 This will be a way of correcting. OK, hello. Good afternoon. So today, we're going to go over some points from Megal and Jackson. And actually, just in doing this course, it really has come to seem to me that a lot of the basic problems here are about a kind of tension between imagination, recognizing the centrality of imagination in our ordinary thinking about the mind, and physicalism, the idea that physics gives you complete coverage of what's there in the world. In lots of different ways, what keeps coming up is that we seem to have imaginative understanding of a sector of reality of the mind in particular. And physicalism doesn't seem to make sense of why we need imagination to understand that sector of the world. If physics is the whole truth about everything, then surely, all understanding of the world is ultimately physical understanding. So why would you need empathy or an imaginative ability to project yourself into someone else's shoes in order to understand what's going on with our mind? But that does seem to be the case. So today, I want to try to set out one way of trying to reconcile these two. I'm not at all sure that it's convincing, but let me try it on you. Next week, we start out on personal identity, the identity of the self, with those readings from Locke and Williams on Tuesday and Thursday. But I want to start out with the question, well, what is physicalism? If we're going to think about what the idea that the world is purely physical has to do with imagination, then let's start out by just saying a bit more about what it takes for physicalism to be true, for it to be true that it's just one world and it's a physical world. So we've had three ways so far in the class of saying what physicalism is. So the way we started out with Descartes was physicalism says there's only one kind of stuff, physical stuff. What's the opposite of physicalism? Jewelism, very good. That's so rewarding. Jewelism being the view that there's two kinds of stuff, right, physical stuff and mental stuff. Another way of stating it, when you have a model like water is H2O, lightning is discharge of electricity, pain is C fiber firing, the idea there is every time you've got a psychological state like pain, you can find some physical state that's identical to it. So that property of being in pain is the same as the property of having C fiber firing. Being angry will be having a particular configuration of your amygdala, something like that. So maybe you could do that for every particular mental property. And then Jackson had still another way of saying what physicalism is. Jackson's formulation was all the correct information is physical information. If you get all the correct physical information, then you've got all the correct information that there is. That seems different. It's hard to know exactly what the difference is, but they all seem different, right? And if you say that all the mental properties are physical properties, presumably you're going to think there's only one kind of stuff. But if you thought that the mental properties are different to the physical properties, would that mean you thought there were two kinds of stuff? No? Be your hand up if your hunch is no. Very good. I think that's the right answer. If you think the right answer is yes, unless you forgot to want the questioners at this point. Let's see, what was the question? If you think that there are two kinds of properties, mental properties and physical properties, and those are different, does that mean you think there are two kinds of stuff? No, there might be just one kind of stuff with two kinds of properties. Stop me if this is getting too technical. Is that all right? There could be one kind of stuff with just two kinds of properties sticking out of it, if you see what I mean. And then Jackson, so these are different ways of saying what physicalism is. And then Jackson says, this is a different formulation. He says all the correct information is physical information. So that's different, right? And just to say the kind of thing that I have going through my head when I see this stuff, there's only one kind of stuff, physical stuff. I mean, I don't think that's actually a very good way to set things up, because it makes it seem like if there's problems with the idea that the mind is physical, we could solve them by postulating ectoplasm, a second kind of stuff. But if you really think that the problems about seeing how the mind can be physical are problems about reconciling an imaginative, viewpointed understanding of the world with an objective understanding of the world, then ectoplasm is just giving you more objective stuff. It's not really helping. So that actually doesn't seem like a very good way to set up the question. If you say that every mental property is identical to some physical property, then the problem there is variable realizability, right? You say pain is C-fibre firing, but here we have an octopus clearly in pain with no C-fibers, no C-fibre firing. So pain can't be C-fibre firing. That was the point about variable realizability. You don't get that one, one map from mental properties onto physical properties. Because for any mental property, there's a whole bunch of different physical properties a thing could have and still have that mental property. Is that familiar? I hope that's familiar rather than something you forgot long ago. Yeah, you can pause me. Does that make perfect sense? So what about this way of setting it up? All the correct information is physical information. Jackson doesn't discuss this formulation of physicalism very much. He just says, that's what physicalism is. And then he gets on with giving this example of Mary, who's got all the physical information, but doesn't know about the colors. That's what makes this example so powerful, because she seems clearly to be getting new information, when she sees the world of color, although she already had all the physical information. But that notion of information, this really came up in the discussion. You guys brought out a lot of this in the discussion. You have to make a contrast between getting information about some new aspect of the world as opposed to getting information about something you already knew a lot about, but getting it in some new format. Someone had the example of romantic love. You've read a whole lot about it in theory, but now it has you in its throes. In a sense, you're not really learning anything there. You're just getting the old information in a new format, information about all this old stuff that you knew about it already, is getting you in a new way. You see what I mean? So does that make sense? So if Jackson says, well, Mary is getting you information, we don't really know yet. Is she getting information about some new sector of reality when she steps out into the world of color? Or is it that she's just getting information about the same old things that she knew about already, but it's a new format for the information? So let me just go over that notion of a format. And I don't mean anything very technical here. All I mean is, if someone tells you all about their trip to Outer Mongolia, if someone tells you all about it, then you can get pretty much the same information from them telling you about it in great detail as you get from being there and feeling the wind on your back as a thunderstorm sweeps across the plains. So when you're there, you're not necessarily finding out anything that you didn't know about before. You're saying, yes, this is just what she told me it would be like. I knew it was going to be like this. So you're not getting information about new stuff here. You're just getting the information in a new format when you're actually there. Or if you look at a photograph and you say, well, yeah, that's just the way it was described to me. Or