 Good morning One more time on a Kruppke or Kruppke's Wittgenstein today And then we'll go on to Pryor's article The Run About Inference Ticket. Pryor's article is a classic. It's only two pages long Is that right? Two pages? Three pages? Something like that But it's completely unforgettable Okay, I want to begin with just looking over something that I think is definitely established Wittgenstein's negative point that I think is definitely established by what's happened so far And then look at what his positive picture of language and meaning is according to Kruppke So a natural picture to have of what's going on when you're understanding a language When you're understanding the words in a language is that the meaning of a word is this contribution to the meaning of sentences containing it And then the meaning of a sentence is fixed by when that sentence is true or false, right or wrong So the meaning of a word will be exhausted by the way it contributes to making the sentence right or wrong So then you get the notion of semantic value That semantic value is how the term contributes to determining the truth or falsary of a sentence containing it So for a name, the semantic value of the name would be the object And then whether any sentence containing that name is true will depend on how things are with the object And the semantic value of a predicate would be a map from objects onto truth or falsity So if you've got the sentence Raleigh Smokes, you've got two terms there, you've got the name Raleigh And its semantic value is Raleigh, very good And the predicate Smokes has a semantic value, a map from objects onto truth values What is that map class? It is a map that takes an object that smokes onto truth And an object that does not smoke onto...fals, very good Okay, so Goethe, we'll refer to Goethe, is human will be true of an object just when that thing is human For not, we have a truth table And then the general negative point here is that Suppose you try working with this picture and you say, I'm going to tell you how to use the term Given that you know the truth, the semantic values of... The given that you know the semantic value, you're going to know how to use the term Well, consider someone who's not capable of logical reasoning And then you say, okay, I'm just going to give you the truth tables for a whole bunch of signs like and and or and if then Will you then be able to work out how to use the terms? Suppose you don't know any logic, you're not able to do any inferring You don't know the input and output rules for logical terms Then if you've given a whole bunch of truth tables specifying the semantic values for terms like and and or Will you be able to figure out how to use the terms? Put your hand up if you think the answer is yes Put your hand up if you think the answer is no What a good class See why the answer is no Put your hand up if you know why the answer is no Or if you think you know why the answer is no Okay, that's a bit less convincing Because in this case it's really stark, it's really very simple If you don't already know how to use the inference rules for and and or and so on Then you can't do the inferences, you can't do any kind of derivation You can't do anything you derive how to use the term from these truth tables And you can't do any kind of derivation at all if you don't already know the rules of inference Or at least some logical constants So if you take a pattern of use like this from A, if you've got A and you've got B Then you can infer A and B and if you've got A and B you can infer A And if you've got A and B you can infer B You can't actually derive that kind of thing from the truth table You've got to be able to do that kind of thing first before you can even make sense of the truth table Yeah, so the classical picture would be something like the natural picture really Or it would be something like I know what it is for all the sentences of my language to be true or false I know how each term contributes to making those sentences true or false And then I can derive that But in fact you can't in general derive the use of a term from its semantic value I think that's one aspect of Wittgenstein's main point here I mean Wittgenstein's challenge is what does it come to that you know that a term like is tall Applies to something if it's tall What does it come to that you know that map from objects to truth values here Well what could it come to? All it could come to is you've got the words It applies to something if it's tall Or again an image of something tall running through your head But the image could be interpreted in endlessly many ways The string of words could be interpreted in endlessly many ways So whatever you think the knowledge of semantic value here is It can be something that you would use to derive your ability to apply the word in particular cases So this is just a parallel point for a predicate like tall or the thing about truth tables You couldn't derive how to apply the word in particular cases from knowledge of semantic value Kruppke's way of putting it is a little bit different But I think it's the same basic point You could say well you use is tall in such a way that the map is from an object to truth True if that object is tall otherwise it's in the maps to false But how do you know that in the past that's how you were using it If you used it that way and I used it to mean stall where something is tall And