 Hi, good afternoon. Today, I want to go quite slowly over Parfit's thing on personal identity. And I want to try to bring out just how powerful Parfit's argument is that we don't really care about identity. But in fact, for all of us, the survival of this particular person is not an important idea. I want to go over quite slowly and try to bring out the full force of Parfit's idea. So I'll be trying to channel Parfit as well as I can. Partly because I just don't see how it can be correct, Parfit's view. And that's what I'll do in Thursday. I'll try to explain why. It seems to me Parfit's view simply must be wrong. But on the other hand, as we'll see today, there are really powerful reasons to think that it simply must be right. So what I very much hope is in Thursday you will help me sort this out. Because I really think, I mean, with consciousness, it is kind of obvious, the minute you mention the notion that this is a very difficult thing, the mind-body problem and so on. With personal identity, it's not quite so obvious that there are real hard contradictions here in the way we ordinarily think about it. But I'll try to bring out on Thursday that that's so. So today I'll start out by just going over, explaining again these notions of continuity and connectedness that Parfit uses, uses them as tools, and explaining what identity means. And then look at the implications of these phishing cases, the cases worth of branching for what we say about identity. And then finally come on to the main topic, the concern to survive. OK, that's the plan. So continuity and connectedness. Connectedness is, it came up before in discussion, that when you're thinking about your memory going back to your past life, there might be all kinds of gaps in your memory. Your memory of your life from a year ago can be patchy, disconnected. You remember some of things, but not others. In six months, some of these things might come back to you. But the idea of psychological connectedness is to go for something very relatively short term and quite immediate. So we say that these might be just five minutes apart or a minute apart, time t1 and time t2 here. So x at some time, t1, is psychologically connected to y at some earlier time, t2. And let's suppose t2 and t1 are pretty close together. Psychological connectedness means the overwhelming majority of x's psychological states at the later time directly, causally, depend on y's psychological states at the earlier time. So presumably, we've all, right in this room, got that from moment to moment. You've got that very direct causal connection. You don't usually have very rapid jumps in your psychological life from moment to moment. And then continuity is when you've got a chain of connectedness. So x at time t2 is psychologically continuous with y at an earlier time, t2. Sorry, x at time t1 is psychologically continuous with y at some earlier time, t2. And now the two times can be as far apart as you like if there's a chain of psychological connectedness linking the later time back to the earlier time. You see what I mean? Yeah, so that's a way of dealing with that problem of patchiness and so on. That's plain enough. Yes? Yes. When you're asleep is a difficult case. Many of your psychological states you still have while you're asleep, right? If you're a good-hearted, good-willed person, that's a psychological characteristic you have. And you still have that while you're asleep, yep. If you have happy memories of your childhood, you don't lose them while you're asleep. It's true that you don't have any active psychological life going on or not a relevantly active psychological life going on while you're asleep. But lots of these psychological characteristics we're looking at, you still have while you're asleep. Yep, that's an important question, OK? OK, so the special case of psychological connectedness we focused on was quasi-memory. How is quasi-memory different from regular memory class? You don't have to have been there. Very good, yes. It doesn't have to have been one and the same person. That's not part of the definition, yep. So that's a special case of causal connectedness, psychological connectedness. You've got this later impression that things were so, because things earlier were so, but you didn't have to be there at the time. And that's how we get around that problem of circularity. Yep, OK. And the way to remember what quasi-memory is is always to think of that example of brain slides. If I can drop a brain slide into your head, that gives you a quasi-memory of what happened back then. Just one other exercise. Are quasi-memories memories? Are all your quasi-memories memories? Put up your hand if you think the answer is no. Put up your hand if you think the answer is yes, right? The correct answer is yes, right? I say this to the three people who put up their hands for yes. Well done. OK, remember, a quasi-memory is just like a memory, except you didn't have to be there. But if you were there, well, all right, that doesn't stop it being a quasi-memory. Yeah, OK. It's easy, right? So all you did is subtract that clause you had to be there, OK? So naturally, if you meet the two conditions that were left, well, if you meet the two conditions, if you meet all three conditions, then you meet the two conditions that were left, yeah? So sorry, I put that around the wrong way. I'm sorry. Let's take this from the top. Let's erase a lot. Let's erase, look at this isn't being taped, but let's erase the last couple of minutes. I asked you all quasi-memories or memories, didn't I? Yeah, that's not what I meant to ask you. That was the wrong answer when you said yes. You three guys, that was completely wrong. OK, OK, oh, well, another jolt to my butt of credibility. OK, let's take this from the top. Are all quasi-memories memories? You've got to meet two conditions to be a quasi-memory, right? You've got to meet an extra condition to be a memory, right? So if you meet the two conditions, there's no guarantee that you also meet the third condition, right? So not all quasi-memories are going to be memories, yes? That's perfectly, maybe too much to expect that it's perfectly clear at this point, but is that OK? OK, so the question I meant to be asking you is are all memories quasi-memories? Can you put up your hand if you think the answer to that is yes? Are all memories quasi-memories? OK, and if you think the answer is no, OK, and if you have no idea what I'm talking about, if you do know perfectly well what I'm talking about, but you just don't know what the answer is, OK, hello? You can't understand that all of those. OK, yes, of course, all memories are quasi-memories, because to be a memory, you've got to meet these three conditions. To be a quasi-memory, you've just got to meet two of them. So if you meet all three conditions, you'll automatically meet