 Good afternoon. So today we moved to a different part of the forest to personal identity for the next couple of weeks, the identity of itself. So the reading for today was locks of identity and diversity. If you looked at that, was it easy or difficult? Easy? So hard, yeah. It is hard. Today, I'll just try to highlight what I take to be Locke's main point. I hope that will make it easier if you have another look at it. It is hard. But OK, on Thursday, we'll look at an easier piece. Bernard Williams' The Self and the Future is really a response to Locke, The Self and the Future. So let's start out by looking at what I think is one of Locke's most famous examples. The Prince and the Cobbler. The whole, there has been an enormous amount written in the last 300 years since Locke about personal identity. And in analytic philosophy, it's all driven by just two examples. One of them we'll look at next week, which is the example of fission. The other example, just these two examples driving thousands and thousands of pages in the last 300 years, is this example of the Prince and the Cobbler. Now, Locke's main point in the reading is you are not human, or perhaps more precisely, you are not a human being. Can you put up your hand if you think that sounds fair enough? If you think that sounds like the wrong view? Does that sound like the wrong view? You are not human? Yes? That sounds like the wrong view. Yeah, if you think, well, it might go one way or it might go the other. OK. OK. I actually think Locke is completely correct about this. He's got this example, the example of the Prince and the Cobbler. And here it is. You are to imagine, imagine if you will, a humble Cobbler. An industrious chap, worked hard all his life, difficult background, takes time off in the tavern, never has quiet enough to eat, perhaps a wooden leg. And on the other hand, a Prince living in a castle on the hill. And one morning, the Cobbler wakes up with his memories of a drunken night in the tavern the night before, wondering where his last is, wondering where his tools are, in a magnificent bed surrounded by servants. Locke says, should the soul of a Prince, carrying with it the consciousness of the Prince's past life, so down in the gutter, there is an irate figure rising up. He looks just like the old Cobbler, but he is shouting for his servants and wanting his tea to be brought in. The soul of a Prince, carrying with it the consciousness of the Prince's past life, should that enter and inform the body of a Cobbler, that body being as soon deserted by the Cobbler's own soul, which is meantime fled to the body of the Prince. Everyone sees he would be the same person with the Prince. That is, that figure in the gutter is now getting up and looking for his servants and demanding his tea. That's the Prince, right? It's the Cobbler who's waking up in the bed on the hill. That could happen, yes? I don't see it happens often, but if that happened, if you woke up in a different body with all your memories, all your awareness of your past life, that would still be you. That would still be the same person. You'd just have swapped bodies. But I mean, I take it this is not the first time you've heard this kind of idea. I mean, I was actually looking this up. There are a ton of novels, short stories, movies. Mostly this century about using that idea in one form or another, the idea of a body swap. I was looking for the most recent example. The most recent example I could find was the story of Yamada Kun and the Seven Witches. This is on the right, this class delinquent, the school delinquent. As you can see from the blue hair, this is a very bad boy. This is the head girl, the brainiest girl in the school. And they discover they have the ability to swap bodies. This came out last year. So this is not just abstract philosophical speculation. You find this in real life, too, in manga comics. OK, so Lux's point is you can make sense of that. You can make sense of a body swap. Everyone sees that that figure waking up in the gutter would be the same person with the prince, right? If the prince, yep, I mean, the body in the gutter, right? If you're pointing to the body in the gutter, that's the prince. Is that what you're saying? No? The body that used to belong to the prince has now been inhabited by the cobbler, yeah? They would see that as the cobbler until he began to speak. They might say you're lying, but they could test him. After all, he knows everything there is to know about the prince's past life. He was there, yeah? Yes? It's not possible. Well, actually, I think it's early days, but I have read scientific articles about head transplantations. Yeah, that's transplanted. And there was a monkey, actually, it's about 30 years ago, which had the head of another monkey transplanted onto it to the extent that it could even bite the researchers. It was functional. It didn't last very long, but it had a few days. I think you'd be very hard-puted to say, it's going to be scientifically impossible. We'll come on to this in a minute, actually, the thing about scientific possibility. But I don't know, I mean, I used to think that when someone first told me about FaceTime on an iPhone, I said, come on. That can't really happen. That's right. It's still the same person if you've got half the torso. That's right. Good, that's exactly what Locke is saying. I mean, if you ampute, you could think of it as like this. You do a kind of limiting case of amputation on the cobbler. You amputate the entire body, leaving only the brain. And then you do a similar complete amputation on the prints, leaving only the brain. And now you think, boy, these guys need bodies, and you just swap around the bodies. There you go. That's what Locke is saying. But notice that, OK, so that's clear. The prince has woken up in the cobbler's body. The cobbler has woken up in the prince's body. But the prince is now waking up in the gutter. Is that the same human being as we had? Human being is a biological term. Human beings are biological organisms. It's perfectly clear that the thing in the gutter is the same human being, the same biological organism that was there last night. The biological organism that was there in the prince's bed was there all through the night. So if bodies swaps are possible for you, if it even makes sense, then you are not the same thing as the human being. It could be the same human being, but a different person. Different person, same human being. Yep. Right, but they're not the same humans. That's the point, yeah? So the sameness of the person is not the same thing as sameness of the human. I mean, human beings