Making Sense with Sam Harris - #321 — Reckoning with Parfit

Episode Date: June 5, 2023

Sam Harris speaks with David Edmonds about the life and philosophy of Derek Parfit. They discuss Parfit’s work on identity, time bias, the “non-identity problem,” population ethics and “the Repugnant Conclusion,” the ethical importance of future people, Effective Altruism, moral truth, and other topics. If the Making Sense podcast logo in your player is BLACK, you can SUBSCRIBE to gain access to all full-length episodes at samharris.org/subscribe.   Learning how to train your mind is the single greatest investment you can make in life. That’s why Sam Harris created the Waking Up app. From rational mindfulness practice to lessons on some of life’s most important topics, join Sam as he demystifies the practice of meditation and explores the theory behind it.  

Thank you. of the Making Sense Podcast, you'll need to subscribe at SamHarris.org. There you'll find our private RSS feed to add to your favorite podcatcher, along with other subscriber-only content. We don't run ads on the podcast, and therefore it's made possible entirely through the support of our subscribers. So if you enjoy what we're doing here, please consider becoming one. Welcome to the Making Sense Podcast. This is Sam Harris. Today I'm speaking with David Edmonds. David is a writer and philosopher and the author of several books. The most recent is Parfit, a philosopher and his mission to save morality.

And that is the topic of our conversation. As many of you know, Derek Parfit was a philosopher I his mission to save morality. And that is the topic of our conversation. As many of you know, Derek Parfit was a philosopher I greatly admired. As you'll hear, I almost interviewed him near the end of his life, but my timing was terrible. We talk about Parfit's place in philosophy, his work on identity, time bias, the non-identity problem, which he actually discovered, quite interesting, population ethics, and the so-called repugnant conclusion, the ethical importance of future people, effective altruism, moral truth, and other topics. Anyway, it was fascinating to talk about Parfit and his work with someone who knew him. So now I bring you David Edmonds. I am here with David Edmonds. David, thanks for joining me. Thanks for inviting me. So you have written a wonderful book. You've actually written

two wonderful books, although we'll focus on the most recent. You may have written more books than that, and they may all be wonderful, but I've read two of them. The recent one is about one of the most interesting philosophers of our time. I think it's almost surely an objective statement. The book is about Derek Parfit, titled Parfit, a philosopher and his mission to save morality. And the other book that I loved, which I believe you co-wrote, was Wittgenstein's Poker, which is about a famous and maybe semi-apocryphal encounter between Wittgenstein and Karl Popper, which maybe we can touch on. But I want to, we'll focus on Parfit, but before we get there, perhaps you can describe your background in philosophy and just the kinds of things you have focused on and maybe your connection to Parfit. Gosh, well, my background in philosophy is that I studied it. So I did what's called PPE at Oxford,

which is philosophy, politics and economics. And then I did a two-year postgrad degree called the BPhil, which back in the 70s was kind of the route into teaching. And then after that, it was then required that you had to have a PhD as well. And then I went off and did other things, went into journalism, but I had a kind of philosophical itch and so started a PhD, which I did, I guess, about, well, in the early 90s, I think. And my supervisor for my BPhil was a chap we're going to talk about, Derek Parfit. And my BPhil was on obligations we have to future people. So these are people who are not yet born. And then I did the PhD later. And my supervisor for my PhD was a very good female philosopher called Janet Radcliffe Richards, who went on to become Derek Parfit's wife, married Parfit at a later stage. So when I wrote the biography, I was sort of well-connected. So I

knew both Derek and Janet, which was fortuitous for writing the book. Yeah. I never met Parfit. I almost interviewed him. My timing was just bad. I reached out to him at the end of 2016, and we set up an interview that was going to be, I think it was going to be written. I wasn't yet podcasting as regularly as I am now, and so we were going to have a written exchange. And then I believe his wife got sick, and then at some point he was unwell. And actually, it was interesting, toward the end of your book, you speculate as to whether or not he had dementia we can talk about his what was peculiar about him throughout his life but he actually i should say he he in this email he did describe himself as having showing signs of dementia to me so i that i thought i assume that was common knowledge no not at all so i'm very

very interested in that. He mentioned that to one person I interviewed, and I was slightly skeptical because Janet didn't think he did, and he didn't tell it to anybody else. So you are a second source. Yeah. So that is interesting. Interesting. Yeah. Yeah.