two of them. Is here, I mean? Yeah, yes? What is it that you have the impression that things were so back then that you were at the Taj Mahal and that that memory is causally dependent in the right kind of way on the Taj Mahal having been this and so that evening, that autumn evening so long ago? Yeah? Those were the two conditions, yeah? And the third one was you had to be there. You had to be the one that was doing that. OK, OK, OK. So as I said, the way to remember what a quasi-memory is is always by way of that example of a brain slide. And then with that, we define the later person is identical to the earlier person. If the overwhelming majority of the later person's memory impressions are caused by the right kind of way by what the earlier person saw and did, yeah? The shoemaker's definition of personal identity. We had that example of this classic example, but you guys brought this up in discussion in different ways. But the entire general remembers being an officer, the officer remembers being a mischievous boy, but the general doesn't remember being a mischievous boy. So if you say memory is what makes it identity, then you're going to wind up with a result so the retired general is identical to the officer, but the officer is identical to the boy, but the retired general is not identical to the boy. Yeah? We must be a mistake. That's a contradiction. Yes? OK, so how do we get around that? How do we get around that class, yes? He remembers both. He remembers both? Who does? The general. He doesn't remember being a mischievous boy. He can remember both. You don't understand the effects of aging. I mean, all that military life has got to him. He doesn't have the cells anymore. It's possible that there would be a different kind of example in which he does remember both, yeah? But I think it's perfectly possible that he remembers one but not the other. Yeah? Yeah? He has the memory, he just can't access it. There again is another possibility, but one of the troubles of getting to be an aged general is that you may not even have the memory anymore. You know, those memories from your really early life, some of them may just be gone for good. At a certain time, you have all your memories. Well, when he's in his midlife of vigorous officer, yeah? He might have full memory of all his earlier life, but he doesn't have memory of what happened later. Did you see what I mean? Yeah? So there's no point of, there may be no point of issue of memories of everything that came from all of your life. Yes? That's right. That's right. Very good. OK, so what you want to say is to be the right kind of causal connection, you don't have to do it directly. You can get one kind of causal connection between two relatively short time periods, and a chain of those will be enough for the right kind of causal connection for identity between two long periods. Right, OK. Yeah, I think that too is entirely possible. I mean, it's always said that people lose their memories as they get older, but there is a flip side which is that as you get older, memories particularly from early adulthood get much easier to access. Yeah? So that too is possible. It's possible that the officer might not remember being a mischievous boy, but then in old age, it comes back to him. Yeah, you know, that's how you get to the old Gafford mumbling away over the chimney piece, you know, yelling about the great days gone by. So that too is a possible scenario. In that kind of case, though, if you remember the thing that someone mentioned a second ago about memory traces, the trace would presumably have had to be there all the way through. Yeah? So he had the trace, even though he couldn't access it. Yeah? Yeah. OK. Anything else on that? Any other suggestions? Yeah, so I think what Parford would certainly say is what last question about one said, you've got a chain from the retired general for the government officer. That's the kind of thing that Parford is calling cause of psychological connectedness. Yeah? That's a short term thing. And then if you've got a chain of those psychological connectednesses, then that's enough for identity. Yeah? So one way people put it is in terms of, if you think about the relation of being a parent, that's like a short term relation, right? You can't have more than two parents. Yeah? I mean, you kind of all want more than two parents, right? And where are you going to have thousands and thousands of ancestors? To be for X to be an ancestor of Y is to be a chain of parent-child relations connecting X and Y. So people sometimes call this taking the ancestral overrelation, taking a chain of examples of that relation. So that's what we're doing here. We're taking those short term psychological connectednesses and saying, take the ancestral of that. The relation that stands to that short term psychological connectedness, the way ancestor does to parent. One other thing about the basic idea here. Remember the thing about the disk being annihilated and having exactly similar disk created? And we said, well, it wouldn't be the same disk because it would just be an accident. It looked like the earlier disk. This shows that the identity of a concrete object is a causal notion. Is it clear what I mean causal? What I mean causal is something like the way it was earlier makes a difference to the way it is now. If it had been different earlier, it would have been different now. So long as it was similar earlier, it was going to be similar now. Something like that? I mean, that needs to be made a bit more precise, but that is the intuitive idea. The way it is earlier is making a difference to the way it is now. So for the later disk to be identical to the earlier disk is for it to be a chain of causal connections from the later disk to the earlier disk. Yeah? This is true for animals, you get the same thing. The later animal is identical to the earlier animal. If the biological condition of the later animal causally depends on the biological condition of the earlier animal. Or a tenured rate, if there's a chain from the later animal back to the earlier animal. Yes? You don't understand what I mean by causally connected? You don't see why it is causally connected. OK, watch a simple demonstration. A simple demonstration. I have here a simple piece of chalk. I put an x on the desk. There is an x in the desk now. Why is there an x in the desk now? Because I put an x in the desk earlier. Because I put an x on that very desk earlier. Watch me very closely here. Here is the lectern. I hope the next person in the class does not mind. But OK, I also put an x in the lectern, right? Yes? Why is there an x in the lectern now? OK, is there an x in the lectern now because I put an x in the desk earlier? No, right? It had to be the same object. It's because I put it in this very object earlier that it's in this very object