can't swap bodies. That makes no sense. You see what I mean? It's like saying, here I have two pieces of paper. Now just swap them around, right? That makes no sense. You kind of want a bit of paper to happen to you. No, there's a notion of the same biological organism that would apply to an amoeba, or a frog, or a fox, or a mothly. There's that notion of same biological organism. And in that sense of same biological organism, it's been the same biological organism in the prince's bed all the way through the night. It's been the same biological organism in the gutter all the way through the night. But nonetheless, the people have swapped over. So the people can't be the same thing as the human beings. Yeah? Absolutely. When you said originally or in response to his point, you said that you have amputated out the brain and swapped them, which means they're not the same human. The biology did change, really, kind of a lot. Very good. OK, yeah. Well, a couple of things here. I actually want to come on to brain transplants in just a minute. But one thing is, the way a lot puts it initially is certainly in terms of souls, right? Should the soul of a prince carrying with it consciousness of the prince's past life? So the picture, the way he puts it initially, is these souls are swapping over. Yeah? And that is the natural idea. But what makes Locke's discussion not just interesting, but great, is the way that he immediately goes on to say, but sameness or difference of soul is not the key thing. Even suppose there are souls, that's not important. Because if people can swap bodies, they could swap souls, too. If I've got a bit of ectoplasm here, carrying the mental life of the prince, and a bit of ectoplasm here, carrying the mental life of the cobbler, these two could swap over. So if you could have body swaps, you could have soul swaps. Yeah? Here's Locke. I have met, as I once met with one, who has persuaded his had been the soul of Socrates. How reasonably I will not dispute? For this I know that in the post he filled, which was no inconsiderable one, this is presumably the prime minister or the king or something like that. He passed for a very rational man, and the press has shown he wanted not parts of learning, but he said, yeah, my soul is the same one as Socrates. But Locke's point is, would anyone say that he not being conscious of any of Socrates' actions or thoughts could be the same person with Socrates? I mean, maybe you do have a soul. Maybe it's been reused hundreds, thousands of times in the course of human history. Maybe your soul was one. I mean, it might be good ecologic. It might be good ecology, right? I mean, you know, just throw away a soul when you're done with it. You know, you wipe it out and give it to you person, right? That could happen. Well, yeah, except reincarnation usually means it's the same person, yeah? But Locke's point is, for it to be the same person, there would have to be some consciousness of that past life. If I'm going to say I was once an Egyptian prince, of course I have no recollection of it at all, but that makes no sense, right? Locke's saying the key thing is not which substance it is. Is it the same biological organism or the same soul? The important thing is if a mental life switches round, yeah? And then we have to go on and look at what that means. So that's a basic prince and cobbler setup, yeah? That's right. He has no awareness of Socrates' past life, yeah? That's what means he's not the same person. So, as came up already, brain transplants are a very common idea in fiction. If you look in the web, there are about a million pictures of brain transplants. This is from one that took place on Mars, as you can see, it's usual for the surgeons to strip to the West. So, suppose your brain is taken from your body, right? I suppose that, I don't know, maybe it doesn't happen this way right now, but suppose that all the jack plugs connecting your brain to your body, suppose they are all pulled out and the top of someone else's head is cut off, their brain carefully taken out and your brain put in there, right? That's the scenario, yeah? I mean, there are different ways to think about this. You could think, well, as the years go on, as life takes its toll on you, a doctor might give you bad news, like your kidney just won't take the kind of pounding it's been getting. You need a transplant, but hey, that's great. We've got a donor, right? That is good news, yes? Yes? If you're told your liver can't handle the kind of pounding you give it, but that's okay, we've got a donor. That is good news, yeah? But suppose that one day, later in your undergraduate career, the doctor says to you, you've been doing too much philosophy. Your brain won't handle it anymore. But that's okay, we've got a donor. Is that good news? I mean, you would feel more than usual apprehension on being told that they'd found a donor there, right? Because the natural worry is that it's not that your life has been saved. Your body has been taken over by someone else who is using your body as a host. Right? That's the situation. Now, the thing is, the brain is just an organ of the body. I mean, the kidney is an organ, the liver is an organ, the heart is an organ. The brain is just another organ. So when you transplant an organ, it's still the same human being, yeah? So if you're getting your kidney, it's the same human being. If you're getting your brain, it's the same human being. But the natural concern is it wouldn't be the same person. Person and human being are different things. So if A's brain was put into B's body, right? The top of it, B's head is opened. A's brain is popped in. Who is the resulting person? Pick your hands up. I'm keeping track of A's and B's here. So A's brain is put into B's body. And then the resulting person moves and talks. Is that person A or is it B? Can you pick your hand up if you think it's A? And if you think it's B, okay, overwhelmingly A, right? I mean, it's not overwhelming. Nobody said B, right? Then you say B, nope. All right, so it's got to be A. So the person is not the same thing as the human being, right? Right? That's the conclusion, yes? Uh-huh. That's right, you take A's arm, you put it on B, yeah. Okay, but it's still a material thing, yeah. Isn't that right? I mean, suppose the doctor said to you, well, you're probably indifferent to quoting case, but suppose the doctor said to you, forget all those exercises you've been doing, right? You don't need to do those tedious gym exercises anymore. No more bending and stretching. We can just pop you into a brand new body. I'd do that in a moment, right? I don't