 Good morning. Well, um, thank you very much for trudging through the rent to get here It is absolutely. It's like the end of the world out there Anyway so today we are Well, we're nearly there. We're shaping up to Come back next time to modes of presentation and formative identities and Finally sort out these problem. Well Revisit these problems with which we began I had meant to bring the study questions for the final exam with me today. I could not get my printer to work So immediately after the class I will email the study questions for the final to everyone Is that all right? If anyone needs a printed copy or can't access email or something then let me know But they should be with you by 20 minutes after the lecture Okay, yeah, and if there are any questions we can discuss that on Friday Okay, is that okay or anything? Okay, so looking at Russell on knowledge by acquaintance and knowledge by description. So Here's an old friend. You remember Remember to enough to enough dear old to enough happy days happy days To an earth you remember is very much like earth except that the stuff that fills the rivers and lakes on to an earth is not h2o but xyz and The general model of these to an earth cases was something like you can distinguish between the inside the head element that's in common between you and your double on earth on and to an earth and Something about the causal or contextual surround that you have Does that make sense so that you on earth and your double on to an earth are Molecule for molecule identical So what's inside your head is just the same But when you say water you mean something different to what your counterpart on to an earth means and that must be Because of something outside the head the fact that you're causally connected to water something like that So you can separate the two aspects of meaning The inside the head element that isn't enough for understanding our meaning because it's in common between two people who have quite different meanings for the words they're using and The stuff that's outside the head which when you put the two together you get understanding and meaning The Zering a bell is that yeah, that was the analysis and I remember We talked about quite a bit about this the inside the head part and the causal contextual factor in virtue of which what's inside your head is representing something and There was a question that someone raised in office hours Back then that really struck me very much they said was really puzzling discussing this is Whether this stuff that's causal or contextual whether that's in your mind or not The question was is that causal or contextual factor something that's in your mind? Because in the one hand it seems like it should be because it's something that is Constitutively affecting which thoughts you're having if you have something different inside you do it some different causal or contextual Surrounding then you'd be having different thoughts And your thoughts are presumably in your mind but in the other hand When you think in terms of causal chains that may go back into history It seems like the causal contextual factor is something outside the mind Something external to the mind something you wouldn't get any knowledge of just by looking inside your mind And I remember say at the time saying Something helpful like That's a difficult question and each must find his own way But I want to start out by suggesting that there's a way of seeing how to make a little bit of progress with that At comments when you think about what happened when we were discussing Wittgenstein and meaning in use and so Truth conditions in use and so on remember the point when we were discussing Wittgenstein was that You could accept Wittgenstein's point that the use that we make of a term is fundamental But still think that there's a role for reference and truth conditions In an account of our understanding of a term You could think that knowledge of what has to be so for a sentence to be true That's your knowledge of what you're about what you're doing when you're using a sentence What the point is of using that sentence the way you do So It isn't Wittgenstein seems to say there is only the use We just operate with inputs and outputs from the environment from other people In using language and that's all that's going on But what this discussion about tonk and so on that the point of that discussion was to suggest there's more to it than that With tonk what's going wrong is not just that there's something strange about the pattern of inputs and outputs Is that you have no idea what you're about in using the sign the way you do? so that reference Wittgenstein's arguing that the use isn't something that's derived from the reference of the sign The pattern of inputs and outputs to your sign isn't something that's generated by what it stands for or is truth conditions or its semantic value And The thing is so long as you were thinking of The pattern of use that was made of the term as something that was driven by Something that was made to happen by the the reference of the term then it's hard to see Why those causal or contextual factors should be thought of as inside the mind if what's going on is that you've got a Person here you've got Oscar here with this pattern of inputs and outputs to from their use of terms and then you've got causal or contextual factors Say from the water outside or the people outside Causing them to make those patterns of use of the terms Then this stuff out here the causal or contextual stuff the stuff that fixes reference is difficult to see Why that should Itself be thought of as something that's inside the mind That's when it's puzzling to think is the causal or contextual factor something inside the mind but What I was suggesting was Wittgenstein is attacking that idea that knowledge of the use of the term is derived from knowledge of the reference