to engage with you because, as we might go on to discuss, by this stage, he was very unwilling to be interviewed. He would have seen it as a slight waste of his time because he wanted to focus on research and writing. I tried to get a podcast interview with him as well, and he turned that down. He was more willing to engage in a written interview because then he could make sure that he didn't make any errors. He was a perfectionist. He didn't want to make any mistakes. So if he had a chance to revise and edit his answers, that would make him happier, I think, than doing a verbal interview where he might fear that he would say the wrong thing. Yeah, yeah. I really consider it one of the

great missed opportunities for me because I just love his work. Although like many who love his work, I can't say that I have read all of his last book, which is 1500 pages long. And for some reason, it may just be due to length, but I also just got sidetracked while reading it, even though I'm quite sympathetic with what he was attempting there. I aspire to get back to it and finish it. But his first book, Reasons and Persons, many of us, I think, appreciate as some kind of masterpiece. It's not a—it's structured strangely, and it seems like it probably could have become an even better book based on some form of editing. I don't know who would have forced Parfit to edit it.

But there's something really otherworldly about the book. It strikes one as written from the point of view of someone coming from outer space and just manufacturing thought experiments by which to understand human morality. It's a very odd but brilliant book. Did you know Parfit before he published that, or you came to him after he...? No, so the book is published in 84, and I study with him in 87. I think I bought Reasons and Persons in 1986, which is when the paperback came out. So he gobbles, I gobble that book up. I think like you, it's a work of genius.

And in fact, that's widely acknowledged. I mean, even the people who are his philosophical enemies, he had very few actual enemies, but his philosophical opponents, even they acknowledge that this is an extraordinary work of philosophy. And what I didn't realize until I was writing the book was that it wasn't supposed to be one book. He was working on lots of books at the same time. And then he had this crisis when, in 1981, the college that was his home, which was All Souls College, which is this college where there were no undergraduates, there's no teaching at all, the people who are based there are purely there for research, they were threatening to throw him out because he hadn't managed to produce

one book in 14 years. And so they give him an extension to his fellowship, but they say he's got to produce a book by 1984. And what he does is he throws everything together. And what was potentially going to be several books turns out to be this strange mishmash. And it covers a whole variety of things. Most famously, there's a huge chapter on personal identity, what it is that makes me the same person I am now to the person I will be at the end of the interview, and the same person I am now to the person I was when I was five years old, and the person I will be when I'm 85 years old, inshallah. And then there's a huge section, which was the section that at the time most interested me, which was on future

people. And he basically invents this whole sub-genre of moral philosophy. Until then, there was nothing that we now call population ethics. And it's an area of philosophy that looks at our obligations to future people and puzzles about how many people we want in the world, whether we care about total well-being or average well-being. He comes up with these ingenious puzzles. Even whatever we were 40 years on, roughly, even now, when people write about this area of philosophy, basically Parfit is the template. People are responding to Parfit. I want to get into many of those specific problems.

But generally, what would you say his place in philosophy is now? How would you describe him as a member of the pantheon of recent great philosophers? Well, he divides people. So I'm a Parfitian. I'm a fan. So you're going to get a biased view. And I share the view of lots of very many philosophers and very many top philosophers, which is that he's one of the great moral philosophers of the 20th century. I wouldn't

necessarily go as far as some and say he's the greatest moral philosopher since John Stuart Mill, but some very serious philosophers make that claim. But he's not like Wittgenstein in the sense that people who don't like Wittgenstein's philosophy, nobody dismisses Wittgenstein. But there are philosophers who think that he does moral philosophy in completely the wrong way. And especially the later work was going down a cul-de-sac when he tries to prove that morality is objective. He's desperate to prove that there are moral facts. So he divides people, but there are many people like me who think he's definitely one of the greats in moral philosophy of the past hundred years. Yeah, well, I'm very sympathetic with trying to prove that there are such things as moral facts,

and I know what sort of pushback one gets when one goes down that path. And he focused on that more in his last book, which is really three large volumes on what matters. And perhaps we'll get there as well. I guess just one more general question about him before we get into his areas of philosophical focus. What do you think the significance of his psychology was for his philosophy? He really did strike me, even just without knowing anything about him personally, and there's a lot in your book that is revelatory as to what sort of person he was. But just reading Reasons and Persons,

I felt I was in the presence of a neuroatypical philosopher. And many of the advantages of that book seemed to me born of a truly atypical angle of attack on all the questions he was touching there. And so I always, without having any evidence for it, I always thought he was someone who must be on the autism spectrum to some degree. I know you entertain that hypothesis in the book and are uncertain as to where you come down. But let's talk about that. Maybe it's true of we could bring in Wittgenstein here, too, because he also struck me, insofar as I think I know anything about him from reading Ray Monk's biography and some other secondary work, he struck me as neuroatypical as well.

