 Hi guys. Okay, so thank you for showing up. I realize that with Thanksgiving coming, the pressure to bunk off is really strong. So we won't meet on Thursday unless you particularly want to. Okay, right. And then we have a review session on Tuesday. So there is no reading for next time, as it were, except everything we've done so far. And then that's it. I'll actually be away on the Thursday. Okay, so am I going back? Are you going home? Am I going home? Where's home? Well, as you go, right. Actually, I'm not really Scottish. I just put this accent on for a laugh. No, this is my best American accent. Where was I? Okay, so today is, I want to look at questions about what in the literature are called internalism and externalism. And Clark and Chandler's article, We Extended Mind. So this is a little bit loosely connected to what we've been doing the last couple of times. But the general topic here has been so important in recent discussions about the mind that we really can't not do this. So suppose we start out by looking at what physicalism is, physicalism, the view that it's one world and it's a physical world. Yeah, how you make that, how you say more explicitly what that means. Well, remember our friends, possible worlds, possible worlds. Yeah. So there are lots of different ways things could have been. And each world is a kind of maximal collection of ways things could have been, but a total, includes each one includes all of space and time, and all the ways that all of space and time could have been. One of these worlds is special, the actual world, and some of them are closer to the actual world than others. That's okay, you remember that? Does that all make sense? Yeah, you can pause this if it doesn't make sense. Okay, each of these ideas is very simple. So if it seems so complex, it's because of the explanation, not because of the idea. Okay, so physicalism in these terms, you can put as the view that if two possible worlds are the same in all physical respects, then they're also the same in all psychological respects. Now, one of the things that has been attractive about this way of putting what physicalism is, is it actually allows for a lot of tweaking. What I mean is, one way you could tweak that would be to say that formulation says, if I look through all of the space of possibilities, then any two worlds, however remote, in which all the physical facts are the same, are worlds in which all the mental facts are the same. And you might think, well, to be a physicalist, I don't really have to believe that in its full strength. Maybe you might say, all I need is that in every nearby world, in every world that's a tall, there isn't a very remote contingency, it's in any world like that, in any world that could easily happen, if all the physical facts are the same, all the mental facts are the same. Maybe there are really weird worlds out here in the periphery of logical space, where you could have all the physical facts the same, but different mental facts. But in any sensible world, if all the physical facts are the same, all the mental facts are the same. So the general idea of supervenience is you've got a set of base facts, namely, in this case, the facts about the physics of the world, and then that determines the fact, the supervening facts, in this case, the facts about psychology. Yep. That's plain enough. Okay. But then, once you start formulating physicalism like that, what that really is requiring is that if you take two possible worlds that throughout all of space and time are exactly the same in every physical detail, then all the psychological facts about what's going on in those two worlds will be the same. And intuitively, you don't really need anything as strong as that. Suppose that Earth is the only planet where there's sentient life. Yep. Just suppose for the moment then why should it matter what's going on in Sirius B? I mean, you don't really require the two possible worlds should be the same in point of every single physical fact in order to have sameness of the psychological facts. And not all the physical facts are relevant to sameness or difference or psychological fact. If one molecule is just one electron different on Sirius B, that shouldn't matter whether you or I have the same mental states. We want some notion of the local or the relevant physical facts being the same. What you want really is that if two possible worlds are the same in all relevant physical respects, then they should also be the same in all psychological respects. You see what I mean? So I don't know if you can see what's coming. At this point, we settle down to quarrel about what the relevant physical respects are. And we could all agree that if one molecule being different on Sirius B shouldn't matter a bit for what the psychological states of the people in this room are, but can we get it any more fine grained in that? Well, one natural way to get it more fine grained in that is to say if two people are the same, if two people are intrinsically the same in all physical respects, that is if you've got two people and what's going on inside the boundary of the skin is exactly the same for both of them, then they'll be the same in all psychological respects. That's called internalism because it's only the physical facts that are internal to the person that matter for whether the psychological states are the same. Can you guess what the opposite of internalism is? Externalism, very good. And what does externalism say? Externalism says if two people and their environments are the same in all physical respects, then these people are the same in all mental respects. So the notion of environment here is not tremendously precise, but it would include just things that you have causally connected with. So molecules out in Sirius B that have made no difference to you physically wouldn't be relevantly part of your environment. So two people and their environments are the same in all physical respects, then these two people are the same in all mental respects. So internalism says all it takes is the stuff inside the skin to be physically the same and they've got the same kind of mind. And externalism says no, you actually need the stuff in the environment to be the same physically for the two people to have the same kinds of mind. Very good. Again, that's really up for dispute. I hadn't been going to discuss that, but whether it really matters