 Hi. Good afternoon. So I managed to keep track of the lectures while I was away, but through the virtues of webcast. And I hope what I'm going to say is going to be on track. So after the fireworks last week, today's lecture will be one of those lectures that starts out slowly and then fizzles out altogether. So it is way of fireworks too. OK, but I want to look at, we're looking at Frank Jackson's thing, epiphenomenal qualia. And next up on Thursday, we'll look at, well, actually, on Thursday, we'll look at Huxley's article on the hypothesis that animals are automata and its history. That's for a seven-page article in the Chalmers Collection. For today, if you get interested in the Jackson, you don't need to do this. But if you get interested, then there are also papers by Lewis and Dennett in the Chalmers Collection. They are very much about the Jackson article. And you might find these interesting if you find the Jackson interesting. OK, so we should have essays back to you very soon. And on Tuesday, we'll give out topics for the next essay. So you can express yourself. OK, so let's just look at what Jackson's key argument is. The key, I think the key move in Jackson's whole argument is one that he doesn't draw a whole lot of attention to, is this statement. And I said many times in this class, there's one world and it's a physical world. Everything is physical. And one way of spelling that out is to say what Jackson does, to say the thesis of physicalism is that all correct information is physical information. Saying that there's only the physical world means if you've got all the true information about the world, if you've got all the true physical information about the world, then there isn't any more true information to get. You see what I mean? So first of all, can I ask you to put your hand up if that's pretty clear as a statement of what physicalism is? And can you put your hand up if, given that you get this, does that sound correct? Put your hand up if that sounds right. Many of you hesitated. Is that because you've got your fingers burnt so many times? Is that because you have a specific reservation about this? Yeah? Right. There might be more true information than the physical information. But that would be because dualism is true, because there's more stuff than the physical stuff. Is that right? Yeah. OK. Yeah? Yes, all you can find is true. Isn't science committed to something like this? Yeah. That's true. But the question is, if you have all the physical information about people, then is there any more information to get? Someone mentioned in one of the first lectures in this class this thing that's going on at the Gallant's lab here in Berkeley, where they are recovering what you can see from brain scans. I'll try and show it a bit. How many people know about this stuff? It's just, sorry, I can't remember. Someone in this class told me about it, and I just saw it to my own amazement the other day. I'll try and show that next time. If you have all the information about someone's brain, you can recover an astonishing amount about what's going on in their mind. Isn't it just that you don't have enough physical information at the moment? You see what I mean? And isn't science really committed to that? All the correct information is physical information. You can tell stories about ectoplasm or non-physical stuff, but that's not going to be correct if the scientific approach is right. So that's pretty powerful. Yeah? Put your hand up if you don't see why you would formulate physicalism like that. You're chance to get off the bus here. One, two, yeah. Dependent, yes. Social historical facts, yeah. Yeah, but there are two pictures you could have of the social historical facts. One is you could be a dualist and say, the social historical facts belong to a different sector of reality to the physical facts. But the other thing you could say is, the basic physical facts that are relevant to social or historical realities are very, very complex. But if you had all that physical information, you'd have the whole truth about what was going on. There wouldn't really be any significant information to add. You see what I mean? That's the dilemma that this way of setting things up is putting you to. Either you have this kind of... Exactly. They've got to translate somehow into physical facts. Yeah? If there's only one world and it's a physical world, there's someone else, yeah? That's very good. Without really the information properly speaking, that's physical, yeah? What kind of... Are there non-physical things? Okay, but that's the whole issue, right? I've been trying to persuade you that the mind is physical and that it is the refuge of the scoundrel to say that the mind is non-physical. Now, I hope there are no scoundrels in this class. I'm sorry. That's not what you'd call an argument. But you see what I mean? You can't take it for granted that the mind is not physical. Yeah, yeah. Is that physical information that one plus one is two? It doesn't sound physical, does it? I mean... It's not correct. So it's not correct? Yeah, it has to be correct. Surely one plus one is two? Yeah, so you might say, this can't be right because there are, after all, mathematical facts. Yeah? Yeah, no, that's great. But the question is, if you sit... I mean, that's already a bit puzzling, really. Are we really going to say there's some mathematical heaven out there where all the numbers are grooving together independently of anything physical? And we kind of act... How do we know what's going on in there? You see what I mean? Do we have some kind of extrasensory perception that gets us onto the numbers? That's really puzzling already. Yeah? And so, although that's puzzling, it's going to compound the puzzlement, if you say, but the mind is like that too. You see what I mean? Yeah, yeah. One, two, yeah. Yes, very good. One plus one is two is a kind of generalization. Every time you get one apple and one apple, you get two apples, you just notice that again and again. Yeah, yes, yes. It's certainly important that you can have some kind of imagery for lots of mathematical stuff. I don't see why that would make it physical or non-physical. How does that bear? Or whether it's... Oh, you've seen it? Aha, very good. Okay, I see who you're saying. Okay, so you're starting from