.

Right.

So is the would it be fair to say that the question of of what things really exist, that that really is just a question of what it's use where it's useful to to draw boundaries, depending on on what you're the scale is of your perception and what the purposes of your talking about those objects, depending on the context and your own purposes and your desire for communication and prediction, you can draw boundaries in different ways that will be more or less useful.

Yeah, I would say that I don't want to sound too relativist on purpose relative. I mean, I think by purposes you mean something like if you mean something like 70, keeping track of the phenomena that we've identified of some kind of description. Yes. Yeah. But if that's what you mean by purposes, then yes, that's that's exactly what I think.

Now the same idea throughout your book at some point gets applied to a concept that you mentioned early on, which is causality itself. So let's talk about causality for a minute, because, as you know, the concept of causality plays a major role, of course, in all this so-called special sciences, which we should clarify. It's anything other than fundamental physics. It also plays a major role, of course, in in metaphysics and especially in what might.

Called a non naturalistic necessarily metaphysics, but even philosophers themselves evolved often have a problem with the whole idea of causality. Going back to David Hume, who thought that it was an unnecessary and unclear concept, that that was just a ploy for convenient purposes. But other than that, it's not it's not doing any actual work. Now, you guys, again, it seems if I understood you correctly, it seemed to strike an interesting balance there, essentially saying look at the at the fundamental quantum level to below the concept, the very concept of causality breaks down.

It doesn't do any work for physicists, so they don't use it. And so one could say at that particular level, because it literally doesn't exist or it doesn't do again any any useful work. But for the special sciences, it does do useful work. And so in some important sense, it it does exist. Now, how do we square those those two concepts, if I understood you correctly?

Yeah, I think you do understand correctly. I mean, if I was being a bit more nuanced, I'd probably say we at least think it's an open question whether there's causality in fundamental physics. So we shouldn't assume that there is. And therefore there are those who who argue that the only true causation is in fundamental physics are things I think, exactly the wrong way round saying how? How causation emerges and how exactly what it is with reference to more more fundamental understanding, it doesn't involve causality, I think really, really difficult.

Are we trying to say something about it? In the book? We developed a theory about it. One important aspect of that is the idea that causation is part of a world where there's already space separate from time and where the the idea of an asymmetry in time can get get a hold of those fundamental physical theories are space time theories where there isn't any such thing as absolute time. Now that business of half a world with space plus time is separate where time seems to exhibit, this asymmetry emerges from a more fundamental, timeless, symmetrical world is.

I wouldn't pretend to solve that problem for a moment.

Do you think that the universe would look any different to like an omniscient, arbitrarily intelligent observer?

Do you think the world would look any different if there were causality versus if there weren't?

That's a really interesting question. It depends what you mean by omniscient. See, when we talk about the pluses demoness, often people do and they tend to say on the plasticine and knows everything about the positions and momentum of all the particles and therefore about everything.

But that's out of the question at this point, right? Yeah, I think that's a mistake because see, if you know too much, then you you may actually miss some of the some of what you could know that you only know if you're limited. So let me explain what I mean by that. Lots of the theories that we have theories of of a reality which with respect to fundamental physics is is coarse grained and approximate. OK, so our theory of gases relies upon us ignoring details about particles and focusing on an emotional level of behavior.

Now that emergent level of behaviour, pressure, volume and temperature is it's it's a approximate and strictly speaking and correct. This is exactly the same way that the planetary laws of Kepler are, which, according to which planets move in elliptical orbit, are strictly inconsistent with Newtonian mechanics. So if you ask in a weird, omniscient being, know that planets move in a lipsitz, the answer would seem to be, well, depends what you mean. I mean, if you mean it being that knows only the most detailed level, then they wouldn't see it.

Lipsius because they're all actually exacta. Lipsitz If you mean by mission of being that knows exactly what approximations to make all levels to see the emergen structure that exists at those levels, then yes, it would.

Well, what if we imagined a much, much, much simpler universe about which we by stipulation know all the fact that it's there ten by ten grid and each square in the grid is either black or white. And there are a few simple rules that dictate how the colour of the different squares changes. Like, if know, if the square is run by three other squares that are black, then it will turn white or whatever. I could apply the rules and the the grid, the universe, which is the grid, just obeys these rules and definitely could like.