whether you're thinking about sameness over time. Suppose that in World 17, Bill is hopelessly in love, and then in World 16, Bill's counterpart has the same physical state for 10 seconds. Could you be hopelessly in love for just 10 seconds? Surely that's a mere infatuation but only last 10 seconds, you see what I mean? Some psychological states just might not be capable of being things that you could be in only for a few seconds. So in those cases you would need to be considering a fairly extended period and how extended is really up for dispute. If it was a pain or an itch, maybe that would work if it was a very short period. Some psychological states, love of your country, could you love your country for just 10 seconds? I was a real patriot for 10 seconds once. I mean, how could that be? You see what I mean? Is that addressing what you had in mind? Yeah. I agree. I just agree. I just had one of the appeals of this possible world's framework for thinking about these things. Is it lets you give an explicit statement of all these questions? Yeah. And this is a dimension I hadn't really been thinking of discussing, but you're right, it's an important one. Can I just ask you, given that I stated internalism and externalism in those terms, and putting it on one side for a moment the question about time, let's suppose the time stretches as long as it's needed. Can you put your hand up if you think internalism is the right? Just straight off, I mean, as it first strikes you. What it takes for two people to be the same in all psychological respects is that inside the skin, be the same physically. Put up your hand if you think that's right, if that would be enough. Yeah, this is just asking you, what strikes you if you have this? It's not a trap. I mean, often my questions are traps, but this one is not a trap, I promise you. Okay, okay. And if you think no, you're going to have the environment the same, for it to be the same psychological states. Wow, that's a mild but significant majority in favor of externalism. Okay, let's look at some of the arguments that people give. Here's Clark and Chalmers explaining the notion of a coupled system. So they have the notion of an epistemic action where what you do is there are all these cognitive tasks that you try and perform, and that you set up gadgets that will help you perform those tasks. And I was just thinking the other day that phone numbers, you guys probably do not never encounter this, but it used to be just 10, 15 years ago, that most adults went about with between six and a dozen, sometimes more, of people's phone numbers memorized in their heads. I mean, presumably none of you guys can remember this, but there was a time when you didn't just key in someone's name and get their number come up. Can you picture this? You had to have their number wired into your head if you wanted to ring them up without a lot of complicated looking up. So then you get this gadget that lets you offload that task onto something else, but other simple ways of doing it are, we talked about this a couple of times, you're trying to do a long division, so you do it on paper, you're doing the mental task on the paper, or scrabble. Do you guys play scrabble? You know what it is anyway. Scrabble? Okay, I never know. Okay, scrabble, we get all these tiles, letters on them, and you're trying to make words. Well, one thing you can do looking at the tiles is move them about in your head and say, oh yeah, I get this word, I get that word. But another way of doing it is to move the tiles about, right? You see what I mean? You just physically move the tiles about, and that really helps. That makes it much easier. Or once you get the hang of this notion, there are obviously lots and lots of examples like this, diaries, calculators, anything with a computer is really doing that, offloading some of the cognitive work that you used to do in your head onto some gadget. Yeah? So, Clark and Chalmers say, in these cases, the human organism is linked with an external entity in a two-way interaction, creating a coupled system that can be seen as a cognitive system in its own right. So if you're asking, is it you or the scrabble tiles, is it you or your phone that are doing this cognitive task? Well, it really is both of you together. You are working with this gadget. The gadget is a kind of cognitive tool. It's an extension of your mind that you are using to get the thing done. If we remove the external component, the system's behavioral competence will drop just as it would if we removed part of its brain. We have actually seen this already a couple of times in this class that when the projector suddenly packs up, then you see that the whole lecture or projector coupled system loses its competence just as it would if you remove part of its brain. You see what I mean? That's a kind of commonplace phenomenon. So then they have this example of Inga. Inga wants to go to an exhibition at the Museum of Modern Art. Inga remembers that the Museum of Modern Art is in 53rd Street. So she goes to 53rd. Here is Otto, whose brain is maybe not in such good shape as Inga's, but in order to compensate for the deficiencies of his brain, Otto has the address of the Museum of Modern Art written in a notebook in his pocket. So when he wants to go to the Museum of Modern Art, he doesn't look inside his mind, just pull up from his brain where the Museum of Modern Art is. He reaches inside his pocket and looks in the notebook where the Museum of Modern Art is, and then he walks to 53rd. So functionally, if you look at what Inga's brain-based recall is doing and you look at what Otto's notebook-based recall is doing, are they functionally the same? Put up your hand if you think the answer is they are functionally the same. Yes, I mean, so far as we've considered anything, of course, that's the whole point. They're doing just the same thing, right? He's got this want, he pulls out the notebook and then he walks to 53rd, right? She's got this want, she pulls it out of her brain, she walks to 53rd. They're doing the same functional work, the brain-based memory and the notebook-based memory, yeah? So Otto's notebook has the same functional role as Inga's memory. So Otto's notebook is just as much part of his mind, it's just as much part of his mental life as Inga's memory is of hers, yeah? There's no difference between the role that the brain is playing and