perception, really. Maths is grounded in perception. And it's certainly true that the ability to count things seems to be really basic to your understanding of arithmetic. Yeah. So you might come back to the last commenter and say, yeah, but the math is physical too. Yeah, I mean, it doesn't seem right straight off because it doesn't seem like... I mean, if I say 101 plus two is 103, yeah, I just can't tell. I cannot put my hand in my heart and say I've ever done it. Got 101 objects together and I did two and then checked and it was, by God, it was 103. You see what I mean? On the face of it are faith and maths far outstrips what we've actually encountered in the world. But I agree it's an important position you're stating. The general principles, yeah. Okay, okay, fair enough. And that is important as a kind of model for what's going on with the mind that you could have these two pictures. Yeah, you could think the mental stuff is in some kind of heaven, some kind of vector-plasmic heaven and God knows what's going on there, but it's not physical. Or you could say, no, it's going to be rooted in the physical somehow and Jackson is right here. Okay, there was one last question and I forgot. Someone who hasn't asked the question yet. Oh, maybe, okay. We're not going to go very far from this stuff, so come back to this, okay. Okay, so that's Jackson's key move, that statement of physicalism. And now here's an example. Mary, Mary is a brilliant scientist who for whatever reason is forced to investigate the world from a black and white room via a black and white TV monitor. So let's suppose that from birth she's lived in this black and white room. She herself is always clad entirely in black and white. Before you ask, there is no mirror, so her eyes can't get, she doesn't get coloration of her own eyes. She never cuts herself, or as she does it is promptly mopped up by her black and white suiting, right? She never ever gets anything but black and white. Yeah, that's all right. That could happen. Yes? It's not that wild. I mean, this really could happen. Incidentally, I was explaining this idea to a bunch of students wondering what major they would do and one girl came up to me afterwards and said, but did that really happen to that poor girl? This is not imaginary, right? This is just something that one of these things that could perfectly well happen. It's not that someone's done this as an experiment, yep. But it's not that hard to envisage. Okay, so she spends her whole life in this black and white room, but let's suppose that she's very smart. She's unreasonably smart. She's very curious about the world around her. So from the isolation in her black and white room, she gets interested in the brain science of vision. She finds out all the physical information there is to get about what goes on when someone sees ripe tomatoes or the sky. She understands exactly the physiology of what's going on when you see a colored object and say that's red. All that scientific information that people have got about the way the brain works, she has got. So here's Mary. I picture her as a somewhat moody, wistful girl. Surrounded, did she but know it by the blaze of colors all around? But perhaps haunted by the thought that there may be something missing. Despite all the richness and fascination of all the science she knows, she thinks maybe life is more than this. If only I knew what, yep. Surrounded by all this stuff the whole time. But she reads through all her texts. She listens, let us say, to Jackson talking about the, what was it, the global workspace theory. So she knows all about this tahain and the cash stuff. She knows that this picture of the brain is having a long distance loops, connecting lots of neurons from different systems in a global workspace there, in a global workspace. So she knows about the idea that when you look at a brightly colored object, you're getting these neuronal cascades, some of which are going over threshold and connecting long distance to your global workspace. Mary's got all that. She knows everything there is to know about that stuff. Still, she feels kind of like the lady of Charlotte. She feels she is missing something. She says, I am half sick of shadows. And here we see her growing up. As you can see at this point, she's got a white coat and a dog. I'm glad to say the dog is, of course, a Dalmatian. And she is just packed with all this knowledge about the scientific study of the mind. Anything a scientist can find out about the mind, she gets down her black and white printer. But then suppose that one day, one extraordinary day, Mary is released from the room. Mary steps out into the blaze of color for the first time. What's gonna happen when she first sees the blaze of color? Is she going to learn anything? At this point, does she find out something she didn't know before? That's Jackson's key question. Is Mary going to learn something when she looks at the rose? Peter, I wonder if you think the answer is yes. If you think the answer is no. Whoa. Okay. Well, there's a substantial majority in favor of yes, but by no means everyone, a significant minority. Okay, so isn't she gonna stare at the rose and say, gee whiz, I never knew this was going on? Yeah? Yes. That's right, yeah. She doesn't learn anything, yeah? It's a great analogy. I actually had that. I had undiagnosed needing a spectacle till I was seven and boy, I remember just how everything fell into place, all these things that had puzzled me. TV, I had never understood. I just could not see what people were getting out of TV. And then I just got it when I got spectacles. But I thought I learned stuff. I learned stuff I hadn't got before. I mean, I got the emotional release, just as you say, because I found out what was going on. I mean, she says, this is why people give each other roses. This is why people care about roses. I never got it before because I've got this basic thing about color. Yeah? So did you? Very good, yeah. She already knows what's going on because she's got all your own stuff. Okay, but do you want to comment on that? Right, very good. But it sounds like you would do... Keep going. Keep going. But you would agree with that, yeah? Is that right? It is like Nagel, I agree. But Nagel's point was forcible. Yeah, I mean, that's the thing that you're accepting. There was something