it's before Wednesday the 7th of November And weighs 150 pounds if it's after the 7th of November Then the way I'm using the term, what I'll have had in my head up until today Will have matched everything that was in your head So there's nothing in your head from which you can derive what the right use of the word today is So there's nothing in our heads that's going to make it the case that we're using the term in one way rather than another Really the ground floor facts are about the rightness or wrongness of particular whole statements We actually do agree on our verdicts in particular whole statements But that's not based on anything, that's not based on knowledge of semantic value So knowledge of semantic value is really this thing that you hope you could derive Whether this one's tall or that one's tall from your judgment of semantic value But this is the thing that keeps dropping out Or you might say it's some bit of language running through your head But that's the thing that keeps dropping out It's just your use of the terms in particular cases that is basic Okay, that's what I think we've got to so far That's the biggest that's correct, it seems to me negative point I mean, I would welcome it if you would find a way of showing that's wrong Because it really makes life very difficult But it seems to me very powerful Any questions about that? Okay, so then the question is how should we think about getting it right or wrong in your use of language Because the picture I just said is wrong, it is really the natural picture How can there be such a thing as getting it right or wrong in your use of language If that notion of knowing what's true or knowing the semantic value of a term just drops out Kripke gives I think the... How should I say, it's very simply stated And it's the best articulated, explicit version Account of what Wittgenstein's picture is But it really is, it's pretty mind blowing It's very hard to believe this account So let's just work through this Here's Kripke giving Wittgenstein's positive picture of how language works Wittgenstein holds with the skeptic that there is no fact as to whether I mean plus or plus Okay, so Kripke's saying that's right Wittgenstein thinks that's right He, Kripke, is going to say I think that's right There is no fact about as to whether you mean plus or plus We're going to give up the attempt to find any fact about me in virtue of which I mean plus rather than plus And then go on in a certain way Put up your hand if you find that kind of surprising That's devastating, right? Read it again There is no fact as to whether you mean plus or plus That means, I mean it's not just plus or plus, right? There are endlessly many substitutes you could make for plus there There is no fact about you meaning one thing rather than another by your use of a sign So we're going to give up the attempt to find any fact about you in virtue of which you mean one thing rather than another And you can see why he says that because what I keep saying is the negative argument here seems very, very powerful But how can that conclusion be correct? There's no such thing as meaning one thing rather than another Put your hand up if you think that's fairly straightforward, what's up there on the screen? That seems clearly correct Wow Okay And if it seems surprising at least Okay If you find that fairly straightforward, could you How come that's straightforward? It's okay to agree with it I just want you to get what it is I mean it's okay to agree with it, I just want you to get what Be sure that you don't agree with it lightly if you see what I mean Oh, hang on a minute Okay, Kripke says to forget the idea of looking for facts here About whether you mean one thing rather than another All we can do is consider how we actually use First of all, the categorical assertion That an individual is following a certain rule And secondly, the conditional assertion If the individual is following such and such a rule Then they must do so and so on a given occasion So every point here is important This is key to getting what the positive picture is supposed to be We are not going to look for facts We are just going to consider how we actually use statements like The categorical assertion that an individual is following a certain rule That is for example, the categorical assertion That Sally is using the cross to mean addition What we actually say We're going to consider In what context we actually say If the individual follows such and such a rule They must do so on a given occasion So for example, in what context do we actually say If Sally means addition by plus Then she ought to say 57 plus 68 is 125 So these are not expressing facts One and two there All we're going to do is consider how we actually use Those kind of remarks The categorical assertion that the individual is following the rule And the conditional rule That if they're following the rule They must do such and such They must say 125 So we're not looking for facts that make it true That someone means plus by the cross And we're not going to look for facts that make it true That if someone means a plus by the cross Then they should say 125 When asked for the answer to 68 plus 57 Does it help us in so far as the categorical assertion Doesn't make reference to past In the sense that if she means Sally is using plus to mean addition right now I think it doesn't matter whether it's present tense or past