Episode 22: Underdetermination / April 09, 2021

With Professor JB Manchak

Hosted by Jasmine Hunt Keir Aitken

Edited by Constantinos Stylianou

Posted in Main feed

In this episode we discuss Underdetermination which explores the limits of scientific exploration, the possibility of time travel, and the non-self.

Listen to hear Keir and Jasmine explore Underdetermination and find out what it’s all about. Speaking to JB, from the University of California, Irvine, we discuss the limits of scientific research, conspiracy theories and time travel. We also discuss Buddhism and the idea of the non-self.


00:45 — What is Underdetermination?

01:52 — What does that mean for the problem of induction?

04:38 — Why would someone disagree with underdetermination theories?

05:45 — Are there then limits to science and scientific research?

07:37 — Is the epistemic openness afforded by underdetermination not worrisome?

10:35 — Is time travel possible?

13:52 — Underdeterminism & Buddhism

16:55 — Do electrons exist/nylon stocking experiments.

22:00 — Further discussion of the non self.


Jasmine Hunt: I think if the only thing people get from this episode is that humans aren’t lizards then we’ve achieved something.

Professor JB: If… yeah — we’ve done a lot [laughs]


JH: Hello and thank you for joining us on today’s episode of Thoughts. 

Keir Aitken: My name is Keir.

JH: And my name is Jasmine.

KA: Today on Thoughts we have Professor JB from the University of California, Irvine, who will be talking to us about Underdetermination.

Underdetermination explores the limits of scientific exploration, the possibilities of time-travel, and the non-self. So as you can tell, I’m pretty excited.

JH: So here are some thoughts on underdetermination, time-travel, and the non-self.


KA: Hello everyone and welcome back to another episode of Thoughts. My name is Keir.

JH: And my name is Jasmine.

KA: And today on the show, we have JB, a professor at the University of California, Irvine, who spends his time thinking about space and time. Hello JB and thank you very much for joining us.

JB: Oh, it’s my pleasure; I’m so happy to be here.

JH: So to dive right in: what is underdetermination?

JB: Well, underdetermination of, say, a scientific theory by evidence is the situation you can get in where you have, you know, some amount of evidence — empirical evidence — but this doesn’t pin down which theory about the world you, uh, uh, to choose.

So there’s lots of different kinds of underdetermination. You know, one of the oldest ideas here is ‘am I dreaming or not?’ Or, you know, if you’ve ever seen the movie The Matrix, you know, ‘am I in the Matrix or not?’ These are situations where you’ve got some sensory evidence coming in, but this is not enough to pin down which kind of possible world you’re living in, or which… which view or theory about the world is right.

KA: Could you speak a little bit about what that means for the problem of induction?

JB: Yeah, so the problem of induction, which was made famous by David Hume — an empiricist — is this, you know, idea that if you’re really empirical about the world, if you’re really just paying attention to empirical, uh, data, then you’re going to be in situations where you can’t pin down which way the world is like. And in the problem of induction, then you can’t rely on past empirical data to pin down what the future is going to be like. So that’s why it’s, uh, a type of underdetermination.

So there’re lots of different types — some skeptical, some not — uk, I think what’s interesting is that, uh, as Quine says: if you are willing to make really radical adjustments to your network of beliefs, you can kind of hold onto any view that you want given whatever empirical evidence is coming in. You might have to do some really radical things like, say, uhm, think that you’re hallucinating or think that you’re dreaming and so on.

KA: Uh, an example of inductive reasoning would be that every time I’ve eaten a banana, my teeth haven’t cracked, but that doesn’t actually prove that the next time I eat a banana, my teeth won’t crack; it’s just, em, through induction I’ve made that — I’ve come to that conclusion. And so what you’re saying here is, is that every time we make assumptions about the world — even if we have all the empirical data we could want — it doesn’t actually assure us that our assumptions are true. And that’s where underdetermination lies. Is that correct?