Is there anything that we could point to that would be different about that universe if there were causality versus if there weren't? And if so, then it is our is our universe different from that in some way?

OK, that's it. That's a really good question. I think causality has to do with questions about what would happen if something had gone differently. And I think if you're positing rules that determine how the grid behaves, describe the sky, already have causal laws and then describe. Yeah, if you just say now here's a universe, I'm just going to tell you everything that actually happens in it.

Yes. That's a better thing to say. Then then that would seem it was then seem to be an open question and we just don't know enough to know whether there's causality or law in that universe.

Now, if I like to point out two things briefly. One is that several times in the last few minutes, in answer, especially to Julia's question, James has done what I've come to love from philosophers when they do it. And when I was a scientist, I hated it, which was it depends what you.

Yes, that's that's to me, yeah, to me, that encapsulates the attitude of a philosopher. Well, let's be precise about what you mean by this. But but I want to go back to something that may have slipped the attention of some people over the last few minutes, which is when, James, you talked about the last demon and all that sort of stuff. So the standard simple, I would almost dare to use the word naive, reductionist determinist explanation for everything is, well, you know, if you had imagined Laplanche Demon, who knows the position of all the particles in the universe, any particular point in time, therefore, anything is perfectly determined.

And it follows that all sorts of things like you don't have free will, you do it all?

And that the unfolding of the universe is determined from the beginning, blah, blah, blah, blah.

Except, of course, that if we take seriously the picture that that you and Ross are getting from fundamental physics to couldn't be able to pass them on because there are no particles of which or of fundamental objects of which we would know the position and behavior of the universe at any particular time.

Right. Right. And so I think that I think the view I've defended with Don is that the evidence suggests that there's no particular reason to think that there's a fundamental level of fundamental objects. Now, we don't claim to know that for sure. We could be wrong about that. You know, a lot of people have assumed that there must be. And I think science kind of proceeded pretty well, assuming that there must be. Right. But we've now reached the point where we've seen so much evidence that each time we think we've got the putatively fundamental level, there's a lot more going on.

As with atoms, for example, which aren't really atoms. You know, they're not individual, they're not constituents of matter. So that makes makes me think, look, there's really just no reason to assume there's a fundamental level to reality. And absent any reason to assume it ought to be an open question. And if it's an open question, you shouldn't build into your worldview an answer to that question. Right. So you need to have a world view that's compatible with that, with that not being a fundamental level.

And that's what we've tried to articulate. But I should stress that on and on we're very much claiming to well, we're very much trying to offer a feasible, scientifically informed metaphysics that based on our best knowledge so far and no, that is not likely to be the final story. And lots what we think could be wrong.

Right now, I want to push you over just one more minute on the issue of reductionism and determinism, because in the book, at some point you actually claim and I reacted with somewhat of a surprise to that claim, that that straightforward physical reductionism is not actually a particularly popular a particular, you know.

Yeah, I guess a politically popular position among philosophers of science or metaphysicians. I may go that wrong. So what do you think is is the status of physical reductionism in in philosophy?

Oh, that's a good question. I think I think lots of philosophers would like to have reductive physicalism. So I think lots of philosophers on the one hand, they want to say, yeah, but there's clearly some sense in which we've learned that physics and it makes everything art or something like that. Right. Right. Everything's physical, that the world's emerging from the physical. There's some asymmetric relation between the rest of science and physics. On the other hand, I think most people find a straight reduction implausible.

Now, the difficulty is, you know, it's one thing to identify a position you'd like to have and it's another thing to actually make that defensible. And I think many philosophers think that actually reductive physicalism isn't defensible. And so they're either reductionists and they think, look, it's just tough. We don't really want it to be like this. But we the arguments force us this way or that. And she reductionists of some kind of a. physicalness stripe as some sort of strong form of emergence that there can be downwards causation and maybe there's autonomous realm of whatever.

And we are really trying to defend, make plausible the sort of traditional middle ground. And that one may wonder, can we really? That seems like having your cake and eat it. Sorry, that's an English, yes. Execution doesn't make a lot of sense. Yeah, yeah, it does make sense.

Yeah, OK.

