Transcrição completa de Evaluating Arguments Part Two

--> 00:05:19,810 You'll have understood the concept of validity. OK. I can see there's still people worrying about the concept of validity. 53 00:05:19,810 --> 00:05:24,710 But if there is time for questions, we'll have a look at the questions that you might have then. 54 00:05:24,710 --> 00:05:29,770 But we must go on today. I'm afraid so. We'll move straight on. 55 00:05:29,770 --> 00:05:33,570 This week, we're going to be looking at common fallacies. 56 00:05:33,570 --> 00:05:40,120 And a fallacy is an argument that looks like a good argument can be easily, easily be mistaken for a good argument. 57 00:05:40,120 --> 00:05:43,540 But that isn't a good argument. 58 00:05:43,540 --> 00:05:51,280 And you won't believe how many fallacies there are, fallacies that you can just identify and explain why their fallacies, 59 00:05:51,280 --> 00:05:58,390 why they look as if they are good arguments and they're not. But I've listed a whole load of fallacies. 60 00:05:58,390 --> 00:06:06,370 I've I've taken the form of a Web site that I've mentioned on the top and that there are I think they are four pages or something of fallacies all in. 61 00:06:06,370 --> 00:06:13,290 I apologise for the smallness of the print. But they wouldn't have let me photocopy it if I'd put it any larger. 62 00:06:13,290 --> 00:06:18,010 And I'd just like to point out the top one fallacy is now I've got my glasses on. 63 00:06:18,010 --> 00:06:26,560 So it says something like, please note that the argument from fast talking on page eight. 64 00:06:26,560 --> 00:06:30,550 That tells you that if somebody talks fast, 65 00:06:30,550 --> 00:06:36,340 you haven't got a chance to work out for yourself whether the premises are true and the conclusion is valid. 66 00:06:36,340 --> 00:06:39,940 And I'd just like to point out that I've gone through these ideas in these lectures so 67 00:06:39,940 --> 00:06:46,060 quickly in some cases that there's no way you'll have had time to stop and think about them. 68 00:06:46,060 --> 00:06:56,050 As I've been talking. And so you could say that a whole of these series of lectures has been a giant fallacy of fast talking. 69 00:06:56,050 --> 00:07:02,290 I promise you it's not. And that if you go back and consider what I've said and of course, they'll all be on the podcast, 70 00:07:02,290 --> 00:07:06,310 so you'll be able to actually go back and listen to what I've said again. 71 00:07:06,310 --> 00:07:10,720 You'll be able to listen to all my mistakes as well as the things I've said correctly. 72 00:07:10,720 --> 00:07:14,520 I hope we've identified all my mistakes as we've gone through. 73 00:07:14,520 --> 00:07:20,830 But but that will give you time to actually think about what I've said and work it out for yourself is actually. 74 00:07:20,830 --> 00:07:26,890 Nobody can teach anybody else anything. You can learn from what I say. 75 00:07:26,890 --> 00:07:30,520 There's nothing I can do to make you understand the concept

of validity. 76 00:07:30,520 --> 00:07:37,450 You've got to put that effort in for yourself. One thing I will promise you, though, if you do put that effort in, you will understand. 77 00:07:37,450 --> 00:07:39,880 And if you still don't, after putting a lot of effort. 78 00:07:39,880 --> 00:07:47,890 Email me and I'll give you a tutorial all on your own, because it really is easy to understand once you've seen it. 79 00:07:47,890 --> 00:07:52,610 And it really is just a question of looking at it in a slightly different way. 80 00:07:52,610 --> 00:07:59,470 And I and you'll see it. It's it's one of those rather irritating things you'll probably remember from maths, from school. 81 00:07:59,470 --> 00:08:04,690 Okay. So fallacy of fast talking. But the list of fallacies is down there. 82 00:08:04,690 --> 00:08:08,830 Just for your amusement. Okay. 83 00:08:08,830 --> 00:08:13,000 Here's a fallacy or rather his deductively valid argument. 84 00:08:13,000 --> 00:08:18,580 And here's a fallacy that looks like it. Okay. Here's an example of modus opponents. 85 00:08:18,580 --> 00:08:23,320 You've come across before. I think you'll agree. Could these be true? 86 00:08:23,320 --> 00:08:32,070 And this one false. If these two are true, could this be false? 87 00:08:32,070 --> 00:08:33,420 No, absolutely not. 88 00:08:33,420 --> 00:08:43,350 So if you negated that conclusion and took away the therefore, if you negated that conclusion, the set would be inconsistent, wouldn't it? 89 00:08:43,350 --> 00:08:48,390 And that shows you it's a valid argument. Would you like us to do that there? 90 00:08:48,390 --> 00:08:59,110 We can look at this counterexamples set if it is snowing the male. 91 00:08:59,110 --> 00:09:06,750 We'll be late. It is snowing. 92 00:09:06,750 --> 00:09:17,190 The mail will be late and we're going to tack on it's not the case that which is just that symbol there. 93 00:09:17,190 --> 00:09:25,020 OK. That's what that means. It is not the case that so we've got the set consisting of if it's snowing, the mail will be late. 94 00:09:25,020 --> 00:09:28,710 It is snowing. It's not the case. The mail will be late. 95 00:09:28,710 --> 00:09:38,720 Do you agree that's inconsistent, that there is no possible situation in which all those three sentences can be true together? 96 00:09:38,720 --> 00:09:50,700 Okay, well, if there's no possible situation in which those three sentences can be true together, then the set consisting of the premises plus the. 97 00:09:50,700 --> 00:09:55,160 Sorry, there's no possible situation where the premises are true and the conclusion is false. 98 00:09:55,160 --> 00:09:59,630 Is that because that's what the counterexample set is? The truth? 99 00:09:59,630 --> 00:10:04,930 The premises, just as they are and the negation of the conclusion. OK. 100 00:10:04,930 --> 00:10:10,150 That's why that test works. But look at this one. If it's snowing, the mail will be late. 101 00:10:10,150 --> 00:10:16,240 The mail will be late. Therefore, it's snowing. Let's create the counterexamples set of that. 102 00:10:16,240 --> 00:10:25,490 So tell me what to write. Somebody. If it's snowing. 103 00:10:25,490 --> 00:10:30,940 The male. We'll be late. 104 00:10:30,940 --> 00:10:38,710 What do I write next? The mail will be late. 105 00:10:38,710 --> 00:10:44,380 No, we don't put the therefore in because we're creating the counterexample set now, we're just making a set of sentences. 106 00:10:44,380 --> 00:10:52,960 So I'm putting it is snowing. And then what do I do? I put the negation sign in front of that and say it's not the case. 107 00:10:52,960 --> 00:10:58,750 It's no. So we've now got the set consisting of the premises just as they are. 108 00:10:58,750 --> 00:11:02,950 Plus, we're pretending the conclusion is false. Okay. 109 00:11:02,950 --> 00:11:11,950 We're putting in not the case in front of the conclusion. Pretending it's false now is that it could these sentences be true together? 110 00:11:11,950 --> 00:11:16,300 Is there a possible situation in which all these sentences are true? 111 00:11:16,300 --> 00:11:23,260 Where if it's snowing, the mail will be late. The mail is late, but it's not snowing. 112 00:11:23,260 --> 00:11:27,590 Yes. Okay. Give me a couple. The postal strike. 113 00:11:27,590 --> 00:11:34,460 Yes, exactly, so, OK. Give me another one, if you can think of one. 114 00:11:34,460 --> 00:11:40,700 The male van's broken down. Exactly. So there are all sorts of situations in which these two premises are true. 115 00:11:40,700 --> 00:11:48,680 And so is the negation of the conclusion. Therefore, it's obvious there's more than one possible situation in which the premises are true. 116 00:11:48,680 --> 00:11:58,340 And the conclusion is false. So making a counterexample set enables you to think about situations where the premises are true. 117 00:11:58,340 --> 00:12:04,670 And the conclusion is false. And that's why it tells you whether the argument is valid or not. 118 00:12:04,670 --> 00:12:08,900 So this is a deductively valid argument and this is a fallacy. 