tense If that's the question Sally is using plus, so Sally was using plus I think Criki's negative thing would apply in either case here Right, but part of the problem seems to be that For an individual we can't know whether we've been using plus For the past years of our lives And now we're using plus So it seems like we can't know that knowledge Outside of an individual as well So if I'm saying you use plus I can't make an assertion about that I can only assert what you're using right now I see, well I think I see There's something here that I didn't really emphasise That's written very large if you read the Criki Which is he talks about how would you know Which in the past you were using Were you using plus to mean plus Or were you using plus to mean plus But at the end of the day The point is not about what you know The point is there's nothing to know And that's really what's going on here Is not that there's a fact about It's not that there's a fact about whether you mean Plus or plus Only it's very difficult to figure out Is that there's no fact here There's nothing to know Right, well the thing is The categorical assertion Looks like it's stating a fact And it must be just one that's very hard to know But the idea is we are going to give up on that Wittgenstein holds with the skeptic That there is no fact as to whether you mean plus Or plus Whether you mean plus or plus now Or whether you meant plus or plus in the past It sounds something about Criki's exposition That makes it sound more innocuous than it is This is what I mean If you get this Your hair should be standing on end This is a really startling idea And it's only even worth considering Because the argument for it seems so forceful But he really means that It's not that you don't know Now or in the past There was nothing to know What does that mean? Trying to do that That seems to me It seems like it But there are other cases I'll talk a bit about responsibility For example, people say Who was responsible for The stone going through that window You say, right? Who was responsible? Well that notion of responsibility You look for facts about who's responsible for what Out there in the physical world They are very hard to find Out there in physics So one reaction people have is to say Will these facts about who ought to do what Who's responsible for what Who's to blame for what They're not really facts about the world at all They're expressions of an attitude to the world Yeah And there are cases where it's very clear If you say good morning Good morning is not a report I mean, if you're learning a language You could just make a mistake And think that when people are saying good morning They actually mean something about how nice the weather is Yeah But that's just a mistake On the other hand there are languages Where people greet each other with a report As to how the weather objectively is Yeah You see what I mean? So when you say good morning It literally does mean good morning But when you're asking how we use the greeting good morning It would just be a mistake to look for the fact As to whether it's a good morning All you could do would be to say Ask when is it right to say good morning In what context do you say good morning Something can look like fact-stating language When it's not And the idea is that This is the categorical assertion that the individual Is following a certain rule The idea that Sally is using plus to mean addition That looks like fact-stating language But it's not It's to be classified with moral judgments On that kind of view of them Or statements like good morning Or maybe just giving someone a round of applause If you give someone a round of applause There's no fact you're stating there But if someone who wants to know What's going on when you're applauding Then all you can do is Consider the context in which you actually do applaud It's not fact-stating You're not reporting some fact when you applaud But it's not either that you just applaud Whenever you like There are contexts that You can applaud whenever you like right here But there are contexts in which Is right to applaud in contexts Which is completely inappropriate So these statements X means plus by the cross Or if he means plus by the cross Then he should say 125 When asked for the answer to 68 plus 57 We're not to look for facts that make that true But we're just asked When is it right to say these things So if you're thinking of a child Is the child's learning How to use the word plus And at a certain point They use it often enough That you say By John, she's got it Then what you're doing Now she means plus by the cross Then what you're doing there Is really a kind of applause When you make that categorical remark It would actually not be a bad model To think of this Sally is now using plus to mean addition As a kind of applause that you give the child You say you're one of us You've made it in Welcome There is something like that You're not actually stating a fact About what's going on That really is the model here So the contrast here is Could you say it's a strict solution to the skeptic Would point out something that the skeptic overlooked It would say When you're trying to say What constitutes my meaning plus rather than plus Or what constitutes my meaning Successor or tall What constitutes my meaning these things You can't say it's something running through your stream Of consciousness You can't say it's