there could be fairly trivial changes in format, like getting it in lowercase text as opposed to using block capitals the whole way through. So is that reasonably intuitive, that idea of different formats you could get the knowledge in, whether it's what kind of type you're using, or whether it's reading it or getting a photograph, or whether it's being told about it or being there? It could be the same stuff you're hearing about in different formats. OK, so I want to have that notion of a format in place, a format of information. And then now here's another new friend. Supervenience. Supervenience. We haven't talked about supervenience, have we? You guys are usually way ahead of me in everything I say. I just want to take pleasure in this moment for a little. But OK, here is a new friend, supervenience. This is actually probably the standard way that philosophers have of saying what physicalism is nowadays. It says, suppose two possible worlds are the same in all physical respects. Then they're the same in all psychological respects. In fact, then they're the same in every respect, whatever. So if physicalism says, if you fixed all the physical facts, then you fixed all the facts there are. So again, here are some little green friends. Here are all the possible worlds. So there are different ways things could have been. If you, as you sit here, are thinking, by God, I wish I'd taken astrophysics, then I wouldn't have to be sitting through all this stuff about schizophrenia or God knows what. I could be finding out about the origins of the universe. Then what you're talking about here is, well, you're talking about what could have happened, what would have happened if only I'd done things differently, or what might happen in the future. So you're not asking questions about what could have happened so far as I know. I mean, sometimes when you say that something's possible, if you say, if I'm saying to you, well, where is Bill? And you say it's possible he's in the cafe, what you mean is so far as I know he's in the cafe, right? But if you're sitting there thinking, I could have taken astrophysics, it's not that you're thinking, hey, maybe I did take astrophysics. Maybe this really is an astrophysics class. Do you see what I mean? If I'm thinking, boy, I wish I'd called in sick this morning so I didn't have to give this lecture. I could have been in a bus out of town, right? If I'm consumed with regret there, it's not that I'm thinking, hey, maybe I am in a bus out of town. Do you see what I mean? The whole poignancy is I could have done it, but it's manifest to me that I didn't. Do you see what I mean? I mean, these guys always know what I'm going to say before I say it anyway, so why? What is the profit? I could have been in that bus, right? So when you talk about worlds here, when I talk about worlds here, these are all ways things could have been, whether I know it or not, right? I mean, even if I know that this is, see, one of these worlds is a special. One of these worlds has got an A on it. Can you guess why? This is an A on it. That's where we are. That's right. That's the actual world, right? That's here, right? That's what's actually going on. All these other worlds are non-actual. There are ways things could have been. So when you express regret or relief, you're saying, boy, when I express regret, I'm saying that possible world is much better than the one I'm actually in, yeah? Or when you express relief, you're saying, hey, there's that world over there that was just terrible things happened to me. But thank God I'm in this world. You see what I mean? Yeah, so that's possible worlds. I mean, I put it in kind of emotional terms, but anyway, they are emotionally important. OK, so we're talking about what could have happened, even though you know it didn't, as opposed to what could have happened so far as you know, right? Regret relates to what could have happened, even though you know it didn't. So we've got three ways of formulating physicalism. There's only one kind of stuff, physical stuff. The only properties are physical properties or Jackson's. The all correct information is physical information. So Supervenience says, suppose you've got two of these possible worlds. And suppose that in two of these possible worlds, all the physical facts are the same. All the microphysics is the same. All the facts about the basic forces in the universe are the same. Everything like that is the same in these two worlds. Then are all the facts whatever the same in those two worlds? Does it follow? This is your question. OK, let me repeat the question. There are all the microphysical facts about this world. There are all the facts about the atoms or gluons or whatever they are. What are gluons made of? Are gluons made of something? Does anybody know? Are there any physics guys in here? Well, take it from me, then, that gluons are the basic building blocks of the universe. They're these fundamental particles and these fundamental forces. And they're the facts about the way they are arrayed in this world. So suppose you take another world in which all the basic microphysical facts are exactly the same. In that world, does everyone have the same psychological states? Does it follow that they have the same psychological states? Put your hand up if you think the answer is yes. Very good. And a lot of somewhat hesitant. And put your hand up if you think the answer is no. Wow, OK. That's slightly more yes than no, but not much in it. I would have said, OK. Did anybody care to explain their answer? Yeah? Oh, very good. Right, we need one here. Convenience seems to say a leap all part. Right. It's very good. Yeah. After a new world is created, they'll both be completely different. Right, there could be some indeterminacy in how it goes. You fix all the basic physical facts about the universe at one time, and it might unfold differently in different possible worlds later. Is that right? Is that what you're saying? No, that's absolutely fair enough. But OK, so in those terms, let me, I didn't say anything really explicitly about time here. But suppose we say that we have two worlds here that are exactly the same in respect of all the basic physical facts over a long period of time. Yeah, I mean, that could happen. That is possible, yeah. So suppose you've got two where everything did, in fact, unfold in the same way over a period of time. Then the question is, over that period of time, are all the psychological states of people in the two worlds the same? Like, if you have a headache, I mean, since all the basic physical facts about the two worlds are the same, then there's someone in this world, there's you in this world, and there'll be someone at any rate who looks exactly like you in this world, because they're particle for particle identical to you. So if you've got a headache, will your counterpart here have a headache? Yeah, does it just follow? That's the question I'm asking. Again, can you put your hand up if you think the answer is yes? We've got helpful clarification. And if you think the answer is no, OK, I think if I keep repeating it, the nose will keep going down. OK, anyone else speak up for the nose? Yeah? The same physical. For every fundamental particle, for every fundamental space time point, you've got a corresponding one in the other world with exactly the same physical properties. Yeah, yeah, yeah. Well, the same thing twice. I mean, if you've got a place here, you've got a place there, and if this place has got electric charge on it, that place has got that same electric charge on it. Yeah? Yeah? Yes? It's had the exact same history. That's right, they've had the exact same history, yes. There's no distinction, right? There's no distinction physically. The question is, does it follow? No, there's no distinction mentally. So I'm not trying