the role that the notebook is playing, okay? Put up your hand if you think that's just fine. Put up your hand if you think that's kind of outrageous. Okay, very good. Do you want to say anything about it? Uh-huh, but in what way? It's functionally similar. Right, but what if she didn't have her brain? You see what I mean on that part of her brain? I see you can say what if he didn't have the notebook, but I sympathize, I mean, but you see how you can already hear yourself how hard it is to explain what you mean by that, because after all, if you could make sense, I mean, it's just physically a bit more difficult to extract a bit of Inga's brain, sorry? Yeah, let's suppose it's a notebook that he keeps chained to his wrist, you know, God himself would have a hard time getting that notebook off him, yeah? Unless suppose, on the other hand, that neuroscience has developed to the point where neurosurgeons can reach in in the twinkling of an eye, extract an unwanted memory, yeah? Then they look pretty similar, yeah? Yeah, so it's hard to explain the difference here. So now consider Twin Auto. Twin Auto is just like Auto, except that Twin Auto wrote in his notebook that the Museum of Modern Art isn't 54th Street, right? So, Auto and Twin Auto are inside the skin molecule for molecule identical, right? Neither of them have got that good brain-based recall, but they've both got their notebooks, and so they've got something different written in their notebooks, and Clark and Chalmers say, since they have something different written in their notebooks, they have different mental states, they have different beliefs, their minds are in different conditions. So, Auto and Twin Auto are molecule for molecule identical underneath the skin, but they have different beliefs in virtue of the difference in their notebooks. Let me just conclude, and then I'll, yeah. So, is this an argument for internalism or is this an argument for externalism? Except, very good, right, okay. So the general picture is you've got the base facts determining supervening facts, right? The physical facts determining facts about the mind. The internalists say is internal base facts that determine what your psychological states are, but the idea here is that what beliefs you have doesn't depend only on the internal base facts, it also depends on these external base facts like what you have written on the notebook in your pocket, yeah. Auto and Twin Auto, yeah, why not? That's right. I agree that when each of Auto and Twin Auto read their notebook, and this is important, when each of Auto and Twin Auto read their notebooks, then they'll go into different physical, internal physical states, yeah. But the notion of having a belief about where the museum is, well, let me put it like this. Do you know, actually I don't mean to put you in this spot, but let me just try this. Do you know where the museum is? Yeah, okay. So it's right across Bankcroft, right? So how long have you known that? Yeah, a year or so maybe, yeah? Okay. But have you been thinking about that continuously the whole way through? You see what I mean? It's not like you keep mumbling, my God, I mustn't forget. The Art Museum is right across Bankcroft, right? You see what I mean? It's not like you keep mumbling, my God, I mustn't forget. The Art Museum is right across Bankcroft, right? You sleep, you think about other things, right? But you think all through that period, I had the belief. So there's the idea that I have the belief, but it's not always activated. It's not always current, yeah? It's not always fired up. So the thing about Auto and Twin Auto is that you're right that when they get fired up, the internal facts about them will change, yeah? But even when they're not fired up, they can still be said to believe one of them that the museum is in 53rd Street, or to believe the other of them that is in 54th Street. Just in the same way, you can be said to believe that the Art Museum is right across Bankcroft, even when you're not firing up about that. They're believing about something that was happening a while ago. You mean the beliefs about what was going on a while ago? Just a second ago, yeah? Right. Okay, and then they're making a mistake about that. Yeah, but they're making a mistake about whether they had the belief for the last year. Okay, this is getting quite complicated. Just one more thing, actually quite a lot of people, one of the last questions, but so long as they've, suppose the quasi-memory was dropped into me a year ago, yeah? I know that's different from your example, but then I've had that belief for a year, even if it hasn't been fired up all through the year, because I've got the traces there, the information is there, waiting for me to retrieve it in the great filing system of the brain. That thing has been sitting there waiting to be called up for all year, yeah? In that sense, it really, in that case, it really is true that I've had that belief all year. And here the point is, for Otto and Twin Otto, the filing system of the notebook is not really that different to the filing system of the brain. And so long as the notebook's been there in their pockets for a whole year, they counters really having had that belief for a whole year, not just thinking that they had that belief for a whole year. Come back to this, yeah? Oh, very good. Yeah, whatever I wrote in my notebook. That's a good move, but what Clark and Chalmers are claiming is something stronger, that they have different specific beliefs about which street the thing is in, because of the difference in, yeah. Let me think about this a second. That's a really good move, because that would defend internalism, right? They've got the same belief when you describe it in that abstract way, but once you get down to, in which particular place is that, then they're going to have to look in the notebook to get a specific belief about that, yeah? I guess the idea would be that, yeah. That's a very interesting move. With for it to be really functionally the same, yeah? The move I began with was, remember comparing Otto and Inge, yeah? That the notebook has the same role in Otto's mental life as Inge's brain, house and hers, yeah? Then Inge doesn't just have a belief that somewhere in my brain I've got the information about where the museum is, right? Inge might not even know that she has a brain. So, you know what I mean? Yeah, you could go through