 Hello, good afternoon. So today we're looking at locks of identity and diversity and Williams' self in the future again. And what I want to do today is go a bit deeper into the arguments about memory and the self, memory and the identity of the self that we were looking at before. So today is a little bit intricate. And you will have to follow me very closely as we go along these elaborate paths. On Thursday, we'll look at Derek Parfitt's famous article, Personal Identity, a kind of bombshell in the subject. And also on Thursday, the essay is due soon, next Tuesday. And we have this thing, the first paragraph of your essay must state the main thesis for which you wish to argue in the essay. The last paragraph must restate the main thesis, summarize the way you have argued for it, and indicate any outstanding problems. So for the first essay, we did a briefing where we asked people in the class, what's the thesis you're going to argue for? You see what I mean? You remember that? I thought that was kind of fun. I haven't tried doing that before. And if you like, if you don't mind, you might try that at the end for 10 minutes or something on Thursday. Is that OK? OK. So let's start out with an objection that I think it was Austin mentioned last time to Locke's whole idea about memory and identity. Locke's idea seems to be you can define the identity of the self in terms of memory. You are whatever past person your memory reaches back to. I will look to ways you might make that a little bit more complicated, but that's the basic idea that the later person is the same person as the earlier person. If the later person remembers doing or seeing what the earlier person did. Yeah? OK, that looks familiar. And one classic objection to this was from Butler who said, one should really think it evident that consciousness of personal identity presupposes and therefore cannot constitute personal identity. So that's very brief. That's kind of compressed. But what he's saying is, in order for memory to be reaching back to someone is got to be the same person as is doing the remembering. Memory presupposes identity. You can't define memory in terms of identity because identity is defined because memory, sorry. You can't define identity in terms of memory because memory is already defined in terms of identity. So the problem Butler suggesting here is really a basic one. Let me give you a much simpler example of this kind of circularity. You know the notion of gorse? G-O-R-S-E? Gorse? I mean, it's a word I often, well, maybe just the books I read, but I often came across the word gorse. It's some kind of plant. The weary travelers make their way through a desert with nothing but gorse in it. And I thought, well, what is gorse anyway? For me, the word was familiar, but I looked it up and there's the definition. Gorse. That's the way you pronounce it all right, but that's what it means, fars. Okay? I don't know if you can guess what my next question was. What is fars, right? So then I looked up fars. What do we find? You see that this is not helpful. We make very little progress with this kind of definition. I mean, just to spell it out why this is circular, that if I now say, oh, gorse. Okay, an old friend gorse. Now, what is gorse again? Oops, then I go back here and then I go back here. Now, you see what I mean? Yeah, so it's kind of circular. You just kind of loop around. Yeah? Now, what do you need as you want to find out what either of these words means fars or gorse? Exactly. A third definition, right? You need a new definition, a third way. So you need something like being shown the thing and just in the interest of general edification, there it is. Gorse, fars, right? Now you've got a third way of explaining what the thing is and now you break out of the circle with that third way of explaining it. So the idea with identity and memory is that these two terms can just be defined in terms of one another. If you try to define memory in terms of identity in terms of memory, you're just going to get a circle. And the way to see the force of this is just suppose you ask. Suppose you remember, say, last week's class. Suppose you remember what happened. Someone asked a particular question. You're saying, oh, yes. Or suppose it was a question you raised, right? And you're saying, yes, I remember raising that question. Say to me, I made that comment last week. I remember it. I made that comment. So what has to have happened for you to have that memory for you to remember making a comment last week? I say the first thing is you have to have the impression that you made that comment. Yes? That's all right. Follow me like a leopard. Follow me very closely here. Is that enough for you to remember making the comment? If you just have the impression that you made the comment. You have the impression that you made that comment. That you made the comment. Not just that the comment was made. So if you have the impression you made that comment, then does it follow that you remember making that comment? Well, my suggestion would be it may only seem to you that you remember. I say, no, my memory of the thing is clear as a bell. You were sound asleep for the entire class. You spoke not a word. You don't remember it. You may think you remember it, but you don't actually remember it. I mean, I'm sorry. If anyone finds this unduly upsetting, they do think they may have been asleep for the whole class. You see what I mean? That's possible, right? So you could have the impression that you did it, but you didn't. And if you didn't do it, then you don't remember it. P.I.2 actually occurred, absolutely. And it's not just that P actually occurred because suppose P occurred, but it's just an accident that you now have the impression that you remember it. Yeah? Suppose that I... Well, let me switch to your front, because this is getting increasingly, what's the word, critical, negative. Suppose I am a kind of fantasist about the great comments I make in our little chats. Yeah? And I say, look, I said that to you last week. Yeah? Now, maybe it actually happened that I said it to you last week, but the old brain cells are not what they were. I have actually no genuine memories, but I just fantasized that I made that comment last week. And just as it happens, this is one of the few occasions in which I got it right. I told you you would have to follow me closely. Are you following me closely here? Yeah? It's a coincidence, right? So you need not just that you had the impression, but that you're