to, it's not exactly what I'm trying to persuade you of anything here, it's that if physicalism is true, then it does follow. Do you see what I mean? It's a way of stating what physicalism is. I myself just find it very hard to believe that's not true. I mean, just to be played with you. But if you ask for a proof of this, Jackson? Well, I have a slide that says that's not so. So OK, well, what I was thinking was, I see what you're saying. You could have the physical stuff and the mental stuff. And when you fix the physical stuff, that causes the mental stuff to be the same. Yeah, you could say that. I agree, and a lot of duelists would say that kind of thing, I think. It's not an academic answer. Right. But remember, we're talking here about possible worlds. Now, how many possible worlds are there? Five? 10? A lot, yes, a real lot. I mean, usually people say there are infinitely many possible worlds. So this is only a small sample. And as you can see, some of them are nearer to the actual world than others. If I'm cycling down the lane here, and you come sweeping by me in your car, and I say, you nearly knocked me off my bike, I say indignantly, then that's to say, there's a world in which you knocked me off my bike, and it's really close to this one. And if you say, I was nowhere near you, you are perfectly safe the whole time. You're going to admit that it's logically possible that I get knocked off my bike. But that world, you say, boy, that's way out here, that couldn't easily have happened. You see what I mean? So some of the worlds are closer in than others. So Jackson's point is, if you take two close-in worlds, and you say, all the physical facts are the same, that means all the mental facts are the same too, because the physical facts are going to cause the mental facts to be the same. That's fair enough, but full strength physicalism says, all you have to do is fix the physical facts. Now there might be some causal process by which the physical facts generate the mental facts, but there's going to be a possible world in which that process doesn't work. Something interferes with the causation of the mental facts by the physical facts. And then you'll have two worlds that have got all the same physical facts, but different mental facts. Am I going too fast? Plenty's a day. Is that OK? So part of the pleasure of this way of formulating physicalism actually is that once you get the basic idea, you can see lots of different ways. You could jig it. So Jackson's way would suggest saying, I think there's a kind of physicalism that says, as long as you've got two nearby worlds, two kind of sensible worlds, not worlds where cows suddenly speak or turn into gas or become neutron stars, you see what I mean? Kind of sensible worlds. Then if you fix all the physical facts, you fix all the mental facts. But the way I'm formulating physicalism is just the simple, full-strength version that says, if you've got any two possible worlds at all, however strange, however weird, however remote, then if you fixed all the physical facts, you fixed all the mental facts. So in that way of looking at it, there couldn't be two kinds of stuff, physical and mental. If there were two kinds of stuff, you could fix all the physical facts, but what's going on with the mental stuff is something else. So there'll be some possible world in which you get the same physical stuff, but you don't get the same mental stuff. And if you say, well, suppose you remember the kind of physicalist that says, pain is just C-fiber firing, the central state materialist. If you're a central state materialist and you say stuff like pain is just C-fiber firing, are you going to think the supervenience is true? Put up your hand if you think the answer is yes. Okay, if you say pain is just C-fiber firing, that's all there is to being in pain. And then you'd fix all the facts about C-fiber firing. Have you thereby fixed all the facts about whether people are in pain? Put up your hand if you think the answer is yes. Well, that is the correct answer. Very good. If you think the answer is no. Not that I'm trying to prejudice you here. Well, I'm not quite sure I can explain it anymore fully, but look, if pain is just the same thing as C-fiber firing, then if you set all the C-fiber firing facts, then you thereby have fixed all the facts about who's in pain and who isn't. I mean, there's nothing more to fix. You see what I mean? But I suppose you get variable realizability. Suppose you've got octopuses who've got pain, but not C-fiber firing. Well, could it still be true that if you fix all the physical facts, you thereby fix all the mental facts? Yes, it could. Very good. Yes. Some people at the front were nodding intelligently. Does that make sense? These are very simple points. If it doesn't seem completely clear, I'm just not explaining it very well. But if you say there are lots of different ways of having pain, lots of different physical ways, there's what the octopuses have, there's the C-fibers, there's what the Martians with silicon-based body chemistry have. There are all these different ways of physically being in pain. So you can't define pain as C-fiber firing. It could still be true that your physics completely fixes whether you're in pain. You see what I mean? So this is part of what is so pleasing about this definition of physicalism. Now then, Mary. The question about Mary is, Mary's got all the physical information about the physical characteristics of the actual world. Mary knows all that stuff. But are there still different possible worlds about which that physical information could be true? That's to say, Mary knows all the physical facts, but are there different possible worlds where people have different kinds of mental lives consistent with Mary having all that physical information? So here's Mary sitting in the actual world. She's got all this knowledge about the physics of our world. Now in this world, people have one kind of psychology. They have one kind of color experiences. But are there going to be other possible worlds where the physics is all just the same, but the mental lives of people are quite different? Yeah, you see what I mean? Yeah. So if that's possible, if that could happen, that the physical information could be fixed, but all the mental stuff be quite different, then physicalism, the way I formulated it, is false. And Mary's finding out about some new sector of reality when she finds out about the colors. Again, every individual point I'm making here is very simple, so keep pausing me if any of it. If I don't explain it, it's something quite clearly here. They're physically set up in exactly the same way. We assume that all the physical information is complete and correct, yep. And if there are any indeterminacies, I mean, as you said, there are indeterminacies. We just factor them in. We just build in which way it went, yep, yep. Does she learn something new when she learns that it's this world rather than this one that she's in? I mean, that's not a very good way to put it. She's got all the physical information, so the question is, are there worlds in which the physical information is the same, but the mental lives of people are different? Physicalism says no, yep. So there's a sense in which Mary's getting nothing left to learn once she's got all the physical facts in, because that completely determines which world she's in. On the other hand, if the psychological life can vary, even if the physical stuff is all fixed, then Mary does have some new facts to learn. Does that make sense? Yep, oh, yep. No, it's not at all meant to disprove the existence of consciousness, yeah. Nobody on the board here, as it were, nobody we're considering is denying the existence of consciousness. We will later in the term discuss people who deny the existence of