your entire life without realising that you had a brain. Yes, okay. And really, for this to be really functionally just the same, it would have to be kind of the same. Otto might not even realise he has a notebook. He just reflexively pulls it out, looks at it and says, I see 53rd Street. You see what I mean? Just an unreflective way that you call up your memories from your brain without knowing what you're doing. For that really should be the very same functional role, yeah? So, I think that's a very interesting challenge that it really is not that plausible that Otto could do this without even realising he had a notebook in the same unreflective way that Inge could do it without realising that she had a brain. Yeah, I mean, I realise it sounds kind of comic to say you might not even realise you had a brain, but all I wish to point out is it is also kind of comic if you say, if someone asks you where is the museum of modern art and you say, wait a minute while I check my brain. You see what I mean? You can make sense to say wait a minute while I check my notebook, but not, I mean while I check my brain is kind of weird, yeah? I try to remember, but that's a different thing, yeah? Okay, so that's a, okay, anyone else? Yeah, yeah, yeah. Uh-huh, yeah, it's very good, yeah, yeah, excellent. But that's what Clark and Chalmers are saying. You get the dictionary, you know all the words, yeah? It is different, but is it relevantly different? I mean it could be just as easy for you to pull up the meaning of any word from the dictionary as it would be had you stored them all in your head somewhere, yeah? There's a subtle difference here which is if you really got all the words internalised then you will just use them unreflectively, you see what I mean? And having the dictionary in your pocket won't let you do that, yeah? But it can also be that you're thinking zygote, what's zygote? And you've got it somewhere in your brain, yeah? And you can pull it up, but it takes a bit of an effort, yeah? That can happen with, um, yeah, technical vocabulary. Say you did a biochemistry course and then never did biochem again, you know, five years later you might have to do that kind of pull up exercise for words that you had learned then. That would be different to having it as part of your ordinary unreflective vocabulary, yeah? So if you think like that, maybe it looks a bit more similar having it in your brain and having it in your pocket, yeah? Okay, uh, yeah, was there anything else? Yeah? Yeah, right. Well, the thing about auto and twin auto is that we're not challenging whether they understand what they read. We're taking it for granted, they understand what they read all right, yeah? We're not giving an analysis of that, that's right. Um, and I see why you say what you're saying that all I've pointed to so far is the functional role and the point, part of the point in the Chinese room is that the functional role is not enough for understanding, yeah? But, um, in the case that, in the ordinary case here the reason that the stuff in the notebook has the functional role it does for auto is that auto understands what it's saying, yeah? It's not just that he looks at it and then for reasons that are completely inscrutable to him he just finds himself marching off to 53rd Street, yeah? So I think they can build that into that example, yeah, that there is semantic understanding here. Anything else on that? So, I just like to know at this point, can you put your hand up if you think that Clark and Chalmers example is a good illustration of what you meant by externalism? That's pretty convincing about externalism. Auto and twin auto have different beliefs. I can always see one hand and one and a half, okay? One, two, okay? Right, and if you think that's completely unconvincing the auto and twin auto just do not have different beliefs. Okay, that's about four. What's going on? And if you think, what is this auto and twin auto example? Yeah, memory. Yeah, that's right. Well, once they've got it in their heads, yeah? Yeah, that's right. But we're talking about before they pull it out. While they're just moseying along. No, that's okay. That's what's the issue, right? Okay. Okay, that's that same move. Okay, I agree that's a good move. Yeah, I want to try and soften you up a bit on behalf of externalism in just a minute, but yeah, I just agree that's a good move. That would fit with internalism, is that right? That would fit with hanging on to internalism. Okay, can you put your hand up if you think, having now seen what externalism looks like, I'm kind of sympathetic to internalism. Okay, put your hand up if you haven't voted in the last couple of rounds. I don't understand what's going on here. Okay, why aren't you guys voting? Does the question not make sense or is it very hard? What's going on? Is the question badly posed? Actually, I've never forgotten what the last question was. The last question was, yeah, having now seen externalism means auto and twin auto have different beliefs, right? Because what's the base class determining what's in their mind includes the notebook. Yeah, so what I was saying was, if you now think, well externalism means I've got to accept this thing about the notebook being part of your mind, then I don't believe that. If that's your position, can you put up your hand? Okay, and if you think, no, that thing about the notebook sounds just fine to me. Wow, okay. I don't understand you guys who are not voting. Is it that you understand the question perfectly well, but you're just thinking, I really don't know which way to go on that. Put your hand up if that's the case. And if you're thinking, I just don't get what the question is. Okay. A number of you are leaving this family inscrutable. Okay, yes? Yes. Yes, right. What's really doing the work here is the internal stuff. The external stuff is just exiliaries. Yeah, I see that. I should say there is something kind of zeitgeisty about the Clark and Chalmers thing here because, I mean, it's just kind of obvious that in a million ways, computational gadgets are helping every day and more and more every day, really helping us do cognitive tasks. And then it's a really interesting question. Is that making a fundamental difference to what the mind is having all these tools? I mean, how radical a change is it making? And this is really a simple dramatic proposal about how it could be making