about the subjective experience of redness that she didn't know. And now she knows. So she is learning something. You might say she's not learning much, but isn't that a difference of emphasis? She's learning a bit. She's learning something about experience that she didn't know before. Yep, yeah. She knows what the experience of color is. Sure. Yeah, she is only kind of black and white meters. She can... Very good, yeah. She knew all the stuff about surface spectral reflectances and what they do to your neurons. And now she can reinterpret that in terms of people seeing the colors. Yeah, that's your point. Yeah, that's completely fair, yeah. I think Jackson would say absolutely, yeah. Yep, yes, yes, yeah. That's very good, right? There must be some reason why people keep getting on boats and planes and traveling to distant places to have a look when they could, after all, just sit at home and read all the books about it. Yeah, I mean, people like going and having a look at the pyramids or whatever. And it is because you do find out something. And this goes back to that first comment. There is this emotional change, but the emotional change is because of something you'd learned, yeah? So that's Jackson's take anyway. Jackson says, it seems just obvious that Mary is going to learn something about the world and about our visual experience of it. Right, that's the key point here. Of course you learn something, but is what she learns physical? She had all the physical information. All the physical information you can think of was written down and came through her black and white screen. She knew the whole lot, but yet she learned something when she stepped out from her room. So the previous knowledge she had was incomplete. She had all the physical information, there wasn't any relevant physical information she didn't have, but therefore, there's more correct information than physical information, so physicalism has got to be false. So that's a very simple argument, but when it's posed like that, it seems like there has just got to be something incomplete about the scientific picture of the world, because she had the full scientific picture. All that to Heine and the cash stuff, she had. She had everything about consciousness, but she did not know what it's like to see the flower. Yeah, yes. Yeah, she can reinterpret all that physical stuff, yeah. I mean, it's very powerful if it's a physical fact, you can write it down and send it through the black and white screen. You know, they print all these journals in black and white, you know, they don't say, well, of course, it would be in black and white were very limited. You see what I mean, you take it for granted that all the world's knowledge can be written down in black and white, all the scientific information. That really is an interesting line of questioning. If physics, if physical means what physicists do, yeah, then she can have all the stuff that the physicists have. Yeah, the physicists just talk about the wavelengths. The physicists let color drop out of their picture of the world, yeah. So she can have everything that a physicist has, yeah. You want to say, yeah, but there's more going on than that, yeah. And I agree, there's more going on in the physical world than that. And I agree, it's a very delicate point, this. If what she's finding out about is something mental, then it's not a physical fact about the world that she's finding out, yeah. But if what she's finding out about is the color of the object, then that doesn't seem like a mental fact, yeah. Well, I'm actually going to come on. Is it spending quite a bit of time on this? But that's an important line, yep. Yes, that's great. Okay, yeah, that's really great. So there's a whole bunch of these questions that are kind of coming together. So if you think of, is this a way to play it back to you? But you could say, well, ordinarily, when a scientist reads a paper about color spectroscopy or something like that, then you're actually assuming the scientist knows pretty much what these colors are, yeah. So an understanding of color is actually presupposed in the ordinary color science books. They might be written in black and white, but they presuppose your ordinary knowledge of color from your experience of color. And that's what people were saying about Mary having to reinterpret what she learned. Because now she's got to get, now she can achieve the kind of understanding of those black and white texts that scientists usually have. You see what I mean? Yeah. So actually, although it's all written in black and white, the usual understanding of the physical information presupposes an understanding of what color is. So if she already had the usual kind of understanding that a scientist has of all the findings and color spectroscopy, then she would already know what the colors were. Yeah. So that's another way of playing out this line that the facts about the color really are themselves physical facts. Yeah. OK, they're not facts of basic physics. That seems important. That seems something where Jackson is clearly right. Yeah, because you know what they talk about in basic physics? They talk about gluons and quarks. And what do they talk about in basic physics? Are there any physicists here? One, OK. I mean, nobody talks about color, right? They talk about gluons. What do they talk about? Gamma ray bursts. Sorry? Mechanics, right. No colors, right? No, none of that stuff. Yeah? Yeah. OK. So the thesis of physicalism was all correct information is physical information. If many, so Jackson's argument, sorry. I don't really understand this. This is a bit like an earlier commenter who was saying, well, of course she learns what it's like to have the experience. But apart from that, she doesn't learn anything. And you're saying, well, of course, something clicks. She now gets why people are reacting the way they do, what those color characteristics are. You know, when she looks at this for the first time, she's saying, wow, now I get what's going on, why people like the way they do. And you're saying, yeah, that's right, but that's not learning much. And Jackson's saying, well, if you're learning anything at all, then physicalism must be false. Because she had all the physical information. Well, you said she was learning. What's this click? What do you mean she's