consciousness. Well, that's kind of an advanced topic, and we haven't got that yet, yeah. So everybody here agrees consciousness exists. The issue is, given it exists, is it physical? And at the moment, what we're just trying to do is pause in the question, what does it mean to say it's physical? Yeah, and very good. It's like, it's the same world. Not for the first time, you guys are making the point I was about to come on to, but if you say I can have possible worlds where all the physics is the same, but the conscious life is different, then that really does seem to lead you to the monkey and the tiger, because the clockwork of the physical world just keeps relentlessly unrolling in all these different possible worlds, so everything goes on just exactly the same. The variation in the conscious life is not something that's making any difference to what happens, yeah. People sometimes put that by saying there's causal closure of the physical. If you think of a billiard table with lots of balls rolling about on it, then you can look at how all the balls causally affect each other, right? They knock each other about, and then sometimes a force comes from outside, a billiard cue, boing, and makes a ball spring into action, even though no other ball hit it, yeah? So the billiard table is not a closed system. There are kind of inputs of energy from outside. The question then is the physical, is the brain a closed system like that? Well, the physical is a closed system because we have all these laws of the conservation of energy. If there was really a mind outside the system that was causally active, then it should be able for the mind to come in like a billiard cue and prod the neuron into life. For example, when there was no physical cause of that at all, yeah? Then suddenly the neuron starts firing. No physical cause, and not because it's indeterministic, it's because this jab came from outside, from the ectoplasm, yeah? Now, that just doesn't happen, it's just a datum that there are these laws that say that kind of thing doesn't happen, the physical is closed, yeah? So if you fix the physical, there are no jabs of input from anything else, then if you say consciousness is not thereby fixed, then consciousness must be an epiphenomenon, is making no difference to what goes on, yep? Okay, so suppose we have two different possible worlds about which Mary's physical information is correct, and suppose that in those two possible worlds, people have different experiences of red. If that were true, would supervenience be true? Very good, right, exactly right. So the mental doesn't supervene in the physical, if that's right, if you're gonna have the same, physical stuff, but different mental stuff. There is going to be a question why you say that the sensation of redness is being rooted in one pattern of cell firing rather than another, and the point we went over a couple of sessions ago is that there is a kind of unintelligibility about that. Why redness rather than greenness being correlated with this pattern of cell firings is not like the average speed of motion of molecules being correlated with water boiling. That's what makes it seem possible that the mental could come apart from the physical in the way it does. Actually, can I just take one last vote on this? Could you have two different possible worlds in which everything physical is the same but all the qualia are different? Put out your hand if you think the answer is yes. And if you think that, yep. Okay, let's just pause a bit. People are slowly, okay? And if you think the answer is no, and if you have no idea what the question is about, okay, and if you didn't understand the question perfectly well but you just don't know what the answer is, I would say it's not quite a third, a third, a third. Okay, yeah. Yes? What do you mean the same thing? Physically the same? Well, listen. Listen. I was hoping to take the answer from you, right? Yeah, but remember everything about them is physically exactly the same over a long period here, yeah? It's not just that they're watching the same movie. Their brains down to the finest level are exactly the same, yep. Identical tones of different personalities. Sure, yeah. That tells you that the identical tones tells you that everything could be physically very similar even though there's quite a lot of psychological variation, right, that's your point, yeah? Supervenous is saying something much more demanding. It's saying everything physical is exactly the same, right? It's not just identical, I mean, identical tones can be very similar. These are really, really similar, right? Every gluon isn't exactly the same, well, I don't really have the technical vocabulary to explain this properly, but every gluon is exhibiting exactly the same physical characteristics in those two twins, yeah. That's a much closer similarity than you'd get in real twins, yeah. I mean, one's got their arm in the air, the other's got their arm down. That's enough of a difference. One atom different and all the bets are off, they might be psychologically quite different so far as this kind of physicalism goes, yeah. So, okay, that's great, so it's very clear what that formulation of physicalism is saying. What makes people say you could have the same physical properties where different psychology is ideas like? Your spectrum, the spectrum of the person in one world might be an inversion of the spectrum in the person in another world, or you could have physically identical people in one world to another, where in the one world they're zombies, in any other case they're like you or me. But as this last question about one said, if everything physical is the same, then all the causal processes are going to be the same through all these possible worlds even though the qualia are different. So physicalism is false, the neti-phenomenalism is true, yeah. If the mental is not just physical, if the mental is not supervenient in the physical, then the mental can only be epiphenomenal, yeah. And the monkey and the tiger thing is right. Okay, yep, uh-huh. Which connection? The connection be- So the top thing is saying, suppose that you don't have supervenience, yeah. That's to say, suppose everything physical could be the same, even though the qualia are different. Then if everything physical is the same, the whole mighty machine of the universe goes on in just the same way, yeah. And that difference in conscious state is making no difference to what happens. So the difference in conscious state is causally inert, it doesn't do anything, it doesn't make anything different. All that's making a difference is the physical stuff. So if you say, the mind can't be reduced to the physical, the price you pay is that you buy into that picture of the monkey on the tiger, and you say the mind doesn't do anything. If the mind is physical, then of course the mind can be making stuff happen. It's just more physical stuff. Oh, it's part of the physical universe, it makes stuff happen, the way everything else makes stuff happen. Plain as day. So I think that's a better explanation of physicalism than anything we had so far. And that's how some of these questions about qualia look when you think of it like that. Okay, this is your last chance. Well, it's actually not your last chance. This is one of your many chances to raise questions about this. Imagination. Imagination. Okay, so imagination is the big puzzle for physicalism. Even put in terms of supervenience, imagination is the big puzzle. And this is Nagel. I think this is Nagel's great point. If the subjective character of experience is fully comprehensible from only one point of view, and that's the key thing, fully comprehensible from only one point of view, then any shift to greater objectivity, that is less attachment to a specific viewpoint. If you try to get an