a huge difference. Let me give you another kind of example that Clark and Chalmers mentioned, though they don't make much of it. I mean, but it's been tremendously discussed, the idea of twin Earth. Twin Earth? We haven't come across twin Earth before. Twin Earth? Okay, well, here's the idea. Suppose that somewhere far, far away in a distant galaxy is a solar system just like ours. A sun just like ours. An Earth just like ours. A USA just like this one. A Berkeley just like this one. A lecture room just like this one. And people in it who each are molecule for molecule duplicates of you or me. So in particular, there's a molecule for molecule duplicate of you and twin Earth. Okay, you with me so far? Is that the same time? That's right. Absolutely in sync. Isn't that amazing? Right. Well, there you go. Okay. And follow me very closely. Okay. Okay. And just so you can see the situation, this is a factual photo of Earth. And this is twin Earth. As you can see, they are very, very similar. Right? Okay. Yes? Now, on Earth, there is a Hawaii. Yeah? And on twin Earth, there is what? Hawaii. Twin Hawaii. Yes, exactly. Right. And again, here is a photo of Hawaii on Earth. And here is a photo of twin Hawaii. Can you see this? Yeah. Can you see the similarity? They are really very, very alike. In fact, they are molecule for molecule identical. Yeah? Okay. So you got the picture. Right? Now, suppose that you are thinking about Hawaii. Suppose that as you just to take an entirely hypothetical example, you are thinking to yourself, my God, if only I had bumped off I could be in Hawaii. Yeah? So you are thinking about Hawaii. Now, meanwhile, completely in sync on twin Earth gazillions of miles away, your duplicate. Well, what is your duplicate thinking about? Is your duplicate thinking about Hawaii? Aha! Put up your hand if you think the answer is Hawaii. And if you think the answer is twin Hawaii. Yes, that must be the right answer. I mean, your twin has never been within a gazillion miles of Hawaii. Your twin has no idea that such a place exists. Right? So your twin can only be thinking about twin Hawaii. You see? You are thinking about this one and your twin is thinking about that one. Right? So you are thinking about different places. That all right? So you and your twin are thinking about different places. You are having different thoughts. Yes? No? Okay. Well, let's take this slowly. This is actually really important, this issue. Why not? I mean, if you are thinking about Hawaii, then whether or not what you are saying is true depends on how things are at this place on Earth. If your twin is thinking about twin Hawaii, then whether what they are thinking is true depends on how things are. That's quite different place. One of you could be right and one of you could be wrong. You see what I mean? So there must be different thoughts that you are having. Yes? I make the following claim. You are thinking about different places. You and your twin are thinking about different places. Yes? Even though you are molecule for molecule identical, for every molecule in you, there is a corresponding molecule in just the same condition inside the skin of your twin. But you are thinking about different places because Hawaii is the one that you have interacted with and twin Hawaii is the one that your twin has interacted with. So your thoughts, your beliefs are different even though your molecule for molecule identical. Well, if a mental state, if belief is a mental state, then if two beliefs were the same, then if one of them is true, then the other one is going to be true. If one of them is false, the other one is going to be false. Yes? Aha. Well, remember talking about Churchland and talking about Dennett? We were talking about propositional attitudes. Yes? Believing that the University of California was founded in whenever it was 1868. Yes? I said belief is an attitude to a proposition. And what class I said is a proposition, a proposition something that's capable of being true or false. That all right? Yeah? Hopes that, fears that, these are all attitudes to propositions. So if the mental state is an attitude to a proposition, then if one person has the belief that is defined as, that is specified by specifying which proposition, then if another person's belief is specified by specifying a different proposition, then those are different beliefs. No, that contains a proposition. If I said contained, I may have said contains a belief, but if I did, that was a mistake. Sorry, say that again. That's right. That's right, but the belief is a propositional attitude. I think I don't disagree, but a belief can be true or false. Yes. Yeah? So your belief is true if it's true because of what's going on with Hawaii here. Your twin's belief is true if it's true because of what's going on over there. So they are different beliefs. One can be true and the other can be false. How could that be if they were really just the same belief? Matters. Well, something else can come up to you today what you just thought was wrong, but it doesn't change what you thought. I still thought it even if it was wrong. Yeah. Yeah, right. But my mental set is something that's capable of being right or wrong. Yeah, I mean, otherwise, philosophical discussions, political debates and so on would all be a complete waste of time, right? If you said, well, beliefs can't be right or wrong. Okay, it has the capability. It has the capability of being right or wrong. So if two beliefs can be right or wrong independently of one another, then they can't be the same belief independently of one another. They're a rational state of being. That's right. Like, for example, on Twitter, but at an exact moment, the volcano erupted, and now the sky is completely black. Right. And he doesn't know that. Right. And on normal Earth, it's fine. Right. But I would think the mental state is about Hawaii's guy being blue, whether or not it is true. That's the argument. They can't be the same if one can be true and one can be the other one false. I mean, how could that be? If I say to you, I completely agree with you, I share your beliefs, but your beliefs are false and mine are true. That can be right. Yeah. If we both, if you and I have exactly the same beliefs, you know, I say you and I really are shoulder to shoulder on this deal with Iran. Yeah. But everything you're thinking is wrong and everything I'm thinking is