Making Sense - Sam Harris - #120 — What Is and What Matters

00:00:00.000 Welcome to the Making Sense Podcast.

00:00:08.820 This is Sam Harris.

00:00:10.880 Just a note to say that if you're hearing this, you are not currently on our subscriber

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00:00:46.860 Okay, so not much housekeeping here, just a few words by way of context.

00:00:51.680 This is the audio of the event I did in Boston a few months ago with Rebecca Goldstein and

00:00:57.220 Max Tegmark.

00:00:58.360 I introduced them both from the stage, so you'll be reminded of who they are in a moment.

00:01:03.480 But we focus in this conversation on the foundations of human knowledge and morality as well.

00:01:10.080 It's really a conversation about what is and what matters.

00:01:15.420 And as is often the case with live events like this, there were some sound issues.

00:01:20.060 The sound is definitely echoey and not perfect, but I think you'll acclimate.

00:01:25.560 Hopefully, you'll find the conversation as interesting as I did.

00:01:30.420 And so, now I give you Rebecca Goldstein and Max Tegmark.

00:01:33.640 Thank you.

00:01:43.540 Thank you very much.

00:01:46.820 Thank you.

00:01:49.560 Thank you for coming out.

00:01:51.240 I have some great guests tonight.

00:01:53.500 I'm really looking forward to this conversation.

00:01:55.580 My first guest is a philosopher and a novelist.

00:02:00.040 She has written about the relationship between science and religion and science and values.

00:02:07.800 And she's also just written wonderful books on some famous people, Plato and Spinoza and

00:02:14.260 Kurt Gödel.

00:02:14.900 And she's received many awards, including the MacArthur Fellowship and the National Humanities

00:02:20.700 Medal from President Obama.

00:02:22.680 Please welcome Rebecca Goldstein.

00:02:30.240 Thank you for coming.

00:02:33.280 And my second guest is a physicist at MIT.

00:02:41.380 He's also a professor there.

00:02:42.280 He's authored more than 200 technical papers on topics ranging from cosmology to AI.

00:02:49.520 And he's the president of the Future of Life Institute.

00:02:52.840 And he's now one of my go-to guests on the podcast.

00:02:55.640 I think this will be his third appearance, if I'm not mistaken.

00:02:59.000 Please welcome Max Tegmark.

00:03:04.320 Thank you so much for having me.

00:03:05.640 Thank you for coming.

00:03:06.000 Thank you.

00:03:06.120 Thank you.

00:03:06.200 Thank you.

00:03:06.700 Thank you.

00:03:07.200 Thank you.

00:03:07.700 Thank you.

00:03:12.940 Okay.

00:03:13.460 So as I said, I've really been looking forward to this because these are two people who I

00:03:17.520 can really just dive into the deep end of the pool with without much concern about whether

00:03:23.240 or not I can swim.

00:03:24.840 I say in the run-up to this, Rebecca sent me an email asking if I knew what I wanted to

00:03:29.960 talk about.

00:03:30.460 And I said something very vague.

00:03:32.380 And then she sent me another email that had maybe a thousand words in it.

00:03:38.100 And it was just the most amazing roadmap to my intellectual life.

00:03:43.120 It's what I want to spend the next 10 years thinking about.

00:03:45.720 So I'm going to use that very much to guide this conversation.

00:03:50.740 And Max hasn't seen any of this, so he should just be terrified.

00:03:53.480 So I want to talk about what we think we know about reality and why we think we know it.

00:04:03.580 And I want to talk about the parts of reality that matter and what makes them matter and whether

00:04:12.720 we have to depart from scientific rigor in order to talk about anything mattering.

00:04:18.100 And so this conversation will take us onto terrain that I love, which is the relationship

00:04:23.840 between facts and values.

00:04:25.860 But to start, I want to talk briefly about the relationship between science and philosophy.

00:04:30.740 And so, Rebecca, I'd like to start with you and just, I mean, there are many scientists

00:04:34.220 who have said very disparaging things about philosophy.

00:04:38.700 There's actually one who we both know who I'm having an event with in about 48 hours.

00:04:44.340 He should probably remain nameless, but his name rhymes with Lawrence Krauss.

00:04:52.020 But you repeatedly point out in your work that science is riddled with philosophy just from

00:05:00.860 stem to stern.

00:05:02.420 And that if you are not aware of your philosophical assumptions when doing science, you're very

00:05:08.220 likely to be making illegitimate claims about how your science maps onto reality.

00:05:13.240 So start us off with a little bit on the relationship between science and philosophy as you see

00:05:18.040 it.

00:05:18.140 Yeah.

00:05:18.740 So, yeah, I sent you this roadmap and now I'm trying to situate myself on it.

00:05:27.660 I think that science is our great arbiter in trying to figure out the nature of reality,

00:05:37.140 of what is.

00:05:38.040 And I think that this increment of science, the amazing trick that it eventually worked

00:05:46.400 out sometime in the 17th century was that it gets reality itself to collaborate with us

00:05:55.660 because our intuitions are all off, right?

00:05:59.460 And so our intuitions about space and time and individuation and teleology and causality,

00:06:06.760 all of these very deep intuitive intuitions we have turn out to be off.

00:06:15.440 I mean, the nature of reality itself turns out that reality out there exists exactly as it's

00:06:21.300 represented to us in our subjective experience is off.

00:06:25.520 And so this is an amazing thing that we've figured out what to do to get reality, to prod

00:06:35.280 reality so that it will answer us back when we're getting it wrong.

00:06:40.960 So, oh, so you think simultaneity is absolute, do you?

00:06:44.580 It seems intuitively obvious that two events are either simultaneous with each other or not,

00:06:50.420 regardless of which reference frames they're measured in, moving relative to each other.

00:06:56.120 Well, we'll just see about that.

00:06:57.800 And somehow we prod reality to answer us back.

00:07:03.280 And that seems to me that's what science does.