clicked if something clicks? So she's learned something. That's what you're saying. Well, what's learning if it doesn't mean getting more correct information? You were coming at this before, yeah? OK, but physicalism said, what is like to see it, all that comes to is the physical stuff. Yes, right? But then knowing what it's like to see is not a physical fact. Well, physicalism says the only facts are physical facts. There's one world and it's a physical world. So if you're saying what is like to see something red is not part of the physical world, then that's a bit that's over and above the physical world. OK, come back to this, yeah? Yeah, no, that's fine for it to be subjective, but the question is, are the subjective facts entirely physical? And remember Jackson's stuff about Tehane and Akash? Right, if I understood what was going on, then I mean, I was listening to this kind of trying to catch up with what is with current thinking. And what Tehane and Akash are saying is all the facts about subjective experience can be captured, can be analyzed in terms of these brain circuits. If you can explain lucidly what the global workspace is, what it means for neurons from all over the brain to be connecting together in this long-distance kind of way, if you can explain that, then you've explained consciousness. And if Mary understands the Tehane and Akash theory and they're right, then there shouldn't be anything more about subjective experience for her to find out. But what you're giving Jackson is, well, of course, Mary can know all that stuff about global workspaces, but still there's something left for her to find out, namely what the experience is like. And that just completely throws out the brain stuff. It says, well, the brain stuff, that was just talking about something different. That wasn't telling you about the subjective experience, because Mary knew all about that global workspace stuff, but she didn't know anything about what the color experience is like. Therefore, the brain stuff is not giving you an analysis of subjective experience. This is important, so don't be shy about coming back to this. Jackson, do you want to come into this? You don't have to. Do you think Tehane and Akash would dispute this? All correct information is physical information. They might, yeah. Yeah. So that's a key point. Everything Jackson's doing is built around this way of saying what physicalism is. OK, one last comment. There was somebody else. Yeah. Yeah. Yes, right. Boy, this is really funny. That's absolutely great. Yes, absolutely. I mean, of course, she could say, well, she sits in her black and white room and learns all about romantic love. And she says, what is jealousy? What is the point of jealousy? I don't understand why people go through this. Well, I mean, you can feel that, right? Jealousy is a complete waste of time. Until it has you in its grip. Yeah. And she says, no, I know what all that was about. Yeah. I think that's, yeah, that's great. I just completely endorse that. Yeah. Is it somebody who hasn't asked the question that? OK. One, two, yep. Yes. Right. There's a really good way to think of it. I mean, a really interesting way to think of it. So would this be another example like, she might read all about riding a bicycle. Yeah. And have all the theory of how you ride a bicycle. But then when she actually rides the bike, when she gets her first bicycle, then it actually wobbles off on it. In a sense, she's learning something, but it's not new information. Yeah. Yeah. I feel like applications of how to apply the old information. Yeah. That is interesting. I mean, it's not that. If you look at Lewis's thing, Lewis is actually not a million miles from what you're saying. The thing is, just getting that blaze of color, it doesn't straight off feel like she now knows how to do something. It doesn't feel like an application. You see what I mean? It feels like a raw confrontation with a sector of reality she didn't know about before. But I agree it's important to think through the possibility of a kind of analysis. I just tried to bring out why it's not the most natural. It's not the thing that would force the car to you. Yeah. That's an important line of thought. I don't want to close that off. I just want to emphasize, it's not intuitive. You have some work to do, even to explain how that's going to work, but I agree. Bravely said, yes. So it's a very similar example, actually, to the last couple, actually, that one. You know the theory of soccer, as opposed to actually doing it. But it's difficult how you interpret that kind of example, because you're taking it here that she is learning something new. The last questioner was saying, in that kind of case, you're not actually learning anything new. You're just getting a practical ability to apply the knowledge you had already. So there's room for movement there. I'm not trying to push you back. But OK. OK, so that's Jackson's main point. That's been a very, very simple this argument. But it seems incredibly powerful just because so much can come down the black and white teleprinter to Mary. And yet, she's still be missing something. So literally, how many articles? Thousands of articles written on this. I mean, it's one of these things where no philosopher really wants to write about it, because everyone just starts to nod off when you get this example again. It's a very, very influential example. That's convinced many people that there's something wrong with physicalism. So because it seems so simple and so powerful, I want to spend a little time just going over it. One of the key issues that came up in all these questions, what exactly is she learning? What is the structure of her learning? And I want to just touch base with something Austin was doing. You remember this action-packed movie of Austin's? I mean, let's see. I had to watch this six times before I got what was going on blasted. I see that's the thing. It's one of these movies you don't know when it started. I think I started it, but I couldn't really swear to it. It's immediate enough to have a little message. Yeah, no, I saw that. On the other hand, I think it says here it is found. But we'll see. Anyway, you remember the point of this? Yeah? I watched this right after watching a James Bond movie. The plane had to say the contrast was marked. OK, but