having that impression was caused by the thing having happened. Yeah, so it's just a coincidence that you got that impression and that thing happened. You need that if it's going to be memory. Yeah? Yeah? Is that enough for memory? Suppose someone made a brilliant comment, and I say, yes, I remember saying that last week. I remember saying that. And suppose that I have the impression of making that brilliant comment, and indeed, that brilliant comment was made. And the making of that brilliant comment is what's causing me to say that I remember it. Yeah? Is that enough for me really to remember it? Follow me like I left. Is that enough? No, because it might have been you that made that brilliant comment. And I just, how should I say, I just took it on board and said, yes, that was me. So it wasn't just a coincidence that I had the impression that that comment was made, because it was the making of the comment that caused me to think that I made it, because I just naturally appropriate anything good that happens in the class. You see what I mean? So I only remember it. I only remember making the comment if it was me that made it. I had to be the one that was there at the time. I had to be the one who actually made the comment. That's what it means, memory presupposes identity. If I'm going to say I remember making that comment, well, for that to be true, it just had to be me that was the one that was there that did the thing. Yeah? Yeah? Very good. This is kind of an elastic phrase in the right kind of way. And you could say, yeah, the right kind of way involves being the same person. I will shortly give an argument that says you might not need the full strength of that to specify the right kind of way. But you're right. In those terms, three is just a kind of elaboration of the right kind of way comment. You might well be right. We'll come on to that in a moment. But even so, it doesn't really matter. Identity is still being presupposed by the definition of memory. Yes? That's right. I seem to remember doing it. No, no, no, no, no, no. Hang on a minute. I seem to remember doesn't imply I do remember. If someone seems to remember having been at the Battle of Waterloo, there's a follow that they remember being at the Battle of Waterloo. That's what I seem to remember. I said there was someone else. Yes, right. Yeah, let's suppose they genuinely think they said it. Yeah. That's not the way we usually talk. The whole point of saying I seem to remember it is I'm thinking. Goethe began his autobiography, said something like, of the things I am about to recount. I do not know whether I remember them or whether they were merely things that were told to me. We usually make that distinction between what you actually remember and what you were told, say, about your childhood. You really may not be sure which is which. That just seems to be commonplace. Caused in the right kind of way by the past thing having happened. Plain as day. You see when you need this condition? You have to be there at the time. If I say, if someone says to me, did you shut the kitchen door? And I say, yes, I remember shutting the kitchen door. I remember it fine. But it wasn't me that shut it. It was you. You did it. That's right. In that case, I don't remember doing it. I think I remember doing it, but I don't. If I say I remember it perfectly well, that implies it's so. And that it was me that did it. If you say no, if you prove to me, no, it was you that did it, then you've taken away one of my memories. It might not be one of my most cherished memories, but if it didn't happen at all, then again it's not something I remember, it's just something I made up. It should be more like that. X is the one that did it, or X is the one that saw it, or whatever exactly it is you're remembering. Yeah, so that is kind of imprecise. Is this plain as day? In that case, you've got the circularity objection. It's the need for some condition or about three. X had to be there at the time. That means there's a problem with the theory of identity. Because what we're doing is it's just like the Gorssen Forge case. You're trying to define identity in terms of memory, but memory is defined in terms of identity. And if someone says, or some commenters were suggesting, or if someone seems to remember the Battle of Waterloo, then they do remember the Battle of Waterloo. Let's note what we say. We say you weren't there. But can you remember the Battle of Waterloo? For you to remember the Battle of Waterloo, you had to be there. So if we think that identity and memory are just giving us a little circle here, you try to define identity in terms of memory, but memory is in terms of identity, then what do we need? A third thing, right? We need a third way of thinking about the identity of the self. Because if I'm going to say, well, you seem to remember being at the Battle of Waterloo, I'm not necessarily sincere about that, but you weren't there, then I must have some fix on whether or not you were there that doesn't involve going by way of your memory. Yes? I've got to have some other fix on whether it's the same person than by way of memory. And the natural thing to appeal to here is the identity of the body. Your body was not at the Battle of Waterloo. The physical person here was not at the Battle of Waterloo. That's why we're going to say you can't remember. This is a little bit intricate, but are we all on board? Hello? Especially right at the back, can you put your hand up if you're still on the bus? I would describe that as encouraging, but not overwhelming. Does anyone want to, if you're not sure what's going on, can you say, can you try and pinpoint? Okay. Okay. Okay. Ah, good. Well, there's no more to the identity of the person than the identity of the body. I mean, if you're going to define identity in terms of memory and then say that memory requires sameness of the person, then I've got to have my third way of getting on to what the sameness of the person requires. So now I say all sameness of the person requires is sameness of the body. So I define sameness of the person in terms of sameness of the body, and that gives me my third way, my thing like seeing the goss. I'm saying at this point we have to throw it out altogether because it just goes round and round. Very good. No, because I think memory requires sameness of the person. So if we're going to get the full force of it, we've got to define it in terms of something that's enough for the person, Jackson. Yes, very good. We certainly