 OK, one last time on, good morning, good morning class, good morning, OK one last time on, brains and a bat and then we sweep triumphantly on to Dritschka on a, to Dritschka, I forget the name of the paper but there's the only one by Dritschka, misrepresentation that's the name of the paper, OK. And in the Dritschka and folder papers that we're doing next, you'll see that really what they are doing is they are amping up the causal theory to absolutely full generality, they are trying to get a theory that will apply to any kind of representation, whatever stated in causal terms. But today one last time on brains and a bat, really what I want to do in this last session and last time too actually is just try and get a good focus on what Putnam's argument actually is. As I said I think there's a real insight in Putnam's argument, whatever specific criticisms you have of it, there is a real insight there which is something about the way in which the mind and the world, the mind is constituted by the world on a causal theory of representation in such a way that it's difficult to see how there can be global error by the mind about the world. There's some insight there that I think is not going to go away but last time I was saying well there are limits on this kind of argument. It doesn't seem like it's going to work very well as to see off scepticism about other minds. If you wonder whether you really know what anyone else is experiencing, the argument is going to have limits there and the argument also seems very threatening to the ordinary picture we usually have about our knowledge of our own minds. So what I want to do with these arguments is not so much to knock over what Putnam is saying but to get more and more of a fix on what the argument actually does achieve. Incidentally, since this is the last session on Putnam and I assume many of you guys will have been thinking about this, feel free to free associate a little bit in questions if you see what I mean. It doesn't have to be exactly about what I just said. If you've got some way of showing that Putnam is wrong then please feel free to air it in questions. So I want to start out by asking, he has a slightly different way of thinking about a problem with Putnam's argument. You can say, well instead of saying as I was asking last time has he really refuted the sceptic and you can look at his analysis of what kind of knowledge it is that he's trying to say that we really do know. What do you have of the world and say, is that it? Do we really have as little knowledge of our environment as Putnam is supposing? I think there's some sense of which is a very minimal conception of knowledge of the environment that he's working with. Putnam says, suppose that the world is the way you and I usually think it is and suppose that Putnam's right about the brain and the that, having knowledge of what's going on in its environment, then Putnam says, well the brain's no worse off than us but it's a natural reaction I think to say, well the insight the brain and the that has into what's going on, there's some sense in which that's pretty minimal. There's some sense in which you want to say it is not the first idea of what is going on and Putnam's really only getting us that we are in that same position. There's some sense in which your brain doesn't know what it's like out there and we usually think we do know what it's like out there. I take for example colour terms. If you think about the way the brain and the that is using red and green and blue and so on, all is there is a kind of grey coloured sludge and the that where it's suppose is of a uniformly monochrom or an interesting colour. So the brain thinks it's confronted by a blaze of colours the whole time but there obviously is no colour in the relevant sense in its environment. So does the brain and the that have knowledge of the colours of the things around it? I mean does it know what the colour terms refer to and are we in that position? Is that the same as us? We don't have any knowledge of what the colour terms refer to. We don't know what the colours are of the objects out there. And you might say well actually what physics shows is that our situation is pretty much that of the brain and the that. And what physics shows is that just as for the brain it has no real idea of what's actually going on. You might say well physics shows that here this space time zone if we could but see it as physics describes it is just this world of alien quantum mechanical forces. No people no colours just these alien forces populations of atoms floating meaninglessly in the void. That's all that's really going on and our usual experience doesn't give us any insight into that at all. So it's actually for us pretty much as it is with the brain and the that. All our experience can be providing with you with some kind of navigational clues as to how this collection of atoms should try and negotiate all these forces out there. But like the brain we don't really have any understanding beyond that. Now I don't think that that is an encouraging thought. Right I find that a pretty... Maybe there is a generation thing here. Maybe you guys are all adjusted to this picture. But it seems to me actually in practice impossible to live with that kind of picture of a new relation to your surroundings. In practice when you're interacting with other people, when you're making your plans for the day. It's simply impossible to try and think directly of the way the world really is. You just take it for granted that the objects have the colours you think they do that the other people and so on are really there. The picture that you're getting from Putnam is something like all your conscious life provides you with is a kind of phosphorescence. There's a collection of atoms here, there's a collection of atoms out there. I get these kind of phosphorescent shimmers of sensation that do have the reliable environmental causes. There really are patterns of wavelength reflectance and so on causing these shimmering phosphorescences. And in that sense they