objective, scientific, or physical understanding of the thing, that doesn't take you closer to the real nature of the phenomenon, it takes you further away from it. And at present, we are completely unequipped to think about the subjective character of experience without relying on imagination, without taking up the point of view of the experiential subject. And the key word there, I think, is imagination. And that's what is so strange about the mind. If it's all physical, then surely we can understand it all objectively. How could there be a sector of the world out there that you can only access by way of imagination? But that's just the way it seems to be. I mean, that is actually, it seems to me that is completely the state of the current debate. On the one hand, there are people who say, it's got to be all physical. Of course it's physical. And then there are the people who say, but you can't understand it without relying on imagination. How could that be if it was all physical? There must be some other way of getting at it. I mean, we've got a bit of the world here. We've got the mind here. We can get at it by imagination. There must be some other way we can get at it, but we have no idea how to do that. That's the puzzling thing. How can that be? How could it be that we are trapped in relying on imagination to understand this? Well, here's one way to think about it. You might think imagination, well, what is imagination anyway? Imagination has to do with a format in which we have our knowledge. You could get the same facts presented in lots of different formats. So isn't imagination just one format among many? And you can have imaginative knowledge of someone else's mental states and you can have an objective knowledge of their physiology, the way they're functionally organized and so on. Couldn't that just be the same thing out there that you're getting knowledge of in two different ways? You're getting knowledge of it in two different formats, just as you might get knowledge of something by being told about it or knowledge of it by being shown a photograph. So you're getting the knowledge of the same aspect to the person. There's the same thing there. Only now you've got an imaginative understanding of it. Now you've got a physiological understanding of it. Let me give an example. Here's the imagination at work. Suppose I ask you, is that block on the left? Is that the same as the block on the right? Who said yes? Anyone else? Anyone else think it's yes? Anyone think it's no? Yes is the right answer. How did you do that? Yeah, right. Exactly. You did it in your head, right? I mean, there are really lots, I mean, let me just make the first of all the point. First of all, this is not an isolated example, right? You can really know that these are the same just by looking at it. And what you did was you kind of mentally rotated it, right? You kind of, you turned it over in your mind. There are lots and lots. You could have many happy hours with these diagrams. Yeah, is the one on the left the same? Is the one on the right? I make the top one the same. Is that right? Yeah. I make the middle one the, I think that's the same. Yeah, and I think the bottom two are different. Yeah, that one sticks out the wrong way, if you turn it around, right? Okay, so what are you doing there? You are using your imagination, right? I mean, these examples, you may know this, but Shepard who started the study of how people do these tasks, found a basic fact that there's the angle, when you mentally rotate, you have to mentally rotate this one to see if it's the same as that one, yeah? So with these diagrams, you can vary the angle of rotation, yeah? And Shepard found that the time it takes you to give the right answer is directly proportionate to the angle of rotation. Think about that. That means you're rotating the thing at a definite velocity in your mind, right? They also did stuff with, I mean, once Shepard found this, of course, hundreds of people started working on it and there are basic findings like, you ask people to imagine an elephant, now zoom in in the head, now zoom in on the foot. It takes you longer to zoom in on the foot because it's smaller, right? You're zooming in at a definite speed. Anyway, so that is clearly imagination, right? Now, you're getting knowledge of the world here and this is really important for just an everyday life. If I'm asking something like, how can I get out of the door quickly, yeah? Then I've got to imagine going this way or going that way. If you're just trying to park a car, you're using imagination in this sense. If you're trying to get a shopping cart through an aerospace, you're using imagination in that sense, yeah? It really matters. So that's one format in which you have your knowledge of the world, imagination. But in principle, you could have done that kind of task, sorry, this kind of task here. There are lots of ways you could have done it. You could have written down equations for those two shapes, yeah? And found if there's a transform of one shape into the other, you could have used analytical geometry. You could have run a computer program. You could have made physical models of those two shapes and turned one to see if it maps onto the other. So it's the same thing you'd be finding out about through imagination as through analytical geometry or running a computer program. Doing it in your imagination as you all demonstrated there, that's really fast, slick, efficient. If you're going for real world, real time, kind of get me an answer quick kind of procedures, that's much more efficient than doing analytical geometry. You'd have to be crazy to start writing down equations there, given that when you can do it so much better and faster using your imagination. But still, these others are all valid ways of finding out the same thing. So couldn't you make a similar distinction to that between having an imaginative knowledge of someone else's mind and having an objective description of someone else's mind? I mean, suppose that you think now not about geometrical shapes, but about two faces and you think, look at that sad, puzzled face on the left. Look at that happy, optimistic face on the right. How did you get from one to the other, right? You can use imagination there. You can say, what's the inner life there like? And as you said, do that thing where you flip your imagination to get the dynamics from the one state to the other. So you could think, look, imagining is just one format in which we have knowledge of other people. And just as with the blocks, there's that capacity for visualization and rotation. So similarly, you could say, how can you make that sad face happy? Yeah, how could you do it? Well, you just do that flip in your head. That's what your imaginative understanding of other people is for, letting you do that fast, efficient, real-time engagement. That's what you need for ordinary social interaction. I mean, just as with the analytical geometry, you could write down equations for these two things or you could do a physiological description here, but that is slow, laborious, inefficient. You'll get there in the end, it's valid to do it physiologically, but you have at your disposal, nature has given you a much faster, more effective way of getting the right answer quickly, yep. Yes, right, very good, yes, I agree. I strongly agree, but okay, so I mean, let me come clean and say that the situation in the left here is more complex than the situation in the right, it's not that simple, but I think this is nonetheless quite a good model that if you even think about turning the cubes, that's the kind of thing you get better at with practice. You recognize that there are trick cases that fool you and so on, yep. Similarly, with getting an imaginative understanding of other people, I mean, partly you wouldn't