00:07:06.840 So any question that we can figure out so that somehow reality itself can kind of smack us around

00:07:15.440 and tell us that we've gotten it wrong, that's scientific.

00:07:19.420 What philosophy, I think, is about is trying to maximize our coherence.

00:07:28.760 We're very compartmentalized creatures.

00:07:31.480 I think for reasons that science is beginning to tell us why evolutionary psychology can tell us why we're such compartmentalized creatures.

00:07:41.820 We live very happily with our contradictions.

00:07:46.920 And it's philosophy's job to vitiate our happiness.

00:07:52.480 And that's been the way of philosophy ever since Socrates was wandering around that agora in his dirty, chitin, annoying people, 1.00

00:08:06.080 getting them, showing them the internal contradictions.

00:08:11.280 It has to, philosophy has to take all of the knowledge that science is giving us about what is,

00:08:18.600 about the nature of reality, and test it against other of our intuitions,

00:08:23.860 and see which are compatible, which are incompatible, what the options are.

00:08:28.540 So if philosophy is always dependent on science, a good philosopher has to know, has to keep up the science.

00:08:38.520 But it's a different kind of skill set that's called for.

00:08:44.040 It's not figuring out how to describe reality and then tell us if it's right or wrong.

00:08:53.220 And it's not merely a matter of being the birthplace of science, because people, it's often said,

00:09:01.140 and I think I've said it myself, that there was a time where all questions,

00:09:05.380 virtually all questions of interest were philosophical,

00:09:07.980 and then what's so-called natural philosophy birthed off these specific sciences.

00:09:12.920 And I think in one of your papers you talk about just people in philosophy signaling,

00:09:18.420 you know, we need some more science over here, you know, come help us.

00:09:21.680 Right.

00:09:21.820 And that's not what philosophy is doing.

00:09:24.860 It happens in the course of asking these questions and trying to get our bearings in the world,

00:09:30.160 that sometimes philosophers very often will put forth proto-scientific questions.

00:09:36.620 The science isn't there yet.

00:09:38.120 The empirical means of prodding reality, getting reality to be our collaborator, doesn't exist yet.

00:09:46.060 And often it's because the philosopher has asked the question that the science emerges.

00:09:51.880 It happened with physics.

00:09:53.160 It happened with biology.

00:09:54.580 It happened with linguistics.

00:09:56.620 It's happening now in, you know, a lot of the fields that evolutionary psychology

00:10:03.660 and cognitive neuroscience is taking over before psychology.

00:10:10.500 So it is, so that happens.

00:10:14.060 But I think that that is a, that's not what philosophy is about.

00:10:18.180 Philosophy is not about prematurely ejaculating scientific questions, right?

00:10:26.860 That's not what we're trying to do.

00:10:29.080 It happens as a kind of accident, you know, in, in, in trying to maximize our coherence.

00:10:37.960 All right.

00:10:38.480 On that note, I'm going to ask Max what he thinks about philosophy.

00:10:40.760 You're quite right.

00:10:45.940 I've been in many physics conferences where someone is, some physicist has accused someone else of being too philosophical,

00:10:53.740 as if that was supposed to be a put-down. 0.85

00:10:56.180 And I find it absolutely ridiculous.

00:10:58.480 You know, to me, philosophy is really a synonym of clear, logical thinking.

00:11:04.620 And if you look at the PhD that I have and ask, what does the PH stand for?

00:11:11.120 You know, I have news for those grumpy physics curmudgeons. 0.98

00:11:13.900 It doesn't stand for physics.

00:11:15.780 It's a doctor of philosophy.

00:11:17.580 Why?

00:11:18.160 Because, well, natural philosophy is the phrase we used to use to describe what we now call science.

00:11:26.200 It's the same thing.

00:11:26.920 And so within science itself, we often distinguish between theory and experiment.

00:11:35.400 I guess in your words, Rebecca, you could say philosophy is the pure theory.

00:11:39.560 We don't do the experiments and we need that.

00:11:43.920 Of course, all theory and no experiment, well, then you get string theory.

00:11:48.660 And that might be too much of a good thing also.

00:11:51.340 Generally, we've had the most healthy progress when we've had both,

00:11:57.060 where you have those theorists who keep annoying the experimentalists,

00:12:01.540 like pointing out inconsistencies and giving them new ideas for things to try,

00:12:05.340 new ideas for them to try to shoot down.

00:12:07.760 And at the same time, you have these experiments who keep annoying the theorists

00:12:12.460 by ruling out their theories.

00:12:14.560 It's this interplay, which has always been at work,

00:12:17.300 whenever we've had really great progress, I would say.

00:12:21.340 I think that's the biggest laugh I've ever heard with string theory is the punchline.

00:12:26.400 Only in Boston did that happen.

00:12:30.760 Let's just cut the enemies of philosophy a little slack here in that

00:12:34.840 there's a difference in how we think about intellectual progress.

00:12:38.980 So to say that there's been scientific progress is to say something

00:12:43.160 that really would find no dissenters.

00:12:45.720 The progress of science is all around us.

00:12:48.780 How do you think about philosophical progress?

00:12:51.660 What sort of philosophical progress have we made?

00:12:54.460 I'm sure you will say that we have made some and that it should be obvious to us,

00:12:58.640 but we rarely talk as though we're making and have made great progress.

00:13:02.840 Before I address that, I just did want to say, in my saying that science is our best means

00:13:11.640 of answering the question of what is, the nature of reality,

00:13:14.960 for me to actually defend that view would take me outside of science.

00:13:20.160 I would have to put forth a philosophical argument, which I'm very prepared to do.

00:13:25.900 But I mean, there are other views about what science is all about, instrumentalism.

00:13:30.740 I mean, that scientific theories never expand our ontology, our nature of reality of what is,

00:13:38.360 but it's just, you know, it's a means of predicting future experiences.