We have to forget that the path that that idea of something coming from outside and making this stuff happen The use that you make of the term is fundamental There was a thing about the bit in the middle that keeps blinking out Yes, the bit in the middle. Yeah, okay So we take the use to the term is fundamental But we need knowledge of reference to make it intelligible to us What we're doing why there's some point to this when we're doing these inputs and outputs the way we do So suppose we acknowledge the Wittgenstein's point the use is more fundamental the knowledge of truth conditions But we keep a role for reference and truth conditions in making use intelligible Then if your knowledge of what the sign stands for is going to be What lets you know what you're about in using the sign? Then it seems much more important that your knowledge of the reference of the term that caught what supplied by the causal or contextual factor That has to be something that's inside the mind if it's going to be if your knowledge of reference Which is what the causal or contextual factor supplies That's going to be something that makes it intelligible to you what you're about in using the sign then That Thing that's making it intelligible to you what you're about in using the sign has got to be something that's inside your mind It mustn't be something. There's just an external driver of the pattern of use It's something that you have cognitive access to that Makes your practice intelligible and I'm going to suggest today that in the most basic cases your knowledge of the reference of The terms you're using is provided by your awareness of the objects You're talking about by your experience of you're not the object you're talking about by your consciousness of the objects You're talking about This is pretty abstract But I'll give some examples in a moment But I wanted to tie this back to this thing of the causal or contextual factor in the twin earth cases and what's inside The head and what's outside the head? Put up your hand if the situation is that this is pretty abstract that you think you've more or less got it But you wouldn't mind seeing an example Okay Okay well, um, suppose we Think about Politions thing last time Politions thing last time where you're doing the multiple you don't have to do any more There's some multiple object tracking, but you remember the multiple object tracking Well, our pollution said the most basic kind of reference you've got is the reference you have in Perception when you just tag a thing so that you can interrogate the scene to find out more about it so you're keeping tabs on these moving objects using visual indexes and Inside your brain is some system like this that lets you once you've tagged an object Interrogate the scene to get more information about it So if you're just looking around the room and your eye falls in a particular person Then you can interrogate the scene to get more information about them and you can think of this as One way pollution thinks of this as one way of explaining Russell's notion of acquaintance The idea is that out there is the object the other person or whatever it is that causes This cognitive system to come into play with the visual index That's the root of reference that external causal connection between the object and the cognitive system in your brain Now on this kind of picture on pollution's kind of picture There's no role for you the fact that you're conscious of the world That you have experience of the object you're looking at that is really just an accident It isn't a working part of the system And this cognitive system here has to be input to your thinking it has to be input to your general thinking and Of course in fact ordinarily when you look round the room and you think about one person now about another then You will have experience of them, but experience is just being how should I say given off like a waste gas It's just a kind of byproduct of the functioning of the system here It isn't a working part of the machinery of how you managed to think about the things around you So in principle, you could do without the consciousness here. I Think this is a fairly standard picture nowadays of how reference works And the thing about it is that consciousness of your environment becomes Dispensable from an account of how you were able to think about the things around you So even if you didn't have any sensory awareness of all the people around you right now You could still think about each of them in just the same way as you do now. You could do it without the waste gas In principle you could have pollution's kind of causal contact with the object even if you had no experience of it One way to think of this is have you guys come across blind sight put up your hand if you have a blind sight Okay, but still about about half. Okay, well blind sight happens when someone gets a bash on the head. I mean the Classical cases happen as a result of injury. You got a bash in the head at the back and half of the Visual signals come from the eye go right to the back of the head and then they're sent up and down for more Processing so what happens is someone gets a bash a result of which they have no experience in Say the left side of their visual field Right, so for this person. There's nothing in the left side of their visual field no experience at all and You say to such a person well What's in the left side of your visual field and they say well I can't see a thing And you say well is it upright or is it tilted and they say let me just repeat that I can't see a thing in the left side of my visual field and You say to them well go on guess is it upright or tilted and they guess and they reliably get it right Characteristically to their own astonishment. I mean these people have the daylights tested out of them You know they spend the lies being tested so they're