 Bydd gennym ni ddweud yn gallun dod hynny i gynnyddiadol yn y gêm, sydd yna gydag oall, yn gyngor a hanesiect yn edrych, i rwyl Eich Llyfrgell yna'r pwynt eich ystod, ond mae'n cerdnas i ddoch yn ei ddal, i ddweud yn ôl yn eich rwyl Eich Llyfrgell o fyny'r llyfr yn llyfr i darn o'r fwyllt o'r cyfnoddau i'r gyfer hynny'r meddwl, a chi'n gweithio gyda'r bethau. So Russell's main point, I think, is that there's a basic class of names that is getting tied up to objects, but not by being defined in terms of descriptions. If that's right, it's a really basic objection to anything like Frega or Sel's approaches. So if there's a basic class of names that is getting hooked up to objects, but the thing is not being done by way of descriptions, then how is it being done? Well, Russell's term for that relation is acquaintance, and he means here a kind of non-propositional knowledge. That's to say, when you encounter an object in ordinary vision, or a property in ordinary vision, say, then you get some knowledge of it just from the sensory encounter just by having that connect with the thing, just by coming into your field of view, you get some kind of knowledge of it. And that's more basic than being able to describe it. That's not a matter of being able to describe it at all. He gives some of the example of colour that when you encounter the colour red, you know from experience perfectly and completely what red is. It's not that you can say red is, thus and so. It's not a matter of being able to say propositionally that red is, thus and so. It's a matter of knowing what it is in some more basic way. So the problem with this kind of view of Russell's, on which you've got the sign and the reference, and nothing like Frega's sense or Selv's cluster of descriptions, is that, well, there were two problems. One was the problem of informativeness. You can have different signs referring to the same thing, and the identity between them can be informative. And how do you explain that possibility if it's not the names that are getting hooked up to descriptions? And the other was the possibility of meaning without reference, because it looks like a sign can have meaning without reference. So what is going on there? How could it be that signs have meaning without reference? If they're defined in terms of descriptions, you can make sense of a description that has meaning but doesn't designate anything. But how could a sign working like this, where there's just the name and the object, how could that have meaning? These are the two key problems he's going to face. So let me just go over his main point here. There's a general contrast between what you might call how many terms and names. For anyone who's done logic, the contrast is between quantifiers and names. In terms that are telling you how many objects a particular predicate is true of, versus names that are telling you which things the predicate is true of. So here's a predicate, wrth Weverly. One thing you can do is say how many people wrth Weverly. Another thing you can do is put in a name there of someone who wrth Weverly. So if you say someone wrth Weverly, that gives you a sentence all right. No one wrth Weverly. Many people wrth Weverly. They all give you sentences. Are any of these terms names? No, these terms are not names. They are how many expressions, right? They tell you how many things wrth Weverly. That's all right. What could be plainer than that? I'll be very closely here. All kinds of radical conclusions will emerge. So if you see a step that doesn't sound right, you'd better protest. That's all right. These are not names. These are quantifiers of how many terms. So the optical illusion is when you say the author of Weverly, what that phrase, the author of Weverly is, is a complex how many term. It is not a name. So the first point you just gave me is there is a big contrast between these how many terms and names. Russell's point is this term, the author of Weverly, is not a name. It is a how many term. There is an optical illusion that makes it look like a referring term, but it is not a referring term. In a simple way to see, here's one way of seeing the force of Russell's point that is not a referring term. Suppose you think very slowly. I know that for you guys this is not easy to imagine, but suppose that you think very slowly. And furthermore suppose that 200 years from now there are all kinds of nobles around. Some of them are generated entirely by machines. Some of them are written by committees. Some of them are written by a mixture of committee and machine. Sometimes you get a novel written by just one person. Sometimes you get a novel written by a bunch of people and some machines. There is also a stylometric analysis that you can do of the novels that are written. Given a novel, you can run tests on it to say what any humans involved in the generation of this novel. Or why is this novel written by one person or by many? That's all right. You can do that. Suppose you're looking at a particular novel, and suppose also you can find out the nationality of the author of a novel by running the right kind of tests of what vocabulary is used, what kind of sentence constructions are used. Then, okay, you're looking at Waverley and you're saying, what about this? Is this one of these entirely machine products or was a human involved in the generation of this text? Well, you can say having run those tests, at least one person was involved in the generation of Waverley. Many machines, but certainly one human. And then you run tests and say, well, was it run by a committee? Was it written by a committee? Was the text generated by a committee? And you say, no, actually, now that we've run these tests, the text wasn't generated by a committee. There was at most one person involved in the writing of Waverley. And we also run the stylistic tests on the nationality of the author. And we say, well, anyone who was involved, this is a work of the purest