119 00:12:08,900 --> 00:12:13,530 This is the fallacy of affirming the consequence. So if you like, 120 00:12:13,530 --> 00:12:20,180 you take the consequence of the conditional instead of the antecedent and you put 121 00:12:20,180 --> 00:12:25,020 that as the second premise and then derive the antecedent instead of the consequent. 122 00:12:25,020 --> 00:12:30,680 And it doesn't work, as you can see. Okay, so that's a formal fallacy. 123 00:12:30,680 --> 00:12:37,790 And we're going to look at fallacies informally and some of the fallacies that we'll look at are actually formal fallacies. 124 00:12:37,790 --> 00:12:42,980 But I'll talk about them informally because it's it's just as easy for you to understand. 125 00:12:42,980 --> 00:12:46,040 Okay. We're going to have a look at three types of fallacy. 126 00:12:46,040 -->

00:12:52,970 We're going to look at fallacies of relevance, parliament, the fallacies of vacuity and fallacies of clarity. 127 00:12:52,970 --> 00:12:56,210 And even then, we're just skimming the surface. OK. 128 00:12:56,210 --> 00:13:02,400 So let's look at fallacies of relevance. The first one is a non sequitur. 129 00:13:02,400 --> 00:13:14,450 And you you commit a fallacy of non sequitur when you cite in support of a conclusion, something that's true but irrelevant. 130 00:13:14,450 --> 00:13:18,860 Okay. So you cite in support of a conclusive one of your premises. 131 00:13:18,860 --> 00:13:23,480 It's true. So that's fine. But it's irrelevant to the conclusion. 132 00:13:23,480 --> 00:13:28,940 Now, you might be a bit worried about this, but let me just give you an example of non sequiturs. 133 00:13:28,940 --> 00:13:33,290 That will be obviously non sequiturs. Bill lives in a large building. 134 00:13:33,290 --> 00:13:43,320 Therefore, his apartment is large. OK. Is there any situation in which this premise is true and this conclusion false? 135 00:13:43,320 --> 00:13:50,930 Hundreds of. Yeah. I mean, he may live in a large apartment, large building, but his apartment may be no bigger than a broom cupboard. 136 00:13:50,930 --> 00:14:00,480 But it's so you can see that that isn't a valid argument. And the reason it isn't is because the premise it doesn't matter how true the premises. 137 00:14:00,480 --> 00:14:07,830 It's completely irrelevant to the conclusion, isn't it? You cannot derive the truth of the conclusion from the truth of that premise. 138 00:14:07,830 --> 00:14:14,400 Now, I can imagine that you're thinking, well, what about those paradoxes of entailment then? 139 00:14:14,400 --> 00:14:23,310 Surely that was a case, a paradigm MATTICK case of irrelevance. 140 00:14:23,310 --> 00:14:34,680 You remember I had grass is green there, therefore two plus two equals four. 141 00:14:34,680 --> 00:14:40,440 Okay, now, surely that premise is irrelevant to the conclusion. 142 00:14:40,440 --> 00:14:49,980 But let me ask again. Is there any possible situation in which that premise is true and that conclusion is false? 143 00:14:49,980 --> 00:14:57,830 Is that any possible situation? Let me ask again in which that premise is true and that conclusion false. 144 00:14:57,830 --> 00:15:05,560 Why not? You're right, there isn't. But why isn't the. We saw here that this premise can be true and that conclusion false. 145 00:15:05,560 --> 00:15:09,840 Can't we? That's that's not a problem. That is a non sequitur. 146 00:15:09,840 --> 00:15:13,230 Commits the fallacy of irrelevance. But why do it? 147 00:15:13,230 --> 00:15:20,170 Doesn't this one do that? That's right, Don. 148 00:15:20,170 --> 00:15:27,150 This conclusion is. Well, no, there's not one. 149 00:15:27,150 --> 00:15:33,330 I mean, that's that's what's wrong with this one is that the premise and the conclusion are completely irrelevant to each other, aren't they? 150 00:15:33,330 --> 00:15:40,320 So so why isn't that a problem with this one? The conclusion is necessarily true. 151 00:15:40,320 --> 00:15:48,060 That's right. So so the reason this is a paradox is that the premise is completely irrelevant to the conclusion, 152 00:15:48,060 --> 00:15:57,390 but it satisfies the definition of validity because there can't be any possible situation in which the premise is true and the conclusion false. 153 00:15:57,390 --> 00:16:07,810 If there isn't any possible situation in which the conclusions false. How can P and Q be true if Q isn't true? 154 00:16:07,810 --> 00:16:13,030 If CU is necessarily false, then how can P and Q be true? 155 00:16:13,030 --> 00:16:17,410 The truth of P just becomes irrelevant, doesn't it? 156 00:16:17,410 --> 00:16:21,670 The truth appears is just unnecessary to the whole claim. 157 00:16:21,670 --> 00:16:26,670 Are you with me? I'm seeing lights sort of going on here, but it's difficult, isn't it? 158 00:16:26,670 --> 00:16:34,570 Okay, so this commits the. This is a non sequitur, whereas that's not that's a case of of of a paradox, of entailment. 159 00:16:34,570 --> 00:16:38,980 And the difference between them is that two plus two equals four is a necessary truth. 160 00:16:38,980 --> 00:16:43,780 It cannot be false. So how could the premise be true? And the conclusion false. 161 00:16:43,780 --> 00:16:49,930 But if it can't be the case that the premise is true and the conclusion false, then it satisfies the definition of validity. 162 00:16:49,930 --> 00:16:54,250 Whereas this doesn't. Okay, here's another non sequitur. 163 00:16:54,250 --> 00:16:58,480 Every year many people are supported through like life by their religious beliefs. 164 00:16:58,480 --> 00:17:06,980 Therefore, their religious beliefs must be true. Okay. Does that premise give any support at all to that conclusion? 165 00:17:06,980 --> 00:17:11,690 No, I mean, perhaps your religious beliefs really do help you live a good life. 166 00:17:11,690 --> 00:17:18,770 Live a life that's satisfying to you, too. That doesn't necessarily mean they're true because false beliefs. 167 00:17:18,770 --> 00:17:24,680 If you believe false beliefs are true, they're going to give you everything that they would give you if they were true. 168 00:17:24,680 --> 00:17:26,500 If you see what I mean. OK. 169 00:17:26,500 --> 00:17:37,310 So those are two non sequiturs and we can see why a non sequitur is an invalid argument, that there's easily a possible situation, which. 170 00:17:37,310 --> 00:17:45,800 That's true and that's false. Therefore, it's not valid. Again, the truth of that bears no relation to the truth of that. 171 00:17:45,800 --> 00:17:50,890 So, again, the two arguments are not valid. Okay. 172 00:17:50,890 --> 00:17:56,830 What? How to arguments like this work? I mean, one of the things we've got to work with for ever falling for fallacies. 173 00:17:56,830 --> 00:18:00,040 I mean, we