try and realize if you're doing this with a friend of yours or someone you know well, you know a whole lot more about the context and background than I've just shown you a couple of, I'm trying to show you evocative enough photographs that you can easily engage, you see what I mean. But in real life, you've got a lot more than that to go on. And of course, there are limits to your imaginative understanding of other people and it seems to me there are three levels in your imaginative understanding of other people. There's what you're born with, the kind of thing that even a child of a few months will have by way of picking up on distress or contentment in their caregiver. And then there's something you get from culture and learning like reading novels, presumably. I mean, people always say that reading novels is very good for you and very improving and why that should be is never really adequately explained. I mean, there you are navigating the ordinary social world and you need a whole bunch of books about people that never existed and that's supposed to help you understand other people better. How is that? How does that work? And it must be something like training the imagination. You're learning to expand. And a third level is the kind of thing I was talking about on Tuesday with psychiatric patients where you can start out thinking, I can't have any imaginative understanding of this person at all. Is it like a bat? It's so alien to anything from my background or my experiences, but you can do it. So I don't think, I see why you say you're confined because so often we're very aware of these limits and what we can empathize with. But I think the truth is that we're relatively elastic about that, we get a lot better at it over time. The third one, when you have that level of scientific expansion, like I was talking about last time with schizophrenic patients or with patients with delusional moods and the violins going off and the dopamine neurons and all that, you remember? That kind of thing was the third one, yeah, yeah. Yes, that's right. Well, I don't want to blur what I just said to the last questioner with what I'm saying to your questioner. What I was saying to the last questioner was, you can use the scientific results to improve your capacity for imaginative understanding. But the other thing you can do is treat it like analytic geometry. Just do the physiology, forget about the mental life, and that will still give you answers as to how you get from this face to that face. But they will just be very slow, inefficient and unreasonably detailed answers, your answers that are far more detailed about the biologizing you really wanted to know. They're not relevant. So what you've got, just as you've got a very fast slick way of finding whether this shape is that, you've got a very fast slick way in imagination of finding how you get from this state to that. But it's not that there's some new sector of reality here. It's not that what you're dealing with here when you visualize rotating this thing is dealing with a different sector of reality than analytic geometry deals with. You're both just talking about shapes. It's just the same thing. So it's just the same thing here. It's just the same physical system that you're dealing with. You just get two different formats in which you can represent information about it. So you could think of the analogy like this. Analytical geometry is the science of shapes. That explains why some transformations are possible and others are not. Why you can get from some shapes and whatnot. Imagining is just the fast slick folk way of doing it. If you really want to understand the nature of shapes, you have to do geometry. But so you could think, look, imagining is just our folk way of going about understanding the mind. If you want deep explanations here, then fair enough, you want to get beyond imagining. You've got to do scientific psychology. You've got to do functionalist psychology or maybe physiological psychology. Maybe both. Do all the boxes and arrows from a scientific diagram. Find out exactly what physiology is implementing those boxes and arrows. That's the real truth about what is actually going on. But imagining is this very fast slick way of getting at it. You see what I mean? So that's a fully physicalist picture that gives a role to imagining. The trouble from Nagel's point of view is, in this case, in the case of the blocks, the real truth, the real facts here are what analytical geometry tells you. You see what I mean? Some people are not very good at visualizing. Some people are really good at visualizing. If you're not good at visualizing at all, you could still know all about shapes and what they are. You just wouldn't have this fast, slick way of getting at when to shapes of the same. But if you apply that analogy here, then suppose you just don't have any empathy. You can't ever get behind someone else's point of view. You can't ever see the world from someone else's perspective. But you're a real whiz at physiology. Then you should still have a deep understanding of what's going on with them. It's not that, there's just this fast, slick way of getting at things that you haven't got. And I think imagining will be just our folk way of going about psychology, functionalism, or physical psychology. That will give the deep explanations about the mind. But that's when you see the force of Nagel's thing. The subjective character of experience, he's saying, is fully comprehensible only from one point of view. And if you try and be objective, if you try and move to objectivity, that does not take you closer to the real nature of the phenomenon. It takes you further away from it. So Nagel's picture is just the opposite of the one I just said, that imagining is just a fast, slick way of doing something that in principle you could do just as well, or even better, by doing physiology. Nagel's saying, imagining is what takes you to the real nature of the thing. And if you do physiology, you've just left the mind behind. So this way of thinking about things says that imagination, that's really something about the format. It's not telling you about a new sector of reality. It's not giving you information about something new. It's just giving you the information in a new format. Nagel's way of thinking about things is, no, imagining isn't giving you stuff just in a new format. Imagining is telling you about something that you couldn't even glimpse the existence of without the use of imagination. Can you put your hand up if your gut is on Nagel's side in this? It's really all about imagining in the end. And if you think, no, imagining is just a fast, slick thing. It's like the geometry, I guess. I was hoping for more on the side of the geometry. Is that it for the geometry, three? OK, well, I'm glad you're here, guys. OK, but that's important to me. I think this is a real issue. Austin, do you want to comment on that? Yeah? Yes. And that's what you're addressing. Referential paths converging. Yeah. What you're addressing, understanding of the same thing when it's got through these analytical, physiological, functional, we're still just understanding the same things. I don't see the sort of motivation for prioritizing one over the other. Right, if I say one's better than the other. Yeah, and there's a slide on here where it says, couldn't it be that the thing that we're understanding imaginatively is just the same thing that the scientists are saying. And the response to that is like, sure, that could be. And so that's a way of fending off the dualists from all of these arguments that we've been looking at. That's a way of fending off dualism, yeah. Right, but the thing, good on that. And it just seems completely unintelligible that what we learn about when we open a psychology textbook is the same thing, or