Scotsness. No non-Scots humans were involved in the production of this work. Anyone involved in the writing of Waverley was Scots. Okay, so you do that. You come to that conclusion. Have you, at this point, referred to anyone? Have you named anyone so far? No, you have not named anyone so far. Have you, in contrast, used a number of how many expressions? Yes, you have used three. You have used at least one, at most one, and anyone who did this did that. You have used three quantifier expressions, three how many expressions. No names were involved in the generation of these sentences, right? Just how many expressions. Is that plain as day? Okay, well then, we're home. For these three sentences to be true, there has to be exactly one person who wrote Waverley. But remember, you're thinking very slowly. You might not have realised that. You just walked through doing all these tests and you got these results. And if you want to state these results concisely, well, you could put it by saying the author of Waverley. You look up in your book, well, what does the author of Waverley with Scots mean? Well, it means this. It means at least one person wrote Waverley, at most one person wrote Waverley, and anyone who wrote Waverley with Scots. So using this is just a way of concisely summing up those three sentences. There's been no reference so far, so just introducing an abbreviation doesn't introduce any reference. So when you say the author of Waverley with Scots, you're just briefly expressing those three sentences. Now, as it happens, when you figure it out, you might think, well, if that's going to be true, at least one or most one, then anyone who did this did that, then if that's true, now your thoughts speed up a little bit and you say, yeah, look at this, there must be exactly one person who wrote Waverley. Now you didn't notice that so far, but now you notice it, but it's kind of an accident that there's got to be exactly one person who wrote Waverley here. And we say, okay, let's call that person if such a person exists, the denotation of the author of Waverley. Now then when you say the author of Waverley with Scots, whether that's true depends on whether the predicate applies to the denotation. So you've got a situation here where you've got a kind of facsimile of reference. It looks like reference because now that you've so smartly noticed that there is such a thing as a denotation of this expression, then you can say whether this whole thing is true depends on whether or not that denotation was Scots. So that looks like reference, but we already agreed that there isn't really any reference here. The existence of the denotation is, how should I say, it's just a kind of accident because you're so smart. You whip through the three aspects of the analysis very quickly. You spot there such a thing as a denotation and you say, ah, that's the reference. But that is a mistake. It's a mistake you make because you think about this so fast. It looks like reference, but it's not because really what we've got here are just these three sentences. And none of them involve reference. So the realisation that there's such a thing as a denotation is in a way accidental to your understanding of the definite description. Whereas if you take something that is using what seems to be an M like Scots and you say Scots was indeed Scots, then you couldn't understand the Scots there without knowing the referring expression. Understanding that term, there aren't any three clauses to break down. There are no predicates in there. It's a simple term. It contains no moving parts. So if we assign Scots, all there is is a reference of the sign. No description here to mediate the reference. So the sign, the author of Waverly, is equivalent to, as used in the sentence, the author of Waverly with Scots, is equivalent to those three sentences, at least one person wrote Waverly, at most one person wrote Waverly, anyone who wrote Waverly with Scots. That doesn't involve denotation in contrast to this kind of situation. Okay, definite descriptions do not refer. One, two. Reference, as I'm describing it, is what happens when you have a simple sign who's been given meaning by having an object assigned to it as reference. Denotation is sometimes happens that you have a complex of signs here so that there's a single object on whose characteristics, the truth or falsity, although you have a single object such that the truth or falsity of the sentence depends on whether the predicate applies to that object. That looks like reference, but it's not reference because that assigning of the object, that object was not assigned to any term there as its semantic value. That object, that's the best way to put it. That object is not the semantic value of any term in this analysis. These terms all have quite different kinds of semantic values. They're all either predicates or how many terms. Where is the object, where is the sign in these three sentences that has an object as its semantic value? There is no sign in there that has an object as its semantic value. That's completely irrelevant. You see what I mean? Where as with Scott, where is it? Scott for Scott. Then the only way you have of saying what the semantic value of Scott here is is by saying which object is its semantic value. When the sign has the object as its semantic value, what that comes to is that when you've got a sentence like that, the truth or falsity of the sentence will depend on whether the predicate applies to that object. That denotation is quite like that. That's why it's so natural to think these are referring signs. Frega and Serl, we're not just being random about this. It's very like reference, but it is not reference because there's no sign there that has that object as its semantic value. I'll put it just one last way. When you see that you can define the denotation and say the truth or falsity of this sentence will depend on how things are with that object, it's