But but so, yeah, that's what that's what we would like to have. So yeah, the status of reductionism, contemporary philosophy I think is a it's a kind of divide between those who, who accept it and those who run in the opposite direction. Give up physicalism in order to avoid it.

Yeah. And just to be clear, because again, I guess I would find myself and on and on those philosophers that are interested in what you referring to as the third way in between in between those two extremes. I certainly reject any kind of strong form of emergent ism. But at the same time, I'm very uncomfortable also with straightforward reductionism.

And it seemed to me while reading well, by the strong form of emergence. Oh, I'm sorry.

That's true. A strong form of emergence would be the idea that that although everything is made in of whatever particle has been building blocks, etc., at some point the interactions among some of these particles, when when the when the objects become complex enough, you have essentially new laws of nature or new patterns of behavior, new levels, of course, that come into existence.

And they cannot be reduced to exactly the lower level. Correct.

Now, that is a strong form of emergence, which I think it's logically possible. I just don't see any particular reason to endorse it. Other then you don't like physical reductionism at the same time? I also find physical reductionism unpalatable for a variety of reasons, one, which is that it, um, it does seem to go away to simplify and get it go away and do away with too many things that are actually interesting at the level of the special sciences.

I should note for our listeners that when philosophers talk about things, about not liking things or finding things unpalatable, they don't just mean it makes me sad, right. Like it makes it hard to account for these other things that I believe to be true. It wasn't just a matter of taste. Yeah, right. So so what I found in in James and Don's ideas throughout the book interesting was precisely what James was saying a minute ago, which is this may be one way to start thinking about an interesting third way.

And if I understand correctly, this third way would essentially would be built on the essential idea that, look, it may turned out that things like causality and fundamental objects, which are, after all, the two main reasons why physical production is built, can build their case, don't actually exist, or at least they need to be reconsidered, reconsidered greatly. And so if the two major conceptual building blocks on which you're you're you're basing your reductionism are going to be at least diffused, if not entirely eliminated, then it seems like physical production has a problem.

Is that is that about right, James? Yeah, that's right.

And I say something else as well. It's often been thought that the entities, the special sciences are problematic.

So if entities like like like influential states or like mental processes of any kind, but also living processes. Now, of course, it sounds strange to say that there is a special science, etc., but if you start talking about sales, you think, well, who things that problematic that loads of people in science labs work on cells all the time? I think that's exactly right. And that's precisely why it's not plausible to have a view that says there are any such things because all there are is particles.

But what has often been thought is that somehow these higher level entities are problematic because they're not as clear cut and don't have the same kind of definite all or nothing reality that the fundamental physical things do. And what we find from fundamental physics is that, well, we have descriptions of things in terms of particles, and they're useful, to some degree an approximation. Let me go to a more fundamental theory. And those particles turn out to be just emergent approximate structures to some some deeper level of reality.

And so if that kind of is always the case, then we don't have any particular problem with things that you might have worried about in the special sciences. So if someone comes along and says, I don't like economics because I don't know what these utility functions are and I don't know where to find them and where are they in space and time, might be inclined to say, well, look, that's not a good objection because even particles sometimes can't say where they are in space and time.

And always what really matters is, do you have a theory which talks about these things that enables you to predict and explain and describe the behaviour of reality? And if you do. There shouldn't be a further question about the oncological ontological status of the things that he talks about.

So does this discussion bear on the realism versus anti realism debate? Like, I don't know whether what you're saying would count as anti realism. Maybe it would just count as it's irrelevant whether things really exist or not.

Yeah, I think I think our view counts as as realism in one sense, because we think that there are organisms, cells, mating strategies, utility functions, markets, economic agents, molecules, atoms, whatever.

It's just how you carve them up that counts as a.. In another sense, because we don't regard any of these things as fundamental and we recall all of them existence is sort of approximate and scale relative.

And this this view is referred to in your book as authentic structural realism.

Well, yes, but I mean, really, you asked at the beginning how the book came about, because I developed on structural realism in the context of philosophy of physics. Don had developed a view about a form of realism, about special science, as he called rainforest realism, and came about because we thought we would put the two together. I never really thought very much about the ontology of the behavioral and social sciences.

And Don said, well, I didn't have a philosophy of physics. And so we set about trying to come up with a unified account that would work for both fundamental physics and the special science you want to see in a couple of minutes.