you remember how this went, right? And Austin had this thing about, is conscious experience sparse, or is it rich? If you don't notice the change of color, is there a change of color in your experience? Is it was that the right? That was the question, right? Yeah. So the austere view is there's no more going on in your experience than what you notice. And the rich view is there's lots more going on in your experience than you notice. And as you look around the room right now, then your experience is very rich. But you might notice only just little bits of what's going on. Yeah, but it's all there. It actually seems to me the rich view has got to be right. So I say this partly to provoke Austin, because he sounded, as I picked it up, he sounded quite sympathetic to the austere view. It seems to me, look, suppose you think of color vision tests. Here's a simple example with color. And I think this shows the rich view of consciousness has got to be right. So you get these tests for color vision, right? Statistically, can you guys see a figure five in there? Yeah? OK, I mean statistically, they're bound to be at least half a dozen people here who don't see a figure five there, right? But the whole point of this kind of test is that you're seeing a figure five on a dappled or brindled background so that the only systemic difference between the five and his background is the color. So if you can see the five, then you've got color vision. If you don't see the five, then you don't got color vision. That's the test. That's the way it works. OK, so if you see that five, if you could say that, that's a five, then you must have green and red in your visual experience. But you could see colors without noticing them, it seems to me. OK, children have color vision in place as early as two or three months. A child of two or three months should be able to see that five if it has regular color vision. But children are very, very slow to recognize colors. It takes children an amazingly long time to... You can take a child of two that has... I mean, there are anecdotes from experimenters of this kind of thing happening. You take a child of two that has hundreds of words in its vocabulary, you show it a red thing, you show it a green thing. You say that's the red one, that's the green one. You do that seven or 800 times and the child still doesn't get it. It's hard to attend specifically to color. Children find that difficult, yeah? Well, you're trying to teach them the words red and green and it really is difficult for children to learn color words. I mean, somehow in today's, color-coded... You know, children nowadays are always being bombarded with color-coded toys. And so they learn about colors much quicker than they used to. But around 1900, children were six years old before they had the basic six color words in place, yeah? Darwin thought that his children were color-blind because he tried so hard to teach them the color words and they just couldn't get it. There's even a word in German for it. Firmendumheit, color stupidity. Colors, you just go, duh, I don't get it. But that's consistent with you being able to see the five. You see what I mean? And when you think about it, if you think about an animal out hunting, then what the animal cares about color? Why do animals care? I mean, why have color vision in the first place? The basic reason you have color vision is not because you want to admire the roses. It's so you can distinguish your prey from his background or whatever's going to attack you from his background. You don't, nobody cares about color or actually only humans care about color for its own sec and attend specifically to the colors. Animals typically just care about the objects. So you could be able to see the five and have green in your color experience even though you can't attend to the green. So Austin's view must be wrong, right? Because you've got the greenness in your color experience even if you can't attend to it. I say this to provoke. Okay, yeah, I know who you mean, but yeah, yeah. Right, yes, right. So I'm saying this is an argument for the block overflow thing. Yeah, yeah, yeah. Yes, right, very good, yes, yeah. So the picture is, the natural picture is you've got a rich conscious experience and then you're going to hook out bits of it to attend to and it's going to be there in order for you to have something to grapple onto when you're deciding to attend to this or to attend to that. Yeah, is that what you're saying, yeah. Okay, okay, yeah. So this would say the colors can be there in your experience in a kind of subterranean way. The great neurophysiologist Luria was in Uzbekistan and an Uzbek peasant said to him, us Uzbeks don't understand the colors of things and so we call everything blue. And he didn't mean that they were color blind, right? They could do this kind of test to get the experience of color, but they just don't know the names of colors. They can't pass it on to colors. And that really makes perfect sense. The ancient Greeks didn't have a color vocabulary like ours at all. They seem to combine names of colors with names for stuffs. So the Wind, Dark Sea, there's a kind of mix. It doesn't seem to be a pure color vocabulary in ancient Greek. So although we take it that color kind of pops out at you, you should really think of an ability to attend to the colors as hard one. It's something you really had to work at when you were two years old. You climbed a mountain to get there, but if you can see the five, you must have color in your visual experience. If you didn't have color in your visual experience, then, and that would be completely uniform. It doesn't make sense, you wouldn't be able to see the five at all. So color can be making a difference to your visual experience, even if you can't attend to it. So think again about Mary stepping out of her room. Mary might just find that now she can discriminate objects from their backgrounds better than before, but it's consistent with Mary having ordinary visual color experience that all she can do is she can now see a rose much more clearly against this background than she could before, but she can't identify the colors yet. She can't attend to the colors, right? So there are actually many phases in what Mary learns. I'm trying to freeze frame this, what happens when she steps