are. Okay. As usual, the class divides into the people who are way ahead of me and the people who have no idea what I'm talking about. Yes, very good. Yes, it would. It would. Let me come on to the Prince and the Cobbler. So keep pursuing this. Just a second. So the idea was, the box idea was we're going to define X as the same person as Y and there's our old friend T1 and T2. Blast it. I think I must have some rare brain defect. Okay. Okay. So the idea was to define the later person as the same as the earlier person if the later person remembers doing what the earlier person did. But in order to know whether the later, in order for it to be true that the later person remembers doing what the earlier person did, the later person has to be identical to the earlier person, right? So there must be some third fix you've got on which person you've got here. Yeah. And that's what body gives you. The idea was, box idea was take memory between people at two times. That memory constitutes the identity. The circularity criticism is this memory already presupposes identity. So the identity you get out is only the identity you put in. An identity was presupposed here. So we're not here explaining what identity comes to. We need some other third explanation of what identity comes to. Please pause me at any moment here. Just a second. Please pause me at any moment here. If you see the point but it doesn't make sense, then let me know. Okay, so the way log set it up is the person with the prince's body has all their memories transferred over to the cobbler's body. But the point here is that's a cheat that way of setting it up because the memory is just the identity with it. Yeah? So of course it is described like that. You're going to say the later cobbler's body person is identical to the prince. But that's a cheat. You don't know how that happened. Of course it is described like that and you're the prince and you're choosing do you get tortured and somebody gets rewarded. That's the choice you're going to make because if memory really went over you'll be saying yes of course my identity went over because memory presupposes identity. Memory just takes identity with it. But if the memory is just something that carries the identity of the self with it then the natural question is well how could that possibly be? Identity's got to be defined by the way outside of memory. The only way we know to do that is in terms of the identity of the body and that makes it look like Williams' picture is much better. All that's going on here is you get two people who've been driven mad that are in the same bodies throughout. The experimenter hasn't induced a change of bodies. He's produced one out of a range of equally possible situations that we'd be disposed to call a change of bodies. But really you should just hang on to the idea that your fears can extend to future pen wherever psychological change is preceded. Your fear about what's going to happen to you in terms of future pen can get over it can cut through you're going mad in the meantime. Until we're shown what's wrong with it we should decide that if we were the person A then if we were to decide selfishly we should pass the pain on to the B body person. That would be risky. There's a fact to the matter here and we're not dead sure what it is but you should assume that your identity goes with the body not with the memory because the memory doesn't give you a fix on which person it is your memory presupposes another fix on which person it is and the only fix we seem to have here is identity of the body. So until we get clear about this we should just assume that identity goes with the body. So I'd just like to check right now suppose that you're the prince how are you thinking about this right now? I see this a couple of times last time but if you're the person with the prince's body and you're in this scenario which body would you choose to be tortured the prince body or cobbler's body can you put your hand up if you choose the prince's body to be tortured and if you choose the cobbler's body to be tortured whoa there's not a whole lot in it but I make it Williams by a narrow head there can you do that again? You'd choose the prince's body to be tortured the apparent memory transfer the cobbler is talking as if you were the prince how was the prince as if you had been the cobbler yeah I'm sorry to say okay so on that understanding if you'd choose the prince's body to be tortured you being the prince and if you'd choose the cobbler's body to be tortured you being the prince this time it's kind of level pegging that's very interesting so Williams has made a lot of progress against Locke here okay what I want to do in the rest of the time today is first of all I want to suggest a way of getting this putting this question about the identity of the self the identity of the person into a more general context a more general context for thinking about questions of identity and then come back to the idea that Jackson raised of talking about of how a memory a memory guy might respond to this and the first time we'll get on to total recall okay object identity in general I mean what is the identity of an object a table do you take a humble table or a lectern and you say this is the same table that was here last week what does it take for it to be the same table here now as was here last week and people are very complicated objects right thinking about their identity is very confusing so suppose we took as an exercise thinking about the identity of something simpler suppose you took the identity of a dog what does it take for a dog that you see now to be the same dog as you saw there last week how would you say what that is memory anyone yes a continuation of experience very good yeah it wouldn't have to have chains of memory yeah okay suppose you had an animal that wasn't conscious or it didn't seem to be conscious I mean something like a shellfish shellfish or shellfish conscious yep you're tough what about a bacterium bacterium what about an amoeba okay what's the identity of an amoeba consistent when's it the same amoeba that you were looking at now as you were looking at last week yep similarities in the structure you might have, couldn't you just have two different but very similar amoeba they're not similar in that case they're not that similar you would have a lot of complaints aha yeah okay okay good how would you define it let's suppose it's a week yep it would be continuous yeah right I mean that's how in the classical stories