And so much of what is interesting about his thought could be born of that. Yeah, so I think your instincts are right. I think both Wittgenstein and Parfit were neuroatypical. There are lots of interesting similarities between them, and there are lots of interesting differences between them. One is, Derek Parfit was just a lot more of a benign character. So Wittgenstein went around trying to persuade everybody to give up philosophy, and I think he damaged quite a few lives because there were people who were potentially good

philosophers and would have had an interesting, successful academic life who he persuaded to give up the academic life and go and work with their hands, go and do manual work. As I say, I think that was very damaging to them. Whereas Parfit was quite the opposite. Parfit tried to persuade everybody to give up anything and move to philosophy because he thought philosophy was basically really what mattered. But they were very atypical, I think. The big puzzle in my book, the puzzle I really wanted to resolve was that I thought I knew Derek when I started, but then I started researching his early life. His early life is extremely rich. He's got lots of interests. He starts off as a historian. He's interested in music. He's interested in sport. He plays chess. He seems to have a kind of social circle. He dabbles in student journalism. He's a debater. he has a very rich life. And yet slowly, he sheds all that. And then in the second half of his life,

he really becomes a duo maniac. He has two interests. One is philosophy, and the other is photography. And every year, he goes to the same two cities. He goes to Venice, and he goes to what was then Leningrad, now St. Petersburg. And he photographs the same buildings. He goes to Venice, and he goes to what was then Leningrad, now St. Petersburg, and he photographs the same buildings. He goes there at dawn, he goes there at dusk, and he photographs the same buildings every single year. What puzzled me was how Derek turns from early Derek to later Derek, and also, which was the real Derek, which was the authentic Derek, as it were. And it's an ironic question, of course, given that he spends much of his life worrying about what it is that makes us the same person. And I was puzzling about what

it was, which was the, as it were, essence of Derek. And he rejects the idea that we have an essence. But I came to believe that the later Derek was really the more natural Derek, that once he got into this strange institution, All Souls, and he didn't have to socialise, he could just focus on his philosophy. I mean, I think there are some interesting parallels. He was essentially a consequentialist, especially in his early philosophy. That's very strong. So he believed that what matters were the consequences of our actions. And if you look at his personality, his dispositions, they were very consequentialist. Just to give you one example. So for example, he would often burst into tears when he read or heard about the suffering of distant strangers. If you told him about what happened in the trenches of the First World War, he would stop and he would cry and be unable to carry on. And yet he felt very weak obligations to his nearest

and dearest. And that's evident when later on, you know, his friends invite him to weddings, and he says he hasn't got time because he's got to work. And again, that's sort of in line with a consequentialist mentality, that sort of everybody matters equally, we don't necessarily have strong special interests with any particular people. And I think consequentialism came extremely naturally to him, and that is one link with his neural atypicality. Yeah, there's one story to touch on the mania for photography for a moment.

There's one story in the book which I think exemplifies what a peculiar person he was, because perhaps you can tell the story where there's some photo, I forget of which building, that he took enormous pains to get exactly right, and then one of his students comes and admires it. And perhaps you can take it from there. But where this story lands is, again, it's so strange. I can't imagine behaving in this way. The philosopher is, I think, his first PhD student, a very good philosopher called Larry Temkin. And Larry is in Derek's office in, or Derek's set of rooms in All Souls in Oxford. And he's admiring this photo that Derek has taken of, I think it's the Radcliffe camera,

sort of outside Derek's room, beautiful, beautiful building. And as you say, Derek just didn't take photographs. What he did was he would take the photographs, and then he would send them. This was in the days before Photoshop. He would send them to a production company, and he would spend thousands of pounds back in the 70s and 80s. He would spend all his savings, basically, on touching them up. He would send them off, and he would say he wanted a bit more pink, and they would come back back and the shade of pink was not quite right. And he would send it back to have it adjusted. And this would go back and forth multiple times, a very, very expensive process till he got the perfect shot. And Larry was there one day and Larry said, oh, I love that.