find that difficult at all. If you're wondering who the resulting person is, right, suppose that you're A's sibling, yep. And you're saying, is this really A? You can ask A anything you like about the good old days. Yeah, but sorry, A's brain was put into B's body, right? So you're asking, you're saying to this thing, do you remember the good old days when you and I played games by the fireside with the old spot, yeah? And this thing says, yes, of course, and don't you remember? That was when Nanny fell off the tree, yeah, right? You see what I mean? You're getting all the right answers. You're gonna say, that's not your brother? Anyway, look, we'd be saying, yeah, don't do that soul slash personality. There's no slash here. There's a soul as one thing and the personality as another. You see what I mean? Well, the difference is that persons can swap bodies, whereas it makes no sense to say, I've got the same human being but a different body. The human being in the body, that's the same thing. Yes, right, still the same human being. If you've got an organ transplant, yes, of course. Yeah, you've got somebody else's heart. Look, if you take a dog, right, suppose you're told poor old Rover's just about had it, right? The heart's going and they say, but we've got this fantastically expensive operation. Yeah, you can get, if you want to, you can give Rover a heart transplant. Well, and you do it. Then if some philosopher comes up and tells you that's not Rover, it's got a different heart. How could that be Rover? That's not right, that is Rover. That's just Rover with a new heart. Dog being. Okay. Dog being, I see, it's the same human but not the same human being, right? All right, these are subtle distinctions. What you'd care about with Rover is, is it the same dog or did they just scour the streets and get me one that looked like Rover? Yeah, but if they actually popped a heart into Rover's body, that's the same dog. And in that sense of same dog, same biological organism. In this kind of case when you've got a brain transplant, it's the same biological organism. Yeah, agreed with a different organ, but it's the same biological organism. No, no, I'm saying it's still the same person if it's a different organ besides the brain. And the same human being if it's any organ at all. That's exactly right. If you switch the brains, it's the same human being but a different person. If that brain gets popped into a different body, then that's the same person, that's the same human being lying there but it'll be a different body, a different person, sorry. I didn't do that very well. Sorry? Yeah, Locke has this notion of it's the same continued life. If you think what makes a tree at one time the same thing as a tree at a later time is not that it's the same cells because the cells of the tree are constantly dying and being replenished, yeah? But look at this notion of the same continued life. And similarly with a colt growing to a horse that the cells are constantly changing but there is a single organized continuing life here and that's what makes it the same biological organism. And the same thing is true of people. I mean, is that right that all the cells in your nose are replaced once every seven years? When I was in high school, people always said that. But, sorry? Is that right? It's just not true. Even faster, okay. It's not true. Okay, well. It's so hard to know what to think with, yeah, yeah. Yes, yes. Well, I'm trying to articulate what common sense says, yeah. Yes, that's right, we do see human being and we know what people are. Right, and we know that they're different. If what, sorry? If you sort out the heart, that's right. Nobody would say it's a different human being, yeah. I agree, yeah. Yes. Yes, all the sense detectors. All of the sensors. That's right, yeah. The sense detectors. It's because of your sense detector, yeah. I have a 20-20 vision with eyes that are really strong. Very good, yes, yes. Drop the bottle. Yes. Well, the experiences would be different. I agree. If you've got a different kind of nose and so on then the experiences are going to be different. You're going to say, I smell much better than I used to. If you see what I mean. Well, I don't smell as good as I used to or whatever. But the thing is, how should I put this? The river of this stream of consciousness into which all these things are being fed is the same old one. What I mean is, if I smell a rose right now, yeah, then I will be saying, in the new body, then I will be saying, that reminds me of that day so long ago in Florence, yeah, I will be integrating that experience with experiences that were had by the person in the old body. So the significance of all those experiences that you're having are going to be being interpreted in terms of the old mental life. Locke is saying, yeah, that's very good. Actually, there's another question. But I want to suggest a way of getting at what you just said, that's very good. It's not the brain, really, it's the memories that's the important thing. That's your point? Yeah. I think that's very important. And I'll come back to that. OK, well, let me say one more thing. And then. I agree with what you're saying. That's not going to change. So I say, and Locke says, the resulting person in the brain transplant case is the good memory experience of A's past life, but not a B's. Another resulting person is A, right? Identity goes with memory. Suppose you try this. Suppose that in a few years, and this is trying to bring out that thing about memory in the brain, suppose that in a few years what happens when they're doing brain surgery is they make a backup of what's on your brain. If you've got a tumor in your brain and they're trying to remove the tumor, then something might go wrong. I mean, the disk might crash as it were. So these people take the precaution of backing up all your brain onto a computer disk. And suppose that while they were removing the tumor from your brain, there was indeed an accident. And all the information on your brain is deleted. And they say, but that's OK. We backed up. And then they restore your brain with all that stored information. That would be fine, right? That would still be you. Your family would still say, is dear old Bill got his dear old sally? Yeah, they wouldn't reject you because this had happened. It would still be the same person. Yeah? If something had gone wrong during the thing, and then you'd been backed up from the computer file. Well, now suppose, yep. Ah, all right. That's right, backing up a hard drive, exactly. Very good, it's not the same hard drive. That's right. That's right. Everything you