 So the essay is due Thursday, and we are keenly awaiting, waiting to see what you make of all this. On Thursday, we're not going to pause. We're going to go straight ahead with Nagels. What is it like to be a bat? A very famous article that's in the Chalmers collection. So for Thursday, if you can, in addition to your intellectual and emotional exhaustion by the time you finish the essay. But try to take a look anyway at Nagels. What is it like to be a bat article? Next week, Austin and Jackson will take over, and you'll get a quite different perspective on the same issues we've been looking at. Today is review, so I want to go back over a lot of the stuff that we've looked at already. I'll try and just rework it, but this is also an opportunity if there is some point in the class to say variable realizability or something that has bugged you and you think, I never quite got that, then please regard this as an opportunity to raise things that have puzzled you along the way. So I want to start out by looking again at the Chinese room. The Chinese room we went from pretty rapidly at the end of last time, and I want to go back over some points there. And then I'll look at the road we took from dualism to functionalism in these first few weeks in the term. And then the problem consciousness poses for the study of the mind. And the notion of representation that these computer guys use when they're trying to analyze the functioning of the brain. I'm just curious about what your opinion was as we finished up in the Chinese room last time. So the Chinese room is meant to show that you can't make a computer that understands a language. It's just not possible. So I'm just curious, how many of you think that the argument achieves that? You just can't have a computer that understands language. Can you put your hand up if you think that's right? And can you put your hand up if you think, no, that's not right. Serl or not, you could make a computer that understands language. OK, so the nose have it. Yeah, I'd say it's about two thirds to a third against the computer guys. OK, yes? Yes. That's right. Did you see Blade Runner? Yeah, I mean, it's possible to be... I mean, I don't... Well, I take that back. I don't wish to spoil anything. But it's possible to be haunted by the thought, maybe I'm not conscious. Maybe I don't think. Yeah? Maybe I'm just a replica. Yeah? Wouldn't everything be just the same? You mean if you watch yourself very closely, you might catch yourself out doing something robotic? Oh, yes, they can't absolutely have the idea of a robot. Yeah, I can dig it out for next time. Actually, there's a passage where they can't absolutely articulate the idea of a robot, something that is physically just like you or me and functions just like you or me, but has no mind associated with it. I mean, if you're a dualist, it's a very natural idea, the idea of a robot. Because you go to all the physical stuff and you've got a mental think bubble, if you see what I mean, associated with it. So it's perfectly possible, of course, to have the very same physical stuff, but no think bubble. Well, that's a good question. I mean, two-thirds of you think that you can't make a computer that thinks, are you guys all dualists? Put up your hand if you think both. You can't have a computer that thinks you're a dualist, and you're a dualist. Aha. Okay, that's a small fraction. Significant, but small fraction. Only one or two people there. Okay. Okay. Well, I want to try and persuade you two-thirds, guys, about the Chinese room. I think there is maybe something actually, the position I want to come to is a little bit complex. But in the first place, there's something about the level which you describe the room that really seems important, and many of you guys were raising this last time. You can see the whole system understands. You take the whole caboodle, the room, the book, the guy, the baskets, all that. That whole thing understands. And I think one way to see that there is something right about that is to say, well, consider the personality that is exhibited by the answers coming out of the room. Consider the personality of the guy in the room. He, let us suppose, is a bitter and resentful individual who hates his job. I mean, it's not much of a job, right? And let us suppose he is consumed by resentment and never thinks anything but thoughts filled with the ideas of revenge and bitterness. Whereas, the answers coming out of the room may radiate wisdom, but may radiate serenity, may radiate a deep understanding and acceptance of the human condition. So, when you think about the personality exhibited in the answers coming from the room, that might be quite different to the personality of this guy. And what really matters is the psychology at the level of the whole thing and the level at which you have a serene, insightful individual and that might be that will be the level at which you have something that understands Chinese. You see what I mean? It's when you move up a level and describe the whole system that you get both the serene individual and something that understands Chinese. So, there will be a particular personality exhibited in the responses from the room and that's going to be quite different to the personality of the individual manipulating the signs. But so far and if you think about this, what it feels like is you've got here a virtual person. You see what I mean? You've got you kind of generated this personality that has the serenity and the wisdom and has the understanding of the Chinese. But that's just like a character in a story. It's like the narrator of a novel. You know, sometimes when you're reading a novel, you get a very vivid picture of who the narrator is. You see what I mean? But that narrator need not be a real person. That narrator is just a kind of virtual person. You've been making a mistake if you suppose that the narrator of the novel must be a must of the same characteristics as the person who actually wrote it. So, thinking about the higher level, you do have a virtual person here. That makes sense. It feels like you're talking to someone who understands Chinese has wisdom, has serenity and so on. But there's no really such any such person there. And I think in the discussion last time, some people