people find out that Clark Kent is Superman right because Clark Kent goes into the telephone box and then Superman comes out and there's only room for one person in the box right it must be spatio-temporally continuous therefore there must be one in the same yeah that's how we argue that's how they argue in metropolis or whatever it is yep okay so I think there's one really basic thing here that you could say is one in the same animal not just a similar animal if there's a continuous spatio-temporal path from the later back to the earlier if you tracked it moment by moment never taking your eye of it at no point would there be a discontinuity a kind of leap from being an animal here to an animal over here yeah that's what it would take for it to be the same animal Locke also has this notion of the same continued life which is the cells are replacing one another but the structure of the thing is staying the same or there was that idea of the experiences are modulating one another from moment to moment over time so I think what that really is is a kind of causal condition that's to say the way the object is earlier is causing the object to be the way it is later the way you are right now is causing you to be the way you are later I mean that's why people are always going on at you about health and diet and stuff like that because you think the way your body is now is going to affect the way it is later you can make differences to the way objects are now are later by making differences to the way they are now and in general for any concrete object the object is identical to the earlier object if the later object is causally connected to the earlier object let me give a simple demonstration of this it's not similarity that matters for sameness of object despite its earlier defense it's not similarity it's not even just spatiotemporal continuity it's being causally connected from um earlier to later objected means something like if there had been a difference in the way the thing was earlier there would have been a difference in the way the thing was later I actually want to try a practical demonstration of this, this is a little bit abstract could I have a volunteer someone help me with this good, thank you will you step up so consider it the simple table ladies and gentlemen, a simple table I make a chalk mark on it right you see the chalk mark this is a table creator hold it gently and be careful where you point it when you point it at a particular place and squeeze it gently it makes a table be careful and don't point it at him okay it will make a table and I have here a simple table annihilator if I point this at a table and squeeze it gently it scatters the atoms of the table to the corners of the universe okay now are we all ready okay on the count of three you point it right there and squeeze gently one, two, three whoa look at that look at that and can you see an X mark there yes, okay I think that that's very well done, thank you okay now the question is is this the same table that was here before the experiment you're tough for the moment except the hypotheses I gave you yes it's just an accident that it turns out that this table looks just like the old one why is there an X on the table now because I put an X on the table earlier no it's just a coincidence right when she pushed the creator as you know it just randomly produced a table it couldn't mean any kind of table it just so happened by coincidence that this has got an X on it just like the old one even if I hadn't put an X on the old table there would still be an X here now you see what I mean so there was a table here all the way through because we pressed our annihilators and craters at the same time the new table is very similar to the earlier table but is it one in the same table on my hypotheses no, clearly not right, because we just destroyed one table and made another one very similar put up your hand if that isn't absolutely plain as day these are different tables right, put your hand up if you think this clearly these are different tables okay so I say if you take a desk it's not and say what makes a later disk the same as an earlier disk it's not really just a continuous spatiotemporal path from the earlier disk to the later disk if you suppose a disk annihilator and a disk crater and we point them both at the same disk at the same time then marks on the disk after the zap aren't caused by how the disk was before the zap right, so they're different disks you see what I mean suppose you go back to your old high school classroom and you're looking around the dear old place and you say my god there is a disk just like the one I used to sit at and you look at it closely and my god there they are your initials carved on the disk and you say it's the same one you're assuming that those marks in the disks there now are there because of your activity earlier yeah the way the disk is now is caused by the way the disk is earlier so that's why you take it they're the same disk if you thought you'd been through that annihilator and crater scenario then you say no this is just a very similar disk to my old one now the thing about that is that's absolutely general when you think about memory memory is when the world reaches in and carves its initials on your brain the way you are now is because of the way you were earlier with animals in general and what you want for it to be the same animal you got now as you had earlier is that the biological condition of the animal now should be caused by the way it was earlier now people as someone said already people are very complicated objects they're much more complicated than a mebe or um um tables or desks or whatever or rabbits yeah so when you're asking is this the same person now as you had earlier what you're asking there really is a question about what kind of causal connections are there between the way the thing is now and the way that thing was earlier and because people are so complicated there are lots of different ways you can ask the question you can ask it as a question about are the psychological properties later caused by the psychological properties earlier or is it what really matters to us that the physical properties later should have been caused by the physical properties earlier so one kind of theory would be the later person is the same as the earlier person if the later physical properties are causally dependent in the right kind of way on the earlier physical properties and if you think that that's the key thing for