represent the shimmering phosphorescences. These shimmering phosphorescences, you know what I mean, you can read it, right? These experiences are maybe minimally helpful in that they give you some guidance to how to get around. And they represent these patterns of wavelength reflectance and so on. But that's all that's going on. In Russell's picture of what acquaintance was, was that there's some notion of our cognitive contact with our surroundings that is giving us something better than that. It's providing us with knowledge of what the world is like. It's not just that we have signs that are reliably caused by some external phenomenon out there or other. It's that you have some insight into what is going on out there from experience. And it's true that physics may be describing the world, as we say, at one level. But there is another level, a common sense level of description of the ordinary mind-independent world that is perfectly real too. And that your ordinary experience is giving you some insight into what is going on at that level. So in Putnam's, on Russell's picture, it would be possible to say we have acquaintance with the ordinary medium-sized world, on Russell's conception of acquaintance. We could extend it beyond sense data, say we do have acquaintance with the ordinary medium-sized world with the objects and properties. But Putnam isn't trying to get us that. All Putnam is giving us is that one way or another we are causally connected to some kind of external patterns of other out there. And it could be practically anything that is going on out there. But we have these in our internal life. We have these reliable signs of it. But I think that is what I mean. It's a pretty minimal conception of our knowledge of our surroundings that Putnam is getting us. Okay, so that's the line of criticism I want to try and push a little bit. Does that make sense? Can you hear music in the distance? Yes. Okay. Just a second. Okay. Okay, you comfortable with that? Okay. Yep. Yes, okay. Okay, so what I want to do now is just go back over a little bit, review a little bit how you could think of the causal theory of reference as an explanation of Russell's notion of acquaintance. So remember Russell said, we'll say we have acquaintance with anything of which we're directly aware without the intermediary of any process of inference or any knowledge of truth. So when you encounter a person, you encounter a sense datum, you encounter a colour, then without the intermediary of any inference of knowledge of truth, you know what that thing is. That was the idea. So acquaintance is supposed to be more primitive than knowledge of truths. You can know lots of truths about the colour red, but no amount of finding out truths about the colour red is going to give you knowledge of what the thing is, what redness is. Knowledge of what redness is is something you get from a direct sensory encounter with something red is more primitive than any knowledge of truths about the colour. But when we look at how the causal theory goes, it's natural to say, well, I said when we were talking about Evans, you should think about the relation between the thing out there, the thing out there, whatever it is. You've got a causal connection to the referring term. And I said, well, one way of understanding why causation is the right notion here is that causation matters for knowledge. What you need is the kind of causation that's going to give you knowledge of the thing so that when you're in a position to refer to something, you can then go on and transmit knowledge of the thing. So just spelling that out a little bit, what exactly is the thing causing? It's not just your use of the term, it's that you have associated with the term some kind of dossier of information about the object. That's what we draw from Searle and Kripke. What's been caused by the thing is the use of a collection of information. And in Evans's terms, you want the thing to be the dominant source of that collection of information. So what's a dossier? How do you explain what a dossier is? Well, here's a way of being just very precise about what a dossier is. Remember this kind of inference? B is F, A is G, B is both F and G. Is that inference valid or invalid? Invalid, all right. The right answer is invalid, right? It needs an extra premise. Is this inference, there you are. Now, is this inference valid or invalid? Valid, that's the right answer. So you could say that what a dossier is, suppose you call this kind of inference one where you trade on identity. Does that make sense? You're just using the identity as a thing here. You don't have to make it explicit. You just make the inference using the identity. So you could say a dossier, the thing that's being caused here is a collection of propositions all relating to the same object. So you've got B as F, you've got B as G, and so on. You've got a whole bunch of propositions like that where in inference you can freely reason back and forth trading in the identity of the object referred to. So that's what a dossier is. If you've got something A as F, that would be outside the dossier because you couldn't trade back and forth with it. OK, then we can say acquaintance with an object is when you know the propositions in a dossier relating to the object. And when Russell says knowledge of things is more basic than knowledge of truths, logically independent of knowledge of truths, what we've got here is knowledge of a whole bunch of truths, B as F, B as G, and so on. That's all the stuff that's in the dossier, knowledge of truths. And then there's that causal connection with the thing that means that it's making the case that all this really is knowledge of the thing. And what's happening is that the object out there is causing your acceptance of all these propositions, B as F, B as G, B as H, and so on. And then you can trade back backwards and forwards reasoning about the thing there. So I think that would probably be, at the moment, the most, the commonest philosophical picture of reference. Is that right, GSIs? I mean, I'm