said well, this really has to do with the who wrote the book that is generating the answers. You're really looking at the personality of the person who wrote the book that is generating the answers. Or else people said look, it's the actual book. That's the key thing. And I think these are important reactions because what you're doing there is you're trying to find the absolutely real thing that could be the personality that understands Chinese and so on. But these are not quite the right answer because it's not, you don't want it to be somebody backstage who wrote the book. And after writing, saying it's the book itself, then Serl's got a really good point about this when he says the person in the room could just memorise the book. The person in the room could internalise the whole book still without understanding Chinese. So it seems like a powerful idea that you want to go up a level and talk about the whole system understanding Chinese. But we want to know when you've got that whole system constitutes a person that actually does understand Chinese. And that's the thing I kept saying that if you just get the book and the baskets in the shell of the room how does that add enough to that poor drudge working through the baskets? How does that add enough for them to be a real person, up a level there not just a virtual person? Do you see what I mean? Let me pause. That is the issue whether there is anybody that is the virtual person. Do you see what I mean? When you're reading the responses coming out of the room they may give you a very vivid picture of who's writing these responses. That's what I mean by the wisdom and serenity. Or if you don't like that you can make this a terrible drunk who goes through phases of lucidity in their answers or you can have a real personality coming out of those answers but the question is is there anybody there who really is that person? Isn't this just make-believe? Don't we just have a virtual a virtual person being generated by the system? You see what I mean? If I'm explaining this correctly that should be plain as day so pause me if that is not plain as day. The computer guy really has to reply to sir by going up a level and say it's the whole system that understands. Sorry? But what makes it the case that when you go up a level you get a real person and not a virtual person? Does that contrast make sense? Yeah, okay. The thing is when you go up a level you wanted to be something that a computer guy could reasonably add on to the computer program and say that's what it takes to understand. And so it's a natural idea a lot of people have said really you want to embed the Chinese room in a robot once you've got the whole system moving and acting in the world picking up things looking at things around it then you've got something that really understands Chinese. But the trouble is that on the face of it if you just embed the Chinese room in here well, that is really just a zombie. If you actually encountered such a system you would say you can be taken in by it it passes the touring test but it really doesn't understand anything. The worrying thing for a computer guy is maybe what you really have to add in is something that a computer guy can't model. Maybe what you have to add in is awareness of what's going on around you. I mean after all, if you think how the question was does the system understand what the word is using? Well, how do you understand the signs you're using? If I say this is Jackson, this is Austin, how do you know what the word stands for? Well, because you have encountered these people. If I say you want to know what chalk is here is a piece of chalk then the reason you understand what I'm saying is you've now experienced the thing that I'm talking about that's what gives you knowledge if I say this is Jackson what gives you knowledge of what the word stands for is you've actually experienced that person. So if that's the right answer, if what has to be happening is that you have consciousness of what's outside the room and that's what underpins your understanding of the language that's not something that the computer simulation guy is going to be able to emulate at all easily. How could you do that? You say, well, the computer model of the mind is just right. The whole artificial intelligence program is just right. All you've got to add to it to generate understanding of a language is consciousness. There you go and that's the problem solved. It seems perfectly obvious there that the problem is it's not completely hopeless, it might as well be. How do you just add that to a computer program? It's not just adding another few lines of code or building a robotic shell. If what you've got to add is awareness then the computer guy seems to have made very little progress towards giving you an explanation of what it is to understand a language. But there really is no scientific approach to the analysis of understanding a language other than a computational model. The computational model is the only account we have. So the stakes are very high here as to exactly what you say has to be added to make this whole thing into something that understands language. There's a connection here to Bloch's homunculus headed robot. Bloch said well that could a homunculus headed robot I mean something with a billion individuals driving it about. That could meet the functional description without being conscious. That could meet the functional description that you or I have without being conscious. And Bloch's point there was about qualitative states or raw fields or immediate phenomenological properties. The thing you get when you get an Indian burner or Chinese burner whatever you call it that the thing doesn't have that. And what I'm suggesting is these two problems for the scientific study of the mind are connected. There's a problem about how you can give a scientific account of what it is to understand the language. There's a problem about how you can give a scientific account of what it is to be conscious. And these are connected. The reason it's so hard to give a scientific account of what it is to understand the language is that understanding a language depends on consciousness. Consciousness is really the fundamental problem here. On that bombshell let me pause for a