identity of the person you'll say that's the prints all the way through here on the left on the other hand you can take this idea about causation and put it in a kind of psychological key you can say the later person is the same as the earlier person if the psychological properties of the later person are causally dependent in the right kind of way on the psychological properties of the earlier person ok? and if you think like that let me just complete my thought if you think like that you'll say look the psychological properties of this later cobbler body person the psychological properties going on over here are causally dependent on the psychological properties going on over here psychological properties of the later print body person don't depend on the psychological properties of the earlier print body person the physical properties do cause them to depend what's going on in this kind of case is a dissociation between what's happening at the level of psychological properties and at the level of physical properties you're getting a causal connection up on this dimension at the level of physical properties So that's what's at issue when you're arguing about how does it go in the Prince and the cobbler case. That's what's at issue between Locke and Williams when Locke says that the cobbler body person is the same as the earlier Prince body person and Williams disagrees. Actually they're just putting different weight on psychological properties or physical properties. They're saying one of them is saying the causal connections among the psychological properties are what matter for the identity of the person. The causal connections among the physical properties are what matter for their entities. It's harder to get that kind of case for a simple table because it's very much harder to think of a case where you'd get that kind of fraction and that kind of differentiation between two kinds of properties that the table has but with people it seems fairly easy to do it, I mean to think of it. So Williams said, well when you're talking about the memories crossing from one body to another, you're supposing that some kind of self is crossing from one body to another with some kind of ghost passing between them and that's clearly just a fantasy. But that's pushing it a bit it seems to me, that's not the right way to put it. The right way to put it is we're not quite sure which kinds of properties to emphasise as really mattering for the identity of a person. Okay, I'm sorry there were some questions that I just rushed over. I'm saying we've got a general notion of concrete object, that's to say there are objects in mathematical heaven like the numbers, there are abstractions like love of country, revenge, there are abstractions like that and then there are concrete objects like a simple piece of chalk or a desk or a person, that's a reasonably clear distinction. There are concrete objects that are located in time and space, just the kind of basic humdrum regular things like you or me or chairs and so on. And I say there's a general notion of identity for any concrete object and that has to do with causal connections between the way the thing is earlier and the way the thing is later. If the way the thing is earlier is causing the way the thing is later then that's the same object. And I say that's fully general, that applies to any concrete object at all and you can think of these puzzles about persons as coming up just because persons are kind of complex objects so there's a lot of structure in that kind of causal connection. That's the idea. So can you speak a little louder? What causes the change of the properties? You should have played something on the first one. Yeah. One of the components. One of the components. I'm not quite getting it. Suppose you have the liver transplantation, then there's going to be a kind of matter quantity here as to how much of what's going on later causally depends on what's happened earlier. So if I've been punishing my liver all these years then what I was doing earlier is causally affecting how it is with a bit of me now. You see what I mean? But then when you transplant the liver some of that causal connection is eliminated. I can start a fresh liver wise. Okay. No, no, no, just a minute. I mean of course there are cases but generally the liver is not the person. Yeah. Right. The liver is just a component. Yeah. The liver is just a part. What I mean is though that I agree, I would agree that the liver wise you're causally getting a new fresh start. The condition of this liver does not depend on what you were doing earlier. So that's part of what it means that it's a different liver if it's the same old liver. That's you getting a new start. That's you getting a whole new start. That's what we would say, a whole new you. But if none of it was causally dependent on what you were doing earlier, the thing in the liver case is the vast majority of what's going on with you later is still causally dependent on what you were doing earlier. The liver's only a bit of the whole picture. Yeah. So it's really a kind of a, it's a matter of quantity here, how much of the later condition is causally dependent on how much of the earlier condition. Yeah. And that's important. That's very good. It's an argument for everything being determined. It's not meant to be for free will. I mean it connects to some of what we said came up earlier about free will. If you think of free will as a matter of, you just get a whim coming from out of the blue and it doesn't depend on anything that you earlier thought or did. Yeah. Yeah. If you have that picture, then I agree there's something threatening here in the idea that the later stages must be being caused by the earlier stages, yeah. But there are two parts to this. One is I think that ordinarily what we want by free will is not that you should be having kind of existential whims out of nowhere. You know what you want is that you should be being true to your authentic self and your actions. You see what I mean? It goes to the core of me. Back since I was a child, since I was a child I've had these strong beliefs in whatever it is, yeah. Healthy exercise or you know whatever it might be. And so the exercise of freedom here is in my being true to my earlier self. That's usually what you think of. Not just a matter of existential whims that just come out of nowhere. I mean who wants to live like that? You see what I mean? That seems more like kind of that sort of randomness than what you call