Before we go back to what I bracketed a few minutes ago, you were interested in feminism. What what does it mean by reinforced realism? I know what it really comes from having read the book and why that was a kind of plural sort of what, John, deprive them, of course, of promiscuous realism. A pluralistic realism is really a reference to the philosopher. Klein there in a famous paper said that he had a liking for desert landscapes. And what he was referring to was the idea that ontology should be very austere, as bad as possible right there as possible.

And Don's image of a rainforest is meant to strike in contrast to the desert ontology here being the description of what things we say exist.

Yeah, well, there is, yeah. I'd also like to get in one more question for you. Yeah. Move to your bracket, Masimo.

James, I'd be curious to hear examples of metaphysics as it is often practiced that you don't think are meaningful questions or that you think are misguided or or like misguidedly detached from science.

OK, you feel free to not name names if you want or to name names if you like.

Well, I think I personally, if I hear people arguing about whether a statue is identical to the marble that makes it up, I find myself thinking I must not be interested in philosophy myself, because is when I hear statues mentioned, my brain shuts off just because they're usually mentioned in examples that I think are right.

And I mean, it's it's that kind of question. Yes. I always say I'm not interested in debates about whether or not Simple's compose composite objects because I don't know what they mean by Simple's. I don't recognize the idea of SIMPLES from my understanding of physics. And I don't like the way that they often think about composition, because I think composition and science is dynamic. And science, if you want to know, for example, if you want to know how the parts of Assael compose a sound, you need to look at how they interact.

It's their interactions that make them stay together in such a way as to as to be yourself. It's not their physical proximity at mere physical spatial relations. That's right. And that's especially true with things with chemical kines, things like water and so on. I mean, it's how things interact that makes them compose other things. It's how how atoms interact with each other that gives rise to that form forming molecules and macroscopic structures. So, yeah, and there's also the kind of style of questioning where you you address questions about composition or about space and time or about the nature of matter in a way that isn't closely informed by our best science.

I think that's problematic as well.

And I think we should make clear that it's just not it's not just the fact that you and I don't like those kinds of that kind of metaphysics. Do you actually refer to it in the book as Neil Scholasticism, which in modern philosophy is pretty much as close as you can get to an insult as as possible right now?

Well. The Scholastic's used to argue about how many angels will dance on the pin and that sort of stuff, right.

So essentially there is a recent paper in mind about how many angels can dance on the end of the day.

You know, I mean, I don't want to be mean. I mean, I think I'm very ignorant about scholasticism. And I think probably the medievalist have been unjustly neglected and they have a lot of insights about logic and and so on. So but I think what people had in mind when they talked about scholasticism was a kind of inward looking academic activity. Right. And that's really what I object to. So I worry when philosophy becomes exposed to be about the world, but it is all about other philosophy.

It's a kind of closed conversation among philosophers. And then I think that's problematic. I think that in the history of philosophy, it's also very unusual. You know, they're never used to be such a thing as professional philosophy. And the great philosophers were all interested in in the rest of of of knowledge and certainly those who did metaphysics or thought about the fundamental nature of reality. So on the whole, for example, you know, Kant Descartes limits so so Aristotle, Plato, you know, so so, yeah, it's not so much the questions that they're addressing, but really whether they whether the subject as a whole is sufficiently paying attention to to the rest of human knowledge.

Well, to be fair and then I want to go to my previously bracketed part before before Julia. It's going to tell us that we're out of time, a time to be fair.

I think what you're describing, what you've been describing the last few minutes as a state of professional philosophy is perhaps an inevitable result of the same thing that has happened in science throughout the 20th century, which is the professionalization of the discipline and therefore the specialization. That is, I can guarantee you that I know a lot of scientists are very inward looking and spent 30 years of their career and like philosophers are spend also hundreds of thousands or millions of dollars looking at things that are quite parochial and not really that different from the sort of from the Scholastic Fixation on Angels and Pente.

But anyway but that's a whole different conversation, which might have to have a sometime. So before we go on before before Julia tell that we need to go back to the thing that I did before, which was this idea of of mathematical relations. Now, at several points in the book, you and Don go on to say, you know, OK, one way to think about what we're proposing is that it may turn out that at the bottom of reality, there are no things, there are only structures, there are relations and so on and so forth.