It's beautiful, beautiful photo. And Derek says, Derek said, well, you have it then. And Larry says, I can't take that photo. That's absurd. And Larry goes off home. And at that stage, he's in Houston. I think he's at Rice University. And sometime later, Derek has been invited to give a lecture at Rice University. And he turns up and he opens his suitcase and he says, Larry, I've got a present for you. And he scrunched up this incredibly beautiful photo that cost thousands of pounds to perfect. He's kind of scrunched it up in his suitcase and he hands it over to Larry. And Larry is just appalled, of course, by the way Derek has treated this photo. But I guess for Derek, he'd achieved perfection and that was what mattered. But Larry then has to spend another few thousand pounds trying to iron out the creases. And I think he's still got the photograph to this day and they've done everything they can. He got the top professionals to work on it,

but there's still the sign of a crease where Derek had scrunched it up in the briefcase. So that's the story yeah so everything up until the the final scene is you know idiosyncratic but amazing and you know compatible with you know every ethical norm and psychological norm we might want to hew to but the scrunching up part is just bizarre. It's either a total lack of awareness, or there's just something very peculiar about a mind that would do that. So can I tell you about a story I have in the preface, which is a similar kind of story because it's totally, utterly baffling. To this day, I can't work it out. What happened was that back in 2014, I wrote an article about Derek and Janet because a magazine in the UK called Prospect magazine had named both of them in the top 50 public intellectuals,

or no, actually intellectuals in the world, top 50 intellectuals in the world. I wrote to Prospect, with whom I had a relationship, and I said, did you know they knew each other quite well? In fact, they were married, and they said, no, we didn't know that. I said, I'll write you an article about their interesting relationship, which was very interesting. They said, fine. So I got Janet and Derek to agree, and I went to Janet's house in North London, and Derek was there. And I was interviewing them, and I was taking notes. And sometime later, I completed the article, and I sent the article off to Janet and Derek just to fact-check it, because I wanted to make sure I hadn't made any errors. And I was walking with my wife somewhere on a hill, and I glanced at my mobile, and Derek

said, I mean, I can't remember the exact words, but, Dear David, thank you very much for the article, but you're not going to like the contents. I'm afraid you can't publish it. So I was very upset. I'd spent a long time on this article. I rushed home, and I looked at the attachment he sent, and there was a list of, I don't know, two dozen, three dozen errors that I'd made in it. And I started going through them. And the first one was not in the article and nor was the second and nor was the third, nor was the fourth. And I just couldn't work out what was going on. And then I realised that what I'd done was I'd sent Derek my notes that I'd been taking while I'd been in Janet's house

when I was interviewing them. To this day, I can't fathom what he was thinking. Nobody could have thought that was an article. It didn't have a title. It didn't have a beginning. It didn't have an end. It didn't have a middle. It had half sentences. It was impossible to believe that this was a finished article in any way. And yet, because I'd said it was the article, Derek thought, well, it must be the article and had commented on it. So it's a similar story to the photographs to it in the sense that one just doesn't know what to make of it. Yeah. I don't mean to be invidious when I keep returning to this phrase, but it does kind of cry out for a neurological explanation, right? Yeah, yeah, yeah, I think so. Okay,

let's talk about the most interesting problems he tackled. You mentioned a few. I think identity is close to the top of the list, and then there's the famous non-identity problem, which is very interesting and has interesting implications for ethics. What were Parfit's insights around the topic of identity? Okay, so as I mentioned earlier, what he was interested in was what it was that makes us the same person over time. It sounds like a very abstract philosophical question, but actually it has quite deep consequences. I guess he had a few insights, but the first was that there was no essence of us. We were constantly changing. Our body was

changing. We were losing memories. We were gaining memories. There was no essence of us. We were constantly changing, our body was changing, we were losing memories, we were gaining memories. There was no essence of us. If you're a religious believer, then you believe in a soul, and you think that soul is immutable. So you've got an answer to what it is that makes a person the same person over time. They have the same soul. But if you are secular, if you reject the idea of a soul, then the question is, well, what is it that makes you you? And Parfit said, well, there's no essence of you. Another insight was that identity, and this was an idea that he kept returning to throughout his life.

He changed some of his views about identity, but this remained the same. Identity was not what mattered. What mattered was psychological continuity. So you, Sam, in 10 years' time, what matters, what should matter to you is whether you're psychologically continuous in 10 years' time to your current self. In other words, whether you have the same dispositions and the same memories and so on. He says identity is not what matters. He has these various puzzles to show that identity can't be what matters. He imagines that there's three brothers,

and one brother's body is dying. They move the two hemispheres of that brother's brain into the two different brothers. So hemisphere A goes into brother one, hemisphere B goes into brother two, and they both think they're the same. They still have exactly the same memories, exactly the same dispositions and so on. And the question is question is, which is the same brother? Which is identical to the first brother? It sounds sci-fi, as it were, but it's based on real-life cases. With epileptic patients, what they've done is they've cut the brain stem and they've created a divide between these two hemispheres of the brain. And what they found is that you get these two spheres of consciousness. I think there's one case where they found that the left hemisphere was kind of

religious and the right hemisphere was atheist or something like that. So you get these two streams of consciousness. So Parfit's question is, well, which is the original brother? Now, it seems arbitrary to say, well, one of them is original. Why would one of them be original and not the other? So that seems to make no sense. But you also can't say that they're both identical to the original, because they're going to both go on and have different lives, and then they'll have different memories, and they will marry different partners and so on. They can't be identical to each other.