natural to think there must be some sign there that has that object as its semantic value. I say I bet it's the description, but it's when you think what are all these complex words? What are all these different words doing in the description? You see the description doesn't have that object as its semantic value as an unstructured block the way a name does. You've got to break down the description and look at what the semantic values of the components are. When you do that, the illusion that you have reference here disappears because you see that none of the signs have that object as their semantic value. That's right. We have predicates that could be in a quantifier, but we also could prove it in a name. That's absolutely right. In the case of definite descriptions, there are only quantifiers over predicates and not names. There might be special cases. In this case, there is a name in there. As I said earlier, that's accidental. That's not to the point. Putting in the description is just putting in a bunch of quantifiers. Putting in the vith is just putting in a quantifier. Vith is a quantifier term. All is a quantifier term. Some is a quantifier term. Vith is a quantifier term. You can't put in a name in the sense that you could write in Scott. That's putting a name into the predicate. It's not that you can only, as we'll see in a moment, there must be some cases where you put in a name. It's not that you're only ever allowed to put in quantifiers. It's rather that when you put in a the phrase, you are thereby only putting in a quantifier. The argument is these the phrases are complex. You understand them by understanding the meanings of the individual words that are in the the phrase. In order to understand the author of Waverly, you had to understand author of and Waverly. You need to be able to explain how, from the semantic values of these terms, the semantic value of the whole phrase is being generated. That's what this analysis does. It explains how from the components, wrote Waverly and Scott on word scotch, you are generating the meaning of the this term. If you really wanted to challenge Russell here, you'd have to say, I think anything is possible, but I think anyone would have to agree that the meaning of a descriptive phrase is complex. How about that? Do we all buy that? It depends on the meanings of the words. The meaning of the whole thing depends on the meanings of those words. You'd have to explain what the semantic value of the whole thing is in terms of the meanings of the components in such a way that the whole thing was being assumed to be assigned a reference as its semantic value. That's not what happens here. If you really wanted to challenge Russell, I think that's what you'd have to do. Fregid didn't really... Fregid founded the subject, so it's not that tall that I wish to be disrespectful about, but Fregid did not ask the question how is the semantic value of a definite description generated from the semantic values of its components. Fregid did not really seem to get, did not seem to focus on the question how do the semantic values of the words produce the semantic value of the whole thing. He just didn't ask that question. He just seems to have taken it for... This is my reading at any rate. He just seems to have taken it for granted that when you've got the whole description, you've got the thing that stands for, and that's what I mean about your mind working too fast. You know, it's true that such a thing is a denotation, and you freeze-frame over that and say, now how come there is such a thing as a denotation? What are all those little words doing in there? That's when you see the force of Russell's point. Yeah, well, there's room for choice here. I'm distinguishing reference and denotation. I should say, incidentally, that Kripke, he will be looking at next, talks about denotation and reference the whole time, and he's not distinguishing between them. So this is for the purposes of this lecture only, if you see what I mean. It's not that distinction is you... That's not the way that the terms aren't used in the literature generally with that kind of distinction. Okay? So that's just an aside. But you could do it two ways. You could say... I said there's such a thing as a denotation in the case of a description. A person such that the truth of falsity of the whole thing depends on how things are with that person. You could say in general that you get that phenomenon, you got denotation, and then that would apply to names too. All I'm doing here is trying to bring out the parallels and contrasts between what a description does and what a name does, how you go on. Suppose there are two Scots and they're both famous. Okay. And are they identical? Yeah. There's still going to be an argument. I mean, this is what I meant by... I began by reminding the argument... I mean, Frigga and Serl were not getting their views out of nowhere. There is still going to be an argument about what's going on with informative identities, then how come there can be meaning without reference. And that's, I think, with a really deep, interesting pressure. So bear with me if you think this is a merely technical question. We'll see very shortly that it's not. But these arguments are still there and they still have to be addressed. And they're obviously not addressed by... Where's it gone? This kind of picture. Because this is where we began that this seems inadequate because of the possibility of informative identities and meaning without reference. So now we've been driven back to it because what we had in the middle was descriptions. And now I'm saying it's actually a mistake to try and put descriptions in the middle there. But now that original problem just returns with full force. Yep. Yep. This sort of that. I agree it can work like that. I mean, you can point to something and use your finger to point to it. And I can point to someone and say, that tall man, and he's not actually