now. An object is a kind of vehicle for transmitting the marks of the past into the future, yeah? That's what you are. You are a kind of vehicle for transmitting the marks of the past into the future. That's what memory is, the way that the past impacts you and generates your future memories. Is that reasonably intuitive? OK, so so much for connectedness and continuity. Plain as day? What could be plain as day? Despite my best efforts to make it difficult, that's plain as day. Yeah, OK. So then the question Parford is raising, with these two basic ideas in mind, the question he's raising now is, what about printing off? Once you've got that notion of psychological continuity, causal continuity, a chain of causal connections from the past into the future, you can see that you could have that even though there was branching. If this desk branched, there would be x's on all three future desks because of the x I put there now, yeah, that could happen. I mean, I don't think it happens very often, but it could happen in principle, yeah. So if you had printing off, you'd have psychological continuity across all the branches. But when you've got a single thing being printed off into three, are the three things that come out at the end identical to the original one? Are they identical to each other? Are those three print offs identical to each other? If you just think about the desk, frisioning, yeah? So we've got three desks here. Are those three desks identical to each other? No, they are very similar. But if they were one and the same desk, how many desks would there be here? One, right? But what was my hypothesis? There are three desks. Yes? I mean, I know there are ductions that you could have three and one, but for the case of a simple desk, it's pushing it a bit, right? I mean, if you've got three desks here, you've got three desks. They're not one and the same desk, right? Although they're very similar. So if you're printing off, you've got three different things here, yes? Are those three things directly causally connected to one another? Is there a chain of causal connections for one to the other? No, there is not, right? So how can they be identical? They're not identical. They're three different things. So are any of them identical to the original thing? Are they all identical to the original thing? OK, put up your hand if you think they're all identical to the original thing. OK, boy, I would like to hear from you guys. How can they all be identical to the original thing? They're structurally identical. Yeah, they're very similar. I'm not disputing that. But when I say identical, what I mean is, is they're one and the same, yeah? Yeah, if you take one of two identical twins and you say they're simply identical, those two twins, right, well, I know you mean, but you don't mean it's one and the same person, because if it was one and the same person, it wouldn't be twins. They're only one person in the family, right? You see what I mean? They're two different people. Two are clones and one's a real one. Yeah, that is a possible case. Yeah, two are clones and one's a real one, yeah. I'm just asking, right at the moment I'm asking, could it be that all three are identical to the original one? Of course not. If they were all identical to the original one, they'd all be one and the same as the original one, so they'd all be one and the same as each other. Yes? OK, I mean, a superman is identical to Clark Kent and a superman is the guy who saved my life, then Clark Kent is the guy who saved my life. You see what I mean? There's no way around that. Yeah, that's identity. OK, so if you get printing off, you get psychological continuity, but you don't get identity. And although you can imagine cases where you've got two clones here and one's the original, that could certainly happen. I mean, people do take clones, right? I mean, actually, twinning is basically a cloning process, someone told me the other day. One is cloned from the other in the womb. That's not the case we're considering here. There's nothing privileging them over one of these over the other. Yep, there's no basis for saying that one's the original and the other's the clones. They're all in equal standing, yep. Yes, yes. Do you have a question? Well, Clark didn't really pursue the thing at this level, right? Well, Clark was really inventing the subject, if you see what I mean. And this kind of fine-grained question is something that came up only after people had spent three centuries arguing about the prince and the cobbler. Do you see what I mean? It really took a long time to come up with these examples. So, Clark didn't really go into this kind of thing. All you get in luck. I'll actually come back to luck on Thursday and try to say what I think is deep insight was actually being missed in this discussion. But on the face of it, he says, psychological continuity is enough for identity. But he doesn't address what happens in this kind of case because it simply hadn't occurred to him or anyone else. Anything else on this? So, in this case, these offshoots aren't identical to one another because then there'll be only one, not three. They can't all be identical to the original because then there'd be one, not three. And there's no way of making out the case, but one of the original one and the other two are copies. Yeah? Okay, so no branch is identical to the original. So, the importance of these fission cases is they make it clear that you're going to have psychological continuity without identity. Yeah? But a moment ago, we were explaining identity in terms of psychological continuity, causal connections, but now it turns out you can't have psychological continuity without identity. Yeah? So what's the relation between identity and psychological continuity? What's the relation between identity and psychological continuity? I've been saying identity is a causal notion. It's when the later thing causally depends on the way the earlier thing was, right? And it seems to be something that we really care about. We really care about each other's identities, are you the same person I met last night, that kind of thing? And we explain identity in terms of psychological continuity, but now it looks like psychological continuity can't be the same thing as identity because here we've got psychological continuity without identity. So what is the relation, is there any relation between psychological continuity and identity? Why can't psychological continuity be identity? Because there is psychological continuity across all three branches here with the original thing. That's right, that's what I mean. The X in every single desk is caused by the X having gone on the original, that's right. There is the causal connection, that's right. That's right, but is there identity? Are these all one and the same thing? In a weird way. You have