say that I completely agree with. That's like saying it's not the same human being. Locke's picture is the files in the cobbler's disk, as it were, are moved to the prints. The files in the prince's brain are moved to the cobbler. Your point is it's not the same hard drive. That's like saying it's not the same human. Sorry? The picture here is, we do a while. Maybe this is out of date, but I all the time talk about moving files from one folder to another, moving files from one disk to another. Not copying, moving that particular file. So it's not that I'm some kind of dualist about files, and I think they're made of ectoplasm or something. It's just that this is a very abstract kind of way to describe. It's something that's purely physical. But there's something kind of abstract about it. It's a configuration, something like that. And that's what you can move from place to place. And Locke is saying, person is like that. It's an abstract notion like that. So the physical realization is in a human being or in a hard disk. But the identity of the hard disk is different to the identity of the file or the person. One, two. Does this? It's only memory that makes a person. Yeah. That's exactly what Locke is saying. Someone with Alzheimer's or dementia is no longer the same person. Yeah. And that is a very harsh result, I agree. I mean, once you find out the situation with someone, people do not say, that thing there's not granny. There's not what people say. That's not what the law says. They say it's still the same person. But I guess Locke's answer would be something like, it's the same human being. And they get respect and dignity in their treatment by courtesy of having once been that person. Yeah. But you're right. It's a really difficult point, that. Yeah. OK. OK. Right. Yeah. Yes. Very good. If you completely lost memories of your earlier self, yeah, of a 20-year-old self, say, then so far as I can see, the view is implying that. Yeah. Well, just one day, if you're fast. Yeah, it shouldn't do. But in Locke's picture, it seems to. I'll come on to it. I will try to deal with that kind of point in more detail in a moment. But you'll see in a moment, I'll put some quotes up from Locke. He seems to be seeing exactly what you're afraid of. If you lose memory of a particular day, then you are not the person that was there. Yeah. But I think there are ways of addressing that within Locke's spirit. Yeah. Was there someone who hadn't asked a question? Last one. Yeah. Well, that's right. That traumatic day two years ago that you can't recall now. But everything about you, personality-wise, is different since then. Yeah. Yeah. That too, that's like the Alzheimer's. That is another important case. Yeah. But it is also a problem for this kind of picture. I said last one. But OK, let's be, yeah. It's possible to change a person? Well, yeah, that was my next slide, actually. Suppose that what's happening is that your information has been stored in the hard drive, and they're doing the operation. And then B, then there's a terrible mistake. All your information gets backed up onto B. It's restored onto B's brain, still in B's body. Then, well, I mean, what do you think? The resulting person, presumably, would be you. Yeah? You just die, let's suppose. I mean, your body, your brain is lost. And then they say, oh, here's B. We don't care about B. Let's just write over. Yeah? You just overwrite your data onto B's brain. Who's woken up? You or B? You, yeah, yeah. OK, one, two. Yes? Yeah, that's right. But you're the same person, even though you've gone through changes. Not for the first time, you guys, are anticipating everything I want to say. I will show you a picture of a car accident in a minute. But I think something of what you're saying, though, is a good way of bringing out why memory is a natural thing to fasten onto here. Because people's personality does change radically, right? Someone meets you and says, boy, I remember you when I first met you 30 years ago. I mean, imagine this happening in the future. And you're saying, well, yeah, you used to be so mellow and generous. And now you're a bitter, twisted, resentful individual, obsessed with thoughts of revenge. Nothing onto biographical in this, I assure you. So you're right that everything about a person's personality can change. And in that kind of case, you'd say lightly, oh, he's just a completely different person. Yeah, just a complete. But you don't really mean that. It's still him, right? Whereas if the memory goes, the actual memories of the past life, if that's all been wiped clean, then you're much more likely to say, but that's not even him anymore. Oh, sorry, I'm sorry. You were first, yeah. Just regarding memory? Well, what are your future opinions? They won't come from memory, presumably. I mean, or at any rate, they won't be the same thing as your memories, yeah? Is it saying that like? Yeah, at the moment, I'm just using this in a very generic way, yeah. But I think when Locke certainly is trying to make precise what Locke is after, it means memories relating to particular episodes in your past life, yeah. Yeah, yeah. Consciousness is generated from more than memory. Sure it is, yeah. Someone was saying this perception, for example. That is a possible view, yeah. That would say the prince and the cobbler didn't swap bodies. The prince has got all the cobbler's memories. I'm not being very precise at the moment in the way I'm using either consciousness or memory. I will try and make that more specific in a second. But the way Locke is using consciousness, it seems to mean memory of particular past events. But we'll come on to that in a second, yeah. Yes, yeah, memories. That's right. There's a mental life as a whole, which will include things like personality, mood, current perception, and then there's specifically memory. And Locke is really, when Locke's saying consciousness in this context, he really seems to mean memory of reaching to the past life from the inside. Remembering what it was like in there back then, yeah. OK, this is really the last one, yeah. Yes. Your friends or something between life, which is why they can't remember it? Very good, yeah. Very early on. On this view, when you're a young infant and not laying down memories at all, you are not a person. You are a human being, but you're not a person at all. And there's some basis for that. You don't have rights, for example, or at any rate, you have a limited amount of rights. But we don't let infants decide for themselves what they do. We say, we know better. We literally are paternalistic about them. We say, we'll tell you what's best