some other definition you have But maybe there's something Maybe it's some pattern of neural firing or something And the straight solution would try to find That hidden fact that makes the case That you mean one thing rather than another So that's a straight solution But Kripke says a straight solution is impossible The skeptical problem is really That intractable The skeptical solution doesn't allow you To think of a single individual Considered by themselves and in isolation As ever meaning anything There's no hidden fact that would allow A single individual to mean plus rather than plus One thing rather than anything other Is rather this If an individual fails to come up With the particular responses That the community regards as right Then we don't applaud Then we say you haven't got it You haven't got it that plus means plus On the other hand If the child passes enough tests If the child gives the right the same answers The rest of us on enough occasions Then after a fair amount of this After we've checked back and forth And been sure that we're getting the same answers Then we will accept that you've got it Now you've got it we say Now you know that plus means And that will allow us to trust them In engaging in further interactions with them To count out the change If we're buying something from them We trust them to engage in interactions That involve counting an addition So once we get a certain amount Of actual responses that we agree on With our individual then we'll say You've got it you mean plus You mean addition when you're using the plus sign And we'll trust them to agree with us Further that's all that's going on And you can't convert that Into an account of the facts that make it true That someone means one thing rather than another Because then agreeing with us On any bunch of any finite number of responses Is consistent with us all going different ways Past that initial finite set So if you look for a fact here That makes it true that we all mean the same thing That would just be subject to the same argument That we keep hammering away at Rather all that's going on is The subject agrees with everyone else Up to a certain point And then we say welcome we applaud We accept you as meaning addition By the plus sign and we welcome you in And engage in further interactions with you It's always been do not kill Do not quill That's right when you said do not kill I meant quill What I thought I was agreeing with was do not quill Well I think the line here would be I think that's important actually To extending this into thinking about How this applies to the moral case But all you could do here I think is Describe what actually happens And what actually happens is that If this person says ah but by kill I meant quill Then we are still going to We are not going to say ah well that explains everything At that point we either just lock them up Or we say here we have So unknown form of madness But we take it very seriously either way So there is a basic point The success of this just depends In this brute empirical fact That we agree with each other in our responses This kill quill thing doesn't happen very often That's the only reason it works We just do keep on going in the same way So these practices of applauding after a certain point And welcoming people in They work But there is nothing that is making it work It is just a brute empirical fact That it does work That is how you naturally think of it Something happened and the child got it Something that we rely on the fact that the child actually did have Some change in him The whole thrust of the negative part of Wittgenstein's discussion Is to attack that idea of the change that went on in the child And to say that just doesn't matter Any change that went on in the child All that matters is what the child does next And the simple way to see it is Suppose the child suddenly had ah of course now I get it You meant addition or whatever is meant to be going on there And if the child then goes on in a deviant way They haven't got it no matter what happened at that point When they banged their head and said now I get it And even if that transformation did not happen There was no point at what the child said Or which the child said oh now I get it But the child actually did start using words in the right way That's all that matters We're doing it Well all there is to say about it is this kind of thing If the individual passes enough tests Then we'll say you're using plus to mean addition Not quaddition But of course it's true that if you were using quaddition You'd actually be going on in just the same way But the thing is we just don't bother about that In practice if the child passes enough tests Uses the word right in enough cases Gives the right answer to enough addition sums We say you've got it, welcome in And then we expect the child to go on agreeing with us With the rest of us And that is just the brute empirical fact That we get this agreement in our responses And everything else depends on that Versus it seems to be a big distinction between us And yet on this account it doesn't That's exactly right, that's very good You'd think there's a distinction between the child That gets it right because they're lucky And it's just a coincidence that's giving the right answers In all these cases And the child that gets it right for the right reasons Something like that And the point here is that you can't make