second. If that seems a tall complex I really encourage you to pause me and say what even if it's just to say what the hell was that. I mean please this is a review session this is meant to be helpful so don't let this just wash over. Playing this game yes. You read the article again. Well that is really a key thing so you've got the robot just to where's my robot there you go you've got a robot right unless suppose it does just fine it gets round obstacles just fine yeah maybe it's like just a very handy to have around the house you say can you pass the pepper and there you go pass the pepper yeah so in your sense that would be enough for the robot to be conscious is that right I mean one of my colleagues has a room bot that navigates around his room hoovering things up yeah is that enough if you could just navigate around obstacles it's actually amazing it navigates around obstacles just fine yeah I mean if it is just a mechanism like that is that how could that really be enough for consciousness yeah but more importantly the question is does getting the thing to be conscious do you have to get the thing to be conscious to get it to understand language suppose you can get the robot to be conscious then surely that would be enough for an understanding of language if you could also do the computational thing yeah but if you couldn't get the robot to be conscious would that mean it didn't understand language what was your hunch actually what do you guys think in general if you couldn't if you could you see what the problem is though the question is if you couldn't get the robot to be conscious could you nonetheless get it to understand language to understand English or Chinese can you put your hand up if you think the answer is yes I'm actually you couldn't get it to understand yes let me try to rephrase that if you cannot get the computer there's no other way to put it but that's okay if you cannot get the thing to be conscious of what's outside it so let's suppose it stays just a zombie from the point of view of consciousness but it's very complicated and it can hold a conversation could it nonetheless understand language put up your hand if you think the answer is yes it could understand language even if it wasn't conscious and put up your hand if you think the answer is no if it wasn't conscious that would be an obstacle to understanding language that's my hunch that we will come back to this yeah yeah I mean the experience of your surroundings it can't be just an ability to differentiate because I wouldn't take long to build a computer that could do that I mean to build a robot that could differentiate in some sense you just pointed at this thing it was eep you pointed at that it goes bap you see what I mean you could do that but I don't know I don't know a definition here but the warm buzzing blooming confusion of everyday sensory experience you know that's what I mean there's rush of sensation you have at the moment right that would be part of the picture yeah that would be an element of the picture there's quite a lot of people were you raising a question it does experience everything or it doesn't you could absolutely do that of course you can do that you're right but the thing is practically anything is capable of learning from its past encounters with the environment a decapitated cockroach will learn you know you can condition a decapitated cockroach I'm not suggesting you try this at home but it's really striking how pervasive the ability to learn is yeah even among things that you really wouldn't want to call conscious at all so a robot would be capable of lots of complex learning yeah but whether that's enough for consciousness is a further question and on the other hand it seems to me I could have a lot of sensation but really not be very good at remembering things yeah as age advances you find that that's not just a thought experiment you know that's really what's going on you don't learn too much anymore but you still have the consciousness of what's going on around you you see what I mean yeah right the way we're thinking of it right now in line with CERL is understanding is knowing what the words stand for right knowing what they refer to that's what understanding is uh huh does it uh huh okay I see where you're going that would be a good way to defend the idea that the robot might not be conscious but it could understand yeah because you're going to say that's enough for understanding yeah um well let me give you an example here have you guys come across blindsight can you put up your hand if you've heard of blindsight one blindsight but okay practically nobody blindsight is a condition where people get a bash on the back of the head they have damage to their visual system in the brain and so one half of the visual field has nothing in it there's no experience in one half of the visual field okay so with patience with this damage to um a visual cortex what experimenters did was you put an object into the blind field say a piece of paper like this an edge like this and you say is that thing in your blind field upright or horizontal what orientation is it like this or like that and what does the blindsight patient say the blindsight patient says I have no idea I can't see a thing right and the experimenter says look we'll give you $5 if you guess um so the um the blindsight patient guesses and they reliably get it right they're not perfect but they're well above chance and this has been um really deeply explored I mean there have been must be thousands now of experiments run on the handful of blindsight patients there are um it's been the lives being tested right can you do this can you do that and there is really significant visual information coming in without any conscious awareness at all so suppose you have someone like that right just amp it up a little bit suppose that when you when I said this is Jackson or this is Austin you are in the position of a blindsight patient or if I said this is the screen here right and you couldn't you couldn't experience a thing at all but they said now am I showing you the screen or am I showing you a piece of chalk guess and you said well I don't know I've um I've no experience of either and they said yeah but guess and you guess right you were reliably