when we crack open someone's skull and look at their brain, is just the same thing that we get when we sort of introspect and think about our own mental lives. And that's the baffling part. And so that's what Nagle's talking about when he talks about the pre-socratic philosophers with the matter and the energy. I think, sure, maybe this picture could be right, but we have no clue how it could be. Yes, yeah, yeah. That's right, I think if you bought my fast slick, my model of, my geometrical model here, then it would be intelligible. I think that would really help. Well, three of you thought that would really help. Anyhow, I find that a little bit helpful. I mean, at any rate in understanding how it might go, that, I mean, if you think about it from an evolutionary point of view, then it really makes perfect sense. Other people are very, very complex organisms. You've got to negotiate with other people. If you had to negotiate with other people, purely as physical organisms, you'd really be in trouble because they just don't behave predictably. Yeah, I mean, did you know I was going to do that? Yeah, I mean, you see what I mean? If you just try and treat people physically, you would need such a fantastic amount of information about them and such high levels of computational ability to do all the math, to predict what they're going to do next, that it really would be impossible. You'd need far bigger brains than we have to do that. So instead, suppose we have this fast slick way, this ability to simulate or imagine other people, and we just use that to negotiate with them. Now, that's going to be, as you put it, a subordinate referential path. It's just what nature gives you is a way of coping with this very complex environment, all these other people. It's really subordinate, it has no authority because it's just, what should I say, it's just a collection of fast and dirty tricks that nature has given you to let you negotiate this complex physical environment. So I think from a theoretical point of view, this geometrical model makes perfect sense. And when you say, yes, but you've completely lost, you haven't, you know, Nagel's thing, you haven't got to the real nature of the mind when you shift to the physiology, that's what you're saying. The real nature of the mind is given to you with the imagination and is really puzzling how the mind can be anything else. Maybe that sense is just a hallucination, and maybe that's just, look, if you think about creatures of the kind I described, who are just using a collection of fast and dirty tricks to negotiate with one another, that nonetheless, that package of fast and dirty tricks plays such a big role in your life that you find it impossible to accept that is really just a way of thinking about physiology. You revere it. You know, it plays a big role in your own motivations and all that, but at the end of the day, there's nothing there but the physiology, and you taking yourself too seriously. Sorry, I don't mean you, I mean, one taking oneself too seriously. Yeah. Yes. Absolutely. Yeah. So just see how those two who have merged, yeah. Jackson. So we have this proposal that ways of getting at the very same thing, do us sort of some sort of synthetic pushes back by saying that it's actually unintelligible to think about like what's that, how these two different ways to be actually capturing, or these two different ways of getting at the same thing really could be getting at the same thing. And then I guess, I'm not quite sure I see what the problem is for the view at that point is, so I guess earlier, one of these slides you had something about, it's intelligible to us to talk about. Oh, sorry. It's intelligible to us to talk about how molecules moving at a certain speed gets you boiling water. Oh, yeah, yeah. But it's unintelligent, maybe on this dualist retort, it's supposed to be unintelligible how my experience of red is getting at the same thing that the wavelengths of light coming off the road. Yes, right, right. And I guess I wasn't sure it seems maybe, what's supposed to be a very intelligible about the contrast case? So here's the way to say that it's actually unintelligible. There's just two different properties, just boiling. Yes. And there's the average speed of the molecules. I can observe that this happens like I have described the relationship, but I don't know why this law holds. I don't know why, why is it that the universe is structured the way it is, it just is that way. Okay, yeah. Well, let me put it, suppose I talk about the hard-nosed evolutionist on the one hand, yeah? Does that make sense at this point in the discussion of I talk about the hard-nosed evolutionist? The hard-nosed evolutionist says, we're all just physiological systems, we're all just physiological systems, but we have to negotiate with one another successfully. And so evolution gives us this package of imagination and talk about the mind. As a way of simplifying our thinking about each other, just as we've got this ability to visualize shapes rotating, we've got this ability to put ourselves into the shoes of other people. It's just a way of getting on in a complex physical world. Now, let's call that an error theory. That says when you take the stuff about imagination in the mind very seriously and you think you're talking about the real nature of some phenomenon here, you're just taking yourself too seriously. It's as if you said the real nature of the shapes is given by visualization and imagination and what I can rotate, not by this so-called scientific analytical geometry. I don't hold with that at all. Then you'd be taking the folk stuff about shapes too seriously. Really, the analytical geometry does tell you the truth about shapes. On the other hand, there's the picture that Nagel has, that I think is the common sense one, that no, the stuff about imagination and empathy is really important. This is what matters most in life. Everything else only matters because it connects back to the psychological. That is where everything else starts. So how could the real nature of some physiological phenomenon be being revealed to you by imagination? That's what makes this unintelligible. Yeah, this real nature is given to you by the imagination but yet you can do this physiological thing. Does that help? That's how I was picturing it being set up. Okay, I really want to whiz through some stuff now. We have 10 minutes left. Is that all right? I have a sense of fatigue in there. Can you bear it if you whiz through some stuff? Should I just wrap up? Okay, fasten your seatbelts. Okay, I want to talk about another aspect of what imagining is. I mean, it really seems to be important in this discussion. And I want to think about how important the environment is in imagining. It's natural to think of putting yourself in someone else's shoes as getting inside their head, seeing the world from behind the furry brow from getting yourself inside someone else's mind. But I think that's not really the right way to think of it. Here's an example. Suppose you're a stage designer and your task is just to hammer together a set for a stage play. But suppose that the auditorium, suppose that work is being done in the auditorium so you can't get into the auditorium. You just have to imagine what the set's going to look like from different points of view, points of view. You have to imagine what's it going to look like from up here? Well, you've got a clear view from over here. Will it seem very cluttered if you're down here? If someone's standing over here, will they be visible from down here once I get the set going? Well, that's imagination, right? You're trying to imagine what people are going to see from different points in the auditorium. You're imagining how the set will look from different positions in the theater. And what you're