But if they're not identical to each other, they can't be identical with the original brother because then they would all be identical with each other. So there's a case where we just don't know what to say about identity. Yeah, I think the clearer case for me is the teletransporter case, which is the... I've discussed this in various places before on the podcast, but people will be familiar with the concept, usually from Star Trek, where, you know, Beam Me Up, Scotty, is imagined to be a procedure where essentially all of the information in the atoms in the body gets read out and encoded and sent at the speed of light to a new pod where the body gets reassembled atom by atom and everything is perfectly intact and the person steps out of what Parfit called

the teletransporter pod on Mars, perfectly intact with all of his memories intact and his last memories of just pressing a button in the pod on Earth, and now he's stepping out onto the surface of Mars. And you can go back and forth from Mars to Earth like that a hundred times, and you see him none the worse for wear. But quite ingeniously, Parfit imagines a few different versions of this procedure, which change our intuitions, I think, fundamentally as to what's happening there. So in the first case, when you just get sort of disassembled and reassembled with all the information preserved, there is this sense that basically you, the person, have been, albeit in a strange and potentially scary way, have been successfully sent back and forth between

Earth and Mars, and you are still you. You remember everything about the process. You remember your life. You're not sick. You're not injured. Your spouse still recognizes you and finds you familiar. Everything's fine. But then Parfit asks us to imagine the version where there's a delay. I forget how he describes the reason for the delay, but do you want to jump in here? Well, yes. So what happens is he imagines that there's a copy of you on Mars, but you're talking to yourself. So there's you back on planet Earth, and there's the copy of you.

And you're about to talk to this copy, and then you're told that you, the person back on planet Earth, are about to implode and your life is about to end, and the copy of you will continue. And he's asking us, I guess, what our intuitions are in that case. And Parfit's intuitions are, you are as good as preserved. The fact that you are made up of a copy of you is irrelevant. You've got what matters. You've got psychological continuity. You've got everything that counts. And you may think that you should be very upset about this, and probably lots of people would be very upset about this, but Parfit's intuitions are not like that. Parfit thinks, you've as

good as survived. This is really what matters to you, that you have psychologically survived, that that person up there is connected to the person that had existed on planet Earth, and that's what you should care about. Except if you let the person on Earth live any appreciable amount of time, then their timelines begin to branch, and then you have to consider that person a different person. Well, exactly right. So that comes back to the twins example. If they're both operating together, and then Parffit wants to say well the copy is as good as you but then the question is well is it identical to you well

if it goes on often has a separate life and and has separate hobby hobbies and whilst you go fishing it goes to play chess clearly you two are different people but in a way that's that's two for the price of one as as far as Parfit is concerned. You know, you're psychologically continuous in two different people, and that's doubly good. Yeah, it's interesting. I think I land in a slightly different spot. I mean, when being transported is synonymous with being destroyed and reassembled, it just seems like a successful maintenance of psychological continuity without problem, right? But the moment there's a delay, and you first make the copy,

and then you destroy the original, that seems like a copying and a murder. And it's hard to see it otherwise. So Parfit changes his mind a little bit about this, but at least in reasons and persons, he thinks that the body itself is almost an irrelevant. So our cells are constantly dying and regenerating. If you cut off your nails, you're not changing your identity. If you lose a finger, you're not changing your identity. Your body, as it were, might hold your mind, but it's the mind that matters. And so at least in reasons and persons, he doesn't share your intuitions about that.