for you. That is what you do to infants. Yeah, they can't know physical capability. Right, and they have no idea what's best for them anyway. Right. Yeah. I'm just going to say that when you actually agree on that. Yeah. You could really argue that. Yeah, we need to get more specific about what we mean here. But you guys are, I mean, this is a very valuable set of discussions, because you are anticipating a lot of big points here. But OK, let's just go back to this case. If the brain is, if the information from your brain is restored onto someone else's brain, then you have survived, right? That's a lot of claim. Does that make sense? If you have the memory experience, if the person that makes it through the operation has all the memories of your past life, then that's you, not the other guy. That's pretty enough at this point. Yeah. So you see why Locke is saying you are not a human being. You are not the same thing as the human being. Yeah. Can you think your hand up? That's a pretty persuasive case that you are not the same thing as the human being. Yes? No? Aha. Locke did pretty well on that one. OK. So the general point is sameness of person doesn't depend on sameness of body or sameness of brain. It only depends on consciousness of the past person. So if you think of what does it take for a later person to be the same one as an earlier person, all it takes is for memories to link the later person to the earlier person. If you've got memories linking the later person to the earlier person, then that constitutes sameness of person. You don't need a physical body or a soul linking the two of them. You just need the memories, and then you've got the same person. That's the idea. Here's Locke again. Since consciousness always accompanies thinking, and is that which makes everyone to be what he calls self, and thereby distinguishes himself from all other thinking beings, in this alone consists personal identity, i.e. the sameness of a rational being. As far as this consciousness can be extended backwards to any past action or thought, so far reaches the identity of that person. It is the same self now it was then, and is by the same self with this present one that now reflects on it that that action was done. So if an action was done in the past, then you are the same person as the person who did that action if your consciousness reaches back to that action. If you remember that from the inside, that's the view. You've got to be able to reach back and remember it from the inside to be the same person. And if you can do that, then it is the same person. How people interact with you will be presumably very different after that kind of operation. You'll be famous for presumably. You might start to believe that you're not that person, but you would be, yeah? Well, you'd be conscious of being that person and in the sense that you had all your memories, yeah? And you might say something like, I'm not Bill, yeah? But so long as your memory reached back to everything that Bill had seen and done, then you'd actually be Bill. Let him once find himself conscious of any of the actions of Nestor. He then finds himself the same person with Nestor. Nestor being a classical hero, I think. Nestor? I used to know who Nestor was. Yes? It's a different body. That's right. Well, that's one view. That's not what Locke says. Consciousness here, remember, means what can be extended backwards to any past action? Yes, that's right. You weren't scooped out because if you sold into the memories to start with, then it wasn't you. If there weren't those memories, it wouldn't be you. The identity goes with the memories, not with any soul or with any biological organism. That's right. The memory of the past experience is necessarily insufficient. Messi's mind doesn't germ his body, yes, right? Yes? That's right. That's very good, yeah. But you don't realize this, but I have to tell you, life's like that, right? You find that your knees are just not what they were. You find that you still think, yeah, I'm the best soccer player, but no, the old knees just can't do it anymore. That doesn't mean you're a different person. He remembers he used his foot to kick that ball, and it's not him, but he's got all the memories. He knows how to play it. He can't tell you, oh, I remember. From this angle, you need to play it, and it doesn't work. Yeah, look, at the broadest level, I agree with you that philosophers tend to be cerebral types, right? So they naturally tend to emphasize very much how important the brain part of you is to who you are, yeah? Whereas if you think about someone who's a great football player or a great pianist or something like that, you know, someone for whom these physical things are really key, and then you're told, well, you could have a brain transplant, you could be put into a new body, not to worry, then it's not going to seem at all reassuring. But the thing is, I mean, that these physical changes, kinds of physical changes, can happen to a pianist or a football player, anyhow. You see what I mean? You get the arthritis, your fingers just won't do it. Yeah, it's still the same person. I mean, if you made a lot of money playing a whole bunch of stuff earlier in life, you don't get that money taken away from you when you can't play anymore because Zabel is not the same person. You see what I mean? Isn't that right? On the broadest level, I agree with you about the emphasis, yeah, but I think that would be Locke's first pass, response. Okay, there's such a stack of questions. Okay, we may have to spread this over two sessions because I find this very valuable and I don't want to cut it off. I tell you what, let me get to the end of this section, let me just read out some Locke to you and then we'll pause for questions, okay? Okay, so let it, actually, yeah. Had I the same consciousness that I saw the arc and nose flood as that I saw an overflowing of the Thames last winter or as that I write now, I could no more doubt that I who write this now that saw the Thames overflowed last winter and that viewed the flood at the General Deluge. The flood and nose arc, presumably, having happened a very long time ago, like thousands of years or something, that was the same self place, that was the same self place that self in what substance you please. And by substance here, he means like some concrete thing, like a biological body or like a soul or a brain or anything else. It doesn't matter what the biological body or the soul or the brain was. So long as the consciousness is reaching back to that past time, then it's the same self as the self that was there at the past time. It's the