out. So the first thing she finds when she steps out is she can now discriminate objects much better than she could before. That's what color vision is good for, but she might not yet be able to put her finger on why she can discriminate objects much better than she could before. She might not yet know what color experience is like because she might have no concept of color. All she's getting is the objects are popping out in a way they didn't pop out before, right? That's possible. She might be in the position of a Newsbeck peasant from Luria's story, yeah? So the next step is that that's step one in Mary learning. She can just discriminate objects better than she could before. The next step is when she can attend to the colors of the things around her, but what's going to happen? Suppose you try it now, suppose you attend to your current visual experience. Suppose you look at the tree, I mean, here's a quote from Harman, Gilbert Harman. When you see a tree, you do not experience any features as intrinsic features of your experience. Look at a tree and try to turn your attention to intrinsic features of your visual experience. Many people said, look what Mary learns when she steps out of the room is something about her visual experience. Harman says, if you try to attend to your visual experience, the only features there to turn to your attention to will be features of the presented tree. So I put a picture of a tree there so you can try this right now. So try this right now. Here is your task. Look, when you attend to your headache, if you attend to a headache that you've got, you can say, is there a dull throbbing pain? Is there a sharp pain? What is it in some particular part of my head or is it kind of diffuse? You can attend to all the features of your headache. You can focus just on what's going on inside your mind. But now look at the, think of the sensation of purple you get when you look at the tree. So here's my question. Can you try to attend to the purple but don't attend to the thing out here? The tree, yeah. Just attend to what's in your mind. Yeah, when you observe the purple-ness. You're getting a purple sensation. So I don't quite know how to put this. What's required is you kind of squint inwards. If you see what I mean. And get the purple in your head. Get the purple sensation. What's Mary's learning when she steps out of the room is something about her visual sensations, what visual sensations are like. Then she should be able to kind of squint inwards and say, I'm not really interested in what's going on out there with the tree. Think about just what's going on inside my visual experience. Now, I put it to you. This is a practical question. Try this right now. Focus on your internal visual experience when you look at the tree and not add anything out there on the screen. Can you do that? Ha ha ha ha. Reading from the expressions, that is a general feeling. You don't totally get the question. Yeah. I'm not asking you to do any of these things. I mean, the reason this is a little bit difficult is that the point is it makes no sense what I'm asking you to do. Yeah. Okay, so the natural picture, what one picture you can have when you're thinking about this stuff is, look, there's a color out there, right? There's a color out there on the tree. And then there's my sensation of color. Now, is your sensation of color out there on the tree? No, your sensation of color is not out there on the tree, right? So if I say, attend to your sensation of color, are you attending to the tree? No, because your sensation is not out there on the tree. Your sensation of color is in your head. Yeah, focus on it. It could well be, yes. Okay. Okay, I don't want to dispute that you could attend to all these resonances of the tree, yeah? But the thing is, if your sensation is in here, if your sensation is not out there on the tree, then you should, and setting aside the resonances for a moment, yeah? You should be able to cast your focus inwards and focus on the sensation itself. Forget about the tree out there. Just focus on the sensation itself, your visual sensation. Put up your hand if you can do that. No, wait a minute, I'm taking a poll. Put up your hand if you can do that. Okay, put up your hand if you don't know how to do that. Okay, great. Put up your hand if you have no idea what I'm talking about. Okay, a surprisingly small number. Okay, right. The key point here is, and it's really a basic point, is that you can't, there's no such thing as looking inward at your sensation, your visual sensation. So that picture of the tree out there, the color of the tree out there and the visual sensation in here, it makes no sense really. It's a very natural way to think of it, but it doesn't make any sense because if there were a visual sensation in here, then you ought to be able to focus on it. But there's no such thing as focusing in the visual sensation in here. I mean, you will find if you go on in philosophy that there are very many occasions when you and the person you're talking philosophy to just wind up staring very hard at the furniture. And it's because you're trying to look inside your mind and thinking about how to describe exactly what subjective experience is like, but you wind up just staring at the tree. And G.E. Moore put it like this. He said, that which makes the sensation of blue a mental fact seems to escape us. It seems, the mentality of the sensation of blue seems to be transparent. When you try to focus on your inner sensation, it's as if you just look through it and you just get the tree itself, yep. Yeah, you can imagine entirely blue sheet of paper, sure. Yeah, but that's a blue out there. The blue is out there on the paper. Yeah, you're not imagining blue in here. The imagining is in here, but what you're imagining is something out there. Look, if you think about ahead, yeah. This is a different case, right? For the moment, I'm just talking about what's going on in vision, yeah, when you see something. When you see something, you have a sensation. The sensation's in here, the thing is out there. So you ought to be able to focus in the sensation in here, but you can't do that. Therefore, the idea of the sensation in here is something, there's something wrong with it. That's not really what's going on, yep. Well, you can, you can't focus in the sensation