we argue incorrectly. 174 00:18:00,040 --> 00:18:08,600 We either make fallacies, we argue fallacious, Leigh ourselves, or we fall for the flat fallacies that other people offer us. 175 00:18:08,600 --> 00:18:11,650 How do I talk to you about the principle of charity? 176 00:18:11,650 --> 00:18:20,910 The principle of charity tells you that your interlocutor's silliness is less likely than your bad interpretation. 177 00:18:20,910 --> 00:18:28,590 Okay. What does that mean? Okay. What's your name? I just think it the lady in front with a nice necklace. 178 00:18:28,590 --> 00:18:34,570 You've probably got nice necklace too. Okay. Margaret. Margaret and I are arguing. 179 00:18:34,570 --> 00:18:39,820 Margaret says something that I think is blindingly obviously stupid. 180 00:18:39,820 --> 00:18:45,250 Okay. Now I've got two possibilities. I can think Margaret's just said something blindingly, obviously stupid. 181 00:18:45,250 --> 00:18:55,570 I'm not going to talk to her anymore. You know, she's obviously not worth talking to because she said not P was surely P is obvious. 182 00:18:55,570 --> 00:19:01,570 Now, what the principle of charity tells me to do in that case is to say, well, that's interesting. 183 00:19:01,570 --> 00:19:06,730 Margaret says, not P. I think not. P is definitely false. 184 00:19:06,730 --> 00:19:15,730 Therefore, I must have misunderstood Margaret because her silliness is far less likely than my misunderstanding. 185 00:19:15,730 --> 00:19:23,210 Her argument. Are you with me? Okay. So instead of saying to Margaret, you must be joking. 186 00:19:23,210 --> 00:19:28,000 Oh, stupid. Can you get. Or anything like that. Or just saying to myself how. 187 00:19:28,000 --> 00:19:31,420 Right. Okay. Thanks, Margaret. Nice to see you. Etc. 188 00:19:31,420 --> 00:19:36,430 And walking off I say to Margaret. That's interesting. You think not pee. 189 00:19:36,430 --> 00:19:42,490 I think pee. Why do you think not pee? And you give me your reasons and I give you read my reasons for thinking whoopee. 190 00:19:42,490 --> 00:19:46,520 And we have a proper argument. We discover actually that pee and not pee. 191 00:19:46,520 --> 00:19:51,340 Not in this case inconsistent. And that we've both got a slight misunderstanding. 192 00:19:51,340 --> 00:19:55,590 Let me give you an example. I don't know why use this example, but I always do. 193 00:19:55,590 --> 00:20:01,870 So I'm going to do it again. Two rats in a cage. They both come from different cages. 194 00:20:01,870 --> 00:20:09,490 And in one of those cages, one of the rats was given an electric shock every time a certain sound was made. 195 00:20:09,490 --> 00:20:15,030 The same sound was resulted in the other rats being given a food pellet. 196 00:20:15,030 --> 00:20:21,250 Okay, so the experiments are finished. They've now been put in the same cage and this sound happens. 197 00:20:21,250 --> 00:20:27,370 Sounds. Sounds. Now, what's going to happen? One

rat is going to rush, shaking into the corner of the cage, waiting for an electric shock. 198 00:20:27,370 --> 00:20:32,070 And the other rat is going to be rushing up to the food bowl looking for food. Isn't it? 199 00:20:32,070 --> 00:20:36,670 Okay. And then they look at each other and think, you're mad. 200 00:20:36,670 --> 00:20:43,070 You know, why have you done that? What they if they were talking to this, I don't know. 201 00:20:43,070 --> 00:20:44,680 I had some I use this example. 202 00:20:44,680 --> 00:20:52,000 If they were able to talk to each other, they would then discover that actually they both overgeneralise, too, didn't they? 203 00:20:52,000 --> 00:20:56,890 Because one's experience was that whenever that this and the other's experience was 204 00:20:56,890 --> 00:21:03,040 whenever that that they assumed that's all they experienced there was in the world. 205 00:21:03,040 --> 00:21:09,220 And in fact, they've now got two counterexamples. That one is there in a cage where the sound goes off, nothing happens. 206 00:21:09,220 --> 00:21:14,710 And the other is that there are places in the world where something completely different happens. 207 00:21:14,710 --> 00:21:19,570 And it's only if they talk about it that they'll discover that. 208 00:21:19,570 --> 00:21:26,590 So arguing is the life blood of of cooperating in the search for truth. 209 00:21:26,590 --> 00:21:31,450 If you want to know what the truth is, you cooperate with other rational animals. 210 00:21:31,450 --> 00:21:38,500 In other words, other people like us. And if you find that there's a constant contradiction. 211 00:21:38,500 --> 00:21:45,940 Don't assume that the other person is wrong, because the only rational thing to assume is that one of you is wrong. 212 00:21:45,940 --> 00:21:49,480 And even that might be false. But it certainly might be you. 213 00:21:49,480 --> 00:21:56,560 And it's the principle of charity that you observe when you argue in order not to do the irrational 214 00:21:56,560 --> 00:22:02,830 thing and to assume that the other person is wrong rather than assume that you've misunderstood them. 215 00:22:02,830 --> 00:22:10,240 So that's what the principle of charity is. And what happens in this case and in the case of non sequiturs is that the principle of charity 216 00:22:10,240 --> 00:22:17,770 can take you get you into the wrong place because you might not notice the irrelevance. 217 00:22:17,770 --> 00:22:22,150 I mean, that that can happen if, for example, large apartment, large building. 218 00:22:22,150 --> 00:22:27,640 You might think the two large is there is enough to make it relevant and you'll let the argument go through. 219 00:22:27,640 --> 00:22:37,040 You wouldn't be right to do that. But it maybe is understandable. But sometimes when people are arguing, you might think, well, hang on. 220 00:22:37,040 --> 00:22:38,420 I'm sure that was irrelevant. 221 00:22:38,420 --> 00:22:45,320 But it can't have been because Margaret's too rational for it to allow and the relevance to go through non sequitur like that, 222 00:22:45,320 --> 00:22:50,540 or you might just want to not be not admit that you can't see the connexion. 223 00:22:50,540 --> 00:22:57,380 So the thing to do is to be aware that there should be an just in any conversation. 224 00:22:57,380 --> 00:23:03,380 The implication is that there's a connexion between premises in conclusion, like the sea as it's assault. 225 00:23:03,380 --> 00:23:09,110 Melbourne's in Australia. When I gave you the context, you could see the connexion. 226 00:23:09,110 --> 00:23:15,740 So if you can't see the connexion, ask for it. So don't be too generous. 227 00:23:15,740 --> 00:23:22,940 Because it's possible that this person is putting forward a non sequitur. And certainly don't be too proud to ask for the relevance. 228 00:23:22,940 --> 00:23:27,380 If you can't see it. OK. Here's an ad. 229 00:23:27,380 --> 00:23:32,270 So this is the second fallacy of relevance. 230 00:23:32,270 --> 00:23:37,430 So the second one is attacking the person is the second one we're looking at. There are many more than this. 231 00:23:37,430 --> 00:23:42,140 You might attack the person making the arguments rather than the argument that's made. 232 00:23:42,140 --> 00:23:48,840 And this is called an ad hominem fallacy. And you may have heard. 233 00:23:48,840 --> 00:23:57,430 Was it Miliband? On the Today programme the other day talking. 234 00:23:57,430 --> 00:24:04,120 Now, who was he talking to, talking to William Hague. And he accused William Hague of an ad hominem fallacy. 235 00:24:04,120 --> 00:24:12,970 He said, you're arguing against the man, not against the arguments on your your stopping the man, not the ball or something. 236 00:24:12,970 --> 00:24:18,580 He said it was a very good example. OK. Here's an ad hominem fallacy. 237 00:24:18,580 --> 00:24:25,330 Nick Griffin is leader of the BNP. Therefore, his claim that some people worry about immigration is rubbish. 238 00:24:25,330 --> 00:24:30,370 Now, I actually heard that fallacy loud and clear the other night on Question Time. 239 00:24:30,370 --> 00:24:42,040 I'm sure you did, too. Does the truth of the fact that Nick Griffin is leader of the BNP bear at all on the claim? 240 00:24:42,040 --> 00:24:47,320 The truth of the claim that some people worry about immigration. 241 00:24:47,320 --> 00:24:52,650 And it could it be the case that Nick Griffin is leader of the BNP and some people worry about it? 242 00:24:52,650 --> 00:24:56,560 Immigration. Of course it could, couldn't it? 243 00:24:56,560 --> 00:25:00,630 Yes. OK. Here's another one. Von Danskin I think you may not even remember him. 244 00:25:00,630 --> 00:25:06,810 He was the chap who wrote books about people coming from space and building the pyramids and so on. 245 00:25:06,810 --> 00:25:12,460 And these books about ancient astronauts are worthless because he's a convicted