same person as the person that was there at the past time. That's what it takes. And sameness of the concrete thing is not important. As far as this consciousness can be extended backward to any past action or thought, so far reaches the identity of that person. That's where you can track the identity of yourself by what you can extend your consciousness back to in memory. You can do that. It is the same self now that it was then. It being the same consciousness that makes a man be himself to himself, personal identity, the identity of the person depends only on sameness of consciousness. That is reaching back in time to what was seen and done earlier. Whether it be annexed to only one individual substance, whether it be annexed to only one body or one bit of ectoplasm or one brain or whatever, or can be continued in a succession of several substances. So the identity of the person comes free is a different thing to the identity of any one individual. Okay. Right. Okay, just a minute. Put up your hand if you've got a question. Are you having a question? Yeah, one, two, three. Yeah. Yeah, what about? I'm going to talk about, yeah. Okay, I'm going to talk about memory much more. Yeah. So according to Locke... Well, come back. Do you have two? Sorry? Do you have two? No. Say that again. I don't understand. Do you have that information where they be the same person? That is a real puzzle for Locke. It's one that he didn't think of. Yeah. And that is actually the second... I said fusion was our second great puzzle case about personal identity. That is the second great puzzle case that we'll come to next week. Yeah. So sorry to put you off, but I really don't want to try to give a sign by doing that. But yeah, that is a real hard question. Yeah. Yeah. Because going back to the exam, we still have the person sort of... I have a teammate who, he was a rower, a really good rower. Yes. And then he got in a really terrible bike accident and now he's a quadriplegic. And so initially I was like, yeah, like when that happened to him, like he was a totally changed person, like and he wasn't the same. But I think upon further reflection, he's the same person, but that person is just different. That's right. And I think that's a really hard distinction to make when we're talking about all of this. But I think that this is totally true and that it'll still be the same person even if you go, even if you are different. Yeah. I mean, these are really terrible cases that you're describing. But a simple way to check, to get a reality check on the distinction is to think about, suppose this person owed you money before, do they owe you money afterwards? If you owed them money before, do you owe them money afterwards? If they owned property before, does that person still own it afterwards? If they had pension rights before, if they had a family, you know, if you just think about the grounding and these kind of simple commonplace things, like if they were an American citizen before, is this an American citizen now? Do you see what I mean? If you think of this just as grounded in these kind of basic things about contracts and responsibilities and so on, then it really gives you a reality check. And I think in your case, that is a terrible accident you're describing, but it's clearly the same person once you think of it in that framework of rights and responsibilities. Yeah. Okay. Okay, memory. So just to talk a little bit about what's meant by memory here. What kind of memory are we talking about? So the basic point Locke's making, it seems to me is, it's, I hope this is, if this slide isn't abundantly clear, then do pause me right now. I know we've had a lot of questions, but for everyone in the room, this slide should make perfect sense. So the general point here is that transfer of memories between the body of the prince and the body of the cobbler means the people of swapped bodies. And it's not a point about souls, because even if you had souls here, transfer of memories between the soul of the prince and the soul of the cobbler would mean that the people had swapped souls. Yeah. Identity doesn't go with body or soul, it goes with memory. Yep. Can I disagree? You can certainly disagree, yeah. But the important question is, is it clear what it's saying? Yeah. Okay, right. Memories what? Our soul. Our soul? Create soul. Memories create souls. I think there's no distinction. I'm going to come on to exactly what kind of memories we're talking about in a second. Yeah. So are you talking about like years ago? Yes, absolutely. So we're not talking about it at the time? Experience, that nice to the two years ago didn't print your brain. I don't really, there isn't really a contrast there. Yes, that's like that example of that traumatic day two years ago that you can't now remember at all, but left you a broken man, let's suppose, right? Yeah, so the question earlier was, might not that kind of connection be important for memory, for identity too? Yeah. Yep. On the face of it, it does. If I get to it, there's a section I'm coming up to called Problems and Fixes, where that is actually one of the problems I want to raise and I'll suggest a fix. Damn. Okay. Okay, what do you, can you talk me through it? What don't you understand? Yeah. When memories are stored? The same. Yeah? Raise our souls and I think distinction you're asking about, what about aspects of the mental life that aren't imprinted in memories? Like if I think plants are really funny, where does that go? Oh right, that doesn't go here, I think, in the way I'm reading Locke. Like if you, it's never occurred to me that someone might think that plants are really funny, right? But yeah, I can see that. Yeah, you could think some plants are kind of pompous or something like that. Okay, I think you lose that, right? Is that right? Then that gets lost. I agree, right. That is a key question what we're talking about here. That's right. And so that's not the point. That doesn't matter for identity. And the argument there would be like the argument about the football player or whatever, that you know, after all you, people's senses of humor and so on does do change as they get older or as they, yeah, as life takes a bitter toll on you. Yeah, that kind of thing just happens anyway, yeah. You used to just love sushi and now you can't bear it. You know, that happens. People do change like that the whole time. But it's still the same person. Whereas the loss of the consciousness of the past event seems much more fundamental. What was going on in Alzheimer's seems much more threatening to the identity of the person. Yeah, that's the idea at any