right. That makes no sense. If you and I really have the same beliefs about this deal, then if what you're thinking is right, then what I'm thinking must be right, too. And what you're thinking is wrong, then what I'm thinking must be wrong, too. Yes. Right, very good. Yeah, yeah, yeah. But that just shows you don't have the same beliefs. If I'm saying to my, if I'm communicating via intergalactic phone with your double on twin Earth and I say, I completely agree with you about this Iran deal, but that's not actually the right way to put it because we're talking about different things. He's talking about a deal over there. I'm talking about a deal here. We don't actually share opinions. I mean, to put it another way, I could have all my current views about the Iran deal here, but completely disagree with your twin over there about the Iran deal and twin Earth. Okay. There is, I agree there is, I agree there is more to say in this. Yeah. That does make sense. Yeah. Very good. Yeah. Okay. Okay. Yeah. Not for the first time. You guys are ahead of me. The thing that you two are saying, I actually want to come on to in a second. Does that thing about the quality of the experience? Does that connect with? Yeah. Are you thinking? Yes. Yeah. Okay. Okay. Good. Okay. I think that whether you agree or not, the claim I'm making here is what propositional attitudes you have, what thoughts you're having depends on what things are around you. You can only think about the things that you're actually interacting with. Yeah. Someone light years away on twin Earth can't be thinking about the same people in places as you because they've never interacted with them. That's okay. Maybe they're all identical. Earth and twin Earth are different places. They're light years apart. It would take you a very long, it would take the Starship Enterprise a very long time to get from here to there. And if you said, well, it's just the same place. That would make the voyages of the Starship Enterprise completely pointless. They're different places. Are you staying for the Starship Enterprise as doing its pointless? Yeah. Steady on. It's very similar, right? But it's not one and the same. That's right. They are different just by their location. That's right. If they're in different places, then they can be extraordinarily similar, but they're not going to be one and the same. I think that's completely correct here. That's exactly it. Right. Okay. It functionally seems the same. I mean, functionally will be the same. But it can really matter. I mean, suppose my father's grave is on Hawaii. Yeah. And I want to visit my father's grave, and I'm whisked off to Twin Earth and taken to a grave in Twin Hawaii. Yeah. It will be functionally very similar. But it's not the one I wanted to visit. Yeah. I mean, two situations can be very, very similar to the point that you can't tell which is which, but it still really might matter to you which one you're in. Sentimental, yeah? Right. Boy. Okay. You're hard. I mean, suppose you have someone whose firstborn child is whisked away. Yeah. But the kindly geneticists at the hospital say, actually, we've got the photos. We can build one that's just like the old one. So you can't tell the difference. That kind of sentiment that says, oh, that really matters. We should just whisk that away. Aha. Okay. I'm so relieved, right? Sometimes I think there's a generation thing. You mean you should take... I see, yeah, yeah. This isn't actually your father's grave, but this will do just as well. It's very, very similar. You say, oh, well, okay. Fair enough. Yeah. Yeah. I don't think people actually think that. You know, if your spouse is whisked away and you get a duplicate, there's actually a short story by Isaac Besheva Singer about a man who sets out on a journey from his home village and age night when he's walking, outside his tent, he leaves his shoes pointing in the direction that he's going in. Yeah. And one night, after he's been out on his trek for a couple of weeks, one night someone shifts around his shoes in the middle of the night. So he just keeps walking. And after many weeks, he comes back to his home village and he finds that the world is even stranger than he thought. He says, my God, this village is just like my home village. These people look just like the people in my home village. This woman looks just like my wife. But he doesn't say, well, this is just as good. You see what I mean? He remains distanced from all of them because he thinks these weren't the people he knew. Yeah, these weren't the people he thought about. Okay, so internalism is saying if two people are the same in all physical respects inside the skin, then they're the same in all mental respects. But what this Twin Earth, Twin Hawaii case shows if what I said is right, is that that's a mistake because you and your twin are in different internal states. But what your thoughts are depends on your environment. What you're thinking about depends on what you're causally interacting with. So you can't think of the mind as something internal to the head. The mind has got to be, how should I say, spread out across the environment. The mind contains the environment as a constituent. Which things you're thinking about depends on what's in your environment. So we've got to be externalists. We've got to say if two people and their environments are the same in all physical respects, then those people are the same in all mental respects. So it's got to be that it's external and a plus internal base facts that are constituting your mind. Externalism must be true. Can you put your hand up if you think that's right? Okay. We're finally getting onto the same page. You're right. We'll see. So if you get two possible worlds that are the same in all, you've got the same internal physical facts plus the same environment, then you've got the same mental states. That's the right way to say physicalism. If what I just said is right. Some of what you guys have said are telling lines of thought in favour of fight back for internalism. But this is a pretty powerful case, it seems to me. This kind of 20-hour example was given by Hillary Putnam. I say, yeah, Putnam keeps coming up, right? But Putnam did this back in the 1970s, this kind of example, that provoked a lot of discussion. It actually bears on... I mean, you guys brought up the Chinese room already, but you remember this guy? Yes, the