freedom, yeah. So freedom you could think, it seems to actually demand accusation of the later self by the earlier self. I know what you mean though, there is that picture, oh I'm just in the grip of my earlier self. And that can happen too where you say well people are just creatures of habit. They're not really free. But I think what you need to look at there are the details of the kind of causation that we're thinking about, yeah, rather than looking for no causation at all. That's an important question. I don't want to suggest that's the end of the story. Plain as day. So you see that's an abstract frame for thinking about identity. That you can just drop in all these questions you're thinking about. Okay, let's look again at this thing about circularity. Remember the definition of memory? What is it for a person to remember a particular past event? You're being told, someone's saying to you that they remember making a comment. So they have to have the impression that the thing occurred and they're having that impression as to be caused in the right kind of way by the thing having occurred and they had to have been there at the time. They had to have been the one who was making the comment or doing the thing. And it's the need for this third condition that makes there be circularity. So if we want to defend luck, if you want to have a memory criterion, we've got to do something about this. We've got this definition of memory and we've got this third condition that brings in identity. So if we want to define identity in terms of memory, but we think, well, this gives us circularity. This gives us that gross force thing. What do we do? How can we proceed? If we don't like defining memory identity in terms of this complex three-part notion, because the third part is giving us trouble. Come on, class. Yeah, we want to get that effect of a memory-type causal connection to the past. Memory is a causal connection to the past. That's caught by the second condition there. Memory is when the world reaches in and carves its initials on your brain. But if that's the important bit and this third bit is giving us trouble, what should we do with the third bit? Throw it out! Throw the rusk out. Okay, let's toss it out. Now that resulting definition is not going to be a definition of memory, because the ordinary notion of memory requires that third condition. But suppose we just toss it out. Suppose we say, I'm going to talk about quasi-memory. Follow me very closely. Quasi-memory. Quasi-memory is when you have the impression that the past thing occurred and you're having that impression is caused in the right kind of way by the past thing having occurred. I mean, this is pretty intuitive, I think. Suppose you know how it is when people travel and they say, well, I saw the Taj Mahal and they say, well, here are some slides of the Taj Mahal and they say the thing that people always say. But of course, looking at the slide doesn't tell you how big it is. You don't really get any sense of the size from that. I mean, it's really, really big. Then think how much better it would be if you were trying to show people what kind of time you'd hide at the Taj Mahal. I mean, let's suppose that in the future, people have their brains machined so that they have memory slides that when you go on vacation, your memories are just laid down in slides. And maybe early in childhood, people have slots machined in their head so that when you come back, you don't need to show them pictures. Of course, you can just drop a memory slide in their head and then they have your memory of the past thing. So they can drop in your head a slide of the Taj Mahal and you say, wow, that's big. So suppose someone drops a memory slide of the Taj Mahal in your head. So there's that evening with people walking to and fro with a beautiful, peaceful scene. Now, do you have the impression now that you've got the memory slide that that scene occurred? Do you have the impression? Class, right? You do have the impression that the scene occurred. Is that impression, is you having that impression caused in the right kind of way by the scene occurring? Yes, I mean, the scene just reached it and impressed the brain that made that slide in just the usual kind of way, yeah? So that's just the right kind of causal connection for memory. You've got the slide in your head. Do you remember, do you now remember that scene? Could you now say, I remember seeing the Taj Mahal. Your friend drops the slide in your head and you say, yes, I remember that summer evening. Of course you can't, you weren't there, right? You never left Berkeley the whole time. You don't remember it at all, yeah? That's right. It would be like watching a film about it. And if you said, oh yes, I remember old India so well, people would naturally say, no you don't. You think you do but you don't. You see what I mean? That is what people would say. If you having got the memory slide say, I remember that evening oh so well, the obvious answer is oh you don't because you weren't there. So this is not memory. Is that quasi-memory? Yes, quasi-memory is when you meet the first two conditions but not the third, right? So this is a notion of quasi-memory. It's got all the good bits of memory in it, if you see what I mean, but not the identity. That too is true, yes. We're postponing that for the moment. It may come back to that on Tuesday actually. On Tuesday, yes. But the thing is if the brain slide was laid down, that bit of brain was configured in the same way that the brain usually gets configured just by observing a scene, then it's very, very similar of a causation here to what usually happens. A room that shows the Taj Mahal. Yes, but we have the same impressions, yes, right. And that might be a recreation of a past scene because of the way it was back then. Are you trying to get a causal connection in here? Or you don't like the brain slides? No, no, you have to have the brain slides. The brain slides are key. I'm sorry. The brain slides are not optional. I mean rooms that look just like the Taj Mahal for some other purpose, they're fine. I don't have any... You do that. Well, it's just like memory except you missed out the identity. That's the point. The identity was a key thing. The whole package, the whole sensory package. Okay, we'll come back to it. He understands the situation exactly. He knows his friend just popped the slide in. And he says, wow. I'm so jealous or whatever, right. But if his friend leaves him the memory slide, then he will always