that distinction Getting it, that distinction depends on the chitly idea That the such a thing is getting it right for the right reason On the right basis And the point is that when you're in these basic uses of language There is no basis The giving of explanations has to come to an end somewhere Here we hit bedrock and the spade is turned You can't keep giving explanations all the way down It just stops rather soon than you might have expected And there's no explanation to be given Of why you say 5 plus 7 is 12 No explanation to be given at all That's just the words you produce Then you can't make that distinction Between getting it right for the right reason And it just being lucky that you got it right One, two Can you take that from the top? There's something to do with how people acquire a skill There's no distinction I'm not sure I really follow When we say if an individual passes enough tests There's some kind of screening that we do at the start When you test the child out in different cases I do that with you guys when I say What would you say is the semantic value of a truth table Of a constant like under off That's exactly what you're doing Just where you're saying can you go on in the same way But after a reasonable number of cases You and I presumably have been through enough testing Of our ability to add that anyone would say Okay, they've got it And that's all there is There's no basis separating you and me All that comes to you that we've grasped the technique Is that we've given the right answers often enough There's no what, sorry? Right, there's no internal basis That's right, that's a picture They are following blindly And when you say it's not devastating I mean Wittgenstein and Kripke are going to say That's right, it's not devastating That's just what goes on But it requires that you throw away the picture Of there being a fact about you meaning one thing Rather than another Because that was the work that the internal thing was doing Making it the case that you mean one thing Rather than another Once you throw that away and say We can do without that Then you lose the idea that there's a fact Of the matter about meaning plus rather than plus Because all your responses would have been the same If you meant plus Yeah, yes, right That's very good I think, is this right? I'm not dead sure what to say about that Someone who seems to understand the wardrobe But they're actually just quite clumsy In using it, I mean I don't, I don't mean that I don't mean that negatively Right, right I guess that you would think Well, this notion of past is enough tests Has room for some complexity in it That if you say, if we take you in a case where you say One plus two, well that's four And then we say no, wait a minute Go back over that, do it slowly Then you will get it right Give you enough time You see what I mean It makes sense that someone might be kind of panicky Around numbers But once you give them enough time They should be able to get it right Or see their error when it's pointed out to them Actually that's very interesting One thing to do with the child That seems to be getting it right luckily Maybe one way you could make the contrast there Is to try to rattle the child And say one plus, the child says one plus two And you say one plus two and the child says three And you say no, no, it's four And then you see if the child stands on the ground Right Yeah, that's kind of fun to do, that kind of thing Yeah, I do know what you're saying The point is there's nothing deeper in the child For which you're probing All you're looking at is something relatively superficial The particular... If you pass the test you're good The test itself might be a little bit complex though It might involve allowing people to correct you Or people to challenge you And seeing how well you stand your ground No I agree I agree Your point is perfectly good One of the things that makes it natural To think that we're probing for something underlying here Is that complexity in the tests But really The whole point of the Krupp-Guy-Wittgenstein picture here Is to say we have to take the surface appearances At face value All that's going on is the stuff in the surface Just describe that Yeah Well I'm actually... I'm trying to blast through a little bit here We could just pause this And hold on until next time But I'm inclined to see if I can get through Many of the points I wanted to hear So this is all right up to this point I mean, you see what I'm saying anyhow Or what Krupp-Guy-Wittgenstein is saying I heard about that And it is pretty wild, I agree If you think that, then I agree Okay, let's see We may have to hold this over for next time It doesn't matter much if we do But let's see A classic puzzle for Wittgenstein's Picture here Which is the idea of a bomb cruiser That's to say Well, one way to start getting at it Is to say Can't you make sense of a person Being right in what he says And everyone else is wrong Doesn't that make sense? Wittgenstein makes sense of that But there's also the idea of A bomb cruiser, that's to say I mean, you can't literally be born In a desert island But you can assume that You're born almost immediately afterwards Your mother sails away And is never seen by you again And you spend your life On this desert island Now that seems to make sense You could have somebody spent Their life in this desert island Making a hut Getting to know the goats Having a