without focusing on the tree. All it means to focus on the sensation is you focus on the tree. That's what nobody can do. Yeah, I said, don't look at the tree. Who cares about the tree? Focus on the sensation. That makes no sense. So, one, two, yeah. Illusion, yeah. Yeah, you focus on the lines and they seem different in length, yeah, yeah. Okay, so you've got a case where it seems like two lines are different in length, but they're actually just the same. It's a visual illusion, yeah. In that case, all you're doing is staring very hard at the lines. Yeah, there's no such thing as staring very hard at something in here, focusing very hard on something in here. The point is exactly the same for cases of illusion. It's not as if when you're looking at the lines out there in a case of illusion, what you're really seeing is a sensation. You're staring very hard at those damn lines and trying to understand what's going on, yeah. That's what I mean about staring at the furniture. You're staring very hard at something out there under the impression that this is going to give you some revelation about what's going on in here, yeah, yeah. Great. Yeah, yeah, right, right. Sure, absolutely, yeah. I think what you're describing is perfectly, of course that's recognizable. You can describe a scene and the scene induces a kind of mood, yeah. But the important point about that is you can attend to the mood that the scene is producing in you, yeah. So if you find the color, I mean, the reason I chose that is it's a nice picture, right? Evocative colors, right? So as an earlier question that I was saying, you can look at the color of the Jacaranda and it can evoke those happy days long ago playing with spot by the firelight and so on, yeah. But what you're attending to then is not the vision, is not what you're seeing, is not the specifically visual thing you're attending to. It's the mood, the resonances, the evocation, yeah. But the point here is specifically about vision, yeah. That when you attend to the color, you're always attending not to a sensation but to something out there. And that stuff out there might be producing all kinds of mood in you, yeah. And you can attend to that too. So that was the idea that visual experience is transparent. When you're trying to look at, it's like staring, it's like trying to see a window. If you say, well, look at the window. I mean, unless the window's kind of dirty, you can't actually focus on the window itself. Your gaze always falls through the window and you wind up looking at the stuff on the other side. And similarly, when you're trying to attend to a visual sensation, you always wind up looking through the sensation and getting the stuff on the other side, yeah. There is such a thing as a sensation. I'm not denying that. I mean, I don't mean to trivialize meditation, but if you've got a pin prick, you know, someone's sticking a pin in you, you can focus very hard on that. Or if you take your own inner mood, you can focus very hard on that. That's true. But we're talking here just about vision. Yeah? You could do that, yeah. But you'd always be staring at something outside you. If you're using vision at all. That's right. But what about other sensations? I'm not denying that there are other sensations. That's what I meant. There's a contrast between the case of vision and the case of a headache, yeah. So the case of, I mean, I don't suppose that meditators usually just focus on their headache, but you could do that, right? I'm not denying that. And then you'd just be focusing on something inner. But in the case of vision, there doesn't seem to be anything inner to focus on, yeah. Okay, so here's another way to put it. This is just freeze framing what Mary learns. So the first step is she goes out, she can now discriminate the object's better, but she might not be able to put her finger on it. Now, people sometimes said that people with autism, the problem is that people with autism don't know anything about the minds of other people. You can be very, very smart, but you might just not care very much about other people's minds or indeed your own mind. Mary might be a bit like that. She might care a lot about physics and the physical world, moods, emotions, sensations. She could care less about that stuff. Maybe Mary only cares about the physical world. Maybe that's her tragedy, that's all she cares about. But when she steps out into the world of color and sees the rose for the first time, she's still going to learn something. She's going to learn something not about anybody's mind because she could care less about people's minds, but she's going to learn something about roses. She's going to learn about that property that the objects around her have. So there are two steps here. There's step one where she just sees objects better. Then there's step two where she focuses on color and she gets the colors of the objects. And then there's step three where she's at this point, she's got a new non-physical fact. I mean, it's not a fact of basic physics. She didn't have this in her black and white room, but it's not a mental fact. It's a fact about roses that she's now learned, what their colors are. So that would already show that she's getting more information than the physical information. But then, which does take the step of saying, and so this is what the experience of redness is, that's a further step. Three steps here. One, to just getting better object discrimination. Two, to getting knowledge that the objects have colors. And three, to getting knowledge about subjective experience. Yeah? That's what I'm suggesting anyway. It goes in three steps when Mary is learning. We've got a couple of review sessions coming up, and I'm going to come back to all this then. But since it's so important, that question won't Mary learns for that very simple example. It seems worth just taking a little bit of time on it and to connect it to these things about attention and richness. Yeah, step one is when she's got color experience, but all that's happening is she can now see objects better than she could before. She might not yet be able to attend to the colors. Step two is when she manages to attend to the colors, but she's only attending to the colors of objects around her, not to anything in her experience. And step three is when she's able