rate, yeah. I don't want those to go away, but I'd like to move on just a little bit. I hope, I still hope to get through your problems and fixes before the end. Give me just a second. It's a clarification. Okay, okay, okay. Okay, so is it? Yes, even though your personality might change, if your memories of particular past events are still the same, then that's the same person. That's what it takes. That's the idea, right. I mean it's certainly open to question. I'm just trying to hammer away at what the basic idea is and why it seems not unreasonable. So as you guys have emphasized, there's a question, what kind of memory matters for identity, right? Because after all, practically anything that happens and leaves its impact on you can be called a memory, right? The burnt child fearing the fire and so on, right? Anything that happens might make some difference to you and you'll be said to remember it. So people make, it's not obvious what the right distinctions are to draw here, but one kind of notion of memory is procedural or habit memory. Like you learn how to make a pot of tea or you learn how to play the piano, yeah? And that is really seems like stuff you could lose but still be the same person, yeah? That's the idea anyhow. Then there's the kind of memory that you can get from a book. If I just read a big book about Napoleon, then I know, I might know every little detail of Napoleon's life. If I read a lot about him, if I Napoleon's biographer, I might spend my entire adult life reading about Napoleon and knowing facts about Napoleon's past life. But that doesn't make me identical to Napoleon. It might make me think I'm identical to Napoleon, but it wouldn't actually make me identical to Napoleon. So just remembering all the details of someone's past life. That's not enough to make you identical to them. What Locke seems to want is something that you might call autobiographical or episodic memory. I mean, if you remember, say, your fifth birthday party or what it was like on your first day at Cal, then you remember that from the inside. Yeah? You have everything from the perspective you were in back then. Locke defines a person as a thinking intelligent being that has reason and reflection and, and here's the key point, that can consider itself as itself the same thinking thing in different times and places. So you can know someone else's biography as well as you can your own, but what you can do with yourself is know of your own past life and think of your own future life from the inside. Consider yourself as yourself. That's what people can do that say foxes or dogs can't. That's why we say foxes and dogs aren't people. Yeah. Higher memory equals identity. Yeah. That's right. Yes. I mean, if you lose a lot about yourself. You lose a lot about yourself, but the person hasn't died, right? That's the key thing. The person hasn't ceased to exist. Yeah, I was saying, okay, the view is at any rate. I don't want to be too dogmatic here, but the view is still the same person, even though something about them has been lost if the great pianist now couldn't longer play. Okay, well, think of it for the reality check. Think of it in terms of who's bank account is it? Who's retirement money is it? Who's family is it? Who's passport is it? Is that all the same? When the... Your birthday is still the same. Sorry? If you forget. Yes, that's right, that's right, that's right. Okay, that's a little bit confusing. If your bank account was laid down when you were five. Right, but yeah. I agree there are difficult cases for the memory thing, but for memory like when you just plumb forget something, but I do want to suggest a way of meeting them in a second. Yeah, but let me just emphasize the reality check. I'm thinking about things like who's passport is it? Because you clearly don't take away the pianist's passport just because they've lost the ability to play. You clearly don't take away their family just because they've lost the ability to play. You see what I mean in that kind of mundane sense. It's just obviously the same person. Okay, we are not going to go away from this. We're going to spend two weeks in this. So I agree that all these things are difficult. Yeah, I'm trying to... As you're saying, I'm trying to channel lock here. Yeah, with that, I should be coming along. Okay, okay. Okay, so the kind of memory he's thinking of is autobiographical or episodic memory. It's always a bit puzzling to me when we're thinking about this memory of your past life, memory of your first day at Cal. Is it that you've got a kind of narrative as the unit of memory, the kind of story that you tell? Or is it your experience? Is it your ability to relive the past from the inside? I think what Locke's thinking of is... You can think of it as a kind of imagination. Right, we talked about imagination a lot in this class already, but you can use imagination to have knowledge of someone else's mental life from the inside. You can put yourself into their shoes. You can see things from your own perspective. And the kind of memory that matters here that Locke's thinking of is when you can project yourself into your own past self. You can think about things from your past point of view. You can remember how it was then for you. So, to remember a past event, you've got to have some imaginative impression of the past event. If someone's saying to you, imagine how it was in the past, I mean, remember how it was in the past, what you've got to have is an imaginative impression of your perceptions back then. I tell you what, I'm actually going to skip over and come back, I'll come back to you another time. Just the detailed development of how you explain what memory is. But I want to be sure today to talk a little bit about... You guys have raised a whole bunch of problems. I want to try and address some of these problems right now. So, the view so far is this. I mean, it's reasonably clear when I'm talking about what I say in memory. Remembering particular past incidents from the inside. Does that make sense? So, the theory is, the later person is the same as the earlier person, if and only if the later person remembers doing and seeing what the earlier person did. So, memory... Oh, was it too fast? Okay. So, X, okay, let me just read that out. X at the later time, T2, is the same person as Y at the earlier time, T1, if and only if X at the later time, T1, remembers in this sense of from the inside, getting the past person's point of view, doing what the earlier person did then. Yes. Possibly the one week's portion of the theory. Okay. Okay, is that better? No, thank you. Okay. So, here's a car