JB: Yeah, that’s — that’s exactly right. Um, there’s just no way you can kind of prove or even be confident about certain ways that the world could be given just the empirical data that you might have. Now, there’s, like I said, all different kinds of underdetermination; some… you have to be pretty skeptical about things to get it going. What I’m interested in when I’m thinking about space and time, I’m not going to be that skeptical; I’m actually going to jump right in to Einstein’s General Theory of Relativity. I can’t prove that it’s right, you can come up with some skeptical argument about we’re, you know, ‘it’s wrong’ and ‘we’re actually living in a world where the earth is flat’ and, you know, you can bring in all sorts of conspiracy theories to deny this, but I’m just gonna jump right into the science, and I’m gonna take Einstein’s theory of relativity as my sort of base, my foundation, and then what I want to say is that, even when you do that, even when you swallow all those constraints, you can still find interesting kinds of underdetermination going on. In particular, you can’t really pin down what the universe is like no matter how much data you gather, no matter how long you look in your telescope, you will never know what the structure of the universe is like.

JH: So that sounds like quite an attractive theory, but what, what would people argue against underdetermination — why would someone choose to agree with it?

JB: Yeah, yeah — good question. So, um, I think a lot of folks maybe are uncomfortable with the limits of knowledge; that this, you know, kind of underdetermination might bring. Because what it means is that we just don’t know things, and we can kind of know that we don’t know certain things. So folks wanna always kind of go past the empirical data and kinda reach for a unique way that the world, uh, is or roughly a unique way that the world is. The idea in the background here is that, ‘yeah with our science, with our empirical enterprise here, we can do it, we can, we can get to the way the world is — the truth’ and what I’m saying is: as far as Einstein’s general relativity goes, you can actually dive in there and sign on to all those constraints, and then still you can’t know what the universe is like, and that’s, uh, that’s a really interesting place to be.

JH: So is that to say that there are some limits to what we can know through science and through scientific research?

JB: Yeah, I think knowing about these limits are interesting. My own area of expertise happens to be in General Theory of Relativity. I’m interested in other examples to, but this is the one I know best and it’s interesting to me because I see the debates play out in physics and philosophy where folks are kind of taking different sides about ‘well, you know, we can know, you know, maybe what the universe is like by making certain kinds of inductive assumptions.’ And so what philosophers are going to do, maybe some folks on the other side and I might, uh, include myself there, we’re going to be skeptical of those arguments, or those assumptions you have to have in the background to get things going.

You know, a lot of folks wanna frame this in terms of ‘well, what is like a — what is a reasonable universe?’ Like sure you can get your underdetermination going if you are appealing to really weird universes, but what about, uh, a reasonable universe within Einstein. And so, for example, time travel is, you know, an example of something that is possible within Einstein’s theory of relativity, uh, some folks are going to want to say that’s just unreasonable though, that’s just like an artefact of the mathematics, it’s not a physical possibility. Whereas I’m on the side of saying, ‘well hold on, I don’t want to say that time travel’s possible, but I think it’s premature to kind of rule that possibility out.’ And so what I like about underdetermination is that it gives us limits to our knowledge, but those limits, that’s kind of the negative side of things, the positive side is those limits allow for all sorts of possibilities — epistemic possibilities — like time travel, that we can entertain. We don’t have to say that, you know, these possibilities are the way the world is, but we can be open, and I like this, you know, this openness.

KA: Are you worried at all that this openness to all these radical possibilities, you’re not encouraging, you know, conspiracy theories and, you know, the whole Q-Anon stuff that goes in modern politics or we think everyone’s a lizard — are you worried that you’re not promoting that sort of thinking?