to raise your game. Wow, okay, one, two, three, four, yeah. Sorry, won't it matter? Yes, when you've got different matter, that's right. Go together, that's excellent. Okay, good, so if you didn't have the branching and had the psychological continuity, then you'd have identity. Is that what you're saying? Yeah, I think that's right, I am defenseless against that. All this establishes is that when you have branching, you're gonna have psychological continuity without identity. It's consistent with that to say what you just did, that if you've got psychological continuity, but you don't have branching, then you have identity. So I mean, in the face of it, that's just the right way to deal with it. That's the kind of brute force way a mathematician would deal with this thing. Don't branch, right? What if you get branching? Okay, don't branch, right? If you don't branch, then you got identity, right? Well, what's right is that the causal connection to the original might get attenuated as you go on. But really what you're talking about here is not identity, because you're not talking about identity after this point, after the fission happens. You are talking about causal connections, but what you was writing, what you're saying is those causal connections will fade and get attenuated as the thing goes on. Yeah, there was, oh yes, yeah, no. Okay, you mean why aren't these all one and the same thing? Okay, well, there is a way of getting that effect here. I mean, these are, there are three things here, right? There are different ways you can take what you're saying. Would you want to say that at this point there are three desks of the disk's fission, or would you want to say there's just one desk? Oh, they're very similar, but one and the same. One and the same means there's only one thing here, yeah? If you come to visit me, and then an hour later you come to visit me, and someone says to me, how many visitors did you have this morning? Well, how many visitors did I have this morning? Two very similar visitors, or just one visitor twice? Yeah, I just had one visitor, yeah? And it's, I can't say, well, it was two different guys, but they were very, very similar, yeah? One and the same means there's just one. It's connected to counting, you see what I mean? Yeah, that's why you've got to say three at the end here. You can soften the effect by talking about, well, they're very similar. They are very similar, they're highly similar, but they're not one and the same, yeah? Components, that's an interesting idea. There's a sense in which is evolution, in evolution the way the thing is later is causally affected by the way the thing was earlier, right? Subordinate or a component is a, it's not clear that's the right notion here. I mean, if you think about yourself as you were a day ago yesterday, right? Are you a component of that earlier self? You're causally affected by the way you are yesterday. The way you are now is a result in part of the way you are yesterday, yeah? But that doesn't mean you're a component or subordinate to the way you are yesterday. Ah, yeah? This is in this way. Whether memory is quasi-memory, yes, right? There has to be another component, yeah. So what's the other component? Does that mean that there's no branching? Because if there's branching, there's gonna be more than one thing, yeah? So, I mean, this is another vote for that thing about, we don't want any branching, yeah? That's right. No, I think that's right, I think that's right. I think that's completely right, yeah, yeah. It shows that identity has two components. There's a causal connection thing and there's a branching thing, yeah? Yeah, oh, sorry, yeah, yeah. Can I give a simple example? Well, a really simple example of this happening in real life might be like an amoeba. I mean, I don't have the technical vocabulary to explain this properly, but I'm told that an amoeba is kinda like this, right? And so it kind of blobs along, right? It's a kind of simple, is it one cell? No, how many cells in an amoeba? One, yeah, okay. And then after a bit, it kind of blobs into two. You see what I mean? Yeah, and now you get two amoeba. And which of them is identical to the original? How many amoebae have you got here now? Two, right? Can they both be the same? Here is the original one from some time ago. Here is T2, here is T1, yeah, very good fission. Yeah, and you can raise all the same questions with the amoeba that we were raising here. Amoeba has no memories. No, it has causal connections to the past. Yeah, if you put an X in the amoeba here, right? It might be brutal, but I don't know, if you inject an X into the amoeba here, that will affect how the later amoebas are. Yeah, you see what I mean? You can do that, I mean, you can try this at home. No, no, no, that's not the way fission works. Okay, but that's important. Yeah, the X is going, does that make sense? Yeah, okay, one, two. That's another way of explaining it, yeah. Well, I'm not talking about that because then you get, it's fine to put in terms of a brain splitting in the two halves of the brain being put into different bodies. You can do that, it raises kind of complicated questions about the relative importance of what each half of the brain is doing, yeah. That's why when I originally presented it, I said, look, take me going left, take me going right, and I imagine me doing both at once, just imagine that very pure science fiction case, yeah. Because then you just abstract away from these complications about what exactly each half of the brain is doing. But yeah, but Paffett does put it in terms of brain halves, yeah, yeah, yeah. Just curious. Yes, yeah, well, the Miba over here will be older and wiser, and more resigned and fatalistic than the Miba here. Well, I mean, maybe I was pushing it a little bit, but there will be differences, yeah. The serious thing of what I'm saying is they are causally connected. Not that you are causally connected to the way you were yesterday, even though you may be sadder and wiser after the intervening events, you see what I mean? So you're not exactly the same, but what happened yesterday has causally affected the way you are today. So there won't be exact similarity between the way I think is earlier and the way it is later. The important thing is that the way it is late earlier is affecting the way it is later. Yes, that's right. So if you just get this case, where you get a single Miba through the time, yep. That's right. It's one and the same. Yes. How can identity not be maintained? Yeah, it really is puzzling. I mean, it is genuinely puzzling. You would think that in order to know whether identity is being maintained, as you put it, yeah. You just have to look at this one and this one. Who cares about what's going on in the rest of the world, right? If you want to know whether the earlier X is identical