00:13:42.220 And it never, you know, so there's no reason to think that these theoretical entities

00:13:45.960 that are used in scientific theories really exist,

00:13:51.180 that there are fields or quarks or, you know, black holes or anything.

00:13:54.160 And, you know, and some very good scientists in the past and some philosophers as well,

00:13:59.720 you know, put forth such arguments.

00:14:01.760 So even to say what it is that science is doing, science, reality can't tell us,

00:14:08.480 is it instrumentalism or is it realism, scientific realism?

00:14:13.400 That, you know, depends on a philosophical argument trying to make coherent, you know,

00:14:23.560 what we're getting, the input we're getting from science.

00:14:27.460 So it's just to, you know, to argue, I can understand how, I call them philosophy jurors,

00:14:35.460 you know, some of our most celebrated or certainly high-profile scientists who just really dismiss

00:14:42.880 philosophy.

00:14:44.380 You know, I understand what their argument is.

00:14:46.980 Their argument is, what else is our intelligence good for other than figuring out what is?

00:14:53.800 science, and it's science that does that.

00:14:56.720 Therefore, you know, there are questions that we haven't answered yet about the nature of reality,

00:15:01.360 but, you know, just give scientists enough time and research grants and they'll get it.

00:15:08.440 Well, there are other kinds of questions, including what is it that science is doing

00:15:14.660 that is not itself a scientific question.

00:15:18.060 So you can't even make the argument without wandering into philosophy.

00:15:24.300 Yeah, yeah.

00:15:25.260 But what was your real question?

00:15:27.320 Well, so I actually want to get there.

00:15:29.920 So I want to talk about realism versus all of its enemies, like instrumentalism.

00:15:34.480 Yeah.

00:15:34.780 But just briefly, it is often thought that we don't make philosophical progress because the

00:15:42.300 same sorts of problems seem to come around, you know, and we're still reading Plato.

00:15:47.500 If we made progress, why would anyone ever read Plato ever again?

00:15:52.020 Yeah.

00:15:52.380 So if you could just briefly address that before we move on to realism.

00:15:56.540 It's a hard question.

00:15:57.640 And one of the arguments that I try to make is, first of all, when you read Plato and Aristotle,

00:16:04.860 I mean, you're really amazed at how good they were at spotting the questions, but how bad

00:16:11.620 their answers were.

00:16:13.440 I mean, a lot of these, you know, answers have been disposed of.

00:16:18.160 And a lot of, the other thing I think is that as we make philosophical progress, science

00:16:26.100 has incorporated in a lot of the arguments about interpreting science that were really

00:16:32.220 philosophical problems.

00:16:33.320 The distinction between primary and secondary qualities, right?

00:16:36.500 That the 17th century philosophers made.

00:16:39.600 The primary qualities are the ones that we captured in the language of mathematics, you

00:16:43.980 know, which was the language of physics.

00:16:46.480 And they really exist out there.

00:16:48.880 So position and motion and weight and anything that can be described and measured in purely

00:16:57.740 mathematical language.

00:16:58.840 And then you can subject them to mathematical equations and make progress.

00:17:03.740 And everything else was deposited in the mind, you know, so the way things look and the

00:17:10.460 way they taste and the way they smell, that was all put into the mind.

00:17:14.160 This was all a philosophical argument made in the 17th century that just sort of became

00:17:20.360 incorporated into what we think of as a scientific point of view now.

00:17:25.700 It's a philosophical interpretation, but it is philosophy and the arguments were philosophy

00:17:31.140 and it is part of what we think of as a scientific, you know, world view now.

00:17:36.520 I think that in general what happens, I think that there has been a lot of progress and I think

00:17:40.780 particularly in moral philosophy, that these were moral, testing our inconsistencies, our moral

00:17:48.060 inconsistencies, pointing them out, making arguments and moving us forward so that it's

00:17:54.720 inconceivable to us now when we look back at our slave-owning, wife-beating, heretic-burning, 0.99

00:18:03.580 you know, witch-stoning. 0.89

00:18:05.800 Immediate family.

00:18:07.260 Right.

00:18:08.500 It's like, how could they not have seen this?

00:18:11.080 Well, they didn't see it.

00:18:12.860 And it was philosophical arguments that got us to see it so that now it just seems, you

00:18:17.720 know, we don't see philosophical progress because we see with it.

00:18:22.180 It becomes the very lens that we're looking at the world with.

00:18:26.720 And so it becomes invisible to us.

00:18:29.800 So yeah, it really is the water in which we swim intellectually.

00:18:33.240 And so I want to talk about realism, which can be defined in a few different ways.

00:18:39.740 But when I think about it, whether you're talking about scientific realism or moral realism or

00:18:45.700 even introspective realism, just trying to figure out what it's actually like to be you in each

00:18:50.760 moment, it's the claim that there are truths whether you know them or not, right?

00:18:59.120 It's possible to be right or wrong about the nature of reality.

00:19:02.240 And it's possible to not know what you're missing.

00:19:04.780 There's an appearance-reality distinction where you're trying to get behind appearances.

00:19:11.800 And science is arguably the most rigorous place where we try to get behind appearances,

00:19:17.240 or it certainly has the most rigorous methodology.

00:19:20.660 Max, how do you think about this appearance and reality distinction as a physicist and cosmologist?

00:19:26.580 How do I think about realism?

00:19:28.480 Yeah.

00:19:28.940 Yeah.

00:19:29.080 I mean, what do you think science is doing?

00:19:30.580 Because as Rebecca said, you can spend a lot of time as a scientist reconciling yourself

00:19:38.000 to being an instrumentalist, which is just, you know, the math works out, we can predict

00:19:41.560 the results of experiments, but who knows what we're actually probing into?

00:19:45.940 Who knows what it really looks like?

00:19:47.920 One thing I've been quite surprised by over the years, actually, is how many scientists are

00:19:54.800 even though you have an incredibly intelligent bunch of people to come to entirely opposing

00:20:01.880 views on philosophical matters?