JB: Yeah, uh, good question — I mean I think the way I’m protecting myself, uh, from those really bizarre situations is, I’ve focused on ‘what is Einstein’s theory of relativity saying and can I say anything interesting about the way that the universe is like within that framework?’ So lizards and all that doesn’t really come into play, uh… [laughs],

But yeah you have a really good point — um, there’s all sorts of kinds of underdetermination out there. Some I think we should take seriously, some we shouldn’t. Um, I have a colleague here — his name is Kyle Stanford — he studies another type of underdetermination where he’s saying ‘our brains are not good at conceiving certain alternatives, certain theories about the way the world could be, and so we have a tendency to kind of latch onto what we can conceive of now and think that’s the way it is, whereas there’s all sorts of underdetermination, because maybe — we just haven’t thought of certain ways that the world could be’ so being open in that sense is also interesting.

KA: I’d like to return to your point about limits and how underdetermination sets limits upon our knowledge and how you actually see that as a freeing opportunity, because now that we know what we can’t know we can work within that, that boundary. And it reminds me of some of the work I do creatively, where we set ourselves liberating constrictions. So for example, when Dr. Seuss, em, wrote, wrote a book he realised there was only 120 words in the book and his, en, manager said ‘right okay write a book in 50 words,’ and then he produced Green Eggs & Ham. And it was actually under those constrictions that he was liberated to create one of his best known works. And so I really see the value in underdeterminating, setting limits on our knowledge so we have the — we know the field we are playing within.

JB: Yeah, yeah I like that example, uh, because these constraints are going to open up all sorts of possibilities and we have a tendency to kind of, I don’t know, gravitate towards things that we’ve heard before or narratives that are already in place and I think that what this does is showing us our limits means backing away or or not grasping at those familiar narrative and and doing some exploring, doing some experimentation, you know getting into the, uh, the physics of time-travel a little bit. What is that like? You know, are the reasons why that’s impossible, are the reasons logical, you know — just start playing around and that’s what I enjoy; it’s kind of fun and so I really like you example because I think those, those limits are actually what make my job fun in a lot of ways.

KA: So, is time travel possible then?

JB: [laughs] Yeah, I would say we don’t know, which is a really interesting thing to say. Just to study a subject for a really long time and then, uh, say, you know, ‘I don’t think it’s clear.’ There are a lot of reasons to believe that it might not be, but I don’t think that, uh, the case is closed, and so I’m actually working on a book with a couple of colleagues right now on time travel and so we’re investigating; we’re trying to see if there’s any way that, uh,  you know something like that could be possible, and what I would mean, and, uh, we’re looking at arguments for why a lot of other people, uh, say it’s impossible.

So, I’ll just give you one that, you know, I’ve heard before: Stephen Hawking has said, you know, if time travel were possible then we would see folks visiting us right now from the future, you know, and so we don’t see that so that’s, you know, evidence that, uh, time travel’s not possible. Um, but that’s just one kind of time travel that may be possible. I think that  that the kind that is much more likely if it is possible is the type where once you build the machine that allows you to do this kind of travelling, that you can’t go back before you built the machine, uh, and you can time travel once the machine is built, uh, perhaps but, uh, going back before the building of the machine, uh, just isn’t possible. So, if time travel is possible,  say in the future after we’ve figured things out, uh, we wouldn’t necessarily expect that we could travel back to where we are right now.

Right now, time, on a global scale, is pretty perhaps boring, maybe it looks like a line. But maybe we can figure out a way to warp space and time in such a way that that time line turns into a time circle. But once we turn it into a circle, you’re not going to be able to get back to the line part that was in the past.

KA: That sounds quite daunting. I’ve gone full circle now.