real Chinese roomer. It suggests one diagnosis of what the Chinese roomer is missing. We talked about the kind of... You guys suggested the system's response. They said you can't just look at this guy whether there's understanding of Chinese here. You've got to look at the room, and I kept coming back and saying, yeah, but suppose you just put the shell of a room around him. How does that convert something that doesn't understand Chinese into a system that does understand Chinese? But what this stuff about Hawaii suggests is that what object you're thinking about depends on how you're embedded in your environment. You can't just think about the mind in isolation from the environment. That makes no sense. If you take the mind in isolation from the environment, that's why you're getting this phenomenon or something that only gets syntax and no understanding. Because what understanding takes is for you to be wired up to your surroundings in the right kind of way. So to understand what thinking is is not enough to just look at the internal machinations of the mind. You've got to look at how the mind is causally connected to the things around it. And of course that's completely different to Descartes. Descartes was saying, it might all be a dream. The physical world might not be there, and I would still be having the very same thoughts. But if you really buy what I said about Twin Earth and Twin Hawaii and all that, that's a mistake. If you had been on Twin Earth, you'd be thinking not about Hawaii, but about Twin Hawaii. And if there wasn't any physical surrounding at all for your mind, you wouldn't be thinking about Hawaii, you wouldn't be thinking about Twin Hawaii, you wouldn't be thinking about anything at all. If you were really just a mind with no physical surroundings, you wouldn't be having any thoughts about anything at all. That's the lesson of this kind of example. It's a very simple example, but it's very powerful, very far-reaching in what it's telling you about the mind. Notice that if you're a Cartesian dualist, you're thinking what the mind is is a bit of ectoplasm with all these thoughts running through it. These thoughts are going through the ectoplasm, and it ultimately doesn't matter what's going on out there. But that kind of picture has got real trouble with these coupled systems. You auto-hooked up to his notebook, or you and your double and twin Earth with Hawaii, because these causal connections to your environment just shouldn't be mattering for what's in your mind on a kind of ectoplasmic picture. But what this suggests is that the way that we actually do think about the mind in real life when we're talking about who's thinking about what, you're constantly demanding that people be causally connected to the objects of their thoughts in order for them to be thinking about these things at all. Is that plain enough? Let me just check. Put up your hand if at this point you think the case for externalism is pretty powerful. Put up your hand if you think the case for externalism is pretty powerful, but I still don't believe that thing about the notebooks. And if you think at this point, I'm softened up, I'm happy to give you the thing. You persuaded me about the Hawaii, twin Hawaii thing, so I'll give you the notebooks too. Put up your hand if you think that's... Okay, that's very interesting. We're still not buying the notebooks by and large. It's a significant minority going with the notebooks, yeah, externalism generally, yeah. Right. Okay, I'm saying you can't... What someone suggested earlier was that might be right for qualia. Yeah, that works for qualia. There's a cause of the qualia. But the thing about the Hawaii and twin Hawaii cases is that you can't separate the question. That was what Rollat 2 and 4 was about, was that you can't separate the question what your thought is from the question what you're causally connected to. It's not that I and my twin on twin Earth are having the same thoughts, but they're different things that are causing us to have them. It's rather, since different things are causally connected to us, we are thereby having different thoughts. Yeah, that's what I mean. The environment is constituting your mind. Yeah, it's not just causing your mind. But as someone said earlier, you might actually argue it's different for qualia. And it seems to be a coherent package to be an internalist about qualia and an externalist about thoughts. Yeah, what you and I were banging away about was whether to be an externalist about attitudes, about thoughts. Yeah, but you could say, okay, I'm going to give you the externalism for thoughts. But what I really... the mind proper is the qualia. The thrills, the feelings, the experiences, that's the important thing. The consciousness, that's the thing that matters about the mind. And I'm an internalist about that. So, with Otto and Twin Otter, Clark and Chalmers are saying, well, they've got different beliefs in virtue of the difference in their notebooks, just as you and your twin and twin Earth have different beliefs in virtue of the difference in your environment. But couldn't we be an externalist about propositional attitudes and internalists about qualia? There's a story that Donald Davidson had that this is a little bit of a scary story. So if you're of a nervous disposition, you might want to kind of blot out this next couple of minutes. But here is the story. It's midnight. And in the swamp outside town, there's a thunderstorm. And as it rolls overhead, there's suddenly a tremendous bolt of lightning that strikes the swamp. And in the swamp, a strange chemical reaction is set off. And out of all the algae and slime in that fitted swamp, there are clambers, a creature, a creature recognizably human, swamp man. Now, as you can see, swamp man looks very like you. Well, once we get him cleaned up a bit. What? Well, you've got to get him cleaned up a little bit. And in fact, let's suppose, once the lightning has struck the swamp, swamp man is molecule for molecule identical to you. Right? So swamp man just comes out at midnight like that. Molecule for molecule identical to you. So what's swamp man's frame of mind on coming out of the swamp? If you are, let's say, at that moment lying in bed thinking about those happy moments on your fifth birthday party. Yeah? What is swamp man thinking about? That same birthday party. Was swamp man at your fifth birthday