right every time you'd be in the position of the robot you don't have any experience of what's going on around you but you are reliably discriminating things yeah so in that situation do you know what the words you're using stand for do you know what you mean when you say Jackson or Austin do you know what you mean when you say screen and your hunch is and this is important your hunch is yes of course you know because you can do the discriminations yeah my hunch is I don't think you have any idea what's going on I think that's what you'd say I have no idea what's going on they keep giving me five dollars they keep saying you got that right but what this is all about I have no idea I don't know what any of these words stand for I don't know who these people Jackson I'm sorry if you don't maybe use these examples I don't know who these people Jackson Austin and so on are I don't know what you mean when you say as we can say if you're in that situation so I go with the guys who said it is not conscious that it doesn't know what the words stand for but I do see the importance of this other line it is an important other line and it's important partly because the machine intelligence approach seems hopeless if what I'm saying is correct it's only going to work if you're right so there's a lot of a lot at stake here in this issue anyone else on that is playing this day let me ask again if it's not conscious could it know what the words stand for can you figure out if the answer is yes if it's not conscious could it know what the words stand for if it's not conscious it wouldn't know what the words stand for put your hand if you think that so I would say that's about 4 to 1 at this point but we'll see we will come back to this I think that's all about the Chinese room okay with that we wave goodbye to the Chinese room or I do anyway we'll wear these onto it next week okay so let's look at how we got here I want to suggest that a lot of the puzzles about the mind the puzzle is what is the mind how do we think about what the mind is and a lot of the puzzles come from how strange our knowledge of the mind is you take it for granted the way you know about your own mind the way you know about other people's minds but it is really a strange phenomenon it is not at all like your knowledge of physical objects and Descartes really put it with a kind of thunderous clarity when he said look you have that certain knowledge of your own mind that you don't have of um the existence of any other thing um you know what your own mental states are in a way that you don't know about the existence of anything else as royal put it describing Descartes view the person has no direct access of any sort to the events of the inner life of another absolute solitude is in this showing the ineluctable destiny of the soul only our bodies can meet um so you've got your own mind and you have that really certain knowledge of it you have practically no knowledge of anyone else's mind that's a natural picture right? can you figure out if you think that's correct? oh boy okay one two three okay not a big percentage if you think that's wrong I see if you have no idea of what the question is okay if you just don't know if you find that very puzzling come on there aren't any other options yes? yes of course I see I see yes you could say that you have certain knowledge of your own existence but deny that you don't know where anyone else is you could accept that you have certainty or peculiar certainty about your knowledge of your own mind but still think you have knowledge of other people's minds too is that the popular option can you put your hand up if you think that's right aha okay well that is an issue does the behavior give you direct access or not is it only guesswork what's going on in someone else's mind what I was suggesting with when I went through these examples remember that thing about doing long division in the board where you're watching someone else think what I was arguing there was that the behavior is really direct access because the thinking is right out there visibly on the board you know that was you might agree or disagree but that was my point that if I'm doing a calculation in the board then you're seeing exactly what I'm thinking if I make a mistake you can see exactly where I went wrong if I say five and four eight you know if I write the five the four and the eight then you can see exactly what happened it's not like I'm really made a mistake back in my mind or I really got it right back in my mind and then it was just what happened in the board that went wrong all the thinking was going on on the board or in a conversation you're hearing what the other person is thinking when we are talking right now we hear what the other person is thinking I think that's right you access the other person's mind in accessing their behavior but again there is another point of view that says no the mind is always hidden behind the behavior and if you think of the inverted spectrum then you might say well I don't know what the other person's color experiences are I get their behavior is like mine but really what's going on right inside their mind I have no idea so there are there are different lines to take there there's a lot of pool to all of these ideas but it's a powerful picture that a lot of the mind can be exhibited in behavior I think thinking is the most obvious example but there are also things like whether you're kind or generous I mean can you really look at I can look inside my mind and tell how kind and generous I am yeah I always if someone asked me for money I always just say get a job but in here I'm very kind and generous it just never shows up in my behavior you might say he was very very intelligent but he just never showed any sign of it you can hide it that's right you can hide your heart away that's certainly possible you can hide your feelings sure I agree with that how should I put this there's a bad case for other people and a good case there's a bad case where you hide stuff from them there's a good case where you let them see what your feelings are that's what I meant about the calculation that I can do mental arithmetic and if I'm just plunged in thought doing a long division in my head you have no idea what's going on