So he wants to say, you can call it murder if you want, it might feel like murder to you, but he's very happy to be there on Mars, continuing psychologically from the person that existed on planet Earth. So where does he change his opinion about it? Well, later on, he becomes more sympathetic to what's called animalism, which is the idea that we're organisms, but he never goes all the way. I think he comes to believe that it's still psychological continuity that matters, but psychological continuity has to sit within a kind of organism. So if you want to know what matters, well, it's still psychological continuity, but psychological continuity can only survive within an evolving organism. So it's a subtle difference. The main thing is that his big

claim that identity is not what matters persists throughout his life. And he continues to believe that it's psychological continuity that matters. And that has implications for how we should regard the past, how we should regard the future. So it has implications, for example, about whether we should hold somebody guilty for something they committed a long time ago and don't remember. It has implications for thinking about whether we should save for the future, because people do save for their pensions. They worry about what their lives are going to be like in 25, 30 years. They want to make sure that they're going to have a comfortable retirement. And if Parfit's arguments are right, then the gap between us and our future and our past becomes greater, and the gap between us and other people narrows. So we're more connected to other people and less connected to our past selves and our future selves.

Yeah, that's interesting. The variable of time here is fascinating. He has one thought experiment. I forget the title, perhaps you'll recall it, but it's the experiment where a person wakes up in the hospital and is told that they've either had a surgery or they will have a surgery in the next 24 hours. The nurse is unsure that she has to go check the chart. But if they had the surgery, they had a very long and painful variant of the surgery. And if there was some glitch and it was 10 hours of torture, and if they're going to have the surgery, normally it just takes an hour

and it's not all that bad. And so I'll be back in a second. Let me figure out which person you are. And so the person is left to wonder and worry whether he has already had a surgery, which he can't remember, or whether he will soon have a surgery. So this is like, this is on a Tuesday, say, so like, you can correct me if I've messed any of this up, but so if you wind back the clock, if you put the person at time zero before any of these surgeries, and you asked him, which would you rather have, a 10-hour botched surgery that is a harrowing ordeal, and then we give you a drug and you no longer remember it, or a much shorter normal want that thing that's far more benign. But if you tell me, well, the 10 hours might have happened yesterday, and the more benign surgery is going to happen

tomorrow, we have such a time bias with respect to past and future suffering, that the person is hoping he had the 10-hour ordeal yesterday and just can't remember it, rather than the more normal ordeal coming on the next day. And so what Parfit was suggesting is that you could be unbiased with respect to past and future suffering, and just recognize that the quality of your life is just the area under the curve of total experience, and you should just want less suffering under the curve in its entirety, and therefore, in this case, you should want to be the person who has the future surgery, not the past one. And he seemed to find it inscrutable that we are so strongly weighting our future suffering and so fully discounting suffering in the past.

Yeah, you've described that brilliantly. I mean, I've nothing more to add to it, really. You've described it exactly right. He says that almost everybody, if they're lying in that hospital bed, wondering about whether they are the patient who's had the terrible operation that lasted all night, or the patient who's about to have a short and painful operation in the next 24 hours, almost everybody will wish that they are the person who's already had- Who's already been tortured, yeah. Who's already been tortured. And he is puzzled by that and thinks that perhaps it would be more rational to prefer to be the person who is about to have the short and

painful operation. And towards the end of his life, time was something that really fascinated him. And he leaves behind sort of indications of what he wanted to work on. And we know one of the things he wanted to work on when he died was he wanted to work more on time. There were various issues he wanted to delve into more deeply. One was free will. He was fascinated by the topic of free will, and he was very suspicious that any of us had free will. He wanted to work more on that. He wanted to work more about time. He wanted to work more about something which he called the sublime experience and what it was to feel the sublime, which he thought was the opposite of pain. He wanted to go back and work a bit more on future people and so on. But had he lived a bit longer,

he died when he was only 74, had he lived longer, I think we'd have had more writings from Derek on the subject of time. So what was the non-identity problem? Gosh, okay. Well, I think the non-identity problem is brilliant. And once I explain it, it will seem so obvious to you that you'll wonder why on earth nobody had ever thought of it before and why it took Derek Parfit two millennia after the great kind of ancient Greek philosophers

to come up with it. How come no philosopher had ever thought of it before? So I should start with an example he starts with, which I think is a slightly awkward example, because it feels a bit sexist and classist somehow. But anyway, this is how Derek sets it up. He imagines that there's a 14-year-old girl, and she is wondering whether to have a child. Now, that might be bad for the 14-year-old girl. Let's put that issue to one side. We also think that it would be bad for the child, that if a child is born to a 14-year-old mother, that's a bad start for the child. And so it would be natural to try and persuade the 14-year-old girl to wait 10 years or 15 years or whatever before she has a child. And then the child would have a better start in life. I mean,

that's the natural intuition. But Derek points out something, as I say, that is bleeding obvious. If the 14-year-old girl has a child, so long as that child's life is not worse than nothing, that child won't regret being brought into the world. And if that 14-year-old girl waits for 10 years and has a child, she won't have the same child. She will have an entirely different child. And so the question is, well, if she has a child when she's 14, who has she harmed? It doesn't look like she's harmed anyone. She hasn't harmed the child who is born to the 14-year-old because that child's life is better than nothing. Now, normally, we think that morality must be about harming particular individuals. If I throw a stone at another human being and hurt that human being, I've done something wrong because I've hurt a particular human being.