You talk about mathematical relations and mathematics in some sense, mathematical objects, which, of course, in many people's minds, including my own and some my students when we were reading the book, brings up the idea of mathematical platonism. You do mention which word. Yeah, which which is. Well, which is which should be which first of all should be separated from Platonism as as in Plato as just just like platonic love. Actually nothing to do with Plato.

I think a mathematical platonism is distinct enough from the original theory of the forms and of a more perfect reality.

That explanation is only making it more confusing. Yeah, I'm actually want James to tell us what he means by mathematical Platonism, but essentially I noticed that you guys just dip your toe in there. They meant you mentioned the word a couple of times and then sort of say, well, OK, maybe that's for another time. What's going on there? What is mathematical presentism and how is that what you guys relate to it, to it?

So mathematical plagiarism is a view that mathematics is describing exist, exist in objects or structures. And usually that means abstract structures that are outside of space and time, great things that causally interact with us, but nonetheless exist. And that famously raises questions about if there are such things, how could we know we're referring to them and talking about them and love about them and so on.

Really, I think the reason why we say what we say is because we know that we take mathematics and mathematical description very seriously, and also because, like many scientists, we have started to wonder about the abstract, concrete distinction and about whether a reality in some sense is mathematical or whether a. Characteristics of the mathematical is being abstracted outside of space and time and not causal, but actually apply to the fundamental physical entities that we can only talk about using very abstract mathematics.

So the other doctrine that is relevant here is Pythagorean ism, according to which the physical world is. This is essentially mathematical. And what we're really signaling is that we we recognize that we pretty much kind of assume some kind of realism about mathematics, and we're agnostic about whether the right kind of realism is Platonism or Pythagorean. Some, I think. OK, OK.

Sorry, James. I've been I've been giving math most stern face for the last six minutes or so. You know, when I teach these workshops sometimes about rationality and we had this policy because all the instructors would go over, we had this policy that one of our volunteers would come in and shoot the instructor with a Nerf gun whenever she went over time. Maybe I'll bring my NURCAN next.

OK, so as noted, we are now out of time. So we are going to wrap up and move on to the rationally speaking PEX.

Welcome back. Every episode, we take a suggestion for our listeners that has taken our rational fancy. This time we ask our guests, James Leatherman, for his suggestion.

James, the book I want to suggest is Roger Penrose's book, The Road to Reality, which is supposed to be a complete guide to the laws of the universe for the layperson. But it has to be said, nothing less than that.

It has to be said that Roger Penrose is conception of what the lay person can achieve is is pretty optimistic, but nonetheless for for readers with some degree of mathematical and scientific training. I think the book is incredibly rewarding. I've been reading it in a reading group continuously for several years going forward, going back, starting and trying to understand more, going away and looking at other books to try and understand enough to carry old and so on. So it's an extremely challenging book worthy of a lifetime study, but one that I think is full of amazing insights and rich information about mathematical physics.

Wow.

And I thought that I was spending one semester on your book was a pretty good project. Now you're going to get me into this kind of thing.

OK, fine. Maybe maybe for our listeners who don't feel exceptionally ambitious, they can wait until the book The Cliff Notes to the Cliff Notes to this book come out.

Right. But at the same time, fascinating.

There's a lot of cosmology in the book and a lot of narrative. So even if you don't get all the mathematics, you can still benefit by reading Penrose's discussion of the other really extraordinary theories that people have come to believe to be true about the extent and nature of our universe.

Great. That sounds fascinating. Thank you so much, James. It's been a pleasure having you as a guest on rationally speaking.

I very much enjoyed it. I hope your listeners get something out of it. I'm sure they will. Yeah. Thanks very much. This then concludes another episode of Rationally Speaking. Join us next time for more explorations on the borderlands between reason and nonsense.

The rationally speaking podcast is presented by New York City skeptics for program notes, links, and to get involved in an online conversation about this and other episodes, please visit rationally speaking podcast Dog. This podcast is produced by Benny Pollack and recorded in the heart of Greenwich Village, New York. Our theme, Truth by Todd Rundgren, is used by permission. Thank you for listening.