not trying to be original here. I'm trying to catch what I think is most philosopher's default kind of picture of reference. Is that right? Uncharacteristic agreement. So that, I think, is the usual picture of reference. And I think Putnam is probably working with something like that picture in mind. But notice that the thing about this is the only real knowledge you're getting of the object is the propositional knowledge in the dossier. The causal link there, how should I say, is just instrumental. It's just something or other that generates all the propositions in the dossier in a reasonable way. So what is happening here is that the causal link doesn't constitute knowledge in its own right. That causal link isn't the knowledge. It's not the causal link itself that constitutes your knowledge of being. It's all these propositions you're getting that constitute your knowledge of being. You see what I mean? The cause is just what made them all happen and made them all happen in a reliable way. The causal link itself is not some way of getting knowledge of being. So that's a picture, then, on which the propositional knowledge, the knowledge that things are so, is really the basic kind of knowledge. And this thing, this link, this causal link, this more primitive, is not itself a kind of knowledge of the world. That's the kind of picture that Putnam has of what's going on with the brain in the vat, or indeed a viewer me. There's all this stuff out there. It generates all this propositional knowledge in you or me. It's just a causal link, and there's no more to it than that. So the causal link only matters because it's instrumental in bringing about propositional knowledge. But that wasn't Russell's picture originally. Russell said thought that consciousness has something to do with it. It's the fact that you're having experience of the world that's really important here. He said the definition was, remember, Russell say that we have acquaintance with anything of which we are directly aware without the intermediary of any process of inference or any knowledge of truth. So the idea there is not that there's just some causal connection between some unknown stuff out there that is reliably producing beliefs and a bunch of propositions in you. The idea is that you're experiencing things and properties, people, colours and sounds and so on. And you're getting a kind of immediate knowledge of them that you couldn't have without the experience. So remember Locke's picture of how you have, what your concept of the colours comes to. Your idea was, your concept to the colours is just this, that you get some kind of sensation of redness. There's some texture out there causing it. Some surface spectral reflectance characteristic out there causing it. And if different people have different ideas of redness, well that just doesn't matter. Because all that your experiences are are things that are reliably caused by something or other, some physical phenomenon out there. So your experience isn't giving you any insight into the nature of the property out there. Your experience is just something that functions like a flag that that unknown thing out there really is there. That's why it doesn't matter whether your experience is the same as mine or not. Because if we thought that our experiences are giving us some insight into what's out there, then one of us would be right and the other one would be wrong. And it really wouldn't matter whether your spectrum was an inversion of mine. So the implication of Locke's view here is that a colour experience doesn't give you any insight into the nature of the colours, the properties of the objects out there. That's why spectrum inversion wouldn't matter. The alternative picture, though, is what Russell said. I know the colour perfectly and completely when I see it. I know further knowledge of it in itself is even theoretically possible. That when you encounter, the world can be described at many levels. You can describe it at the level of basic physics or you can describe these characteristics of the object at the level of common sense. When you say things are colours, there are people, there is coffee, all that kind of thing. Then that relation is not just a causal connection. Is you experiencing the thing? The thing is out there for you to experience. And your experience gives you knowledge of it. That's more than just some causal connection to something unknown. G.E. Moore had that kind of picture of what's going on in experience. Moore said there are in every sensation two distinct terms, consciousness in respect of all, in respect of which all sensations are alike, and something else in respect of which one sensation differs from another. We discussed this earlier, actually, that there is this picture on which what's going on in your experience of the world is the colours, the people, the tables, the chairs, the ordinary medium-sized world, just as you think it is, common sensically. That's all out there, independent of you. All the colours, all the tables, all the other people, they still exist even if you don't experience them. So you could take away this relation of experience and all that stuff would still be there, the medium-sized world. And what experience does is it gives you knowledge of what those properties are, that non-propositional knowledge of what those properties are, just knowledge of what red is. That's the thing that Putnam doesn't seem to give us. Putnam just gives you, there's something going on out there. You have no idea what it is, but your uses of signs are reliably caused by that. When you build up a dossier, it's reliably caused by something or other out there. What we want, I think, though, common sensically, is to know what the world is like. The brain in the vat has no idea what its world is like, what its environment is like. But to me it seems absolutely basic to everyday life, that you take it for granted, that you know what the world is like, what other people are like, what the colours of objects are like. What the sounds and smells and tastes out