less surprised after a bit But initially it's extremely surprising the way it would be for you or me if you were if it turned out You could accurately guess what was going on behind your head without having to look So here is a graphic illustration The patient is looking at the screen with stripes on it saying but I'm blind there I can't see any stripes and The experimenter says will have a guess well in I guess I see horizontal red stripes And the patient is reliably correct Now what's going on I mean Yes good Sorry, yeah, that can't see his clothes No, neither I can see or it's the left half of the whole visual field The visual field of the two eyes You see what I mean. Yeah, it's not just one eye that's been taken out There's quite a deep injury. Yeah Individual system Any other questions about what the scenario is there so There's quite a lot patients that turns out can guess correctly about what's in the blind field And I Not aware of anything having been done specifically on multiple object tracking I mean they do lots of tests But it is astonishing just how much patients reliably get right you can tell a patient to reach for what's in the blind field and They will shape their hand correctly to get the size and shape of the thing You can ask them to guess about the emotional expression of a face in the blind field and they will get that right and From an engineering point of view, it's not that there's anything mysterious about this you just have You have I mean never write this down But my picture the physiology is something like this you have something like sickness This is the eye your signals going from the eye to the back of the head and then Going off in two visual pathways And what happens is that one pathway is the one that Subserves conscious experience so down here you have conscious experience at the scene That's the circuitry that supports conscious experience up here. You have another pathway there is supporting action on the objects in the scene and That what's happening is that this one's been taken out in that half of the blind field by damage and This one is still functioning. It's still getting a lot of input is still functionally intact So the patient can move reach make guesses correctly Without the benefit of conscious experience so physiologically, I don't think there's any great mystery here But the question is suppose you can do that suppose you have something In your blind field and suppose you're completely correct So suppose you have a vast volume of information about it. You can guess I Guess it's a piece of chalk. I guess it's white. I guess it's upright You can do all that stuff. Are you then in a position to refer to the object? You've got the causal connection But you don't have experience of the thing is that enough for reference Well, it seems to me if you think about this in vignesh tiny in terms then what the patient's got there is they can use the sign They can get the inputs and outputs right They could talk pretty much like a regular person using a sign like that thing that piece of chalk But yeah reading in the blind field I've never heard of anyone raising that question about reading in the blind I mean not every answer is known if you see what I mean and even all the answers are known aren't always known by me But I don't know of anything about reading in the blind field it would really be astonishing if there's anything like that Okay Okay But I mean what the hell for our purposes we're philosophers We can suppose I mean isn't there's no contradiction in the idea the circuitry adequate for reading Could be left in the blind field But you but will you you wouldn't have any awareness of what you were reading? You know that you if you're an ordinary language speaker you might find yourself Guessing that the words were thus and so I know what such words meant It's just that you wouldn't have any sensory awareness of the words on the page So it seems to make It seems to make perfect sense I think to suppose that it was subtract conscious experience But leave intact the ability to use the sign But still it seems like when the patient is doing this guessing about what's in the blind field guessing what's going on in there There is still something they're going to learn When this comes into view When they do get experience of it the patient learns something at that point and what they learn is Which thing they were talking about I mean intuitively if you don't have sensory experience you don't know what you're talking about You like someone using a sign like tonk or star Where you've got a pattern of use for it all right But you don't have the knowledge of reference that would make it intelligible to you what you're doing with this sign So it seems to me in those blindside kind of cases The patient doesn't know what the sign stands for It's your sensory experience of the objects around you that provides you with knowledge of reference So it seems to me you wouldn't be able to think about the other people in the room in just the same way If you subtracted sensory experience Sensory experience is really not like a kind of waste gas being given off It always seems like that if you say the only real thing here is the use and you forget About knowledge of reference and knowledge of truth conditions the thing that makes it intelligible to you What your objective is in using language? Let me give just one other example Suppose that you and I are sitting side-by-side in a crowded room. So suppose you and I are sitting over there and and You say look at that woman over there and I say well who which one what are you talking about and I I don't know who you mean I say and you say well Guess what she's wearing And I say but I have no idea who you're talking about and I say well I guess it's something red and it turns out I'm right and you say guess Where they're from I? Say, but I've no idea that