little farm And maybe they keep a diary Maybe, you know, they write their diary And you come upon them And they have to invent their own language Of course But just by coincidence It looks just like regular English And when we pick them up When the boat finally comes to pick them up You look at their diary And it's full of long ruminations The richness of my life here It's unimaginable and so on It looks just like regular English And doesn't that make sense? Couldn't you have someone like that Outside any of this context Of rule following or applause And here's what Kripke says about this Kripke says, if we think of Cruzo as following rules We're taking him into our community And applying our criteria For rule following to him So that the discussion so far Need not mean that a physically isolated individual Can't be said to follow rules Is rather that an individual Considered in isolation Whether or not they're physically isolated Can't be said to be following rules So if you think of saying Oh, he's got it He means addition by the plus sign If you think of that as a kind of applause What's going on here is We're reading Cruzo's journal And we're saying, by God, look at that Well done, Cruzo You see what I mean? The ascription of meaning to Cruzo Is being done in the context of this activity Of us regarding him as one of us Saying, look how well the usage matches up To the way we use words And so the temptation here Is always to read Kripke As if he's giving a straight solution To the skeptical problem And saying, what makes it true That Sally means addition by plus Is that she gives the responses We agree with in enough cases Or what makes it true The 57 plus 68 is 125 Is that we all agree That that's the right answer But if you try to give that kind of account It would be hopeless Because you run right back into these plus Quests problems And what makes it true That Sally means addition by the plus sign Can't be just agreement And some bunch of responses Because that would be consistent With our meaning Quests by the plus It would be consistent with us All meaning Quests by the plus Is rather got to be That we're thinking here of Cruzo In the context of a skeptical solution Where we are taking Cruzo in And saying, well, you're one of us That's all that's going on When you say Cruzo means addition By the plus sign The striking remark on that By Vickerson of language Is to be a means of communication I think we quoted this earlier There must be agreement Not only in definitions But also queers this may sound In judgments So we don't have very much time So let me So the suggestion here is That all we're doing With statements like X Means plus by the cross Or if he means plus by the cross X should say 125 We're not looking for facts That make those true And it's similar To how you explain What goes on with good morning Or saying when it's right to applaud You don't describe when it's right to applaud These things Should be given a description of When it's right to applaud Or when it's right to say good morning But not by giving facts That make them true And similarly, the use of signs Like X means plus by the cross Or if you mean plus by the cross Then you should say 125 When you asked what 68 plus 57 That shouldn't be dealt with By saying when it's right to say these things Not by looking for facts Now the thing is That means that there isn't any Fact of the matter about whether it's true That if he means plus by the cross X should say 125 When asked for the answer to 68 plus 57 That's an implication There's no fact of the matter about that If he means plus by the cross Then you should say 125 When asked for the answer to 68 plus 57 So presumably that means That there isn't any fact of the matter About whether 68 plus 7 Plus 57 is 125 Presumably that's going to have that implication I mean, if there isn't a fact Of the matter about whether it's true That 68 plus 57 is 125 Given the meanings of the signs Then how can there be a fact of the matter About whether 68 plus 57 is 125 So if you say there aren't facts Of the matter about meaning It seems that you're coming You're going to have to say That there aren't any facts of the matter About anything at all And that point applies to language generally You could put just in just anything there And there wouldn't be a fact of the matter About whether it's true Given the meanings So there wouldn't be a fact of the matter about Whether the thing itself is so Number where 68 plus 57 Does mean it's 125 No I don't know that it's a posteriori The a posteriori would suggest There is a fact of the matter That you just have to use your senses to find out about it But it's not something special about maths It's something about anything you can talk about Again, it's a little bit mind-bending What's going on here When you talk about a social construction That suggests there's a fact of the matter About what we're talking about We're just talking about this social construction You see, it wouldn't be right to say Good morning is a social construction It's not a thing at all That's not the right way to think of it So what's going on here is We're losing the notion of a fact There could be facts about a social construction If you see what I mean It doesn't even have the dignity of a social construction It looks as though What's happening is that We're losing the very existence Of a fact stating use of language And other than that Bombshell