tall, but he doesn't matter. I did the whole flourish, including the words, in such a way that you got locked on to the right thing. And the words there were just in gas to help you look at the right thing. You see what I mean? So there this kind of analysis doesn't really seem appropriate at all because if I'm saying the tall man is talking, that tall man is talking, then I'm just using the words as a way of getting you to look at the right person. And it's as if I pulled you in front of the person and waggled the person at you while forcing your head to look at him. If you see what I mean. But in polite society, we don't do it just like that. Once you're over about two years old, we don't do it like that anymore. If then. So I just do some talking to get you to lock on to the right thing. I don't tend to the talking isn't important. That can happen. I agree that can happen. And you say, well, it doesn't matter that he's tall. I meant him. But what I'm talking about, what we're talking about here is when you take the terms literally, you take them as saying exactly what they are. How should I say canonically mean? Because so far as that kind of thing goes, I mean any word might do. If I could say boo boo boo. And that would work to get you to look at the right person. Last one we should move on. That's right. It doesn't have a semantic value in and of itself. Well, you can know what the denitation would be if the thing were put into a whole sentence. But there's a very general point here that there's no such thing really as understanding words outside the context of a sentence. I mean if I just say, well look, I mean suppose listen up class, this laptop, this cup, and this remote. Well, what happened? Nothing. I mean I just gave you a list of words. In order to make a move in language, in order to do something that makes some sense, you've got to a whole sentence. So all these notions of reference or denitation have to keep being tied back to the truthful falsity of sentences. I mean if I just say to you right now, the king of France. Well, what of it? I mean what do you want to say about him? That's the question. I haven't actually said anything yet. So there's some sense in which you can know the denitation, but that's just, well let me fill it out. I would know what the denitation was. I said last one. I really think we should move on. If that's okay. Because we're not going to go very far from this point for a while. Okay, so I mean, arguing you need to, that you should think of the expressions, that you should think of the as a quantifier. Think of the as a how many term. And now the thing is, suppose you consider how you explain the meaning of a general term. Suppose you've got a child, or someone intelligent to understand English, but who just doesn't yet know what the meaning of the term is tall, is how do you explain it? I mean in general you don't explain the meaning. Sometimes you can explain the meanings of terms by definitions, but that's not always, even usually how you explain the meaning of a general term. So if I'm right here and you're right before me and I'm saying to you, well what does that mean is tall? I keep using it as an example, but I actually have no idea what it means. Then how would you explain the meaning? Well one thing you could do is to say, well look at the room, someone is tall. Or you might say look at this room, none of them are tall. None of that is going to help. You can't in general explain the meaning of a general term by putting quantified expressions in. If you want to explain the meaning of a general term, and you want to explain what red means, you can't do it by saying, oh well there are lots of red things. You've got to get down to specifics and say something about which things are red and which things aren't. The way you explain what red and what green mean is by saying look this one's red, this one's green, this one's red, this one's green, that one's not red, that one's not green, this one's red, this one's green. You take lots of examples, that's how you explain the meaning of a general term. So it is tall, you might go round the class and say look there's Tom's tall, Sally's tall, Hanyo's tall, this one's tall, that one's tall, that one's not tall. You see what I mean? You could only explain the meaning of a general term by putting names into the slot using the names. Keep running the names through the slot in the expression. So you're going to explain the meaning of a general term, you need names. I don't mean to be saying anything very controversial here, I hope this is sounding like common sense. That's right. You could do that by saying suppose you're trying to explain to me what red means and you take some set theoretic description of the class and you say you take the union of these two sets and the intersection of that with this set and eventually narrow it down to one. That's red. Someone's wearing red. That might be true, but the thing is that's not going to help me until I say there's exactly one thing meaning all those conditions and that's red. I don't know yet until I can say oh it is, if you don't mind me pointing out to that one, that's right. You see? Once I've got the that then I'm in business and I might have done the set theoretic thing to clue me in but the set theoretic thing in its own wouldn't help me. Sorry, there's someone else. Was that you? I'm sorry, can you do that louder? It's not a name, I agree it's not a name. It is like a name in that it has its semantic value by standing for an object. It's a little bit fancy because it does have that person and you might say wait a minute that's a general term. What is that doing there? We should be perfectly reasonable. The only thing is that we don't usually describe it regarding as courteous to describe people as that. You can see what I mean, but yeah, well he can only use for people you see what I mean. But to set aside courtesy in favour of purity there you go. That is