to the lesser Y, you just have to look at X and Y, and what's going on with anything else should be completely irrelevant, yeah. So if you're just gonna look at whether this one's identical to this one, you should be able to just look at this and that. And who cares what's happening over here? And your point is what's happening in here is just the same as what's happening in here, yep. So how can you justify saying this isn't identity, yeah? So I think that is a really natural line of thought. It is just a basic puzzle in this area because it seems very compelling what you're saying, but it just can't be right because I mean, this is one of these things where both the statement and it's contradictory. It seemed compelling, but if you follow that line of thought, you wind up with the idea that there's only one thing here. Yeah, only one thing in that situation. There are three things there, yeah. So we have to just ride over that, but it's puzzling. Are you agree? Yes, sorry? We have to, what does that mean? We have to change our, yes? Identity is a very simple notion. You know, one and the same is a very simple notion and it's very hard to see how you make any differences to it. Let me suggest one thing that, I mean, here's something David Lewis suggested. Lewis had the notion of a person's stage, which is like, if you look at you through time, if you look at you over time, you're kind of stretched out. So take a kind of slice of you as you are at this moment, right? And now take a slice of you as you are a moment later. Now, there are lots of slices of persons, yeah? And all those slices of persons, those person's stages are causally connected to one another. That's all right, following me so far? Okay, so we can talk about a person's stage or a person's slice and we can talk about a person as a set of stages that are causally connected to one another. Right? Now, suppose you take my set of slices as I stand here right now, from here, from now, to now, right? So that's just a little set of slices, yeah? Is that a person? Well, if that's a person, then there are actually two people talking to you right now because I hope to live to a ripe old age and I may yet do it, right? Yes? And whereas that little bit there has gone forever. So if that was a person and my whole life is a person, then there were actually two people during that period. You see what I mean? Because these are different things. So you don't want that. So if Lewis says a person is a maximal set of person stages, take a set of person stages and take the biggest one you can find that has those person stages in it and they're all causally connected to one another. That's what a person is. That's all right, yeah? So a person is a maximal set of person stages. So think about the person stages along here. Boop, boop, boop, boop, okay. All these person stages is this one a maximal set of person stages up to the joint? No, why not? Right, because if you go to put in the beginning slice, right? They're all causally connected to. So this whole thing up here is a maximal set of person stages. Yeah, that's what a person is. And what about this one? Where's the maximal set of person stages here? All the way down, right? So that whole thing is another maximal set of person stages. So this one here, you've got to go all the way down again, right? That's another maximal set of person stages. So how many maximal set of person stages have you got here? Three, okay? So down here, right? These person stages right at the start are elements of three different maximal sets of person stages, yeah? Okay, so that means that suppose that it returns out to be true, that I'm going to fission at some point in the future. So that in a year's time I'm going to split into two. Then how many people are standing here talking to you now? Two, nope, two. Because the elements of these person stages right here now are elements of two different maximal sets of person stages. Look, that's what you just said. Here I am talking to you right now. There's my upcoming fission, right? So we said there's this maximal set of person stages and there's this maximal set of person stages and indeed there's this one, yeah? So the stages that stand here talking to you right now are elements of three different maximal sets of person stages. No. Remember I said maximal, right? Can't be just a little bit, yeah? As of now, yes, maximal up till now, yeah, but that's not the way you count a person. I mean, it's not like I die right now. Yeah, I'm continuing any resistance for a good long time if the Lord spares me, yeah? You see what I mean? So one way, a radical move to get round this is what Lewis did and say, in a case of fission, there were actually three people there the whole time or two people there the whole time. I mean, this view has generally been thought to be brilliant but unsound, right? But I just want to mention that because people were saying, well, you need some radical rethinking here. Well, that is one kind of radical rethinking, yeah? Yeah? Yeah, you're making a, you're making a, yeah, yeah. You're making a point about what you know when, right? If I don't know right now I'm going to fission and then I do know that I fissioned here or that there was fission, that's fine but this is not a point about knowledge. This is a point about, suppose this is what really happened, yeah? Then what is the right way to describe the situation? I'm not thinking about what anybody knows when, yeah, yeah. That's right, they just separated, yeah, they were different the whole time but they just each came into their own as it were, yeah. That's right, it is a way of resolving all the formal puzzles about fission, yeah? It's very elegant, that's why it's worth mentioning to you right now, it has a kind of force but as someone said, please, not two people, right? It just seems too breathtakingly wild and to most people to say, the right is a stand right here, right now. There are two people speaking to you or five or whatever it is, yeah, yeah. It just seems completely incredible. You can't believe that, yeah, yeah. No, because none of these three people have got a divisible mind. There are actually two different minds talking to you right now in this picture. Neither of them is divisible. How does one? No, that's not the way it works. They're in the same place at the same time. They're doing the same thing, yeah. No, there you go too far. Okay, we should move, one, two, three, yeah. Yes, I agree that's a natural question, yeah, but clearly they weren't independent because up until the time of the fission, they were composed of the very same atoms. So it's not an accident that they just randomly happened to do the same thing. By the laws of physics they had to be doing the same thing because they're made of the very same atoms, yeah, up until the fission, yeah. Oh, yeah, we