crash. A natural problem for this view is one that you guys have raised already, is amnesia, yeah? That if someone gets a head injury and a car crash, amnesia is not uncommon, yeah? You have the grieving family around the bedside saying, don't you remember us, Bill? And Bill saying, who are these people, right? I've never seen these people before in my life, right? That's a very, it certainly happens quite a lot. There are many cases of this, very upsetting for everyone. But in that kind of case, people never say, that's not Bill, right? You always think if we're granted, it's still the same person, even though they can't remember anything of their life before the car crash. Well, here's one way of thinking of what's going on here. It seems to me there are two kinds of amnesia. One is, your memories have got a kind of filing system, so you can call up files from your past memory, your kind of tags to call up files from your past memory. So, what can happen is that you've got all the memories, but you've just lost the tags, so you can't access those memories from your past life. Then usually in cases of head injury, amnesia, was people usually get better, people usually get their memories back. The memories were actually there the whole time. The memory traces were still there the whole time, but the person couldn't get them, and then later they get them, yeah? So, one kind of amnesia is where you've got the memory traces, but you just can't access the memories, like you've got a filing system, but you've just lost all the tags in all the folders, so you can never get any particular folder you want. But another kind of amnesia would be one where, I don't know, you're visiting a physics lab somewhere on campus, and as you go through the lab, you go through a very powerful magnet. Your head gets subjected to a very strong magnetic field, and all the memories are actually permanently erased. Now, suppose that's what happens. Suppose it's that kind of amnesia, and it seems to me that if the family around the bedside found out that what happened had been, that Bill's head had gone through a very powerful magnet, and there weren't even any traces there of all the old memories. It seems to me it would be a perfectly natural reaction to say, that thing there's not Bill. Bill's gone. I mean, it might be ruthless, but it seems to me accurate. If the memories have really been permanently deleted, not just the usual kind of amnesia that I can't get it, then a lot can say that is destruction of the person. So we could put that by saying the later person, plus I've done it again with a T1 and T2, but you see what I mean. The later person is the same as the earlier person, if and only if the later person remembers, or at any rate, has the memory traces in their brain, even if they can't get at them for the time being, of what the earlier person saw and did. Yeah. Yes, absolutely, yeah. Very good, yeah. Yeah, I agree. It can't be right to demand memory of every individual event for you to be the person that was in that event. Yeah, that's your point. Yeah. Yes. Yeah. OK. That is actually my next slide. The way Locke addresses this kind of thing, or sorry, the way Locke and Locke didn't really get into this, but the natural way to address this kind of thing is suppose you take the itch and the scratch, yeah, then a moment after you've done it, you remembered it, yeah? So what you've got to look at or not being able to reach from now directly to the past event, what you want is a chain of memories linking you to the past event. So a minute after you had done the scratch, let's suppose you still remember that. And then a minute later, you remember doing whatever you were doing that other minute, if you see what I mean, yeah? And so on, minute by minute. So if you think of it not as directly reaching back, but minute by minute, your memory is connecting to the past self, then you can address that kind of question, yeah, yeah. OK. How can we tell the memory is just, we can't trace it already? It is, how can you tell the difference between the memory having means? For example, from the first, if you see longer. Yes. Yeah, whether the trace is there or not. Well, the reason, first of all, there really is such a distinction, it seems to me, yeah, because, yeah, and the way we tell in practice is people who have the traces usually manage to access them in the end, yeah. But I agree that there might be cases where you're really very unsure as to what's gone on. And actually, with Alzheimer's, it very often seems to be like that. You don't quite know what's been damaged, yeah, yeah. The moment, the number is opening the door, which is before he lost all the memory. So then the chain is still there, like there's still a link before he lost his memory. So the chain of. I see, yes, very good. Yeah, that would work. He could hang on to himself in that way, yeah. So you could hang on to yourself through a parent arm easier that way. So the classical version of this was given by Thomas Reid. The groutier general remembers being a gallant officer. The officer remembers being a mischievous boy, stealing apples. The general doesn't remember being a mischievous boy. Right, so that is actually the same structure as that scratch thing, the itch and scratch thing. Or this case, what you really want to say is, I got a chain going back. The retired general remembers doing what the gallant officer did, the gallant officer did, and so on. And as long as you get enough of that, that's the same person. Do you see what I mean? So what you want is not. How far back? Listen, who's speaking? I can't see who's speaking. Oh, right, right. OK, yes. A person is a person from the actions you can expect. Yeah? Yeah. Well, sometimes they don't, and sometimes they do. Is that right? I mean, it's just obvious. If I change the pattern, what is my name? And if I change the pattern, where was I born? And if I change the pattern, am I a human being? So if I change all those, yeah. Well, Hollywood is full of people who have different names. You see what I mean? That doesn't make them different people. Yes, that's memory, right? You're asking something about their memory stretching back. But just changing how you interact with people. I mean, if you could continue with Hollywood as you take. Well, I remember her before she was famous. Yeah, but the moment that movie came out, she was completely different. That happens. Still the same person. We actually do. I'm sorry, we will continue with this for the next couple of weeks. So I don't know, but we have to stop there for today. OK, thanks, guys. Great questions. Great discussion.