tall. As John McCain would say, that one is tall. OK Last one. That's how you tell someone what is tall means. You see a whole bunch of people and you say look that was not tall. That was not tall. No, that has to do with feeding and genetics and I suppose. It doesn't explain how you come to be tall. What is the good? That's right. Well if you take that example explaining what the good is that's a very special case. But one view of it would be it's like colour words. You can say this is red and that's red and that's red and that's not red and when you do that you've done all you can to explain the colour word yes but in addition what makes something red? Well there isn't really anything you can say there. You can talk about the physics or something but that's not what makes it red except in the sense that that's how you can construct something red and similarly with good there might not be anything general to say about what makes something good. If there is something general to say about what makes something good like it pleases the king or something then it makes mom happy. You might say I have a general theory of what goodness is. That's fine but that's in addition here that's a quite special feature of this case. So to explain general terms you need names. You can't explain general terms with how many expressions. So if we take it for granted then the meaning of a general term like wrote waverly is explained by its use and sentences involving names then we've got to understand how that explanation of wrote waverly connects with other uses of the term. So what you do is you first of all explain the meaning of red in the context this is red, that's red, that's red, that's red and then you go to explain how does that relate to someone wrote waverly. Because anyone might say look you just explained the meaning of red or wrote waverly in the context of sentences with names in them but now you're going to say someone wrote waverly and I have a ghast you know you didn't say you didn't say anything about that you see what I mean. If you explain red to me by saying look this one's red, this one's red that one's not red, that one's not red, this one's red then all right now I and I get that and I say now you've explained the meaning of red as are the cars in sentences with names in them but then you say something is red and I'm completely thrown I don't know what does that mean? I need a whole new explanation here well the natural way to connect them if you're going to say well how do I explain the relation of these how many sentences to the sentences of names what I was suggesting last time was you can read someone wrote waverly as meaning there is at least one potential name you can introduce a name A and then put in A wrote waverly and that comes out true so if you explain is red to me by saying this one's red, that one's red, that one's red and then I say okay I know what red means and now you say something's red well my way of interpreting that is to say that means there's at least one name that that I could put in the red slot and it would come out true that's how I connect the how many term to the use of the names on the other hand if you say no one wrote waverly or you're saying there's no potential name such that A wrote waverly is true or if you say many people wrote waverly what you're saying is there are many potential names A1 and A2 such that A1 wrote waverly, A2 wrote waverly and so on so this is a picture on which names belong to the ground floor of language and and names are more basic than how many or quantifier terms quantifier terms are explained in terms of names in order to explain general terms you've got to have a rack of names so how many terms come in at a much higher level of language use than either names or general terms so if we've got and we've got how many terms we've got names and we've got general terms then explaining how these work the how many terms in particular is relatively straight forward once we have Russell's analysis but the real hard thing is how we explain what's going on at this more basic level and now we can't appeal to descriptions in explaining what's going on at this more basic level so that leads us to Russell's conclusion there's a basic class of names that gets tied up to objects but not by being defined in terms of descriptions so at this point I think that completes the case for throwing out fregat and cell on descriptions how about that are there any remaining imbers of descent aha that's a spirit speak up well when you say descriptions are the more basic case take the denitation of a description to be the more basic case the two questions for you are are you taking descriptions to be complex or simple if you say I'm going to treat descriptions as if they're simple and explain their meaning just by hooking them up to a denitation then this is treating descriptions as names and that's not really any different to Russell's theory because you're saying although it looks like you've got familiar words in the description they're not really doing any work on the other hand so that's not an alternative to Russell that's treating descriptions as names on the other hand if you say descriptions are complex and those individual words in them are doing significant work well if you accept Russell's explanation of what all those terms in them are doing then the denitation of the expression is not basic the expression has a denitation only because these general terms have already been explained and understood but for those general terms to be already explained and understood they had to have been coupled up with names that was the argument I was just giving and so we move gloriously on this is just the one last slightly technical there's a notion of witnessing that is helpful to have sometimes suppose you say someone is F then that can't be the end if you say someone is F there's got to be it's got to be possible to name the thing that is F you can say give it