If I just throw a stone on the ground and it doesn't hit anybody, I haven't harmed anybody, I've done nothing wrong. What's wrong is when you harm a particular individual. That seems to be the basis of morality. But Parfit spotted that there are lots of areas where it looks like we've done something wrong, and in this case, the 14-year-old girl having a child, where nobody is harmed. And he then extrapolates that to a whole series of policies. So for example, think about climate change. If we did nothing about climate change, then several generations, well, in fact, probably not several generations, probably only two generations down the line, we're already feeding the effects of climate change, but two or three generations down

the line, people are going to have very bad lives. There's going to be hurricanes, there's going to be typhoons, there's going to be droughts, there's going to be mass migration. The world is not going to be a happy place. But let's assume that although it's not a very happy place, those lives are still better than nothing. Now let's assume that we did something about climate change. For example, let's say we did something drastic. Let's say we said people could only drive on Mondays and Wednesdays and Saturdays, or people couldn't fly planes. Now, if we did something drastic like that, that would affect who was born. Each of us is a product of a unique sperm and a unique egg. product of a unique sperm and a unique egg. And if my mother had come home late on a particular day, or my father had been delayed for some reason, I wouldn't be here to talk to you today. I'm the product of a kind of unique union of sperm and egg at a unique time. If you did something drastic,

like you stop cars, then you would change who exists I mean and the way Derek says puts it is imagine that trains had never existed which of us would still be alive today none of us would still be alive today because our lives have all been changed by the invention of the train

I can't remember if you do this in the book or not but I feel like you or someone imagined whether we would all exist if Hitler hadn't existed, right? How fully can we regret Hitler if half the world would be people by different people? Yeah, I had a very annoying review of the book where the reviewer just didn't understand the point. And I made exact the point that you made that I, I wouldn't exist if Hitler didn't exist. And she said, well, your mum and dad, she wrote in the review, might still have met each other. It's absurd. I am actually the product of two Jewish refugees. They would work not for Hitler. They would not

have arrived in England. They would not have met each other. There was no way I would exist if Hitler hadn't existed. But that's true of almost everybody. I mean, he changes the whole world. So you wouldn't exist if Hitler hadn't existed. Nobody would exist if Hitler hadn't existed because he changes the world. And actually, that raises interesting questions, which maybe we shouldn't go into, but it raises interesting questions about reparations and so on.

go into, but it raises questions about reparations and so on. Because, you know, Hitler did obviously very bad things, but I owe Hitler my life, as it were. So one has a complicated relationship with the past when one begins to think of it like that. Yeah. But back to the case Parfit's making here. What is inscrutable about this, as you said, we have this intuition that for something to be wrong, there has to be a victim. And the idea that there's a category of crime called a victimless crime has seemed to many of us to be just a logical contradiction, and yet here Parfit is exposing these cases where there are better and worse options, and yet they're better and worse for no existing people because the people are different. Exactly. There's no one person for whom they are better or worse. But nonetheless, we can still make the judgment that if we do nothing about climate change, we've done something very bad. We can still make the judgment that the 14-year-old girl has made a mistake by having a child at 14 rather than delaying becoming a mother. other. So the way he does that, and it's very easy with same number, what he calls same number

cases, if you've got a choice between a person born at X time and a different person Y, then the way to judge whether you should bring X or Y into the world is, well, who has the better life? So the reason why we should do something about climate change, let's assume that if we got rid of cars and planes, it would help a great deal. But let's make the absurd assumption that it wouldn't affect the numbers of people being born. On that absurd assumption, the reason why it would be a good thing to do is because two or three generations down the line, the people who would exist will be better off than the people who otherwise would have existed had we done nothing about climate change. And that's how he solves the conundrum. Ray's identity is not what matters to slightly different use here. It's just that the identities of the people isn't what is relevant for the moral calculus. It's just the fact that there are people in each case, and in one case, the people are much better off. Yeah, yeah.