have that quasi-memory to treasure. Yeah. Yeah, okay. He now gets it from the inside is the thing. You see what I mean? It's from the inside for him just as it is for his friend when his friend was remembering. The whole thing. Oh, yes, the good thing. Yes. That's very good. That's very interesting. Yeah, that's a great kind of case. It really connects to that thing about the right kind of way because suppose that you and I saw the Taj Mahal together. And I have a picture of the scene. And you're saying, I just don't remember any of that stuff. Is that really true? I don't remember that at all. And I show you the picture and you build it up. You believe me? You build up your sense of how it was back then. And you say, okay, okay. But I still don't remember it. Then you've got a memory impression that's caused in a way that's very like, regular memory. I mean, it's accurate. It's reliable. You build up this impression of what it was like back then. But you still say, I don't remember it. Yeah. And the thing is, as you rack your brains, there might come the moment when you say, aha, now I remember. Yeah. Intuitively, the thing is, if this is your head, I'm sorry, it's not a very good likeness, but if you suppose that's your head, then there's that past scene at the Taj Mahal and a causal connect going from the past scene through the pictures to your current impression. But the reason you say it's not memory is that you want, one wants intuitively, I mean, commasensically, one wants an internal connection, something in the brain that for it to be memory is not enough that the past scene be causing in a reliable way your current impression. Is it the past scene at the time had to lay down a trace in your brain? And what happens when you say, aha, now it all comes back to me? Is it that trace gets activated? I think that's the commasense picture of memory. That's what you meant, yeah. That's the commasense picture of memory and that's something you do with the right kind of way. And that's why it's important that it's memory slides, because you're getting that internal thing of the memory trace being activated. Yeah, you and your childhood friend both remember creating a poem. Each of you remembers that you were the one that did it. Yes, very good, that's excellent. Yeah, because you've got, well, let me just think about that a minute. You say you meet your old friend and you say, remember that great rhyme I created and your friend says, wait a minute, that was me, I treasure that memory. Yes, that's the kind of thing. Yeah, that's a great case actually that on the first pass it can't be, you can't both be right, because only one of you can really remember, can really be the one who did it. So that third condition wouldn't be met. But then if you ask, is it caused in the right kind of way for both of you, is it even a quasi-memory for both of you? Then I think probably not, because just for that kind of reason that only one of you has had the memory by laying down a trace in the right kind of way. The other one, it went in some more indirect way. Yeah, but that needs more discussion, I might come back to that on Tuesday, that's a great case. Okay, so now we've got a notion of quasi-memory that doesn't involve identity, that's okay. So can we now define the later person is the same as the earlier person, if the later person quasi-members what the earlier person saw and did. Let me first ask you, is this definition circular? No, that was the whole point, right? This one is not circular, right? We dropped out the identity bit. So that was what Jackson was saying earlier, couldn't you stick with a memory criterion but just drop out the identity bit? So this is going to give you a definition of identity in terms of memory that is not circular. But does it work? No? That's a bit of a blow. All that heroic effort, now it doesn't work, how come it doesn't work? Who said that? Very good, okay. So just one slide, I'm going to quiz, I remember what happened, but that doesn't mean I was the one that was there. Was that your objection too? Yes, I agree that's pretty devastating actually. But consider another scenario. Suppose that I come back from my trip to the Taj Mahal. Let me just... Suppose we have these brain slides, I suppose you've got that scenario. Suppose I come back from my trip to the Taj Mahal and I say to you, hey look, come and see my slides and so I drop in a couple of slides and that's no more boring than it usually is when people show you slides, right? You say okay, you say fantastic, yeah. And so then, I'm not identical to you at that point, right? I've got the quasi-memories, yeah. But suppose that what happens is I just keep going. I give you some and then I'm just saying quasi-memories with you. So, I keep going. I give you the slides of my trip to the Taj Mahal. I give you the slides of my trip to the pyramids. I provide you with slides from my early childhood. I keep going. Eventually I'm having to scoop out bits of your brain to make way for the new slides coming in. After a bit, I'm not just very, very boring. This is authentically scary, right? Because if I just keep going, then what's happening is not that I am sharing too many memories. I am taking over your body. You are ceasing to exist. If I flood out your memories with my quasi-memories, well, in the end, I annihilate you. I take over your body. So, if that's right, the right way to think about it is you can define identity in terms of quasi-memory by saying the later person is identical to the earlier person if the overwhelming majority of the later person's memory impressions, the overwhelming majority of these later quasi-memories have been caused in the right kind of way by what the earlier person saw and did. Now there are definitions. The key thing is the overwhelming majority bit. If you think about that scenario, where I just flood out your brain, then by the end of the process, it might be clear that I've taken over your body. At the start of the process, as people said, it might be clear that I haven't taken over your body. I've just shared a couple of slides. But then there's going to be some intermediate cases where if you stop the process there, you're not quite sure what to say has happened here. It's really a terrible situation, though. But if you have that notion, I mean, I think there's some indefiniteness in the way we'd ordinarily think about the identity of the self there. But if you are at the end point where it's clearly the overwhelming majority of the later