forger and embezzler. 246 00:25:12,460 --> 00:25:18,800 Now he is actually a convicted for forger, an embezzler. Does that mean that his books are worthless? 247 00:25:18,800 --> 00:25:26,160 OK, so could this premise be true and this conclusion false? 248 00:25:26,160 --> 00:25:34,960 Yes. Could this premise be true? The conclusion false. So the arguments he uses, aren't they, they're both invalid. 249 00:25:34,960 --> 00:25:38,740 There are possible situations in which the premise is true, inclusion, false. 250 00:25:38,740 --> 00:25:40,990 They're not good arguments. 251 00:25:40,990 --> 00:25:50,170 Now, it's very important when thinking about ad hominem fallacies to distinguish between ad hominem attacks and ad hominem fallacies. 252 00:25:50,170 --> 00:25:55,150 And the difference between the two is this. You can attack somebody is right to say something. 253 00:25:55,150 --> 00:26:04,520 So you can cast doubt on on why they're saying what they're saying by saying something about who they are. 254 00:26:04,520 --> 00:26:09,250 And what you can't do is cast doubt on the truth of what they're saying. 255 00:26:09,250 --> 00:26:14,440 So here's a difference. The difference between the two. Here's the ad hominem attack. 256 00:26:14,440 --> 00:26:20,170 Nick Griffin is a self professed racist. So you should take care when listening to his claims about immigration. 257 00:26:20,170 --> 00:26:24,460 Now, that just seems sensible, doesn't it? That's an ad hominem attack. 258 00:26:24,460 --> 00:26:33,520 That's not a fallacy at all. All you're doing is warning somebody that this person has a vested interest in making you believe something. 259 00:26:33,520 --> 00:26:38,740 So you should take his claims with an extra pinch of salt. 260 00:26:38,740 --> 00:26:42,670 But it doesn't say anything about the truth of the claim. 261 00:26:42,670 --> 00:26:47,040 So here. Well, the only thing it says about the truth of the claim is, 262 00:26:47,040 --> 00:26:54,010 is that you should be aware of the truth of train claim because this person wants you to believe that. 263 00:26:54,010 --> 00:26:59,350 And of course, that's not a good enough reason for believing it. Nick Griffin is leader of the BNP. 264 00:26:59,350 --> 00:27:04,910 Therefore, his claim that some people worry about immigration is rubbish. That is a fallacy. 265 00:27:04,910 --> 00:27:13,940 If you attack a person instead of what he says and your attack on the person is actually irrelevant to the truth of what he says, 266 00:27:13,940 --> 00:27:17,450 in other words, your attack might be a correct attack. 267 00:27:17,450 --> 00:27:23,030 You're not saying something false about this person. But the truth of what you're saying bears. 268 00:27:23,030 --> 00:27:27,380 No has no bearing at all on the truth of what he is saying. 269 00:27:27,380 --> 00:27:35,550 That's a fallacy. What do you what you could be saying is warning somebody so so. 270 00:27:35,550 --> 00:27:44,910 I've gotten your name again. Ashley comes to me and tells me that, oh, so-and-so came and told her that the coffee's ready in the common room. 271 00:27:44,910 --> 00:27:51,420 And I say, yes, but I know why he told you that. That's because he likes everyone else to go to the common room first and then discover 272 00:27:51,420 --> 00:27:56,580 it's actually being served upstairs today and he gets all the chocolate biscuits. 273 00:27:56,580 --> 00:28:04,580 I mean that when I'm doing that, I'm giving her a reason for why he said something. 274 00:28:04,580 --> 00:28:12,240 It doesn't actually bear on the truth of what, sir, but is a good reason not to be sceptical about whether the coffees being in the common room. 275 00:28:12,240 --> 00:28:17,940 You'd want to cheque with someone else that the coffee was in the common room before you went there, perhaps. 276 00:28:17,940 --> 00:28:18,030 Well, 277 00:28:18,030 --> 00:28:27,070 you wouldn't come down from you at house in order to get coffee from the common room on the basis of what Ashley said or what what this person said. 278 00:28:27,070 --> 00:28:32,180 Okay, so that's the difference between ad hominem. So I don't know if that's answered your question. 279 00:28:32,180 --> 00:28:39,430 Yeah, I mean, an ad hominem is an attack on the person making an argument, not on the arguments he's making. 280 00:28:39,430 --> 00:28:49,440 And therefore, the attack, even if they attack, is justified. It doesn't question the argument itself. 281 00:28:49,440 --> 00:28:55,620 So those were fallacies of relevance. Now moving on to fallacies of vacuity. 282 00:28:55,620 --> 00:28:59,080 OK, the first one is a circular arguments that we'll be looking at. 283 00:28:59,080 --> 00:29:05,010 What do you when you argue in a circle, you, Supai, sort cite in support of a conclusion? 284 00:29:05,010 --> 00:29:13,570 That's a very conclusion. So your premise or your conclusion is amongst your premises here? 285 00:29:13,570 --> 00:29:18,270 A second fallacy we're looking at here is the fallacy of question begging. 286 00:29:18,270 --> 00:29:26,550 And thirdly, a self sealing argument. So let's start with circular arguments, then come back and look at these again, a circular argument. 287 00:29:26,550 --> 00:29:29,430 The conclusion is one of the premises. 288 00:29:29,430 --> 00:29:38,070 And the difference between that and a question begging argument is that here the conclusion actually is one of the premises, exactly the same thing. 289 00:29:38,070 --> 00:29:41,710 And here the conclusion is assumed by one of the premises. 290 00:29:41,710 --> 00:29:49,560 You haven't actually got the conclusion amongst the premises, but you've got amongst the premises of a premise that assumes the conclusion. 291 00:29:49,560 --> 00:29:53,220 So here's an example of a circular argument. All whales are mammals. 292 00:29:53,220 --> 00:30:00,100 Therefore, all whales are mammals. Now, that

argument valid. 293 00:30:00,100 --> 00:30:04,240 Well done. You're absolutely right, it is valid. All circular arguments valid. 294 00:30:04,240 --> 00:30:09,160 How could there be a possible situation? That's true. And that's false. 295 00:30:09,160 --> 00:30:13,720 If they're the same thing. If that's true, that's got to be true, hasn't it? 296 00:30:13,720 --> 00:30:17,710 So there's no possible situation in which that's true and that's false. 297 00:30:17,710 --> 00:30:23,590 Therefore, that argument is valid. So circular arguments are always valid. 298 00:30:23,590 --> 00:30:28,750 And what that tells you is that there's got to be more to a good argument than the validity. 299 00:30:28,750 --> 00:30:32,770 And what's more true premises, because this is actually a true premise as well. 300 00:30:32,770 --> 00:30:37,270 So that's a sound argument, but it's not very good, is it? 301 00:30:37,270 --> 00:30:43,990 It wouldn't convince anybody of anything. But do you remember last week I got myself into a bit of a tangle by trying to 302 00:30:43,990 --> 00:30:48,460 draw truth tables on here and convince you that once you've got a premise, 303 00:30:48,460 --> 00:30:56,050 once you've got a conclusion in amongst the premises, it doesn't matter what you add to the argument, it remains valid. 