JH: This is making me want to ask you about all of the, em, different theories of time travel in all the movies ever and just ask you to analyse each one [laughs]

JB: I am not — yeah, I’m not that familiar actually with a lot of the sci fi movies. Of course, I’m familiar with Back to the Future, the original with Marty McFly. But yeah, a lot of those, uh, portrayals just — when I’m viewing them, like Back to the Future, it just doesn’t make a whole lot of sense, uh, to me, because… for example, in that movie, you have folks who are travelling back in time and then trying to change events, or change the past, and I think the kind of time travel that I’m usually thinking about is one in which I’m looking at a four-dimensional space-time model so time is already kind of built in, so at every point on space-time, something’s sort of happening there, uh, and so really it’s not — it does’t really make any sense to talk about going back in time and changing things. Things are the way they are, uh, and, uh, there’s a sense in which, perhaps, if time travel is possible, you’re revisiting those events again and again in a sense. But it would’t be the case where you’d have the chance to change things. And I would say a lot of the Hollywood movies are of that type.

KA: Well, that’s a shame. I kind of like the idea of becoming my own grandfather, but I’ll have to let that go. [JB laughs]

So in your other writings, and some of the stuff that you were teaching us, you also link underdeterminism not just to the strict hard sciences, but also to the, em, more spiritual side of life and, eh, Buddhism. Could you talk a little bit about that?

JB: Yeah, I run a science and religion class where we sometimes have looked at similarities between an empiricist perspective of the world and a Buddhist perspective of the world.

So buddhists — one of the key beliefs there is this idea of, of non-self. That the self doesn’t exist. Now that might seem strange to folks, uh, especially if you might be, you know, scientifically minded or something like that, but here’s David Hume who is a paradigm example of an empiricist who’s thinking about the idea of the self from the empirical perspective. And so here’s what he says, I think this is in 1740, so he says:

‘When I enter most intimately into what I call myself, I always stumble on some particular perception or other, of heat or cold, light or shade, love or hatred, pain or pleasure; I never catch myself at any time without a perception, and I never can observe anything but the perception.’

So he’s saying ‘look just in the same way that if you are an empiricist you’re going to be skeptical of, you know, the future being something like the past, or you’re going to be skeptical of things like causes because you don’t actually observe a cause, it’s the same with the self.’ You can observe all sorts of thing — you can observe the brain, you can observe all sorts of stuff — but when you try to identify ‘oh there’s the self, it’s hard.’

And what’s interesting is that some folks actually believe that Hume got this idea from the Buddha. Of course, this is the way the Buddha himself reasoned originally. He said, you know, ‘I’m looking at my physical body; that’s not me; I don’t identify with that. I look at my perceptions and those aren’t me; I don’t identify with that.’ And he comes to the point where he’s like ‘this idea of the self is something I’m laying on top of the empirical evidence, and I don’t actually have to do that — I have freedom.’ Again, we’re back to the idea of underdetermination — maybe there are some limits to what we can actually know about what’s going on with the self. And so whatever I’m doing here, I might be prematurely settling on a certain idea of myself when there are all sorts of other possibilities out there.

And so the zen way is to kind of, you know, just not grasp onto that narrative of the self. Uh sometimes I like to put it like this: coming to the point where you understand that you are not the idea of you can be really liberating because you’ve been attached to this, this idea of yourself for a long time, you’ve been telling a story about you for a long time, it’s nice to let that go a little bit, and then see what other possibilities are out there, that are all consistent with all the empirical data that has come in, uh, so far in your life.

KA: So, just as having a self is one possible narrative that is coherent with all the input data we have, that is similar to lots of theories that we have in science where we go ‘this is the theory we’re going to go with,’ but you know there are other opportunities. And I remember when I took this class, you talked about the electron. And the electron just being one narrative that works with the data, but isn’t actually necessarily true, and I remember being almost convinced as I walked out your class believing electrons didn’t exist. [JB laughs] Can you maybe expand on that and try and convince our listeners… that electrons don’t exist either?