have two things and they can't both do the same thing, yes, that's right. They can't be, two different things can't be one and the same thing. That's the point. It's a simple logical point. It doesn't really matter about whether it's time or not. It's just whether you get two different things or one thing, yeah, and when I say logical, I don't mean to imply that it's technical, I just mean it's particularly obvious, particularly compelling, you know, you just got a contradiction if you deny this. Two different things can't be one thing, that's all. And if this is the same thing as that and that is the same thing as that, then this would have to, then, well that's what this thing suggests that this would have to be two different things. Either that or these two would have to be the same thing. I said, we should move on. Let me just, if there's anything you can hold, please put it on hold. Okay, so if you have that, as I do actually have that, oh please, please note two reaction due to that kind of analysis, then I think the only thing that's left is to say that identity is psychological continuity and no branching, right? That was a suggestion that you guys are coming up with. Identity is a special case of psychological continuity. You can define identity as psychological continuity and no branching. So actually, let me just skip over this a little bit because time is pressing on. We had this definition from Schumacher. The later person, the identical to the earlier person is the overwhelming majority of the, are caused in the right kind of way by the earlier person's memory impression. And you go to add, and there isn't any branching, right? You need that for your definition of identity. Because you've got this position in the fission case and so even in the case of the tables, what we were saying was it's not enough that the later table causally depend on the earlier table. You've got to add, and there isn't any branching. So we're going to say sameness of the person is sameness of the physical body. If Williams is going to say sameness of the person is sameness of the physical body, what that means is the condition of the later body causally depends on the way the earlier body was and there isn't any branching. So if you're going to say, I really want it to be me, if there's going to be an earthquake and everyone in the room doesn't make it except for one, and I want that one person to be me, right? That's why I always sit right next to the door, yeah? Then if you want it to be me, right? What you're saying there is what I want is that the one person who makes it out of here should be causally connected to this person and there should not be any branching. So identity is causal continuity without branching, yeah? Okay, and now we put the bite on. What is that? Tell us about the concern to survive. Now we get the critical, now here's a critical point. If you're saying, someone told you there's only going to be one person that makes it out of the room and you say, oh, I want it to be me, well, you say I want it to be me because he or she is identical to me, or you can say, because I want causal continuity between the person that makes it out and me, right? These are two different ways of thinking of it. So suppose you say, well, the future person matters. What I care about in the life of this future person matter is that the future person should be identical to me. Well, what's identity? Identity is causal continuity and there's no branching. Now, I think if you just think about it at that abstract level, you can see why causal continuity should matter, right? You want, I mean, everybody wants that the world later should have some bear some impact from what you did now, right? If someone says Steve Jobs lives on in the iPad or something like that, yeah, then, or in the cultural revolution he generated, right? Well, I don't say it's much help to Steve Jobs, but that's the kind of thing you would like, right? I mean, academics care passionately about that kind of thing that they're, just to take the profession, I know best, that they want some impact of them to live on in the future. You want your friends or your family to remember you. You want there to be some lasting impact of what you're doing, yeah? So applying that to your concern with a future self, wanting that there should be a future self that is very closely, causally connected to your current self, that seems to make perfect sense. But if you care about identity, that's saying, I really care about branching. Branching is really important. I really am not actually concerned about branching. Well, causal continuity with your current self is a reasonable concern. I mean, caring about what happens to your children is a reasonable concern. I mean, caring especially about what happens to your children because they're the ones that you're causally involved with. That really seems like a reasonable concern. But I mean, if you had one child and you really care about it, well, that's all right, right, you care about it because it's causally connected to you. But suppose you have three children, and in that sense, there was branching. So you can see, oh my God, there was branching. I mean, right? So I can't care about any of them. I accept that they're all causally very related to me, but there was that terrible branch. And now I think, oh no, no, no, no, right? That would be a very unusual reaction. I mean, it's one that is fine. It makes perfect sense to care about causal connectedness to you. But caring about branching is really kind of crazy. I mean, just if you say I care about branching, how could you possibly justify that or even make it intelligible? Another way to think of it is to think of these exploded diagrams we had where you say, well, I can show the person is like, made up of these components. And now you realize that all you care about when you care about me, when you say, I really care about my survival, is that you realize that all that's going on is that in this room right now, there are all these strings of experiences causally connected to particular bodies. And when you say, I care about the continued survival of this person, what you're saying is, I care about the prolongation of the string of experiences causally connected to this body. So but why should you do that? It's kind of like rooting for one football team as opposed to another. Yeah, I mean, the reason it's fun is there isn't any objective ground for profit. I mean, some people do sometimes get people who root for a particular football team because they're the most successful. You know, they're the one that has most wins. That is a very shallow and thoughtless kind of person. Yeah, I mean, rooting for a particular football team is arbitrary. I mean, it's fun to pretend as not, right? But it really is arbitrary. You know, it's not based