304 00:30:56,050 --> 00:31:00,750 This is called the monotonic property of entailment. 305 00:31:00,750 --> 00:31:09,430 And if I had lots of other premises, too, that the circularity will no longer be as obvious as it is now, will it? 306 00:31:09,430 --> 00:31:13,450 But actually, you are validity detected. That's what you are. 307 00:31:13,450 --> 00:31:21,580 Virtue of being rational animals. So somebody stands up in parliament and gives a circular argument that's long and convoluted and so on. 308 00:31:21,580 --> 00:31:24,790 It's a valid argument. And you hear that. 309 00:31:24,790 --> 00:31:30,250 You can tell that it's a valid argument that there is no possible situation where the premises are true and the conclusion false. 310 00:31:30,250 --> 00:31:35,200 But what you don't see is that it's only valid because it's circular. 311 00:31:35,200 --> 00:31:41,210 Do you see how it happens so nobody would put forward an argument like that. 312 00:31:41,210 --> 00:31:47,240 But if they embed that premise in with the story, that conclusion in with the premises, 313 00:31:47,240 --> 00:31:54,440 they've set up a situation in which there's no possible situation where all the premises are true and the conclusion false. 314 00:31:54,440 --> 00:31:58,430 How could that be? Because it doesn't matter what other premises are there. 315 00:31:58,430 --> 00:32:05,420 If all the premises are true, the conclusion must be true as well, because the conclusion is one of the premises. 316 00:32:05,420 --> 00:32:12,470 So circular arguments are always valid and some secular arguments like this one are sound. 317 00:32:12,470 --> 00:32:20,230 But that doesn't make them good. There must be more to a valid argument. Sorry to a good argument and just soundness. 318 00:32:20,230 --> 00:32:25,700 In the final analysis, the point of an argument is to persuade someone of something. 319 00:32:25,700 --> 00:32:34,940 So it's to persuade you. If you don't believe me, and I think you should believe me, I think peer's true and therefore you should believe it. 320 00:32:34,940 --> 00:32:39,650 I put together an argument in the hope of convincing you that P. Okay. 321 00:32:39,650 --> 00:32:45,550 So what I want from an argument more than anything else is that it should be persuasive. 322 00:32:45,550 --> 00:32:50,470 Okay, but I don't want it to be persuasive because of a fallacy. 323 00:32:50,470 --> 00:32:57,360 I actually wanted to be a good arguments as well. And therefore, I want it to be sound and valid. 324 00:32:57,360 --> 00:33:06,370 But if it sounds valid, not persuasive. It's pretty useless for any practical purpose. 325 00:33:06,370 --> 00:33:11,770 So you actually you can't have a productive argument with somebody unless you agree with them. 326 00:33:11,770 --> 00:33:17,140 Didn't anyone tell me why that might be the case? Productive disagreement. 327 00:33:17,140 --> 00:33:26,350 Always depends on on agreement. Which is why if you've really got two sides who absolutely disagree on everything. 328 00:33:26,350 --> 00:33:33,780 You may as well forget it. Why should. Productive disagreements depends on agreement. 329 00:33:33,780 --> 00:33:37,140 I can only argue with you if you're prepared to accept my premises. 330 00:33:37,140 --> 00:33:44,400 If you reject my premises, then then I can't draw anything from those premises that's going to convince you of anything. 331 00:33:44,400 --> 00:33:51,470 Can I? So I've got to convince you of at least one of my premises before we can even get started. 332 00:33:51,470 --> 00:34:00,990 And of course, what I might do is say, will you agree to take this for the sake of argument and then take you through the arguments. 333 00:34:00,990 --> 00:34:07,530 But of course, if you still don't accept the premise, really, you know, you're never actually going to accept the conclusion of my argument, are you? 334 00:34:07,530 --> 00:34:13,380 So in order to disagree productively, you've got to agree on something. 335 00:34:13,380 --> 00:34:20,960 You've got to agree on the premises. Okay, so that's a circular argument and it's a valid one, 336 00:34:20,960 --> 00:34:29,870 but it's no good and it's no good because there's no possible situation which the premise is true and the conclusion false. 337 00:34:29,870 --> 00:34:37,200 But that's because the conclusion is amongst the premises. OK, let's look at begging the question. 338 00:34:37,200 --> 00:34:44,130 Here's an argument. It's always wrong to murder human beings. Capital punishment involves murdering human beings. 339 00:34:44,130 --> 00:34:51,370 Therefore, capital punishment is

wrong. What s question begging about this argument is. 340 00:34:51,370 --> 00:34:57,070 Exactly. This, too, to talk about capital punishment as if it were murder. 341 00:34:57,070 --> 00:35:02,930 Just to assume that capital punishment is murder is to assume your conclusion, isn't it? 342 00:35:02,930 --> 00:35:09,160 Most people say that actually capital punishment isn't murder because murder is illegal killing, 343 00:35:09,160 --> 00:35:14,710 whereas capital punishment is legal killing, isn't it? Judicial killing. 344 00:35:14,710 --> 00:35:22,870 So by talking as if capital punishment to murdering human beings are interchangeable here. 345 00:35:22,870 --> 00:35:26,530 You're actually begging the question, aren't you? You're begging the question. 346 00:35:26,530 --> 00:35:33,820 Well, hang on a second. You know that. Why should I believe capital punishment is wrong on the basis of these two premises? 347 00:35:33,820 --> 00:35:38,820 I do not accept that one at all. Because you're just assuming your conclusion here. 348 00:35:38,820 --> 00:35:41,030 You with me. 349 00:35:41,030 --> 00:35:50,070 So so when you say that an argument is a fallacy, you're not necessarily saying it's invalid, but you are saying there's something wrong with it. 350 00:35:50,070 --> 00:35:55,080 There's something wrong that means it's not persuasive. It shouldn't persuade you. 351 00:35:55,080 --> 00:36:04,490 Often that'll be the case because it's invalid, but not always. And certainly with cases of circularity and question begging, that isn't the case. 352 00:36:04,490 --> 00:36:08,590 OK. Any other question? We'll move on. 353 00:36:08,590 --> 00:36:15,010 Okay, let's. Okay. Where are the question begging premises in each of the following arguments? 354 00:36:15,010 --> 00:36:22,720 Let's do it. So intoxication. Intoxicated beverages should be banned because they make people drunk. 355 00:36:22,720 --> 00:36:28,060 Let's set out the arduous logic bookstall. Before we do that, we might need to suppress Froese. 356 00:36:28,060 --> 00:36:34,920 So what's the argument here? Think about it for yourself and then put your hands up when you when you've put out the argument. 357 00:36:34,920 --> 00:36:43,520 Logic books style. Yes, being drunk is bad or something like that, or beverages that make people drunk should be bad. 358 00:36:43,520 --> 00:36:48,260 That's probably the right one. Beverages that make people drunk should be bad. Should be banned. 359 00:36:48,260 --> 00:36:53,480 Intoxicated beverages, beverages make people drunk. Therefore, intoxicating beverages should be banned. 360 00:36:53,480 --> 00:36:59,430 What's the question? Begging bit. Which premise would you reject? 361 00:36:59,430 --> 00:37:03,840 You couldn't have a beverage that's intoxicating without having a beverage that would make 362 00:37:03,840 --> 00:37:08,550 you drunk because an intoxicating beverage is exactly a beverage that makes you drunk, 363 00:37:08,550