there for you to encounter are like. And since the brain in the vat doesn't have that, we need to know if we're going to... What's the word I want? If we're going to vindicate our ordinary picture of what's going on, then we need to know that we're not in just as bad a pitch position as the brain in the vat. You might think this is a bit pedantic, but I'm just trying to be fully explicit about what a dossier is. My definition of a dossier is it's a collection of propositions, which are all linked in such a way that take any two propositions from the dossier. If you've got millions of propositions in here, then just take any two, take this one and this one at random, and then you could do one of these inferences that trade an identity. That's right. It's just a way of saying this is manifestly or transparently all about the same thing. That's what a dossier is. I should say that partly what I'm trying to do here is just draw together lots of things that we've talked about in the last few weeks. But I think that'll let you be fully explicit about what a dossier is. When you give that definition in terms of reliable knowledge generating causation, that I think is the usual picture that most philosophers now have, and I think it certainly fits with everything Putnam says. I want to try to bring out what seems to be a limitation in this, that there's that kind of knowledge we think we have of our surroundings that isn't caught here. That doesn't seem well, the controversial. Are you all happy with that? You think that we are better off than the brain in the vat is, even if Putnam's right about the brain in the vat. Yes, that seems pretty plain. Yes? Okay. I don't think I can be explaining this correctly. The thing is, though, that if at this point, if we accept this kind of picture, then skepticism seems to be just as much of a threat as ever. The skeptical question was, are the causes of my experience where I take them to be? Last time I was talking about knowledge of other minds or your knowledge of your own thoughts. Now I'm talking about your knowledge of the medium-sized world, the world you encounter in ordinary perception, which is really the home place, the natural place for Putnam's argument to work. So the question is, are the causes of my perceptual experiences where I take them to be? Now if you have Locke's picture on which it's just patterns of surface spectral reflectance, the causes of your experience aren't as you ordinarily take them to be. Locke himself thought common sense makes a mistake about the colours. We ordinarily take it that the objects outside are coloured, but what science has shown is that they're not really, there aren't really colours out there. Colour is just a characteristic of something in your mind. So that is a kind of skepticism. That is throwing away saying we don't have knowledge when we thought we had knowledge. If it wasn't for science you'd have thought, I know what the colours of objects are all right, but Locke's picture is there's an error here. The guy who's pushing the brain in the VAT hypothesis can say, but that's just the general picture. Everything is like the case of colour. We are always making a mistake about the characteristics or even the existence of medium-sized objects. Here's Locke. He's saying you can't get this idea out of people's heads. People continue to think that objects have colours. Men are hardly to be brought to think that sweetness and whiteness are not really in manna. And he's saying these are not really in manna. These are but the effects of the operations of manna by the motion size and figure of its particles on the eyes and palate. So he's saying there's this error that we just keep making. And what's going to turn out is that the whole medium-sized world, other people, your family, your friends, none of that's really out there. What's really out there are just the motion size and figure of particles producing sensations in you. The university, your GPA, none of that, none of that really exists. It's all just sensations being produced in you by the motion size and figure of particles. Your mother, hello? Locke's way of putting it was our ideas of perception might be caused by external stimuli, but there's more to it than that. When you're experiencing redness, there's not just the thought that, well this is being reliably caused by some configuration of particles out there. It's that what's out there resembles my experience of it. Very hard to make that motion precise, but that's very intuitive that if what's out there is not a colour causing the experience, but just some configuration of particles, then there seems intuitively to be some way in which colour has just disappeared from the world as described by science. When you're giving a full physical description of the room, you don't need to mention colour at any point. So if that's right, the world doesn't resemble the way experience presents it as being. Locke's saying our ideas of colour are caused by the external stimuli, but it doesn't resemble any of these external stimuli. But if that's the general case, and even something as familiar as motion size and figure of particles, that's not at all what quantum mechanical descriptions of the environment look like. In the most basic level, you don't even have such friendly concepts as motion size and figure. You are just alien forces operating. So then the threat is, the sceptical threat is, maybe none of our ideas of perception resemble the external stimuli. But then this is something that Putnam's argument doesn't address at all. Putnam's argument only gets you that one way or another, there's some causes out there causing your sensations. It doesn't say anything about whether the world out there is like your sensations. But if that's right, there's some sense in which you have completely lost the common sense world. I was once at a talk, it took place in the summer's evening, with the windows open like this and people walking around outside, and the speaker got quite excited at one point, and he said, look, what's really upsetting