party? Does swamp man know anything about your fifth birthday party? Sorry? He has the memories of it. But let's just bear in mind, when was swamp man created? In your... He's not causally connected. He was created by a random bolt of lightning hitting a fetid swamp. Right? It's only a coincidence that he's so very similar to you. It's exactly like your brain. Picks up. All I said was he's physically very similar. But it's just a coincidence. I mean, I don't know if I have to go through for you how lightning and swaps work, but it's not a copying process. Yeah? It's just a coincidence that it came out. I don't know any plainer English in that. He is molecule for molecule identical to you. I don't know what you mean in what way. In every way. Sorry? Let's suppose memories are a physical thing in your brain. Is memory a causal notion class? In order to remember an event, does your impression that that event occurred have to be caused by that event having occurred? Good. Right. Okay? Are swamp man's memory impressions caused by any past events? Was swamp man, for example, at your fifth birthday party? No, you'd remember. Right? So can swamp man be remembering your fifth birthday party? No. Right. Well, what does under the impression right mean? He can't have any thoughts about any of the stuff around him. He can't have thoughts about Hawaii. No. No interaction with Hawaii at all. No more interaction than someone in twin earth has had with Hawaii. He doesn't have the right kind of environmental embedding. He's not embedded in the world in such a way that he, you know, thoughts about it. Does he have a mind? Yeah. Well, I guess that's what I wonder. This is kind of picking up what people were saying earlier. Surely he is qualia. Surely he has experiences. When he's coming out of the swamp, he may be saying, my God, this is wet and icky. You know, I can't wait to have a nice hot bath. I mean, he may have qualia feelings. He just can't have thoughts about the things that you have thoughts about. You can have two people with the same physical state and different propositional attitudes. You and your counterpart in twin earth. You and your counterpart in twin earth are embedded in different environments. So even though your molecule for a molecule identical, you have different thoughts. And you and Swampman are molecule for molecule identical, but Swampman's not embedded in any environment at all. So Swampman doesn't really have any thoughts as yet. But if you and Swampman and your double and twin earth, if one of you is in pain, are the others in pain? They're certainly the same molecule inside the skin. It's a good impulse for me to say yes. Right, if one of them is going to C5 or firing, they'll all get C5 or firing. No, you're saying they're identical. Yes, that's right. Yes, that's what I mean. If one of them is going to C5 or firing, rather than all of them have C5 or firing. What I mean is Swampman and your double and twin earth and you. Whether you have pain? Yes, but then you'd be different inside the head. But what I mean is, as the last question you said, if you've all got C5 or firing, everything inside your skin is exactly the same. So you've all got C5 or firing, unless suppose you are all screaming. Then if one of you is in pain, are all of you in pain? I think what people were saying earlier was yes. Swampman is not... You and your double on Hawaii, you're not completely unlike because your internal feelings are presumably just the same. Even if you're thinking about different things in the world around you. So here's a possibility. Incidentally, is that clear? I guess I'm assuming that everybody's happy with that distinction between propositional attitudes and qualia. Is that okay? Do you say that? No. A quasi-memory... Remember the example of brain slides? A quasi-memory has to be just like a memory except you need not to be not the past event at the time. You need not to be present at the remembered event. It's just like a memory in every other way. So a memory requires that causal connection from the past event through to the present impression that the thing happened. Exactly. Swampman certainly doesn't remember stuff because he wasn't at any of that stuff. And he doesn't quiz I remember because if I explained the technicalities of the situation right, the lightning bolt hitting the swamp, that was just an accident. It wasn't caused by what really went on. Yeah? Yeah. Well, that's what I don't see. That's the point about propositional attitudes and the Hawaii case that what's inside the head is just the same but which thoughts you're having is different. I'm sorry, I don't really see how to explain this in such a way that I don't just keep repeating myself. Do you see why I say that you and your twin are having different thoughts? Yeah. Okay. Then if you still look for something the same, then isn't really what you're after to be an internalist about qualia that if two people are the same in all physical respects, then they're the same in all those experiential respects but they may be different in which thoughts they're having. They were not the same in all qualia. Who's not the same in all qualia? You're a super vignette, but the qualia could be different with two people who are molecule for molecule identical. Yeah. You have to forgive me, I don't remember arguing that, but maybe I did, but... I don't actually want to revert back to our earlier discussion about what to believe in them. Okay, you've really rattled me now. I don't remember arguing that you could have people who are molecule for molecule identical but with different qualia, but I can't rule it out. I don't remember. Does anyone else remember me arguing that? Yeah. I actually want to develop something like externalism about qualia next time. Yeah. I'm actually in connection with Jackson's argument, so I don't remember explicitly arguing that, but you're right, if you picked up, that was where the discussion was going, and I will try and... in reviewing what's going on, I will try to make a case for externalism about qualia. For the moment, I just want to say... I want to say that given these twin Earth cases, the case for externalism about propositional attitudes seems very powerful, but as you guys were suggesting, you could be an externalist about propositional attitudes, but an internalist about qualia. Okay, have a great Thanksgiving, guys. Okay, thank you.