--> 00:37:19,620 isn't it? The fact is you're not going to be able to reject that argument because it's it's assuming its conclusion in its premises. 364 00:37:19,620 --> 00:37:24,600 So beverages that make people drunk should be banned. 365 00:37:24,600 --> 00:37:32,040 Intoxicating beverages make people drunk. Therefore, intoxicating beverages should be banned. 366 00:37:32,040 --> 00:37:38,430 It's a valid argument, but it's not ever going to persuade you. Well, let's go back to this one. 367 00:37:38,430 --> 00:37:42,630 Let's go back to can you can you see that? 368 00:37:42,630 --> 00:37:51,240 Now, you might be for capital punishment or against it, but anyone who made this argument is clearly against capital punishment, aren't they? 369 00:37:51,240 --> 00:38:01,320 Okay, so they would be making the argument in order to try and persuade someone who's for capital punishment or neutral either way, 370 00:38:01,320 --> 00:38:06,930 to agree with them that capital punishment is wrong. Right. OK. 371 00:38:06,930 --> 00:38:16,650 And the problem with the argument they offer is that it's not going to convince anyone who isn't already convinced of the argument. 372 00:38:16,650 --> 00:38:21,660 Is it because I might say I'm against capital punishment? 373 00:38:21,660 --> 00:38:26,760 Sorry, I'm no, I'm for capital punishment. I might accept that premise. 374 00:38:26,760 --> 00:38:32,040 There's a that's our starting point of agreement. But as soon as we get to that one, I'm going to say what? 375 00:38:32,040 --> 00:38:39,270 Hang on. No. Why? Why should I accept that you're assuming that capital punishment is wrong in making that premise. 376 00:38:39,270 --> 00:38:45,060 You know, if you change that premise to capital punishment involves killing human beings, that's fine. 377 00:38:45,060 --> 00:38:51,660 But then your argument isn't valid. The only way you make your argument valid is by putting murdering in. 378 00:38:51,660 --> 00:38:56,330 And then it's valid because it begs the question. OK. 379 00:38:56,330 --> 00:39:02,580 And therefore, it's not persuasive. So in exactly the same way. 380 00:39:02,580 --> 00:39:07,040 If somebody was making this argument, say, I didn't believe whales were mammals. 381 00:39:07,040 --> 00:39:14,520 I thought whales were fish, whales, obviously fish, aren't they? I mean, we've discussed this before. 382 00:39:14,520 --> 00:39:20,250 Anyway. They tell me whales are mammals. Okay, so I don't believe whales are mammals. 383 00:39:20,250 --> 00:39:26,070 And you're trying to convince me if you offer me this argument and say, well, here's a good argument. 384 00:39:26,070 --> 00:39:31,530 Whales being mammals, I would say, no, no, that's not a good argument. 385 00:39:31,530 --> 00:39:38,760 Why should I agree with you on that premise? In that premise, you're just assuming your answer the obvious or your conclusion. 386 00:39:38,760 --> 00:39:45,260 So you've got a valid argument, but it's hopelessly unpersuasive. Therefore, it's not a good argument. 387 00:39:45,260 --> 00:39:54,960 And this one is only slightly difference in that instead of the the premise actually being the same as the conclusion. 388 00:39:54,960 --> 00:39:57,750 The premise assumes the conclusion. 389 00:39:57,750 --> 00:40:06,640 So if I actually if I'm if you're arguing using this argument against me, it's not going to persuade me of anything, is it? 390 00:40:06,640 --> 00:40:13,350 And that's what's wrong with it. Not that it's not a valid. So we're looking at fallacies of vacuity. 391 00:40:13,350 --> 00:40:17,600 OK? We've looked at fallacies of relevance. We're now looking at fallacies of vacuity. 392 00:40:17,600 --> 00:40:25,190 And we've looked first at circular arguments where the the the conclusion is one of the premises. 393 00:40:25,190 --> 00:40:31,970 Why? Tell me again why that would convince anyone if you've made an argument whether the conclusion is amongst the premises because 394 00:40:31,970 --> 00:40:38,600 it's valid and because the fact that the conclusion is amongst the premises may be hidden amongst all sorts of other premises. 395 00:40:38,600 --> 00:40:42,590 So you just don't notice that the conclusion is there. OK. 396 00:40:42,590 --> 00:40:48,830 Then we looked at question bagging arguments and we tied ourselves in knots or I tied myself in a knot. 397 00:40:48,830 --> 00:40:50,210 But the idea here is this. 398 00:40:50,210 --> 00:40:59,900 Instead of the premise, the conclusion being amongst the premises itself, there is amongst the premises a premise that assumes the conclusion. 399 00:40:59,900 --> 00:41:04,280 That's the difference between those two. And finally, we're going to look at arguments. 400 00:41:04,280 --> 00:41:12,860 This is self sealing, OK, a self sealing argument to today at two forty five, you're going to be doing exactly what you are doing. 401 00:41:12,860 --> 00:41:18,230 Well, it will be a true statement, won't it? I mean, that couldn't be false, could it? 402 00:41:18,230 --> 00:41:22,160 But it's not a persuasive argument. Why not? It's completely vacuous. 403 00:41:22,160 --> 00:41:28,460 It says absolutely nothing doesn't it doesn't give you any prediction. It doesn't limit the possibilities at all. 404 00:41:28,460 --> 00:41:35,010 It just tells you you're going to be doing whatever you're going to be doing, which has to be true, not persuasive. 405 00:41:35,010 --> 00:41:40,280 Here's one that actually lots of people do think is persuasive. We must respect all moral beliefs. 406 00:41:40,280 --> 00:41:50,620 Therefore, relativism is moral. Relativism is true. This is called vulgar relativism by chuckle Bernard Williams, famous philosopher. 407 00:41:50,620 --> 00:41:57,590 And the reason that's a self sealing argument is that is a moral absolute. 408 00:41:57,590 --> 00:42:04,700 We must respect all moral beliefs. You cannot derive moral relativism from a moral

absolute. 409 00:42:04,700 --> 00:42:08,840 If that premise is true, then that conclusion is false. 410 00:42:08,840 --> 00:42:16,280 And if the conclusion is true, the premise is false. So it's it's a bad argument because it goes around in circles. 411 00:42:16,280 --> 00:42:26,070 It's self-defeating, actually self-defeating rather than self sealing. Yes, that's actually should be in a slightly different category. 412 00:42:26,070 --> 00:42:33,450 But here's another one that you may have variants of, it will have caught you out at some point, I'm sure. 413 00:42:33,450 --> 00:42:40,770 Global economy is controlled by Jews and any parents. The country is the result of Jewish cleverness. 414 00:42:40,770 --> 00:42:49,170 Women are stupid. And any appearance to the country is just because they are quite good at covering it over sometimes, you know? 415 00:42:49,170 --> 00:42:55,320 So, again, a self-serving argument because you know that you can't be refuted because whatever happens, 416 00:42:55,320 --> 00:43:00,300 you've got some reason for why what you're saying is is true. 417 00:43:00,300 --> 00:43:05,850 So some self sealing arguments move back and forth from interesting but false claims. 418 00:43:05,850 --> 00:43:11,460 For example, you might say all human beings are selfish. And you won't say, well, hang on, that's not true. 419 00:43:11,460 --> 00:43:15,060 Lots of people are altruistic. They do things for other people. 420 00:43:15,060 --> 00:43:20,580 And then you say, oh, yes, but they still do. It does. They want to. I mean, Mother Teresa. 