I can keep it a secret but when I do it in the board you are really seeing the whole thing and similarly if you exhibit your feelings openly that's what I was suggesting the other people can really be seeing all the reasons going on in your mind it's just the one in the same thing can be done now openly, now in secret it's not that it's always been done in secret and then there are just occasional behavioral manifestations of it things are hotting up one, two, three I do know what you mean I hammered it up when I was saying in secret or letting everyone see there can be cases where as you say you're just daydreaming it's not that you have something to hide and there again it can happen that other people find out exactly what's in your mind if you give free vent to it you're daydreaming and suddenly a thought strikes and you blurt it out that can happen so that's the thing that can all be openly exhibited in behavior so that picture absolute solitude is the ineluctable destiny of the soul that really does not seem to be right yeah yes that's a great story where was that it's on the web I can find it in the web that's great thank you for that in some cases you do this is against dickart's view dickart's view is each of us has associated with our body a particular think bubble and you can look inside your own think bubble and see exactly what's going on there but other people's think bubbles are not directly accessible to you you have to go via the body and that only gives you an uncertain inference as to what's going on back there I'm saying that's a much more realistic kind of picture you can doubt that they're existing you can do that but all I mean is if everything's cooperating if they're really existing they really are doing the stuff you think they're doing their whole mind they can be showing you exactly what's in their mind in their behavior so you can see someone being generous and it's actually the generosity you get if someone exhibits a great sense of humor you can see that yep it's a great start I don't agree with analytical behaviorism but that's great absolutely that's exactly what a behaviorist would have to say but you got these pretend cases and some of the dickart things in the pretend case what you've got is the mental state but no behavior it's subtracted something but the behaviorist is going to say what you said is really excellent this is actually a very complicated mental state here being in pain but pretending you're not that's the mental state not wanting anyone to know and if you had that mental state how would you exhibit that in behavior by biting your lip and smiling cheerfully that's exactly what you'd do if you were in that complex mental state yeah I think that's a very good point that's exactly what an analytical behaviorist should say so an analytical behaviorist really pushes this stuff to the hilt and says all we're ever talking about when we talk about the mind is complexes of behavior and if you're pretending or trying to keep something a secret that's a still more complex mental state issuing a really actually particularly complicated behavior it's hard for other people to know exactly what kind of behavior they're encountering but that's all that's going on they don't know how to classify your behavior it's always behavior that's being classified when we talk about the mind yeah and the problem for analytical behaviorism was the the dear old Super Spartans remember the Super Spartans yeah the first encounter of the Super Spartans who for generations have been bred so that they never exhibit pain in their behavior and they never want to I think that's a really good point that's really it's hard for a behaviorist to get around that there might be no connect to behavior there but what I was suggesting in that class was you don't you have to be careful how hard you push that point too because if you say maybe people have been bred so they don't exhibit their pain in their behavior then you could also have people being bred so they don't even internally attend to their behavior they're all like this football player they just focus on the job in hand whatever jolts of agony they're getting they don't attend to that and then you get to the point where you think maybe we could all be like that right now maybe a few thousand years ago humans were bred so as not to attend to their pain so actually we all have icebergs of pain going on in us now at the moment and we only notice the very tip of the iceberg but the pain is there so maybe everyone in this room at the moment is experiencing an imaginable pain it's just you don't notice it and you don't exhibit it in your behavior hello is that a crazy idea yes that is a crazy idea yes can you put your hand up if you think that's a crazy idea if you think that's not that makes perfect sense that's really good do you want to elaborate any of you guys want to elaborate yeah if you're not feeling it that it's not there yeah that's a view on the other side yeah yes right well that's what I think yeah I think that fits very well with the last comment it hardly makes sense there's this massive pain going on but it's making no difference to you yeah right yeah that is the picture that is the picture that the last questioners were saying doesn't make sense because how could it be all buried if you don't feel it in the sense of knowing that you've got it then it's not there yeah but that is the issue I don't think it's an obvious issue that one I don't think it can be right that we're all in a sea of pain at the moment yeah yes that's against the last comment yeah that's not playing with languages making a very definite point you say that I'm in great pain but I just don't feel it what I mean yeah it's just a mistake to say that you could be in this pain but not feeling it to have the pain is to feel it anything else do you want to comment on that okay yeah yeah yeah I do know what you mean the thing is it's very hard to know how to measure how much pain someone is feeling independently of how they react to it do you see what I mean what would you do how much would you pay to stop this pain you see what I mean it's very hard to know what measure there is of how much pain someone's feeling so that you could make sense of the possibility of differences