JB: Yeah so I — I certainly don’t want to convince anyone of anything. Here’s what we were talking about: I think it was during a discussion of scientific realism where you have some folks who are saying ‘what — what is the aim of science?’ And some folks think ‘well, it’s to get at the truth; that’s really what we’re up to.’ Some other people, some empiricist types — Bas van Fraassen is a name that comes to mind — he wants to say ‘no: the aim of science is actually to come up with theories that are, are empirically adequate and so I’m gonna actually gonna back off from thinking that a statement like ‘electrons exist’ is a true statement. Our scientific theories — they’re going to posit all sorts of entities that we can’t observe and I don’t want to be in the business of saying that that stuff, you know, exists or not. I’d much rather focus on the empirical evidence coming in and talking about how my, my scientific theories are adequate in the sense that they are consistent with that data.’

So, from an anti-realist perspective, or from this type of empiricist perspective,  what you might want to do is say ‘well, yeah, I’ll talk about electrons and electrons exist in some sense, but I’m not going to bang my fist on the table and say “electrons exist in this other sense, in this in this sense that I’m going to, you know, I really am — I believe in the truth of , of this claim.” No, it’s that I’m — you know, this is a useful fiction that I can talk about.’ And perhaps I guess when I’m, you know, what I’m getting at here is that perhaps the self is a similar kind of entity.

I don’t want, from this perspective, to grasp onto some idea of the self; I’d much rather leave it open because I think there are interesting possibilities that are out there for.. for, for what’s going on. And, moreover, I think that science itself shows us that we don’t really have a good idea of… of ourselves. So could I maybe talk about a scientific experiment that is related here?

So this bit in Wilson, in 1977, they have this experiment that they do that kind of shows a sense in which we are strangers to ourselves, we don’t really know ourselves, and whatever narrative we have of ourselves, uh, can’t quite be right. Um, so what they do is they get a bunch of folks and they line up, uh, nylon stockings, and, uh, from previous psychological research, we know that when, uh, people are presented with a series of objects and asked to judge which one is the best one, the best quality, they go with the latter one more often than not. There’s a bias towards just thinking that the last one is, you know, the best one. So they, the, uh, Nisbett and Wilson know this going into this experiment and they have folks, uh, judge the quality of these nylon stockings and the quality is actually all the same, uh, the same stocking, they just look a little bit different. Um, and then they ask everyone ‘well which one, you know, do you think is the best quality?’ Of course, a lot of folks say, you know, ‘the one on the end — the last one,’ but then what’s interesting is they ask folks ‘well, why did you choose that one?’ And of course we know the reason, the actual reason is cause they’re human beings and human beings have this built in bias, and that’s really what was going on. But they don’t say anything like that. Instead they, they go on and on — they have a story about why this last one was the best one. And that’s part of the, the narrative that I think we’re grasping to, I think we want — we’re doing all sorts of stuff — well why are we doing it? Well we, of course we have a story, but that may not be the right story. And so backing off from that story I think is, uh, is important.

Um, in fact, the next thing that, that Nisbett and Wilson do is they say ‘well, what do you think: do you think it was possible that you picked that last, that… the one that you did because it was on the end?’ And the people are just like ‘NO! NO! You’re so crazy! Of course it couldn’t be that?’

So anyway, what is actually the right picture turns out looking crazy from a certain perspective and why is that happening — well, because we’re grasping on to, uh, particular idea of ourselves. So the Buddha’s perspective, the Zen perspective is just to say ‘why don’t you just try not grasping?’ Try not grasping onto that idea and see what happens.

KA: Uh, I remember, em, studying that experiment and being quite, quite blown away by how determined people were to, to attach themselves to some sort of truth in their opinion, and they couldn’t accept that it was maybe just a random bias that they didn’t even know they had.

Em, I think what we can learn from the… this kind of analogy between the self and the electron though is that… and looking through an underdetermination lens is that, eh… though there is no guarantee that the electron is there, it’s quite a helpful tool; quite a helpful story to have when doing science. And I think in the same way the self is. And though it may — it is just one story that we tell ourselves, it is quite helpful to assume that you have a self. Just when you’re trying to have a conversation with people, if you’re completely buying into the non self, it would [laughs] be quite difficult to live your life.