421 00:43:20,580 --> 00:43:26,460 I mean, she wouldn't have helped all those people. And if she wanted to. And you say she did it out of duty. 422 00:43:26,460 --> 00:43:30,900 And so you say, well, yes, but she wanted to do her duty, didn't she? 423 00:43:30,900 --> 00:43:36,120 I mean, she still wanted to do what she did. So everything she did was what she wanted to do. 424 00:43:36,120 --> 00:43:42,060 So she as selfish as everyone else. And you know what's happening here? 425 00:43:42,060 --> 00:43:49,500 Well, what's happening is that someone's moving from an interesting but false claim to a true but vacuous claim. 426 00:43:49,500 --> 00:43:57,490 And what they'll do is they'll move backwards and forwards between the two until you've got yourself thoroughly tied in a knot. 427 00:43:57,490 --> 00:44:08,920 And what do you need to do is separate, separate out the two claims that are being made and show why one of them is meaningless, even if true? 428 00:44:08,920 --> 00:44:15,730 So three ways that's an argument can be self seat ceiling. It can invent ad hoc ways to dismiss criticism. 429 00:44:15,730 --> 00:44:20,800 So if my prediction didn't work, it's because there are negative vibes in the room. 430 00:44:20,800 --> 00:44:28,930 Okay. You know, it's all your fault. It can attack its critics as unable to see the benefits of the position. 431 00:44:28,930 --> 00:44:34,570 So, you know, the only reason you don't see that the world's being taken over by Jews or women 432 00:44:34,570 --> 00:44:39,940 or or blacks or whatever is because you've been taken in by them or another one. 433 00:44:39,940 --> 00:44:51,430 There is you know, you're in denial. Therefore, you you don't understand what I'm saying about your appalling desires and what have you. 434 00:44:51,430 --> 00:44:59,470 It can also redefine key words. So it's selfish to always be doing just what you wants to do. 435 00:44:59,470 --> 00:45:05,300 Well. It depends what how you interpret just what you want to do there. 436 00:45:05,300 --> 00:45:14,520 If you interpret so you've Mother Teresa was doing just what she wanted to do, then you might need to have another look at what you mean by selfish. 437 00:45:14,520 --> 00:45:19,680 OK. And finally, we're going to look at fallacies of clarity. And I want to lose you some time for questions. 438 00:45:19,680 --> 00:45:33,350 Sorry, you've got a question. Well, on the on this one. 439 00:45:33,350 --> 00:45:40,760 As soon as you have the feeling that you're being moved from between two different propositions, one of which is false. 440 00:45:40,760 --> 00:45:45,620 An interesting and the other is is safe. Ask for time out. 441 00:45:45,620 --> 00:45:50,810 If you can, because that's the only way you're going to do it. And of course, this is what you won't get. 442 00:45:50,810 --> 00:45:57,590 And try and identify what the two propositions are. So in this case, you want to say, OK. 443 00:45:57,590 --> 00:46:03,830 The meaning of selfish is usually isn't interested in what anyone else wants. 444 00:46:03,830 --> 00:46:10,790 In which case, Mother Teresa wouldn't be selfish because she is interested in what other people want. 445 00:46:10,790 --> 00:46:15,530 Then you say, but then your other claim is that somebody is selfish. 446 00:46:15,530 --> 00:46:24,050 Only if they saw some. It's sufficient for being selfish that somebody acts on what they they themselves want. 447 00:46:24,050 --> 00:46:26,580 And actually, that's not usually the definition of self. 448 00:46:26,580 --> 00:46:35,430 So identify the weasel words and get out the two definitions and then show that somebody is flipping between one and the other. 449 00:46:35,430 --> 00:46:43,530 Is the way to do that. Okay, fallacies of the heap. 450 00:46:43,530 --> 00:46:50,110 If you have only one penny, you're not rich. If you're not rich and I give you a penny, then you still won't be rich. 451 00:46:50,110 --> 00:46:54,080 Doesn't matter how many pennies I give you, then you won't be rich. OK. 452 00:46:54,080 --> 00:47:02,600 Is that a good argument? No one knows. 453 00:47:02,600 --> 00:47:06,670 I mean, is that false? No. 454 00:47:06,670 --> 00:47:14,950 OK. Is that false? Is that is not false, is it? 455 00:47:14,950 --> 00:47:18,840 I mean, that's true. If you gave me a penny, sadly, you wouldn't make me

rich. 456 00:47:18,840 --> 00:47:22,690 Sir, fully, you know. OK, so that's true. 457 00:47:22,690 --> 00:47:26,530 And that's true. Is that true? OK. Is this valid? 458 00:47:26,530 --> 00:47:32,960 Is there any possible situation where those two are both true? And this is false? 459 00:47:32,960 --> 00:47:36,970 Yes. Okay. This is actually not a valid arguments at all, is it? 460 00:47:36,970 --> 00:47:41,340 It's trading on the fact that many words are vague. 461 00:47:41,340 --> 00:47:45,750 They admitted borderline cases. So any words you can think of, like tall, fat? 462 00:47:45,750 --> 00:47:50,230 Clever. Can you think of a few others? Richard is one of them. 463 00:47:50,230 --> 00:47:54,280 Yes. Long. Paw. Yep. 464 00:47:54,280 --> 00:48:01,590 And any word that admits of of degrees Mitsu borderline cases? 465 00:48:01,590 --> 00:48:05,850 You can construct a heap of arguments for the fallacy, the heap. 466 00:48:05,850 --> 00:48:10,350 And so that's the fact. The words do admit a borderline cases. 467 00:48:10,350 --> 00:48:16,110 And the idea that a series of insignificant differences can't result in a significant difference. 468 00:48:16,110 --> 00:48:22,110 And of course, it's this one here that's that's at fault because a series of insignificant differences. 469 00:48:22,110 --> 00:48:30,720 If we take blue at this end of the stage and read at this ends of the stage, they're two different colours, aren't they? 470 00:48:30,720 --> 00:48:40,110 But we can go from one to the other in a series of gradations where you would say in each case are the same colours, the same colour, the same colour. 471 00:48:40,110 --> 00:48:44,550 But so A and B are the same. B and C are the same. 472 00:48:44,550 --> 00:48:50,330 And C are not the same. OK. The intransitive. 473 00:48:50,330 --> 00:48:59,320 And so when you're making an argument, you should try and avoid words that her grading words, scaling words. 474 00:48:59,320 --> 00:49:03,270 And how would you stop these being vague if you had. 475 00:49:03,270 --> 00:49:10,400 John has a nice income. What might you say instead of that? 476 00:49:10,400 --> 00:49:20,970 Said, besides getting some new good, John, this is in the top ten percent, 10 percentile of income earners or something like that. 477 00:49:20,970 --> 00:49:26,680 Yeah. Okay. Cocaine is a dangerous drug. Cocaine is addictive or cocaine. 478 00:49:26,680 --> 00:49:31,320 And cocaine. You could say the same sort of thing. 479 00:49:31,320 --> 00:49:37,950 Yep, or whatever. Exactly. That's what you're trying to do, is eliminate the vagueness by being more exact in some way or another. 480 00:49:37,950 --> 00:49:46,350 So Mary is a clever woman in just say Mary has got three degrees and APHC or something like that. 481 00:49:46,350 --> 00:49:53,000 Jane is a terrific tennis player. Jane is what? 482 00:49:53,000 --> 00:49:57,930 Yes. Okay, good. That easy. Slippery slope fallacy. 483 00:49:57,930 --> 00:50:02,130 This is another fallacy of ambiguity. Humans are rational. 484 00:50:02,130 --> 00:50:09,030 Sorry. In clarity, human irrational because they act for reasons. Radiator's turn themselves on when it's cold. 485 00:50:09,030 --> 00:50:18,460 Therefore radiators are rational. Now don't laugh because actually lots of people try and convince me of this because I. 486 00:50:18,460 --> 00:50:27,570 I do not believe animals are rational. And people always told me that I should believe animals rational because they act for reasons. 