00:20:04.900 And often when you probe a little bit deeper, it's because they're quite naive about it and

00:20:08.000 haven't even bothered understanding, you know, the various opposing points of views, and

00:20:11.480 because they dismiss all of this as too philosophical, but then they have their own closet philosophy

00:20:16.180 that they just don't call a philosophy.

00:20:18.440 So basically, they haven't thought it through.

00:20:20.300 And some scientists take this very instrumentalist point of view that, hey, who cares about if

00:20:26.740 there's an ultimate reality or not?

00:20:29.980 We should just focus on building gadgets that work and so on.

00:20:35.820 That's, I guess, really just a preference, a matter of interest.

00:20:39.460 Some people like chocolate ice cream, some people prefer strawberry, you know, if someone

00:20:42.900 doesn't care what exists.

00:20:44.580 But I do, I find it absolutely fascinating.

00:20:46.780 It's this deep curiosity to try to understand more about the cosmos we live in that made

00:20:53.320 me want to be a scientist.

00:20:54.760 Then there's a second school of dissent, you know, not the ones who say, I don't care about

00:21:00.120 what reality is, but that deny its existence at some level.

00:21:05.500 You get people who deny what I call the external reality hypothesis, this hypothesis that there

00:21:11.320 actually is an external reality independent of us humans.

00:21:13.700 Of course, you get some extreme folks like solipsists will just say that nothing outside their

00:21:19.720 hand exists.

00:21:20.460 But they're a small minority.

00:21:21.520 Why do they bother to say it?

00:21:22.760 But you...

00:21:23.600 Yeah, yeah.

00:21:23.960 Who are they talking to?

00:21:25.300 But you also get the very famous people like Niels Bohr, one of the founding fathers of

00:21:29.960 quantum mechanics, who said, no reality without observation about his quantum theory.

00:21:36.000 Which, when you think about it, means that humans, it's our observing that somehow makes

00:21:44.100 things real.

00:21:46.360 And this, to me, feels extremely arrogant, I have to say.

00:21:51.820 No offense to you folks, or you folks, but I'm pretty sure that if all of us disappeared,

00:21:58.080 the Andromeda galaxy would happily keep doing its thing.

00:22:02.160 And it feels, to me, more...

00:22:04.100 Less of a thought-through, really, scientific position, or philosophical position, and more

00:22:10.000 like just the continuation of this human hubris that set us back in so many other ways.

00:22:15.320 You know, we used to be so obsessive about Earth being the center of the solar system,

00:22:20.220 and then denying the idea that there could be other solar systems.

00:22:23.580 We even burnt Giordano Bruno at the stake 400 years ago for saying that.

00:22:28.520 And then there's now a resistance of the idea of maybe parallel universes, also this idea

00:22:34.260 that somehow we're so special relative to animals or slaves or whatever.

00:22:39.860 So now when we say, oh, we're so special that reality couldn't exist without us, I think

00:22:46.440 it's silly, but it's a viewpoint I encounter quite a bit still.

00:22:51.620 In some scientists.

00:22:53.740 Yeah, so the interesting thing is, of course, if philosophical education was part of scientific

00:22:58.960 education, they would find these kinds of viewpoints having been put forth.

00:23:05.860 I mean, Bishop Barclay, nothing, you know, S.A.

00:23:08.660 S. Perkipi, nothing exists unless you perceive it.

00:23:12.700 You know, he was putting forth these views, and other people were criticizing them.

00:23:17.800 I mean, there's a whole long history where these things have been argued out and its weaknesses

00:23:24.160 explored.

00:23:25.680 And, you know, it just would be good. 0.94

00:23:28.420 It would be so stupid of me as a, you know, as a non-biologist to think that I'm just going 0.76

00:23:35.040 to charge in and say what's wrong with, you know, evolutionary biology or something without 0.94

00:23:40.960 educating myself, there is a discipline in which all of these views have been argued out and

00:23:49.020 hammered out and their strong points and their weak points evaluated.

00:23:54.080 And since physics and all science raises these philosophical questions, why not study the field?

00:24:01.480 Exactly.

00:24:02.100 But you see, this is precisely where this anti-philosophical snobbery comes in as a psychological defense

00:24:07.840 mechanism, because these scientists will say, well, I don't do philosophy. 1.00

00:24:12.640 I think philosophy is stupid. 0.99

00:24:14.520 And then they will charge in and talk about all these philosophical questions, make up their 1.00

00:24:18.400 own non-standard terms for things that philosophers have discussed for hundreds of years, and completely

00:24:25.440 ignore everything that's been done.

00:24:26.520 And then effectively, what they're doing is this bad, uninformed philosophy, right?

00:24:30.020 Yes, yes, exactly. 1.00

00:24:31.560 And they justify it to themselves by saying it's all, that philosophy is somehow stupid. 0.95

00:24:36.380 I don't think that philosophy can be avoided, not just by scientists, but by all humans. 0.92

00:24:43.060 I mean, I, in fact, think, you know, one way or another, we're all trying to get our bearings

00:24:48.600 in the world, figure out what is and what matters.

00:24:51.340 There's, and you can't avoid, you know, some kind of philosophy in doing that.

00:24:57.340 I think that it's part of being human.

00:25:00.760 Yeah.

00:25:00.980 And unfortunately, there are impressive reasons to be skeptical that we're good at doing any

00:25:07.040 of that.

00:25:07.540 Yeah.

00:25:08.420 Yeah.

00:25:08.900 And it's not just the sort of the outcomes we see around us.

00:25:12.940 It's that if you take an evolutionary perspective, if you take the perspective of evolutionary

00:25:18.000 psychology, it's pretty clear that there are two inconvenient facts here.

00:25:22.860 One, reality wasn't designed with us in mind.

00:25:26.760 It wasn't designed so as to be perfectly interpretable by us.