about this kind of picture is that in the world as described by science of basic particles and fundamental forces, in the world as described by science with all its gamma ray bursts and molecules and so on, there simply isn't anything it would be possible to care about. And as he said that, just from outside, there came a scream. You really lose a lot if you lose the common sense world. You lose all the world that is connected to our ordinary motivations. There's some really far-reaching sense in which if you take this picture seriously, you're alienated from your surroundings. None of it is a tall like you think it is. So that's a dimension of the kind of knowledge that we ordinarily take us to have of our surroundings that just isn't caught by Putnam, because all he's talking about is if you have that picture of the thing causing the dossier, there is that other dimension that it's not just the thing causing the dossier, it's that you're aware of the thing. And your awareness is not just a matter of you being causally sensitive to it, it's a matter of you getting to know what it's like, what it is. Putnam actually throws out the idea of resemblance and says it doesn't even make sense to talk about resemblance here. But if you throw out the idea of resemblance, then without some further discussion, that question of whether the world is like you think it is, that can't even arise. You don't even have a way of stating what's been lost here. You find yourself in a world that has nothing to do with your ordinary motivations, a world that you can't connect with at all. All there is is your own sensations in this alien environment. That's basically the situation of the brain and the vat. And if Putnam's right, that's the best you can aspire to. That's all there is. That's not a sceptical threat, a far-reaching, a far-fetched worry that you might wonder about if you're doing philosophy. That's the position that all of us are actually in, being in an alien world that doesn't connect to our motivations at all, simply locked in to this bunch of sensations that are merely causal responses to physical patterns out there. That's all knowledge is. So the natural question here is, does the causal theory of representation do justice to the knowledge we have? Can causal theory really be the whole story? I think we take ourselves to have knowledge of what our environment is like that goes way beyond the knowledge that the brain and the vat has. The brain and the vat doesn't have that knowledge. That's what's wrong with the brain and the vat. It doesn't know what a big environment is like, and you don't really get that just by saying, oh, well, it's systematically connected up to Putnam's of activity in the vat-tending machinery. You could have that without knowing what your environment is like. That suggests that going right back to when the causal theory of reference comes in, if that's right, it suggests that the standards are right or wrong for the sentences that you're using. If you say that chair is brown, then the standards of rightness or wrongness for the sentence aren't set just by causal connections. The causal theory of reference, when you generalise it the way Putnam is doing, is saying, what is it for a sentence to be right or wrong? Well, that's fixed by what the causal connections are between the parts of the sentences and what's in your surroundings. That's the causal theory of reference, right? But if what I'm saying is right, what it takes for it to be true that a chair is brown is more than just that there'll be something or other out there that's systematically causing your uses of the terms that chair and brown. Your awareness of the chair and your awareness of brownness are providing you with some knowledge of what brownness is and what a chair is, and that's giving you knowledge of what it takes for a chair to be really brown, not just that there'll be something or other out there, but you know what the thing is out there that would make it true that the chair is brown. So there's got to be more to standards of right and wrong for sentences than just the causal connections that the causal theory of reference is describing. Russell did restrict acquaintance to sense data and the self. As I said earlier, that's a few weeks ago, that is, as I say, you live a fairly narrow life if you can only ever think or plock about ultimately about your own sense data and yourself. So the natural thing to do is to expand that notion of acquaintance to include the medium-sized world and really that's what I'm presupposing we should do is say that we have some kind of non-propositional knowledge of what the medium-sized world is like and there's not just a matter of experiences of the uses of terms being caused by the medium-sized world, it's that experience reveals the medium-sized world to us. So we can think of acquaintance then as knowledge of reference provided by knowledge of what the world is like. What your knowledge of what it takes for something to be read is provided by your knowledge, the acquaintance you have with the colours themselves. But then it seems possible for the skeptic to strike back against Putnam. Once you get it, once you accept this, that there's more to our knowledge of the world than just reliable patterns of causal connections, then it does seem to reopen the possibility of radical error. If you say, well I'm not just going to let the common sense world go, I'm not going to let go the world I care about, I say I have knowledge of that, the minute you say that, then the skeptic can come back and say, but how do you know you're not a brain and a vat? How do you know you really have got that knowledge of what the world is like? That you think you do? I am resolutely returning us to more or less square one on this. That's so often. Okay, are you content with that? In that case I think that's the end of the message for today. I'd expect it to be assailed by protests at various points, but we all seem to be in the same team. Very good. So we marched triumphantly on with Dritschgut on Friday.