I guess and again. I'm right, but now that really could happen. There's no contradiction in that You say try to point to them Alright, and I do I get it right In that case what I'd say is I'm getting all this right I'm using the sign. I have the Vickenshtynian use of the sign that woman Pretty well, but I have no idea who I'm talking about I Only know who we're talking about when I finally Focus and I get it or it's that one and I now manage to single them out in my experience What I'd say is I didn't know who we're talking about Until I got that experience of them So it seems to me in that kind of case that that's a simpler case than a blindside case You know, it doesn't involve supposing. I don't have any sensory experience It's just that I'm not able yet to hook up my sensory experience to our conversation And it seems to me I can't be said to know who you're referring to until I'm conscious of the person Yeah I would have to say that you do know who you're talking you can still know who you're talking about when you talk about Aristotle without Having sensory experience of Aristotle that would be too too demanding Is one thing to say that the sensory experience plays a role in this kind of case Well, you're discussing an ordinary conversation about things right in front of you using terms like that tree or that man or whatever It would be a different thing to say all singular reference is like that Yeah So what I'm suggesting is there are cases that and I think these are basic class of cases where you can use terms to refer to objects you currently perceive and There that's happening in virtue of sensory experience But there's a whole further class of cases of objects that you know about from literature or objects that you know about from Other people telling you or from memory. There are not like that and then you separate discussion Yeah, my point is only in this special kind of case There is work for sensory experience to do not that it all this has to do that work Yeah Yeah, if they're not just I mean born blind is one thing and having no sensory experience at all is another yeah Suppose you have someone born in a sensory deprivation tank Yeah, then then it follows from what I'm saying. They are never going to be able to refer to anything. Yeah, I think that's right if this is a basic case the perceptual case as I'm suggesting and and The basic case require sensory experience then if you don't have sensory experience or anything ever then you're not going to be able to Think about anything ever And that's I think that's the right answer. Is it is that right? I mean I Think yeah, that's a great question. You could have so yeah, so suppose I said a sensory deprivation tank But suppose someone born in a tank that provides them with no experience of their surroundings But allows them to make correct reliably correct guesses as to what's going on in their surroundings Yeah, and they just use the words in the right way And I think you're then going to have I mean that that's the kind of situation you have if you have a robot Yeah, well you have a robot. There is no sensory experience of anything that's going on around it but Can nonetheless turn out the right phrases to say That's someone wearing a hat or whatever it can do that stuff And what you wonder is is it thinking is that expressing genuine thoughts about what's around it? And what I'm suggesting is that wouldn't be expressing genuine thoughts because it wouldn't be grounded in sensory experience You have so far as the use cause a facsimile of an ordinary human being and you have everything that Wittgenstein looks for In understanding, but that just shows what Wittgenstein missed out Namely the importance of sensory experience in giving you this knowledge of reference that Let's you know what's going on when you're speaking and thinking who it is what it is that you're speaking and thinking about Yeah Okay, okay, so I think If you look at Russell's discussion of Knowledge by description and knowledge by acquaintance There is such a thing as Being able to pick out someone just by a description Arisoto might be one case like that the last great philosopher of antiquity or even the blind site patient can say Whatever it can have a description like whatever it is my blind field that the experimenter is pointing to Then you can frame these descriptions all right You can frame a description like the first headache I will have in 2013 will it be a sharp pulsating headache or will it be one of those dull heavy ones you can Speculate like that. Yeah, we would have been caused by Wittgenstein Yeah, I mean that makes perfect sense, but Russell's contrasting that way of Specifying I think the first headache I'll have in 2013 with Simple reference like this headache or this pen Yeah, and Remember there was I won't go over it here, but there was that argument that These are basically Quantified expressions and whatever you go quantified expressions how many expressions you got to have them grounded in the use of simple names Does that ring a bell? Okay, then When you've got that use of simple names I think when you look at what Russell is saying Russell is saying that use of simple names always involves experience of the object is Not quite like I mean pollution offers his account as a way of saying what a quaintance means But I think if you look at what Russell means by a quaintance It always has to do with your consciousness of the object. You're talking about I'm Quinted with an object when I have a direct cognitive relation to the thing i.e. when I am Directly aware of the object itself. So Russell was trying to pin down. There's really basic class of Referring devices that are the foundation of all other reference and That's direct awareness of the object and He said the word acquaintance is designed to emphasize the relational character of the fact with which we're