in how they react to the very same quantity of pain you could assume that if I cut you a little bit but the thing is if you get differences in reaction to the same physical injury or electronic shocks or something then there are always going to be two interpretations one is it was the same moment of pain produced in both people but they reacted very differently to it the other would be how fascinating we found that in different people the very same electrical stimulation can cause different amounts of pain yeah yeah it's going to be very hard to make that distinction yeah the last one yes yes they both reacted differently to the same input well there would have to be some difference in the brain yes I mean there's only one world and it's a physical world if two physical systems like the hands and input cells of these two people are behaving differently something physically different must have gone on in the middle unless they're kind of random systems I mean but if you're getting systemic differences between the two people there must be something systemically different going on in the middle right if they're two physical the whole of science is built around that idea I mean there's one thing to question how much science can tell you about the mind but wow it's not wrong from start to finish yeah okay okay the last one there really are terrible cases like that where children just get very young children just get used to chronic pain but it's very hard to know exactly what's going on if someone's gotten used to managing pain the same thing as not feeling the pain all you care about here is their perspective I mean if you're kind of cold hearted to well from my perspective it's perfectly fine you see what I mean what you care about is the child's perspective yeah so we go to analytical behaviorism and then we said well maybe it's the brain maybe being in pain is a brain state that the super Spartans can have even if they're not exhibiting any any pain behavior and then the problem for that kind of picture is variable realizability you remember our old friend variable realizability so you can make an octopus that feels pain you can have a Martian that feels pain you don't have to have exactly the biology of a human being in order to feel pain so you can make different physical systems that all feel pain so it can't be that some one particular bit of biology is required in order to feel pain but as people in the class said when this point came up what matters is not what the particular physical system you have is what really matters is how it's wired up to the rest of the system yeah synthetic materialism is the pain it's a T-fiber firing thing yeah yes I think it's fair to say that the philosophy of mind actually evolved in exactly this order with pretty much these arguments Jackson Austin that's pretty much the way it went I'm summarizing about it took people a long time to think of these things you're on telescoping it now but really it took a long time to do these things but yeah it's possible to go over it pretty rapidly now but these were the key points yeah yes well that's a fair way to put it is the arguments against synthetic materialism like that it's speciesistic if you see what I mean it supposes that humans would be unique in having the kind of mind that we do but of course there could be other species with different kinds of brain structures or maybe no brain structures at all that still have our kinds of minds yeah that was the argument of a variable realizability seems to make perfect sense yeah absolutely this is the key this is probably the key argument well one key argument for functionalism yeah it's the key argument for functionalism I think so it's a very important argument that what matters is not what it's made of but how it's hooked up to the other stuff I mean even if you thought I'm only interested in human brains you would still be interested in functional organization a scientist who's trying to understand what's going on with the visual system in the brain is going to want a box and arrow chart diagram of what all the bits are doing even if they say well I've never really thought about octopuses or Martians or any of that stuff you see what I mean so even if you weren't impressed by variable realizability you still might be a functionalist but this is one of the decisive arguments though it seemed to many people decisive anyway that made functionalism look compelling yeah yes I'm saying variable realizability is a key argument for functionalism yep same question yes you don't know what it is no functionalism is saying the way to find out what's going on in someone else's mind functionalism is saying is not what you make the thing of is what it does so it's like a switch it's not what you make a switch of that makes it a switch it does in the system you put it into yeah so you're characterising the thing the mental state by its inputs by what outputs it gives what inputs that's all very clear at this point should I elaborate that anyone not remember what this means yep who said I don't remember did someone say I don't remember don't be shy is that okay yeah okay so finding out finding out about someone else's mental states is a matter of finding out about their functional structure so it's not saying that mental states are always hidden it's a bit like if you took the electrical system in this room you want a functional characterisation of the electrical system in this room then you could find out about that by testing it by seeing what happens when you put on various switches by seeing what happens when you put the switches on in different combinations by seeing what happens when you take the power out here or there so finding out about someone else's functional structure is a matter of finding out about internal states that they have but you could do that by pushing their buttons by testing them in various ways just the same way you could explore what the electrical system is and the way we do this in practice is either explicit you can say you could actually try drawing a flow chart for one of your friends you could say mention Sally and he always gets grumpy you see what I mean unless he's just had some good news or whatever or you can say about someone he's a fiend when he's drunk