doing there is, there's something in the real world, something in the physical environment, and you're trying to imagine of it how it will look to people from here or there, right? I mean, in my humble way, I think about this with the slides, right? How will that look from a distance? Will that be, is that text too small, right? We all do this the whole time. You're trying to do a drawing. You're trying to do a painting. You're imagining, how will that look to someone? You're just deciding how to wear, what to wear? How will that look to someone? So you can be imagining this from lots of different perspectives that you don't yourself occupy. Now, the set is there as an element in your imaginative exercise. It's not that you're trying to imagine that something elusive or hidden here. I mean, you're talking about people's relations to this external structure. First of all, you identify the thing in the world, and then you ask, how will all these people be related to it? Now, I think the way that we start to learn about our other minds is not really forced by getting inside other people's heads. What you find out about is, what's the environment that you and the other person occupy? There's Moll and Meltsoff in a recent paper talk about, these are developmental psychologists, talk about joint attention, joint engagement. It's this basic thing that young children do of getting to the phase where they around, what is it, 12 months? Yes, about a year. That they and the caregiver will both look at an object and the child in the caregiver loop backwards and forwards at each other and at the object. And this gives great pleasure to all concerned, right? Reference your reactions to the object and what you're doing with it. But this is the three mountains test developed by Piaget that this is about a yard square, blocked with three mountains on it. And you put a child sitting here and a child sitting at the opposite side and you ask the child sitting here, what was the child sitting in the opposite side seeing? And you show them paintings depicting what the child in the other side might be seeing. Do you see what I mean? And as an early stage, children will say, oh, is this painting with the red and the green and the gray visible that the child in the other side is seeing? They take it for granted that the child is seeing the mountains but they take it for granted that the child's perspective on the mountains is the same as theirs. This is like an earlier question. There is an early stage of which you literally assume that other people's perspectives in the world are the same as yours. So you're showing the painting, showing exactly what you see sitting here and you say, that's what the guy sitting on the other side is seeing. It takes a while, it's an achievement to liberate yourself to the point where. Now, the thing about that kind of task is you first of all get the bit of the environment that the other person is responding to and then you imagine what their take on it is. So think about the bat. If you're going to do that kind of exercise with the bat, then the first thing you have to do is know what things and properties the bat is experiencing. Then at level two, you have to know what perspective the bat has in those things and properties. So it seems to me the fundamental problem with bats, the reason bats are so weird is that you have no idea what it is in their environment that they're responding to. They seem to be seeing and responding to things that aren't even visible to you, right? I mean, they're going after bugs. What do you care about bugs? I mean, unless they're particularly big and scary, bats are really caring about bugs that are too small to be visible to humans. You know, if a bat comes into a room that does not see chairs as a relevant aspect of the scenery, yeah? So you can't even get to level one. Your trouble with the bat is not knowing what perspective it has on the things and properties in its environment. You don't even know what its environment is in the first place. You don't even get to that stage. So what you don't know about the bat is not something about what's going on inside its head, what you don't know about the bat is what's its environment? I mean, in principle, given a lot of time and study, you could laboriously write this down in real time. You could put, people do try to figure out what aspects of the environment the bat actually is responding to, but you wouldn't get something that you could use to interact with a bat in real time. I mean, with this kind of setup, what you're getting is something where you get the other person's take on it, and now you're at the point where you can engage in games with them. You can hide things from the other person. You can reveal things to the other person. You can interact successfully because you've identified, you've done this two-stage exercise. You first of all identify their environment, then their take on it, and now you can interact with them in that environment. You could have a social engagement in that environment. With a bat, it's not that you don't know what's going on inside its mind. It's that the thing about this picture here of the bat gazing at the flower is it looks like it's kind of sniffing it the way a human might be, but really, it may not even be seeing a flower at all. The salient thing for the bat may be a cloud of bugs, and the flower does something off in the background. Yeah, something unnoticed. You have no idea what kind of environment the bat's in. That's not a matter of what its perspective is, is getting to the stage of getting what the relevant objects and properties are in the first place. What's so alien and hard to understand about the bat is not what's inside its furry little head. What's so alien is what world are we in? What three-dimensional set of properties have we got here? So, in the last 60 seconds, Jackson's way of formulating physicalism was all the correct information is physical information, and there's a dear old Mary, okay. But what happens when Mary steps out? When Mary steps out, the first thing she finds out, and we spent some time in this in class, the first thing she finds out is kind of like the set or the mountains, the first thing she finds out is about the colors. The first thing she finds out about is not mental at all. She finds out a new fact about the non-mental environment, namely all the colors. She first grasps what the colors of all the objects are, and now she's got that scaffolding, that understanding of what the environment is, and then within that scaffolding, she can start to imagine the scene from different perspectives. But that suggests, it seems to me, that Mary may just be getting, well, the knowledge of what is like to see color wasn't part of her physical information, but what Mary's getting is just something about what the environment is, and what other people's perspectives are on it. I'm sorry, we're right on time, and I'm aware that you have other classes to go to, but let me see. You could think, what Mary's getting here is information in a new format about what she can do now. She's got the color, and now she can imagine other people's taking the color. But it's like this, it's like being able to play basketball either, being able to understand basketball either as a commentator or as a player, that what Mary's getting is a real-time ability to interact with other people using this fast, slick visualization of their experiences. She could have had that purely physiologically, but it would have been slow, laborious, and then effective. So the argument for staying with physicalism here is that you can think that what Mary's getting is information in a new format about something that she could have had otherwise. Okay, thank you, a bit hasty at the end, but that's the end of the message, thank you.