to say, and now I'm seeing something red. And those are kind of a hierarchy. Each one builds in the previous one. Yeah, so it's important to freeze frame that if you want to get what this example is telling you about physicalism, yeah. I didn't say she could communicate about color at step two, because at step two, she doesn't do anything about the mind, but she gets it that the tulips do have redness. Yeah? She knows about, step three is she knows about experiences of color. She has experiences of color already at step one, but at step one, all that's doing is it's letting her pick out the objects from their backgrounds as she can't attend to the color. Yep. Okay, I know, let me just try and whiz over a couple of things, finally. I want this, how this relates to Nagel. Nagel's argument is very similar structurally. The physical information doesn't tell you what it's like to be a bat, what it's like from another point of view. The way Jackson put it is his argument is about, Milmeri knows about the intrinsic character of color experiences, not about the point of view from which the experiences are had. And this is where this stuff about qualia, that idea of qualia that we had before with Chinese or Indian Burns or whatever it is, where that comes in. Jackson's talking about qualia, about those intrinsic characteristics of the sensations, the redness of the red sensation, the blueness of the blue sensation. Jackson's point is, you can have knowledge of all the physical facts without having knowledge about qualia, the intrinsic character of the sensation. Nagel's point was, you could have knowledge of all the physical facts without having knowledge of the other person's point of view. The things that preoccupy these two people are quite different. Nagel's big thing is this thing about point of view or perspective, not qualia. If you think about this guy, remember this guy? Yeah, there he is, still doing it. There's nothing puzzling about this guy's qualia. There's nothing puzzling about the intrinsic character of any one sensation he's having. Yeah, that's all just fine. What's so puzzling about him is what's the perspective, what's the point of view that he has in the scene? So the problem with a split brain patient isn't a problem about the qualia that the patient's having. It's not what kind of sensation is he having. It's how are they structured? How has he got a perspective on the scene at all? So you must never write this down and if you quote me on this I will deny it, but it's like the intuitive picture is there are two aspects to the mind. There's a point of view from which the scene is being surveyed, the perspective you have in the room right now, and then there are all the qualia filling up your perspective, yeah? These two different aspects to the mind and what Nagel is always banging on about is the perspective, the importance of the vanishing point from which you observe everything. And what Jackson is going on about is how you have knowledge of the qualia, that the qualia are non-physical. Nagel's big thing is it's hard to see how that understanding of a point of view can be explained in physical terms. Jackson's point is hard to explain how the qualia can be understood in physical terms. So the point about Mary stepping out is that the qualia are left out of the physical story. Well, actually, I'm gonna skip that. Okay, now, one last comment. This is all about how, these arguments are all about how there are aspects of the world, aspects that we really care about that are left out of physicalist or functionalist stories. But there is what you might call the revenge of functionalism here. There is always a kind of revenge coming from the point of view of functionalism or physicalism, which is to say, suppose that this is right. Suppose there are these sectors of reality that we don't know about with a bat or that Mary only finds out about when she steps out of her black and white room. Those sectors of reality aren't part of physical reality. So they can't make any difference to what's causing what. What's certainly true when you say there's only one world and it's a physical world is that all causation is physical causation. So if there is any more to the world than physics describes, it's not something that makes any difference to what happens. Jackson has this example of, you see here a familiar scene from a Western with bullets traveling across the screen. Yeah, now the thing about that kind of scene is, or suppose you're playing a video game, suppose you're playing Pong, right, Pong? Surely some things stand fast. This is not something that gets hit by the vagaries of fashion. Suppose you're playing Pong, right, and so you get a ball going across and you're honestly trying to battle across with your paddle and maybe put a little bit of spin on it. Then what's going on there is that the pixels are going across and they bounce into the bat and it looks like the bat is causing the ball to move back across the screen. But is one collection of pixels actually causing the other to move across the screen? No, that'd be daft of him, so it's a game, right? It's a video game. What's going on? The only causation here is something in the central chip. The only reason, I mean, I hope I'm not destroying anybody's illusions here, but the only reason this kind of game is fun to play is that it looks like one set of pixels is causing another set of pixels to act, just as here what it looks like that bullet traveling across the screen is causing this guy to topple over. But that's not really what the causation is. It's really all the work is going on in the chip, in the central processing of the game. So with your ordinary experiences, with your ordinary experience life, it feels like you're making things happen. It feels like your grief is turning to anger. It feels like your anger is leading to rage and so on. But actually, although it's very convincing, that illusion that you have, that your mental life has got as rich dynamics and is making things happen, that's all an illusion. Your brain is like the chip. The only causation is physical causation. And these appearances of causality are just being spun off by what's going on in your central processor, in your brain. And we'll have more on that melancholy theme next time. Okay, great discussions. Thank you, guys.