JB: Yeah [laughs] Absolutely, yeah, you-you’ve got to — in order to be in this world, uh, you’re going to have to use this idea of the self, uh, and-and use it all the time. And I think it’s really important to do that [laughs], uh, because living your life without an ego, um… yeah that’s like being on mushrooms all day every day — that’s not going to be good.

Uh, but! What I will say is, uh, that practicing every once in a while to kind of let go — say in a mediation session — to let go of your idea of yourself, that’s good practice. To every once in a while do that. I think we’re all going to die someday, we’re all going to be in a… at the point where we’re gonna have to let go of ourself in a sense, and having some practice doing that I think is really, really beautiful and, um, can help us understand what’s really going on here, in the universe.

KA: So practicing not having a self, just like mushrooms, [JB laughs] is good to do every so often.

JB: Well yeah so that is why a lot of folks are interested and that is why it’s been shown to help folks who struggle with mental illness, for example, because, I mean, just think about what a lot of therapy is trying to do. It’s trying to, like cognitive behavioural therapy, it’s, you know, you’ve got a story about yourself, and it lends you jumping to conclusions, to thinking in certain ways that are kind of, that kind of distort perhaps the way things really are. And so one of the steps there is to kind of back, back away a little bit, not grasp onto, you know, certain kinds of, uh, jumps in your reasoning, certain kinds of stories that you’re telling about yourself. And I think what’s interesting is that they’ve seen some success giving folks some of these medications, like mushrooms, to help them to let go a little bit of, of they’re idea of themselves, they’re, uh, ego, and it does open up a space for them to think about themselves in a different way and to approach the universe in a different way, alright? And I think it’s beautiful.

If you haven’t checked out, uh, Michael Collins’ book How to Change Your Mind, this is how you can change your conception of yourself and maybe let go of, of, of some things that maybe you ought to let go of.

KA: I think it’s so fascinating that underdeterminism can be applicable in such… strict and… in fields such as science and in such spiritual ones like in, like Buddhism. That kind of understanding that we don’t quite know the whole subject and are accepting of that; I think it’s really powerful.

JB: Yeah like I said, this tension here between an empiricist world view and underdetermination, it’s… it’s a really beautiful idea. There’s a Buddhist, Nagarjuna, who said ‘thanks to emptiness, everything is possible.’ What he’s saying is, you know, thanks to these limitations, you know, when we’re really… when we get really empirical about the world, when we’re doing what David Hume was doing when he was trying to, uh, observe himself, when we’re doing that and we find ‘oh hey, maybe I’m adding on top of this empirical data this idea of myself there, when you pull that away, there’s this kind of emptiness.’ One of my teachers — Thich Nhat Hanh — said ‘you don’t need to be scared of that emptiness, you don’t need to be afraid of it, what it is, it allows everything beautiful that there is.’ Um, it’s, it’s this place where, um, there’s so many possibilities.

JH: It’s like the least arrogant philosophical view I’ve ever heard, it’s just… it’s just taking the idea of the self out of everything and I think it opens up — it opens you up to so much more. It’s such a nice…

JB: Yeah

JH: nice view of the world.

JB: Yeah, I mean, I, I think if we can practice doing that we can be so much kinder to ourselves, we can be so much kinder to other folks, I think the world would be a better place.

JH: We could definitely do with that kind of viewpoint spreading across the world right now [laughs]

JB: But it’s so hard to do — it’s so hard to back away from thinking that basically you’ve got the right story. It’s just so tempting to get into that way of thinking.

JH: Yeah.

KA: Fantastic. Alright, thank you so much for that, that was really beautiful and thank you so much for coming on; it’s been an absolute pleasure.

JB: Oh yeah, no, this was so fun! Uh, I could do this all day!


JH: Thank you for joining us on today’s episode. We hope you enjoyed it.

KA: And don’t forget to follow us on all our social medias. ’Til next time, thanks for joining us.

Transcript written by Adam Nicholson