00:25:31.540 And that's provided we're not living in a simulation that was run by the Mormons who actually 1.00

00:25:36.920 conquer the world at some point.

00:25:38.580 I'm waiting to find that out, that Mormonism is in fact true in this simulation and everything 0.99

00:25:44.760 I've been saying is going to consign me to hell.

00:25:48.580 But there's also the fact that we have not evolved our cognitive toolkit, our intuitional

00:25:55.280 toolkit, and we'll talk about the primacy of intuition in a moment, has not, it hasn't

00:26:00.500 been tuned up by evolution to track reality as it is.

00:26:06.140 It's just, that's just not the sort of apes we are.

00:26:08.340 Yeah.

00:26:08.480 And so what do you, I think that's very astute what you're saying there, Sam, because

00:26:13.140 the, one of the reasons that has caused a lot of curmudgeonly scientists again and again

00:26:20.200 dismiss philosophers and often dismiss even other scientists, like who were a little too

00:26:24.920 radical for their taste, you know, Einstein type, was precisely by saying, oh, these ideas

00:26:29.940 are too weird.

00:26:30.840 And when they couldn't refute them with experiment, they would refute them by saying, that's not

00:26:36.440 science.

00:26:37.940 And, but what that really meant, saying that it was too weird, if you reinterpret that sentence

00:26:43.620 in the context of evolutionary psychology, really meant that, you know, you know, obviously,

00:26:49.780 as you said, we evolved our brains to have intuition for the things that were useful for our ancestors,

00:26:54.420 right, like how to hurl rocks at people and not get hit by the parabolic motions and stuff.

00:26:59.280 We had no intuition whatsoever for anything that wasn't useful to them, like things moving

00:27:04.840 much faster than us near the speed of light, or things much smaller than us, like quantum

00:27:08.480 particles.

00:27:09.620 So what evolution actually predicts for science is that whenever we use tech to see things

00:27:18.120 that our ancestors had no access to, it should seem weird.

00:27:21.240 It should challenge our very notion of what the boundaries of science are.

00:27:27.100 It should probably force us even to redefine from time to time, you know, what we mean

00:27:31.180 by science.

00:27:32.360 So one could say, in that sense, that people who are being dismissive like this, of things

00:27:38.760 just because they say they're too weird, or this is not science, or too philosophical,

00:27:42.920 are really denying the fact that they're evolved apes.

00:27:46.640 And they're taking this evolved evolution, and they're a notion of what's intuitive and

00:27:54.760 what's weird, we're conflating that with some kind of truth.

00:27:58.180 Listen, it's actually a point that we hit in a previous podcast, but I think it's worth

00:28:01.780 reiterating, is that you would be suspicious of any final description of reality that was

00:28:09.500 commonsensical.

00:28:11.120 Oh, yeah.

00:28:11.360 Because we know our common sense isn't fitted to timeframes in billions of years, or to

00:28:16.780 the Planck scale, or to anything else that is at the frontier of your discipline.

00:28:21.700 Exactly.

00:28:22.160 The common sense, we should assume from evolution that it should simply be a useful approximation

00:28:27.080 for that very limited domain of reality that we had access to without microscopes, or telescopes,

00:28:32.440 or particle colliders, or any modern tech.

00:28:35.100 Yeah.

00:28:35.360 So that's, of course, I mean, of course, science has come too far, we could never go back to

00:28:40.460 something that's commonsensical.

00:28:42.780 I mean, relativity theory, you know, general relativity theory, quantum mechanics, it's

00:28:48.120 already blown our minds, right?

00:28:49.700 And so we know that reality does not correspond, so some of our deepest intuitions about space

00:28:55.980 and time and causality, they've already been, you know, they're gone.

00:29:00.440 And so, I mean, there's no going back.

00:29:04.520 Except for those people who believe that all of this was created by a person just like us

00:29:09.120 who doesn't like homosexuality, for some reason.

00:29:13.620 Yeah.

00:29:15.440 And I guess that's, I mean, you said that there are two great obstacles to our understanding

00:29:25.320 the nature of reality, what is and what matters.

00:29:28.500 I mean, to me, those are the two big questions.

00:29:30.440 Yeah.

00:29:32.100 And, you know, and one is that, yes, obviously, unless this world was created by some designer

00:29:41.720 who made sure that our cognitive abilities are up to the task, not much evidence for that.

00:29:49.300 But, yeah, this world, the laws of nature, they were not designed with our cognitive faculties

00:29:58.800 and capacities in mind.

00:30:01.500 And so it's amazing.

00:30:03.580 To me, when people talk about all that we don't know, I'm not amazed by that.

00:30:09.240 I'm amazed that we know anything, given that we are these evolved apes.

00:30:15.080 And the other thing that keeps us, and here is a little more about moral knowledge, that

00:30:21.960 keeps us from understanding nature of certain aspects of reality, including moral reality,

00:30:30.420 is, you know, our own self-involvement, our own way of privileging ourself and those we love,

00:30:40.580 and our kin, our tribe, all of that.

00:30:42.780 And so, and that also is a tremendous obstacle in terms of, we've made very slow moral progress.

00:30:52.700 We've, you know, we've made it, but it's, there's a real, and there, it's not getting

00:30:58.200 reality to answer us back.

00:30:59.880 It's more looking at the various things we believe and seeing the internal inconsistencies.

00:31:04.800 So we've got science to this great thing of just, you know, we need reality to answer

00:31:11.580 us back, because reality, you know, wasn't created with our, with our capacities in mind.

00:31:16.220 So we've developed this, these scientific tools.

00:31:19.340 And I say philosophy is these other different set of tools, thought experiments, and forcing

00:31:28.380 people to put all their premises out on the table, digging them out, going further and

00:31:33.340 further, what are the presumptions of your belief?