a name so logicians call that witnessing the statement someone is F you witness it by saying giving a name A is F, give it a name and similarly if you say there's exactly one X which is F and any Y that is F is also G then you can say oh what's its name you can ask for it to be witnessed you can say namely so since you can say namely with a definite descriptive with a the sentence there's always got to be that lower level when you say the F is G you can say well and which one is that the F and be able to name it somehow so that's just how should I say rounding out the point that there's a class of names that's more basic than descriptions so if there's a class of names that's more basic than descriptions and they're hooked up to the world somehow what does that look like well we have these problems of informativeness and meaning without reference and they're not going away so how are we going to address them here Russell says so long as names are used as names then Scott is so Walter is the same trivial proposition as Scott is Scott so that's a really radical claim he's saying with real names true names you cannot have uninformative identities sorry you cannot have informative identities ok let me take that from the top so you might think this is Scottisford Walter could be informative but if they're really being used as names then Scottisford Walter is trivial is always uninformative when you've got names and he turns it on his head take the idea that there can be meaning without reference you can inquire significantly whether a home or existed but you couldn't do that if Homer were a name because if Homer's a name if something's a name then it has its meaning just by standing for the object it's like that example of smudge I was giving where the name has meaning just by standing for its object so you can't meaningfully inquire whether the name stands for anything that would make no sense so since you can meaningfully inquire whether Homer existed Homer can't be a name it must be just some kind of descriptive phrase really an ordinary language no names of car names in the sense of this ground floor level of language what look like names aren't really names no names in the strict sense of car but what seem like names are really descriptions with exception and these are the true proper names this or that and a few other words meaning varies on different occasions so what he's got in mind here is suppose you take a term for a current sensation you're having like a headache suppose you say this headache could that term have meaning even though there was no headache well it's characteristic of your own sensations that if you think they're there then they've got to be there you can't be wrong about that Homer out there in the concrete world it might for all the world appear as if there's such a thing but the thing don't be there in the case of your own inner life if it appears as if the thing is there then it's there that's what your inner life is that totality of ways things appear to you and think about it with informative identities I said an informative identity that's when you can have two different takes on one in the same object now that makes perfect sense for a three dimensional concrete object in the physical world so you can have the table from this angle or the table from that angle but suppose you take this headache and I say ok I've got a pain in my foot too or I've got an itch in my foot is that itch this headache well in your inner life things are completely obvious there is no such thing as being able to formulate an informative identity about your own inner life so the problem of informative identities does not arise if the most basic class of names here is really a set of signs referring to your own sensations or your own sense data you ask is this sensation of redness the same as this headache that's always if it's true it would be trivial if it seems like an exciting possibility then it's not true properly speaking names refer only to your own current or recent sense data and as your acquaintance with those sensations Russell says that fixes their reference but look at the implication of this when you or I and you're just driven to this by these problems about informativeness meaning without reference and the analysis of descriptions there is nowhere else to go at this point but we are driven to the idea that each of us is interpreting the whole of our language in terms of their own sensations you can never refer to my sensations I can never refer to your sensations there is really a strong sense in which communication between us is impossible because you are ultimately interpreting everything you say in terms of your own inner life and I am ultimately interpreting everything I say in terms of my inner life there is a very revealing Russell gave some lectures on logical atomism in 1912 something like that question if the proper name of a thing of this referring to a sense data varies from instant to instant how is it possible to make any argument I mean your own inner life is shifting from moment to moment and Russell says well you can keep this going for a minute or two I made that dot a mark on the board I made that dot and talked about it for some little time I mean it varies often if you argue quickly you can get some little way before it's finished I think things last for a finite time a matter of some seconds or minutes or whatever it may happen to be question you do not think the air is acting on that and changing it Mr Russell it does not matter about that if it does not alter its appearance enough for you to have a different sense datum so the key thing in your understanding of your own use of language is the sense datum and it's only such stability as that has over time that your meanings of your language have over time and it's only in some very extended sense that we can ever be said to understand each other sorry I went to overtime but thank you for bearing with me