impressions, then here we have a definition of identity in terms of quasi-memory. So I said the circularity objection that we started out with, that seems to show you need a third way. You've got to appeal to the body or something like that. But this strategy shows you don't need the third way. You could do it without appealing to the body at all. You could just define an ocean of quasi-memory and define identity in terms of that. That's right. Very good. I could hang on to that frame. I could think, this is terrible what's happened to me. I'd be living with all your memories. I agree. That seems possible. Yes. These are both fair enough. The trouble with the kind of sense you're talking about of this isn't really me is... I don't want to give away too much about myself here, but it seems to me you can't have this thing of feeling distanced from your own life and saying this isn't really me. You can have that sense of alienation in your own life. This is not my beautiful house. This is not my beautiful wife. What's going on? You can have that anyway. That doesn't mean that your framing thought here, the alienation thought, is the correct one and the actual overwhelming number of memories you've got are the wrong ones. There's a kind of balance of power thing here as to which is getting to constitute the identity of the self. Yeah? Yeah. What happens? Yes, right, right. I'm saying it could happen. I mean, I agree with the previous question that it could certainly happen. You continue to have that feeling of alienation. My only comment in that was we don't always regard that feeling of alienation as authoritative. You can say, well, you've just got to live in the real world and get on with things. Yeah? And it's not clear when that's going to be the right reaction and when not. But if the memory theory is right, then it's going to be the quasi-memories. There are the key things. So you could accept Locke's thing about the prince and the cobbler and say body swaps are possible. People can swap bodies. It makes perfect sense. That doesn't mean that we're dualists. We don't have to say that people are just human beings either. People might not be human beings. So I think it's a live option to say we think that the notion of a concrete object in general is a causal notion about the way the earlier characteristics and the later characteristics. But I think that in the case of people, it's a psychology always that really matters. That's certainly a possible view. I think. I want to make just... Total Recall is a movie I've had. I've never actually seen it, but it's one of these things. I find this plot explained to me so often by students, but I feel like I have seen it, which I guess doesn't mean that I remember having seen it. But I certainly have a very vivid visual imagery of what goes on in it. What? Yeah, well, I don't know. I certainly have vivid impressions of it. So the story is something like this. Douglas Quayle... Do you guys know this movie? Yeah. Some people do. It was a classic Schwarzenegger movie, and then there was a remake. Douglas Quayle, a simple and ordinary man, wishes to visit Mars. As that is what he does, right? He has a very tedious grinding job, and he wants to visit Mars. But he can't afford to visit Mars. So he visits a company, Recall Incorporated, but instead of taking you to Mars, it offered you something much cheaper, implanted memories of a trip to Mars. So they try to implant some racy Mars memories into Quayle of his life there as a secret agent. But in the course of doing that, they get a very violent reaction from Quayle that reveals that he actually is a dangerous undercover government assassin. His mind is full of dangerous secrets. They've just been masked in order to let him carry out his regular job and keep his cover. So they get Quayle out of their office, and now he's keen to find out who the real me is, right? This is not mere abstract speculation we're doing here. This is a real guy, right? We're real concerns about the identity of the self. He wants to find out what the real self is. He's no longer going to take his regular memories at face value because they've been implanted as an overlay on his real identity. These regular memories he has of his regular job and so on of his regular life, these are actually Quayzai memories. These are things that really happen, but they don't relate to him. His real life is the life as an undercover government assassin. The government initially seeks his death, as they would, but instead Quayle manages to make a deal that he turns to recall to have his Mars memories once more suppressed and is offered by way of compensation, a set of heroic wish fulfillment, false memories. The recalled staff begin the memory and planting procedure and uncover a different and older set of suppressed memories, revealing that the unbelievable memories they're about to insert are already there. I don't know if I say that earlier, but anyway. Okay. So what you've got here, I mean people are very comfortable working with this kind of idea, is a set of layers of Quayzai memories, and you take it that you can make perfect sense to talk about a person's memories having been subsumed under a layer of implants or under several layer of implants and there's some notion of the true person there that seems, I mean, if you thought something like this had happened to you, it would seem terribly important to you to sort out what was going on, which one was the real you. Very few people would say, well I don't, you know, hold on, I care which one is the real me. I'm just going to get on with things. It would seem like the most important thing in your life to find out which one was the real you. And the picture I think we have is that the real person is the person whose memories are at the bottom level here, whatever exactly that means, the lowest level of Quayzai memory. So what that brings out is actually the importance of memory for identity. The mere sameness of body, that's not what matters for sameness of person at all. I think the Williams thing is very powerful, but he must be wrong. What we think matters for sameness of person. One practice anyone would really take it is the important thing for sameness of person. It's not the human being at all. It's the memories and the connections between the psychological properties at one time and the psychological properties at a later time. Any of those comments? Okay, then on Thursday we'll come to Parfit and the survival of the self. Okay, thanks guys.