00:31:36.240 And the end game of that is to, the end of that game is to, to expose our, our inconsistencies,

00:31:44.940 our internal incoherencies.

00:31:47.200 And we don't like that.

00:31:48.900 That's, I'm really, that's, that's our saving grace, really.

00:31:53.000 If you, we find all sorts of ways of denying that we are internally inconsistent, because it's

00:32:00.080 usually working to our advantage to deny these inconsistencies.

00:32:05.200 But if you really keep hammering at it, and you push people's faces into it, eventually

00:32:11.380 they give it up.

00:32:12.760 And I think that's a different kind of reason.

00:32:18.000 It's not science, a different kind of reasoning activity.

00:32:21.960 And it also helps us to make progress.

00:32:24.080 It's humbling to consider just how ill-prepared we are for our modern circumstance by evolution.

00:32:31.280 When you think of something as simple and as obviously evolved and as fundamental to

00:32:37.740 our survival as pain.

00:32:40.080 Like, so we are, we've obviously evolved to feel pain, but we have not evolved to sense

00:32:45.620 pain in a way that is especially useful in a modern context.

00:32:49.440 For instance, you can feel excruciating pain or be at least seriously inconvenienced by

00:32:55.040 having an eyelash in your eye, right?

00:32:57.100 Which is, means nothing, but you can, your body can be riddled with cancer and you feel

00:33:02.920 no pain at all because we have not evolved in a condition with oncologists and hospitals.

00:33:07.980 But it would be very useful to feel pain associated with cancer.

00:33:11.380 And so it was detected early.

00:33:12.920 There's almost certainly intellectual equivalence to that sort of disability where it would be,

00:33:18.280 it would be so much nicer to be able to do something intuitively or effortlessly that is in some

00:33:25.120 way crucial to the whole enterprise.

00:33:28.040 You're at the frontier of thinking about AI.

00:33:30.920 And so we're now talking about the prospect of building minds better than our own at doing

00:33:35.700 some of these things.

00:33:36.880 Do you spend any time worrying that there are certain questions that can be posed that are

00:33:41.340 interesting, but take string theory as an example.

00:33:44.720 Is string theory just a intellectual dead end that has absorbed the careers of now a full

00:33:51.600 generation of physicists?

00:33:54.020 I don't want to be able to make you any enemies here, but if not string theory, do you worry

00:33:59.500 that there is something very much like that where we are just, we're playing with tools

00:34:03.560 that are too blunt or not shaped appropriately for that corner of the universe?

00:34:08.540 Well, let me say two things, first about string theory, and then more broadly about what we

00:34:13.700 can and can't do with our evolved minds.

00:34:16.600 For string theory, even though I was joking about it earlier, and even though Sheldon on

00:34:21.420 the Big Bang Theory has now broken up with string theory, hope I'm not spoiling it for anyone

00:34:25.540 who hasn't seen that episode yet.

00:34:26.780 So the fact of the matter is that most physicists today who say they're working on string theory

00:34:32.900 are actually working on much more broad questions than just fundamental theoretical physics.

00:34:38.600 And string has just been kind of the thing they call themselves to sort of have a little

00:34:42.260 community and get jobs.

00:34:43.900 But it's more like what was the theory formally known as strings.

00:34:48.860 And I think there's a lot of promising avenues in there, for sure.

00:34:53.260 That doesn't mean every physicist should work on it, obviously.

00:34:56.100 But it's good to take swings for the fences sometimes.

00:34:59.140 On the broader question about what we can and can't do with our evolved mind, I think as

00:35:04.860 an antidote, we had a lot of negativity here where we were lamenting, oh, evolution has

00:35:09.880 limited us so much like this.

00:35:11.820 We can't get intuition for this.

00:35:13.420 And we're no good at putting it be great if we could have better pain sensors for this.

00:35:17.660 And so the flip side of that is I think there's a lot we can be very grateful for also that

00:35:22.840 works remarkably well.

00:35:25.420 And as you said, that's in a way worked way better than expectation.

00:35:30.660 It is a kind of a miracle that it works as well as it does.

00:35:33.180 It is.

00:35:33.880 Look at the chimps.

00:35:34.840 And the chimps are not doing much of anything.

00:35:36.840 It is.

00:35:37.380 And first of all, if you think about what we actually evolved for, our bodies haven't

00:35:43.960 evolved that much in the past thousand years.

00:35:46.440 But yet, we're living lifestyle.

00:35:49.080 Now we're sitting, we're in a big giant wooden stone box with weird artificial suns here

00:35:56.260 and strange stuff on our bodies.

00:36:00.540 Everything is about, we spend large fractions of tangles.

00:36:05.340 Might have a loose, hold on one second.

00:36:08.520 I just want to remedy this problem because civilization is not working as well as advertising.

00:36:17.340 Maybe it's the Mormon simulators. 0.98

00:36:19.560 This will be the first time.

00:36:23.060 Okay.

00:36:23.300 So, but on the optimistic side, first of all, it's remarkable how adaptable we are.

00:36:30.580 And second, I do think it's actually really remarkable how much better we've been able

00:36:37.220 to do with science than one might have thought.

00:36:40.700 We are actually the masters of underestimation is, I think, the summary of what we've learned

00:36:46.200 from science in the past many thousands of years.

00:36:48.880 First, we've, of course, underestimated dramatically the size of reality and everything we thought

00:36:53.920 existed with just a small part of a much grander structure, right?

00:36:56.580 A planet, a solar system, a galaxy, galaxy cluster, universe, maybe more.

00:37:01.280 But more fundamentally, we've also underestimated our own potential as humans to figure out our

00:37:08.960 world.

00:37:10.580 I think when Plato and Aristotle and so on were trying to understand a little bit of physics,

00:37:15.320 almost everything was mysterious.

00:37:19.260 And there were just a few things they thought they could find some formulas and regularities

00:37:23.500 for, like, motion.

00:37:24.360 And then it turned out that was also completely wrong, what Aristotle had.