concerned Is not that your mind is if your mind is over here And the object is over here Then it is not that your mind is forming a representation that represents that object is the awareness is a Relation between your mind and the object in virtue of which you can represent it Does it make sense It's a little bit complicated in Russell's case because the objects are sense data which are not strictly They're not really external. They're not ordinary physical objects They are as it were outside the mind, but only just outside Right, there's a little way outside the mind so that you can be related to them by this relation of acquaintance So it's not a type of representation And you might think it's like that just an ordinary perceptual experience that if you experience someone else if someone else is in your visual field You attend to someone you can see then that's a relation between you and that person That's not basically a matter of you representing them is what makes it possible for you to represent them 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 And then he says when we ask what are the kinds of objects with which we're acquainted the first and most obvious example is Sense data your headache your sensation of red you can talk about them because they're just outside your mind But you're certainly having awareness of them when I see a color or hear a noise I have direct acquaintance with the color or the noise In addition to awareness of particulars, we also have the not not in quite the same sense awareness of universals Not only are we aware of particular yellows, but if we have seen a sufficient number of yellows and half sufficient intelligence We are aware of the universal yellow So when vittgenstein was saying what happens is you go, this is yellow. This is yellow. This is yellow This is yellow and the person you're trying to teach the meaning of yellow after a bit They go yellow yellow yellow yellow two Then that picture of vittgenstein's is a picture that doesn't give any role to sensory experience In your understanding of what yellow is Someone born blind Who had neural circuitry that would allow them to say that's yellow. That's yellow. That's yellow. That's it. That isn't They would know they would understand the word yellow perfectly well on vittgenstein's picture But russles here is saying that's not right For in order to know what yellow is you need sensory experience of yellowness And the reason you need it is not to tell you which particular things are yellow Because after all a robot could have that a robot could have a light meter that was differentially sensitive to yellowness Without having any experience of yellowness a human could have circuitry that would let them be differentially sensitive to the yellow things without having any experience of yellowness But if you'd never had any experience of yellowness, you wouldn't know what the thing is You wouldn't know what the colors are if it weren't for your experience of them And russles saying here, that's what's the key thing for knowing what the term stands for Seeing a sufficient number and thereby becoming aware of the universal yellow And then that universal becomes the subject in judgments like yellow differs from blue or yellow resembles blue less than green does So just as with that man or that woman is your sensory experience of the object that allows you to think about it So too with a color yellow is your sensory experience of the thing that allows you to think about it And the universal yellow is a predicate in judgments like this is yellow where this is a particular sense datum So the real sticking point in russles is this when he says among the objects with which we're acquainted Are not included physical objects as opposed to sense data nor other people's minds That's what that's what leaves us all shut away behind our own sense data Without any possibility or real communication with other people That's What I want to do on friday is try to see how we get over this and liberate this talk about sensory experience as acquaintance with from russles restriction to Sense data And how we can address these problems about informative identities and meaning without reference That are what drove russle to this position He talks about physical objects and other people being known by knowledge by description And we have merely descriptive knowledge when we say we know that the thing exists We know that the so-and-so exists then even if we're acquainted with the fact that the so-and-so We don't know any proposition of the form a is the so-and-so where a is something with which we're acquainted and with that example of You and I sitting there and you talking about that woman and I making my guesses then I can say There's that woman that my friend is referring that is referring to there's that woman that I'm causally responsive to But I'm not in a position to know anything of that form A is the so-and-so where a is something with which I'm acquainted But is that knowledge provided by sensory experience? That's the foundation of all other reference That's what we're trying to take down next time Yes Yeah um I mean to be suggest talking about robots in such a way that I'm kind of taking you for granted The robots don't have sensory experience And of course you can give a robot a sensor Yeah, but does it feel pain? Does it have the sensation of yellowness? That's what I'm assuming it doesn't have yeah What you could easily do is make a robot that has some kind of sensor that vice to discriminate yellowness Okay, are you are you but you're not suggesting that having Conscious experience would be an easy thing to do with a robot Okay Right That's correct. That's correct And you do need to have so much more and that's what I mean to I mean, I don't for a moment think that vigneshtine was um Uh, just making a mistake Yeah, um There is the whole pattern