And I think both in his arguments about personal identity and in his arguments about future people, about personal identity and his arguments about future people, he converges on a kind of consequentialist conclusion, which is, it's the consequences that matter. We should prefer the better consequences rather than the less bad consequences. In the case of personal identity, because my future self has become less like me, as it were, than we thought, we should be more interested in the lives of others. That's a consequentialist conclusion. When it comes to future people, we should prefer the outcome in which the people are better off. That's another consequentialist conclusion. So lots of his arguments, although he comes at them from very different angles, have very similar

conclusions. Yeah, there's something very Buddhist about him. I don't know that he was ever aware of how reminiscent of Buddhism much of his reasoning is, but it's, you know, yeah, it's... He was, he was. There's an appendix, actually, in Reasons and Persons where he draws a connection

between his views on personal identity and his views on the self. And there's an anecdote in the book about how a philosopher goes to Tibet, I think, or North India, and somehow they get a copy of it. They're talking about personal identity and the connection between Derek's views and Buddhist views, and they give a copy of Reasons and Persons to this Buddhist monk. The monks in Dharamsala, I think.

Yes, yes, yes. And then later on, the philosopher goes back and he discovers that the monks are reciting or chanting extracts of reasons and persons. Yeah, I'd forgotten that. Yeah, that's a fantastic story. Okay, so let's talk about population ethics as it's now called, and the repugnant conclusion, which was the, again, one of these found objects of philosophy that he drove to on the basis of a very clever thought experiment, which it's very hard to think about. It does seem, in some sense, destructive of the whole enterprise of doing population ethics in a consequentialist way. Let's just describe it. What is the repugnant conclusion? Right. Well, some of the arguments to get there are quite complicated, and it helps to be able to draw diagrams, which we can't do in a podcast. But I'll tell you what the repugnant conclusion is. The repugnant conclusion is Parfit's claim that for any set of people, let's say there are, imagine there are 8 billion people on the planet who have, all of them, very happy lives. For any set of people like that, there must be a set of people much, much larger than that, maybe

trillions of people whose lives are barely worth living. They're just better than nothing. And that outcome is better than the outcome where there are 8 billion very happy lives. Now that seems an absurd conclusion. Parfitt called it the repugnant conclusion. He felt it couldn't possibly be right because it's so counterintuitive. And yet, he thought that there were arguments which suggested that it was the right conclusion to draw. And to the end of his life, he was trying to find a solution to the repugnant conclusion, trying to find a way out of reaching the repugnant conclusion. But that find a way out of reaching the repugnant conclusion.

But that's what it was. It was that for any set of people, there must be a much greater number of people whose lives are barely worth living, which is a better outcome than the first set of people whose lives are very well worthwhile. I think that we can get people there without diagrams, although those diagrams in the book are surely helpful. But if you just imagine, if you imagine a billion people who are more or less perfectly happy, you know, that's one circumstance. And just imagine adding some more people who are not exactly as happy as the first billion, but they're still remarkably happy, far happier than any average population on Earth today. Surely that is, if moral value is in any way additive, right, if more is better in any sense, well then surely more good lives is better than the first

billion. Or at least, if I can just interrupt, at least it's not worse. It seems like you can't say that if you add a few happy lives, even if they're not as happy as the lives that already exist, if you add a few happy lives, you can't be making the universe worse. Maybe you're not making it better, but you're not making it worse. But you carry on. You're doing a very good job. I think I would push it a little further than that. I think most people will recognize it to be obviously better because then if you don't recognize that, then you seem to be saying that the average is the most important principle. And so let's just rule this out in advance.

So many people might be tempted to think that what we really care about is the average happiness. But if average is what concerned us, then a world in which there's one perfectly happy person and billions upon billions of extraordinarily happy people, but they're just not perfectly happy, well, those billions have brought down the average. So it would be better just to have a world with one perfectly happy person, and all those billions of wonderful lives can be annihilated to the advantage of the universe. That seems crazy. Yeah, and you can also do it the other way around as well. I mean, the average view is bonkers, because the other way around, the flip side of that is you can imagine

that there are a billion people whose lives are totally miserable, who are tortured the whole time. And then you imagine that you bring in another person who's tortured only six days of the week, and the other day kind of scraps around. Well, according to the average view, you've improved the universe by bringing in this really horrible life, because you've increased the average. That's obviously nuts. I mean, so the average view makes no sense at all. Right. Okay.

Back to you. Okay. So now we're adding people. So we started with the perfectly happy people and now we're adding billions upon billions of, again, extraordinarily happy people. I mean, the happiest person you have ever met on the happiest day. If you'd like to continue listening to this conversation, you'll need to subscribe at SamHarris.org.

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