and there you're explicitly drawing the box and the arrow diagram yeah you see what I mean or else it can be the way that you get to know someone else as a basketball player you just played against them a lot and you know how to lead them astray you know how to get past them you know when they're going to beat you because you've just learned how to work with them and that's what we do it seems to me with each other the whole time you just get to know how to work with someone else and that's a matter of getting their functional structure how to push their buttons but it's not something that you necessarily write down explicitly it's something you just do yeah infinite is a lot very large yes yeah that is important the writer Borges says something about one of his characters he says like all individuals he was fathomless and you know that feeling that I remember someone saying to me about his wife of 40 years you know I look at her sometimes and I think I have no idea what's going on with you and you know that feeling that you can have a family member you've known your entire life and just be struck by how alien they seem how little you understand of them really of what is going on and it's an important I don't know quite how you make that explicit it's an important idea that you couldn't catch someone by a box and arrow diagram there are always going to be more boxes and arrows than you could capture yes I think that's an important sense though the brain is very very complex I mean the brain is the most complex physical system known I think and when you chart however many trillion connections that are in the brain yeah that's good it's not going to be infinite but it is going to be very very big and it really I think that the hope must be that complexity is really it's just a matter of complexity it's really very very big but it's not actually completely unmanageable that may be true but it may not be true the artificial intelligence guys are going to say to you that is just a matter of brute complexity the way you thought you couldn't make a machine that could play chess successfully that was just the first thing to crack and then the rest is just more complexity yeah yes it's meant to be an alternative to central state materialism and from the functionalist point of view the central state materialist is like the guy that says well a switch has got to be made of copper and Bakelite and they're just making a mistake that's not what makes it a switch you're going to make up something but it doesn't really matter what particular thing you make it of functionalism it's like saying that an electrical circuit is something physical yeah so an electrical circuit it's not like there's some people are dualists about electrical circuits right the electrical circuit is always physical but what makes it a switch is not what is made of but what it does that's the important thing so similarly you could say humans are always completely physical but what makes it they have passions and pains that they feel anger and hurt what makes that so is not what they're made of but how they're wired up yeah does that make sense so it's not something it's not what their physical constitution is this the important thing is how it's wired up yeah there's a more abstract thing than that basic thing yes very good yeah that's absolutely it okay it's like variable realizability you could make a mind out of an octopuses style brain out of a martian silicon style brain or a human biological brain but you could also make a mind out of ectoplasm yeah excellent question yeah okay okay so the functionalist is going to say that knowledge of someone else's mind is a matter of knowledge of their functional structure and that's really whether it's right or wrong it's certainly incredibly important in everyday life that you'd be able to work with other people's functional structures I gave that analogy of the way you could know how another basketball player works the functional structure of a basketball player you could do that explicitly or just by being able to play successfully okay so that's how we got to functionalism any questions about that yep the mind is the functional structure it's a bit like asking where's the electrical system well it's there in the cabling but what makes it the electrical system is the way the cabling is all hooked up together it's exhibited as yeah how it's shown to everybody else is usually through behaviour but in principle you could track functional structure by looking at imaging in the brain seeing what bits of the brain light up when the person looks at something lots of different ways you could get at functional structure the way we do it usually is through behaviour through interaction it's not just behaviour you're not just passively observing we test each other the whole time we interact with each other the whole time you try saying this to somebody to see how they react are they shocked or what the behaviourist would say the important thing is if it's passing the touring test if you can't tell whether the behaviour is exactly the same as the regular speakers then that understands so it wouldn't even require the same functional structure it would just say if it manages to get out the same responses as a regular person would have that's good enough yes I don't know exactly what you mean it's certainly a chain that's what makes them outputs that's what makes them inputs the one causes the other there could be loops yeah and surely there are loops yeah I I'm suffering from insomnia which is a mental state so when I go to bed I worry about my insomnia and that keeps me awake which makes me worry about my insomnia yeah so we go round and round so there can certainly be loops it's not necessarily a linear chain okay consciousness do you remember our old friend the inverted spectrum yes okay so what you see when you look at that is what I see when I look at that what you see when you look at this is what I get when I look at that yeah that kind of idea our spectrums might be just as discriminating as one another but your experiences intrinsically are quite different so these two people could be people who are having quite different experiences could be functionally exactly the same yeah there's something about the nature