of use of the term um That whole ability to respond and say this is yellow that's yellow uh to talk about yellowness to say What a sumptuous yellow? um to Yeah, um, that is an egg colored yellow Something like that. Um, you could there is all that a creamy yellow I'm not suggesting that Just having a presentation of yellow things Allows you to do that an animal could have that a sensory presentation of yellow things and just have no idea What to do with it? Yeah, so the whole pattern of use is something that can't be derived from the sensory experience but what I was suggesting with tonk was that Um with a logical constants with a logical signs like and and or and all that you can't derive Their use from knowledge of truth conditions But still you need a truth table to give you some idea of what you're doing in using this sign and I'm suggesting that For reference generally it's not it's kind of like the truth table. It's not all that Just getting the scene in front of you and you can say well now you know how to go on Now you know how to continue the series. That's not the way it works But neither is it the case that if you just drill a robot or just drill a human In such a way that they can go on that's enough for understanding Sensory experience comes in as providing you with your knowledge of what you're doing When you engage that skill Is that addressing what you said at all? Yeah, okay Yeah, Russell's picture is that acquaintance is the relation that makes representation possible So if I'm going to talk about this headache There has to be the headache and my having experience of it Yeah, so experience of the headache is not itself the same thing as Representing the headache It's something more basic Then and when Russell's talking about sense data generally like a sensation of red When you say this sensation of red is Very evocative or whatever then the idea is here is the sensation of red You are related to it by acquaintance And in virtue of that you can represent it To the red sensation yeah By acquaintance and in virtue of that you can think about it Yep So the the basic point there was that acquaintance is more basic than representation Somehow when you're thinking about perception It's very natural to think that perception just involves representing everything in the room around you But what I was suggesting in cases like that woman in that case where I'm just guessing It's uh What makes it not guessing when I finally get a good look at the person and I manage to single them out visually Um, that's what was making it possible for me now to think about that person And so it's more basic than thought Is that sensitive relation to the thing? Yeah, um I'm denying that the sensory experience should be thought of as a representation Yeah, that's right Is more basic than that because the sensory experience is what's making representation possible So the line of thought here is exactly the same as Russell's when he says The order acquaintance is designed to emphasize the relational fact with which we're concerned Is not a type of representation Yeah, so I'm just using that same argument since sensory experience is the platform on which Your ability to represent the world is built Um that platform itself can't consist in a whole bunch of representations Uh, yeah, yes, that's right Yeah Yeah, well Fasten your seatbelts What rossels says is when you think of the the, um, uh, relation of acquaintance Yeah, it's natural to think that the relation of acquaintance holds only between you And a sensation or something that is there right now Yeah, but when you think about memory Um, I particularly say memory or something that happened just five minutes ago. Yeah, uh, say someone looked in the door and I'm trying to make everyone look at the door But say someone looked in the door and um, then a few minutes later you think who was that Yeah, then the idea is you can have a sensory experience if this is time um You can have you know can have a acquaintance With a sensation or an item that was distant in time that was not present um russel says uh The memory the act of remembering here Straddles the time series and can be assigned no definite temporal location Yeah Your memory may be faulty, but um, uh, suppose it's not I mean, I I don't mean to cheat here, but Um, suppose you are in the good case Yeah, there it is clear Dear old spot, right You remember dear old spot, right? Um, dear old spot comes right before your mind And then the picture is when that's happening you are acquainted with spot through memory Is not of the thing itself Did you say it is of the thing is Yeah, it's of the thing itself. You said the sense they somewhere whatever That's correct. Yeah, um, so I mean, I actually think this is quite intuitive when you think about it that um If you think if you suddenly find yourself You eat a piece of cake and suddenly there's spot live before your memory You remember those happy days with spot in the firelight the family sitting around Um, yeah, um, all those winters evenings Um, uh, dear old spot watching the game of dominoes. Um Then uh, uh Your experiential connect with the past there to the past object That is what's straddling the time series and that's what allows you now to think about what was going on then Is because it's just like the case of suddenly identifying which person in the crowd it is That your other person is talking about Getting that lock onto the individual that sensory experience with the individual is what lets you think about them And similarly in that memory case if you're talking to me about spot If you're saying do you remember dear old spot and then I suddenly get it when I that moment when I say aha Now I remember that's what allows me now to take an intelligent part of the conversation and communicate about spot Okay more next time. Thank you again for trudging through the rent. Okay