on anything. You just root for this one. So when you realize that you can analyze yourself in terms of a bunch of components, you realize, I'm just rooting for this string of experiences. And there is something arbitrary about it. Here's Parfit. We are strongly inclined to believe that our continued existence is a deep, further fact, distinct from physical and psychological continuity. When I believe that my existence was such a further fact, there's the essential me, and I care about whether that makes it. I seemed imprisoned in myself. My life seemed like a glass tunnel through which I was moving faster every year, and at the end of which, there was darkness. When I changed my view, when I realized that all that's going on is that I am rooting for the prolongation of the causal influence of a particular set of experiences and a particular body. When I changed my view, the walls of my glass tunnel fell away. I now live in the open air. There is still a difference between my life and the lives of other people, but the difference is less. So, the point of this kind of technical analysis of what you're caring about, when you care about yourself, when you say what's in it for me, is to undermine that kind of obsessive picture on which you're in the glass tunnel. What you care about is causal impact in the future on analysis to see that that's what's going on, then you realize that that effect could be had without the continuance of your identity, and there may be lots to be discussed about what kind of causal influence is in the future. Okay, I'll just pause for a second. You want to see that again? Where I believe my existence is a further fact, meaning that there's something, the essential me where you might say, well, either that makes it through fission, or it doesn't, yeah? And if it doesn't, that's the end of the world. That's when the light goes out. That's death, yeah? Yes, yeah. That was the picture of which fission is the same as ordinary death, because that deep further fact about whether you continue to exist doesn't hold anymore. That's right, that's right. You can say, well, why do I care about causal continuity? What kind of causal continuity do I care about? I mean, after all, a great war criminal might have a huge causal influence on the world later. But that shouldn't be no consolation to anyone, right? That you think, well, you know, I've left my mark on all these people. Yeah, you see what I mean? Causal continuity, once you start thinking about causal continuity, causal continuity as such isn't important either. Everything depends on the kind of causal continuity. So you start thinking, well, why do I care about myself so much anyway? Not because I care about branching, and not because I care about causal continuity as such. And now we start to, let me just give you another example here. The kind of thing that Parfit's doing here is people often try radical attacks and self-interest, right? I mean, you know, any pastor is going to say, well, of course, we're all very selfish, and we ought not to be so selfish and so on. That's not what Parfit is doing. He's saying, be selfish. Let's stick with the selfishness. Stick with it that you're just out for your own interests and you care passionately about your own survival. Now just pause and put a microscope on that concern. What is it that you're concerned about when you're concerned about with self-interest? What is it that you're concerned about when you're concerned about yourself? So this is not a radical critique. This is saying, let's live with the self-interest and see what it is. So just to give an analogy, suppose you live in a village where they have baptism, they have a baptism ceremony at which lots of the elves are present and the newborn child is named and initiated. I suppose it's not religious. Suppose it's a secular tradition, right? You could have a baptism ceremony like that. Well, you can imagine two kinds of critique of that kind of thing. You could say, well, on the one hand, a conservative could say, well, what we all value about the baptism, of course, is not the ceremony itself. It's just that we celebrate somehow the birth of the child and that we bring it into the community. That's what's really important about it. So really, what we want the ceremony for, you could have without the actual ceremony itself. You know, if it's very expensive, for example, you could say, let's not bother having a ceremony. We could equally well get this effect without the ceremony, yeah? Exactly. Exactly. You could say, look, what do we really value about marriage? And one kind of critique would be the things that are important to anyone about marriage you could have without the actual ceremony itself. Yeah, that's a very familiar thing. So that's a conservative critique in the sense that it keeps in place the structure of the concerns that motivate the ceremony. But it says there are maybe other or better ways to satisfy those concerns. You see what I mean? It's not challenging the concerns we have. It's just saying there are better ways to get the effect. On the other hand, a radical critique would say, actually, what we should be doing is growing children in test tubes and sending them all off to live in communes. We don't go for any of that stuff that the Baptist has said. That would be a radical critique. We should be designing the children in test tubes and they should all be being brought up in communes. That would be a much more efficient thing to do. So you could say, look, forget about your ordinary concerns. I'm going to stand right outside that, redesign the whole thing from scratch. Now, that's what somebody's doing when they say don't be so selfish. They're saying, anyone's reaction to that is, but I've got to look out for myself. This is part of your task in life, right? So minimal looking out for yourself is just required. So it's not really, it's not, you can't stand outside on Mars and look at us all from the outside and then of some way of critiquing what we're going on. I mean, the problem is, if you do reach that kind of radical critique, that radical perspective, that Martian perspective, then you don't have any idea of what you'd want. You've got to stick with our actual concerns. So a radical attack on self-interest says, well, my death doesn't matter anymore than anyone else's. Look at it from the standpoint of the cosmos. My death is not important. But that's not what Parfit is saying. Parfit is saying, don't radically challenge self-interest. Just ask, what is it that you're concerned about when you're concerned about yourself? Just as you might say, what is it that I value about marriage? Or what is it that I value about baptism? So he's giving a conservative critique. What concerns us in self-interest? Couldn't we get that what we really care about without concern for the self? So