487 00:50:27,570 --> 00:50:34,470 And some people want to say that even radiator's irrational because when it's cold they turn themselves on except in Rowly House. 488 00:50:34,470 --> 00:50:37,380 But I mean, it's usually the case. 489 00:50:37,380 --> 00:50:45,790 And therefore there is it has a belief that it's cold and a desire that it should not be cold and therefore it acts. 490 00:50:45,790 --> 00:50:52,370 A, why isn't that rational? But again, we're doing the same thing, aren't we, 491 00:50:52,370 --> 00:51:00,050 because here are radiator's down at one end of of acting for reasons and here are human beings up at the other end of acting for reasons. 492 00:51:00,050 --> 00:51:11,000 And we're saying that there's no difference between the two. So any slippery slope arguments can fall foul of that just quickly slippery slope. 493 00:51:11,000 --> 00:51:16,940 Depends on the idea that we shouldn't distinguish between things that are not significantly different. 494 00:51:16,940 --> 00:51:25,550 And the belief that if A isn't significantly different from B and B, not significantly different from C, then A isn't significantly different from C. 495 00:51:25,550 --> 00:51:30,470 And again, that's true. Only if you've got something that's transitive. 496 00:51:30,470 --> 00:51:34,740 And there are many, many things that are not transitive. Of course, sometimes. 497 00:51:34,740 --> 00:51:39,230 And you I mean, one way of avoiding a slippery slope is actually to define something. 498 00:51:39,230 --> 00:51:42,710 We have to use slippery slope sometimes, don't we? 499 00:51:42,710 --> 00:51:52,310 When we think about, you know, well, why should we have the age of being allowed to marry at 16 without your parents permission or whatever it is, 500 00:51:52,310 --> 00:51:56,850 or the age of being able to drink whatever it is. 501 00:51:56,850 --> 00:52:00,920 I have no idea which this 18. Is it right. 502 00:52:00,920 --> 00:52:05,720 And what happens between the last day that you're 17 and the first day that you're 18? 503 00:52:05,720 --> 00:52:09,740 That makes it possible for you to drink on one day and not drink on the other. Legally. 504 00:52:09,740 --> 00:52:14,100 I mean, this is just daft, isn't it? Well, it is daft, of course. 505 00:52:14,100 --> 00:52:18,150 But but here you you have to make a Cut-Off point at some point. 506 00:52:18,150 --> 00:52:24,560 And what the slippery slope

is, it can say, well, OK, there isn't an obvious difference, 507 00:52:24,560 --> 00:52:30,330 but we have to make it on somewhere or that we can just make one by regulation or whatever. 508 00:52:30,330 --> 00:52:36,440 But slippery slopes trade on this particular problem. Here's another one. 509 00:52:36,440 --> 00:52:40,850 Mary had a little lamb. He followed her to school. Mary had a little lamb. 510 00:52:40,850 --> 00:52:46,730 Then she had a little broccoli. We can see that that's an equivocation. 511 00:52:46,730 --> 00:52:53,740 It's not actually clear what it's an equivocation on, is it? Is it lamb or is it had. 512 00:52:53,740 --> 00:52:59,010 Or little well, and little actually, isn't it, because had means possessed. 513 00:52:59,010 --> 00:53:05,050 Whereas in the first one and the second one, it means AIDS, doesn't it? 514 00:53:05,050 --> 00:53:09,160 Little Lamb in the first one is a bit different from a little lamb in the second one. 515 00:53:09,160 --> 00:53:12,940 And so on. Here's an equivocation. Yep. Okay. 516 00:53:12,940 --> 00:53:17,650 A feather is light. What is light cannot be dark. Therefore, a feather cannot be dog. 517 00:53:17,650 --> 00:53:22,000 What's the equivocation there? The word light. 518 00:53:22,000 --> 00:53:26,230 In the first case, it means light as a feather weight wise. 519 00:53:26,230 --> 00:53:30,220 And the second case, we're talking about light as opposed to dark. 520 00:53:30,220 --> 00:53:38,470 So that's the fallacy of equivocation. But there are three types of ambiguity, lexical. 521 00:53:38,470 --> 00:53:43,780 So what's wrong with that one? I thought it was rum. Is that rum is itself ambiguous. 522 00:53:43,780 --> 00:53:50,590 That's a word that can mean different things. And the second one, Bert, was a fat stock breeder. 523 00:53:50,590 --> 00:53:59,900 What's the ambiguity there? Give me the two understandings of that term. 524 00:53:59,900 --> 00:54:03,700 Right. Either Bert was fat or the stock was fat. 525 00:54:03,700 --> 00:54:14,580 That's right. So is the scope of fat. Just so Bert was fat and Bert was a stock read breeder. 526 00:54:14,580 --> 00:54:20,880 Or is it the fat goes with stock breeder? So Bert was a fat stock breeder. 527 00:54:20,880 --> 00:54:26,310 Those are the two. And then finally cross-reference, my wife's cousin engaged her for her former husband. 528 00:54:26,310 --> 00:54:39,180 What's the ambiguity there? So either my wife's cousin's engaged to my wife's former husband or my wife's cousin is engaged to the cousin Chey, 529 00:54:39,180 --> 00:54:44,460 the wife's cousin had before now that she's married for the second time to the same person. 530 00:54:44,460 --> 00:54:51,570 Okay. Explain the ambiguities in this sentence. These sentences, no one likes Oxford and Cambridge Cambridge's students. 531 00:54:51,570 --> 00:55:01,640 Good. Okay. Nobody likes students who've been to Oxford and Cambridge or nobody likes Oxford students and nobody likes Cambridge students. 532 00:55:01,640 --> 00:55:06,040 Oh, yes. No one likes Oxford and no one likes Cambridge students. 533 00:55:06,040 --> 00:55:10,360 Yes, that would be another one. OK. Every nice girl loves the sailor. 534 00:55:10,360 --> 00:55:14,740 Actually, if you were able to formalise things, you would find it very easy to do this, 535 00:55:14,740 --> 00:55:25,900 because this could mean there is a sailor such that every nice girl loves him or every nice girl is such that there is a sailor whom she loves. 536 00:55:25,900 --> 00:55:29,480 You're with me. So every girl is such sorry. 537 00:55:29,480 --> 00:55:37,100 There is a sailor such that every girl loves him or every nice girl loves some sailor. 538 00:55:37,100 --> 00:55:44,420 OK. So in the second case, there are lots of different sailors in the first cases, just one sailor who is loved by all the girls. 539 00:55:44,420 --> 00:55:50,480 So that's a structural ambiguity. Our shoes are guaranteed to give you a fit. 540 00:55:50,480 --> 00:55:56,240 I can see you've got that one. OK. Irritating children should be banned. 541 00:55:56,240 --> 00:56:02,570 That's right. Ed, what are we banning? Children who are irritating or the irritating of children. 542 00:56:02,570 --> 00:56:07,250 Okay. What about the last one? Can anyone tell me what the ambiguity is here? 543 00:56:07,250 --> 00:56:13,390 This is more difficult. You'll kick yourself. But but you'll also think that I've cheated you. 544 00:56:13,390 --> 00:56:19,160 Why do swallows fly south for winter? Why do swallows fly south for winter? 545 00:56:19,160 --> 00:56:22,430 Why does swirlies vice south for winter? Well, I just. 546 00:56:22,430 --> 00:56:27,250 Well, fire south for winter is. That's ambiguous. 547 00:56:27,250 --> 00:56:31,400 Okay. And all it was is the intonation there. 548 00:56:31,400 --> 00:56:33,710 I managed to give it lots of different meanings. 549 00:56:33,710 --> 00:56:43,670 So you shouldn't think that actually the young biggity might just be in this in the lexicon, in the structure and in the cross references. 550 00:56:43,670 --> 00:56:51,640 Sometimes you can put it in just by the tone, the emphasis you give on the words that you use. 551 00:56:51,640 --> 00:56:56,640 Right. Okay. That's it for the lectures. Thank you. 552 00:56:56,640 --> 00:57:02,621 Thank you. Well, thank you to.