of experience there's not being captured by functionalism here you could know someone else's functional structure perfectly well you can interact with them we can interact with each other perfectly successfully but still wonder whether you're having this kind of experience or that kind of experience and it makes no difference to your functional structure or with a split brain patient you could say well I know what's going on with this guy functionally perfectly well but I have no idea what his conscious experience is like yes right I think that's different because you'd be functionally different in what you could do with the lenses and without so the thing about the inverted spectrum is if this guy can drive then this guy can drive the colours are just the same the behaviour is just the same the outputs are just the same but with the lenses it doesn't follow that with the lenses you can drive it doesn't follow that without the lenses you can drive you see what I mean no wait a minute that's not black and white everything's switched but there are lots of different possible mappings of the colours you could try out here it's actually technically quite difficult to get a good inverted spectrum you can map the reds onto the greens and the yellows onto the blues but whether or not you can really make an inverted spectrum is a significant technical challenge, Steve Palmer in the psychology department here has spent a while on that exercise trying to show how you could do a good map of one spectrum onto another and he thinks yes it can be done but if for detail on that there's this article by Byrne and inverted qualia in the Stanford Encyclopedia of Philosophy do you guys know the Stanford Encyclopedia of Philosophy? yeah that is absolutely state not always but usually that is state of the art anything you want to read anything you want to google up on Stanford Encyclopedia you'll find good reading on okay this guy you understand functionally but there's something again elusive about his conscious states you remember this guy you can predict just what he's going to do you can predict the kind of thing he's going to say but you don't understand what his conscious experience is so there's again something about conscious experience that's eluding functional understanding so you know the functional structure but you still don't know what kind of visual experience he's having you don't know how to explain in functionalist terms what it is that seems to be so puzzling about this guy there's nothing that's puzzling about this guy functionally you don't know how to explain in functionalist terms what it would take to have a unitary point of view I can't remember did we discuss the example of honey bees before I don't think we did sorry no suppose you think about the way scientists study honey bees honey bees are very intensively studied most they have great navigational abilities they go out and they look for pollen and then they come back to their hive and they do a dance for the other bees to tell them where the pollen is and the other bees make intelligent use of this information one set of experimenters manipulated their honey bee so it came back and told the other honey bees the pollen was in the middle of a lake and the other honey bees just ignored this they make intelligent use of a lot of information and recently I mean just a few years ago it was long been known that they are very good at navigating they get to their hive they use this communication to get to the pollen really successfully and a few years ago they did this thing where the experimenters basically kidnapped the honey bees they put them in the box and put them in the trunk of a car and drove them to a distant destination and then let them go and the bees flew back and forth a little bit and oriented themselves and then they just flew straight for home so they made a bee line for home now that's telling you that there is a lot of cognition there they have a map they have a map of where the mountains are where the lake is where home is with respect to the mountains in the lake they are using the sun as a compass they are flying about to orient themselves with respect to the mountains in the lake and once they get that they can use the map to plot the direct root home so they have a lot of cognition but are they conscious? well they're too small right how can they be conscious how can something that small be conscious the important point really is not whether they're conscious or not but the thing is that you can do this immense amount of scientific study of them without caring about whether they're conscious right? it might not even occur to you that they're conscious but you do the study as to how they get about now suppose that Martian psychologists study us Martian psychologists could study us just the way we study honey bees they can say look at them marvelous little chaps they navigate about the place in these little cars they build all these roads just incredible you wouldn't really think it but it might never have occurred to the Martians that we are conscious right? they just don't need to ask the question they say soft squashy things like that couldn't be conscious doesn't make any sense yeah? and maybe some Martians think they are but they're just regard that a sentimental kind of very fairy nonsense really by everybody else who just studies the way we cognize and the way we get about now when you think about it the way that scientific psychology studies humans is exactly the same way that Martian psychologists would be studying us or that we study the honey bees you look at reaction times you look at what people can do you look at their functional structure you know all about the functional structure of the honey bee you don't need to ask the question is it conscious? you know all about the functional structure of the human you could do all that scientific study and say is it conscious or not who cares? I don't know doesn't matter yeah? so there is something about the scientific study as such of an organism that seems to just miss out consciousness every time and on that bombshell we'll pause for today I have to stop a few minutes early today and we'll pick up with Nagel on Thursday and good luck with the essay okay great questions thanks guys