00:37:26.900 And it took 1,500 years until Galileo fixed it.

00:37:29.660 And yet today, we can turn it around and note that actually, you know, whereas Galileo, he

00:37:36.720 could have a grape and a hazelnut and tell you how they would move if you threw them, right?

00:37:40.100 But he couldn't tell you why the grape was green and the hazelnut was brown and why the

00:37:43.680 grape was soft and the hazelnut was hard.

00:37:46.260 Now, we can answer all of those questions with electromagnetism, with quantum mechanics.

00:37:51.700 And we have managed to bring into the domain of science almost all aspects of the physical

00:37:58.560 world now, except for consciousness and intelligence.

00:38:02.440 And continuing just on the optimistic, you know, gratitude side of this, this understanding

00:38:08.640 has been wonderful, not just for satisfying our philosophical curiosity, but it's precisely

00:38:14.740 this deeper understanding, which has, of course, given us the technology, which has transformed

00:38:20.780 our lives.

00:38:21.420 That's why our life expectancy isn't 35 anymore, right? 0.96

00:38:24.860 And so even though, yeah, it kind of sucks that I'm so dumb and, you know, that evolution... 0.95

00:38:30.640 That's the Tegmark quote I want on Twitter. 1.00

00:38:33.720 It kind of sucks that I'm so dumb. 0.95

00:38:39.420 You know, actually, things were not mysterious to Aristotle. 0.99

00:38:43.240 That was the problem.

00:38:44.640 I mean, he had a complete worldview that seemed to answer everything.

00:38:48.800 But it was just all wrong.

00:38:52.980 It was a completely wrong methodology of explanation because teleology was at its center.

00:39:01.340 I mean, the incredible thing that happened in the 17th century with Galileo and then even

00:39:05.480 more with Newton is that this marriage of mathematics with empirical observation and prediction, this

00:39:15.860 is an extraordinary thing.

00:39:16.820 It's not at all intuitively obvious that you take this, you know, what philosophers call a priori

00:39:23.340 mathematics.

00:39:24.300 It's a priori.

00:39:25.880 It's not at all dependent on experience, right?

00:39:28.240 It's completely deductive.

00:39:29.940 And you marry it to observations and you get this powerful methodology for exploring reality.

00:39:39.920 And for Aristotle, you know, the quantitative was just one of the 10 categories of description

00:39:46.640 which were not very, very important.

00:39:51.280 It was all teleology.

00:39:52.360 What processes have an end and we understand a process, a physical process, all processes,

00:40:00.440 by understanding what it's supposed to be accomplished through it.

00:40:04.100 So it was a, you know, it was a way of explaining, but it just didn't work.

00:40:09.200 And so, you know, it was, so really, you know, science, we haven't been at work in science,

00:40:14.680 I would say, for thousands of years.

00:40:17.460 I'd say we've been at work since the 17th century.

00:40:20.340 So it's even more amazing how much progress we've made.

00:40:22.620 May I just add a little bit to what you said there, Rebecca?

00:40:25.980 I think this is also a tribute to modern philosophy where the key word, I think, is humility.

00:40:32.040 The idea that to get things right, we first have to be open to the idea that we might be

00:40:36.840 wrong and actually question everything, in particular, question our own prejudices.

00:40:41.700 And that's what was really missing in Aristotle's time.

00:40:45.320 And once we got used to this idea that not only were we often wrong, and it was a good idea to question it,

00:40:53.320 but often when we questioned ourselves, that's precisely when we were able to get great new breakthroughs,

00:40:59.360 which helped ushered in the modern revolution, the Renaissance, science, and all the tech.

00:41:06.300 Yeah, no, it's great.

00:41:07.420 I mean, you're right.

00:41:08.120 There's a kind of collective humility, I think, in both science and in philosophy,

00:41:13.580 which very fortunately doesn't require that the actual practitioners be humble.

00:41:21.420 Scientists are known for their humility.

00:41:23.360 We can be thankful for that.

00:41:24.060 Yeah, but there's a kind of collective humility.

00:41:28.040 And I, yeah, so I often think of, to me, the very definition of me being a scientist

00:41:33.160 is that I would rather have questions I can't answer than answers I can't question.

00:41:40.460 That's good.

00:41:42.300 Yeah.

00:41:43.580 So I want to talk about the concept of possibility.

00:41:51.120 So much of what we talk about in our personal lives and in science and in philosophy takes

00:41:58.040 as an assumption that there is a world of possibility.

00:42:01.580 To talk about counterfactuals, things that might have been different make sense.

00:42:06.740 To talk about certain things that could have happened, but in fact didn't happen.

00:42:11.540 What gives us license to say that we might have done this event yesterday as opposed to today?

00:42:17.660 And is this necessarily a scientifically or philosophically meaningful statement?

00:42:24.420 I guess there are two views in philosophy and science that seem on their surface to be almost the same.

00:42:31.660 They have different origins.

00:42:33.000 So I wanted you to describe what's called modal realism in philosophy.

00:42:39.620 And I wanted to connect that up with this picture of the many worlds interpretation of QM and then just talk a little bit about what it means to think in terms of possibility.

00:42:49.660 Because my default setting now is that it may not make any sense at all to talk about possibility.

00:42:56.900 That what is actual is in fact all there is and ever is and ever will be.

00:43:03.200 And that possibility is just a fiction that we have spun in our conversation about what is in fact unfolding or seems to be unfolding.

00:43:11.580 So bring us to modal realism.

00:43:14.800 Yeah.

00:43:16.000 Actually, Max would be better about modal realism because I think he believes in it and I don't.

00:43:21.960 Do you use that word for it?

00:43:25.160 Well, you're more of a card-carrying philosopher than I am.

00:43:28.360 We should defend.

00:43:29.860 I could explain what it means, but yeah.