when you put the microscope on what you're concerned about with self-interest, you realize there's kind of junk in there. There's stuff about branching that really, who cares whether I branch or not? That's not important. Or you say, I'm really concerned about the continuance of this set of components. Well, why should I care about that? And you can ask lots of questions you couldn't ask before. When you have that exploded view, you can now start asking, well, what do I care about in this causal relation? What kind of causal connection is important to me? Couldn't there be cases in which you say, I can have the causal impact on the future world in a way that's better than if this body continues to exist. So this is the naive picture that it's natural to have. I mean, the naive picture that it's natural to have is, what I care about when I'm wondering if I make it through to 2014 and thinking that that's terribly important, is that there'd be one in the same thing as me in existence in 2014. But you break it down. Is this body in complex of experiences be causally effective in a later body in complex of experiences? This self has really vanished. What I care about really is not the survival of the self, but the causal continuation of a bundle of things. And you've now subverted that self-interest from the inside. What I really care about is that the string of experiences going out into the future, that's causally related to my current experience, to these current experiences and this body, that that should be as long-lasting and rich as possible. So we've got a microscope and self-interest now, and you can subvert it from the inside. We haven't had that much time left, but the idea was that it might be good to hear what people were doing for the essay. I mean, deadline is a terrible word, but the deadline is thirsty, and are you guys up for this? Sometimes you'll look pretty good. We were going to hear what theses people were going to argue for in the essay. Yeah? Okay, so the thesis is that Huxley is wrong about epiphenomenalism. So epiphenomenalism is wrong. Okay, very good. Yeah. I'd like to spring people a little bit, because there's some of you guys I never hear from and I'd just like to know how you were thinking about this thing. You don't have to speak if you'd rather not. You can plead the fifth, but I just caught your eye. So yeah, yeah, good. Okay, so Jackson was right. The thesis is Jackson was right as against physicalism. Yeah, okay. So you don't think it's just one physical world? His argument, the Mary argument, because what's that? Oh yeah, they are all hard topics. Okay, let's just go down this. Let's just arbitrarily fasten on this section. Okay, so you're agreeing with Williams and saying identity doesn't matter the way, I mean memory doesn't matter the way Locke said. Very good, yeah. So you have to take on the prince and the cobbler head on and say body swaps are impossible. Is that right? Does that what you mean? Right, so are you going to say that memory switches don't make sense? Good, yeah, yeah, excellent, yeah. Okay, the identity thing, yeah. Very good, yeah. That's great, that's a very interesting case. So he's got all the apparent memories from earlier, but he doesn't have any sense of ownership of them. He doesn't, he feels like that wasn't me. Yeah, what does that to do with me? So is it really him? Yeah, that's a great question, great case. Yeah, yeah, excellent. Right in the back, in the far corner? Yeah. Okay, that's why you're sitting in the back. Okay, person beside you? Sorry, pass, okay. Negals thing shows that physical is unfunctional, as in can't be the whole story, yeah. Yeah. Yeah, so what more is it? Okay, fair enough, yeah, yeah. Yeah, yeah, the green stretcher, yeah. Oh, I see, so in principle, we could find out everything there is to know about the bat. Yeah, maybe. Okay, great. Well, actually, what I love about all the theses that people have put forward so far is that they are nice, strong theses. You see what I mean, this is great. I mean, the whole point of setting up the essay in this way is to ask you guys to nail your colors to the mast, you know, if that's the phrase I want. So that's great, don't be afraid to go for a strong thesis. I mean, subject to the recommend of you, advice you, your GSI. Yeah, yeah. Okay, so boy, this is quite a strong antiphysicalism, set of responses, but the person next to you is, yeah. It is better, epiphenomenalism is better than dualism. Yeah, yeah, yes, okay. I mean, it's not, it's hard to believe though, isn't it, epiphenomenalism? But your point is, the argument forces you there. Is that what you're saying? Yeah, yeah, yeah. Yeah, I mean, nobody would say about epiphenomenalism. Yeah, that's what I've always thought. You see what I mean, it's, well, actually, you'd be very unusual with any rate if you were like that. But yeah, that, the argument forces you there. Yeah. Somebody else who doesn't, whose views I don't know about that, well, in the, I don't know what the word is, scarlet, crimson, the women scarlet, any scarlet? Yeah, it's like Jackson and Jackson's thing about physicalism, are you for it or against it? I mean, what's the line, what's your line? Against physicalism, boy, physicalism is taking a pounding. Is it, is there anyone I'm gonna argue in favor of physicalism? Whoa, okay, all right. Okay, you, whoa, okay, I guess I know what you're thinking. Right, uh-huh, very good, okay, that sounds good. Yeah, what's the untrue premise? Great, very good. Yeah, let's go, let's just see if you guys, okay, these are great lines, yeah, yeah. Does Neagle have a definition of physicalism? Very good, great, okay, yeah. Okay, this is great, okay, this is quite a dialogue between you guys and the guys who came up earlier. All right, okay, just another couple, what are you? Are you, yeah? No, no, we just talked about a whole ton of stuff. Oh, all right, all right. Yes, right, so yeah, okay, I see, okay, so that's the take that you need some kind of from the inside understanding of what went on in order to be the person. Is it, would that be a sound bite? Yeah, yeah, okay, no, no, no, you put your personal view in at the start. I'm sorry, that's the whole idea. It's not like meant to be a mystery. What your personal view is that just the reader is absolutely agog when it comes out right at the end, you gotta get away from that. Put your, I strongly encourage you to put your personal view right at the start. Yeah, but anyway, carry on. Okay, that's good, that's a pretty sophisticated kind of take, yeah, okay. Anyone else is, we just have a couple of minutes. Anyone else? No, yeah. Oh, actually in the frogs and epiphenomid was a great, yeah, yeah, great, okay. Okay, well, on Thursday we'll do one last time on identity and then we'll move on to the next phase. Just like, okay, great, thanks guys.