00:43:32.780 But if you loosely speaking take it to mean that everything that could exist does exist, I find that an interesting idea, but it's a little bit too wishy-washy to be really scientifically testable.

00:43:45.220 And the various theories of physics that give you some kind of multiverse, whether it be distant regions of space that light hasn't reached us from yet, which are predicted by some versions of inflation that gave us a big bang, or the ones of quantum mechanics or something else.

00:44:07.280 Those are more restrictive in a way.

00:44:09.700 It's not like everything I could think about after I had too much wine exists, but rather if you have some particular equations, physics have this solution, you know, if they have another solution too, maybe that exists.

00:44:24.280 That's the kind of alternative realities that these theories tend to give in.

00:44:28.140 But the shocking thing is that those alternative realities are still, in those cases, very many.

00:44:34.640 And this bothers a lot of people.

00:44:36.480 So, for example, my colleague Alan Guth here at MIT, when he and others came up with this inflation theory, which is the most popular mainstream theory of science right now for what caused our Big Bang, you know, what it basically says is, yeah, you took something smaller than an atom and it kept doubling its size over and over and over again until it was vastly larger than all the space that we can see, that we call our universe.

00:45:03.460 And it also predicts that all this other space is also kind of uniformly filled with stuff initially.

00:45:09.560 We know that in this neck of the woods, that stuff, those atoms and so on, gradually coalesced into form, among other places, the Milky Way galaxy, our solar system, and Sam Harris, respect Rebecca Goldstein, and me and you, and here we are, you know.

00:45:23.700 But we know that the probability that this would happen in some random place isn't zero because it happened here.

00:45:32.200 And inflation typically predicts you actually have an infinite amount of other places with stuff.

00:45:36.760 So if you roll the dice infinitely many times, of course, it's going to happen again.

00:45:40.840 And the shocking prediction is then that if you go far enough away, you're going to get to another place where this identical conversation is taking place.

00:45:53.980 The first one you come to, the person wearing the red sweater is going to be named Max Schmegmark, and he's going to be speaking some incomprehensible different language, whatever.

00:46:03.740 But if you go far enough, you'll even find someone who speaks English and has the same memories.

00:46:08.680 Very disturbing notions.

00:46:12.040 But you can't dismiss it just by saying it sounds too weird, right?

00:46:16.080 The way you dismiss it would be to falsify this physics theory, Alan Guth's equations.

00:46:21.880 And there are people building experiments right now to try to falsify it or test it better.

00:46:27.820 And that's how we're ultimately going to sort it out, not by having prejudice about it.

00:46:32.100 Yeah, yeah, yeah.

00:46:33.740 So the philosopher who argued very strongly for modal realism was David Lewis.

00:46:43.340 Did you know him?

00:46:45.200 Yeah, no, when I was a graduate student at Princeton, he was actually on my dissertation committee.

00:46:52.800 I won't pry any further, then.

00:46:55.460 Maybe I will pry.

00:46:56.460 Yeah, he's a very sweet man.

00:46:58.420 He's a very sweet man.

00:46:59.740 I never met him, but he was supposed to be very smart.

00:47:02.440 He was a formidable philosopher and a very sweet man.

00:47:05.460 I actually have a very strong mental image right now.

00:47:08.580 He had a train set in his basement, and he would only take people he liked very much down there.

00:47:14.000 And I did go down there once.

00:47:16.300 You were your train set material.

00:47:17.740 And it was.

00:47:18.660 That sounds kind of sketchy when a professor says, hey, do you want to come down to my basement?

00:47:27.760 So, anyway, yeah, you really stole the thunder from this David Lewis story, I have to say.

00:47:35.160 We can edit that out.

00:47:36.760 We'll edit the thunder back in.

00:47:38.320 But, anyway, when he was running the train set, he put on this little engineering cap.

00:47:44.520 And it was just the cutest thing I ever saw, right?

00:47:48.000 But, yes, he took, you know, very, very seriously.

00:47:51.900 Well, he had a way.

00:47:54.120 You asked, is it meaningful to talk about, you know, had I not gone to college, then I would not now be a philosopher or something.

00:48:04.600 You know, what are the truth conditions of that?

00:48:07.100 I mean, how do you figure that out?

00:48:09.140 And the way he did it was by reifying possible worlds and saying, you know, that there are a whole bunch of possible worlds and they really exist.

00:48:20.000 And you go to the nearest possible world, in which I didn't go to college, and you check it out.

00:48:27.800 You know, we can check it out, but what would make it true is if that antecedent, you know, were true, would I not be a philosopher, right?

00:48:39.860 Or, you know, if I didn't go to college and I wasn't a philosopher, then I'd be a millionaire now or something.

00:48:45.320 And you go to the nearest possible world.

00:48:48.520 So he really took possible worlds very, very seriously in order to formulate what he took to be the truth conditions for counterfactuals.

00:49:01.220 He got there for none of the probability reasons that Max just...

00:49:06.640 No, it was about, you know, counterfactuals make sense, right?

00:49:11.100 We understand them.

00:49:12.240 You know, if I, you know, if you hadn't called me right then, I, you know, would have missed the most important phone call of my life or something.

00:49:21.380 You know, we'd say these things all the time and they seem meaningful.

00:49:25.060 How, what are the truth conditions?

00:49:27.420 And he thought that the only way to do it was to say that all these various possible worlds in some sense really exist.

00:49:36.120 And, you know, so when I didn't get hit by that truck this morning, which was a very near miss, there is a counterpart in a very close possible world of me who did get hit, who did get killed.

00:49:54.780 So...

00:49:55.380 It is funny that it is strangely convergent with the many worlds interpretation.

00:50:00.020 Yeah.

00:50:00.360 It is.

00:50:01.220 It is.

00:50:01.660 And I reflected a lot about that because I was almost hit by a truck going biking at school one day and I was wondering...

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Making Sense - Sam Harris - March 19, 2018

#120 — What Is and What Matters

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