TRANSKRIPTIO 🔗
1
00:00:00,600 --> 00:00:06,030
OK, here we are at week six. The very last week of our course and this week we're going to have a bit of a romp.
2
00:00:06,030 --> 00:00:13,970
We're going to start looking at phalluses. Fallacies are bad arguments that look like good arguments and can easily be confused for them.
3
00:00:13,970 --> 00:00:19,590
OK. Let's get started. Just a recap on last week, as always.
4
00:00:19,590 --> 00:00:27,990
If you remember, we looked at what makes a deductive argument sound. And we looked at what makes such an argument valid.
5
00:00:27,990 --> 00:00:37,590
So just a quick reminder for you. Would the argument be sound in this situation where it's valid but it has false premises?
6
00:00:37,590 --> 00:00:44,820
Put your hands up if you think that sound. So it's a valid argument, but false premises.
7
00:00:44,820 --> 00:00:50,790
OK. What about if it's an invalid argument with false premises?
8
00:00:50,790 --> 00:00:56,810
Look. OK. If it's an invalid argument with true premises.
9
00:00:56,810 --> 00:01:01,010
And a valid argument with true premises. OK, good.
10
00:01:01,010 --> 00:01:09,980
Well done. Yep, it's only sound if it's a valid argument and it has two premises at all, its premises must be true and it's valid.
11
00:01:09,980 --> 00:01:13,820
Well done. OK. Now, here's the tricky one. OK.
12
00:01:13,820 --> 00:01:22,160
The question is, could the argument be valid when it's got false premises and a false conclusion?
13
00:01:22,160 --> 00:01:28,550
It could be valid. Well done. Could it be invalid? Well done, good.
14
00:01:28,550 --> 00:01:33,320
Okay. What if it has false premises and a true conclusion? Could it be valid?
15
00:01:33,320 --> 00:01:40,800
Put your hand up this time. Could it be valid if it has false premises and the true conclusion?
16
00:01:40,800 --> 00:01:45,570
Could it be valid? OK.
17
00:01:45,570 --> 00:01:50,790
Those few without your hands up. Is that because you don't know? No. Okay.
18
00:01:50,790 --> 00:01:56,360
What about if it's got true? Previs isn't a true conclusion. Could it be valid then?
19
00:01:56,360 --> 00:02:04,490
Okay. Could it be invalid then? Oh, yes, it could be okay.
20
00:02:04,490 --> 00:02:09,260
There is only one situation in which it couldn't be valid.
21
00:02:09,260 --> 00:02:14,960
Only one situation which it couldn't be valid. And that's on this one.
22
00:02:14,960 --> 00:02:20,480
If it's got through premises and a false conclusion, it couldn't be valid.
23
00:02:20,480 --> 00:02:31,700
Otherwise, it could be it could be either valid or invalid. And the reason for that is because an argument is valid if and only if there's no
24
00:02:31,700 --> 00:02:37,220
possible situation in which all the premises are true and its conclusion false.
25
00:02:37,220 --> 00:02:47,120
So it's a sufficient condition for an argument being valid that there's no possible situation in which its premise is true, in conclusion, false.
26
00:02:47,120 --> 00:02:53,540
And that's a necessary condition, too. And if you remember, I said to you last week, there are two things you've got to remember.
27
00:02:53,540 --> 00:03:00,710
One is that it's the possibility, not the actuality of the combination of true premises and false conclusion.
28
00:03:00,710 --> 00:03:07,070
That's important. And the other is it's the combination of true premises and false conclusion.
29
00:03:07,070 --> 00:03:12,140
That's important. Okay, I gave you another test.
30
00:03:12,140 --> 00:03:17,810
So if that was one test of validity and the other test I gave you is that an argument is valid.
31
00:03:17,810 --> 00:03:22,490
If and only if it's example set is consistent.
32
00:03:22,490 --> 00:03:29,030
And the counter example set is the sets consisting of the premises plus the negation of the conclusion.
33
00:03:29,030 --> 00:03:32,690
So if you have if it's Friday, Marianne's wearing jeans.
34
00:03:32,690 --> 00:03:37,280
It is Friday. Therefore, Marianne's wearing jeans. That's an argument.
35
00:03:37,280 --> 00:03:42,020
An argument. If you take the conclusion Marianne's wearing jeans and negate it.
36
00:03:42,020 --> 00:03:50,870
So you've got it's not the case that Marianne's wearing jeans. The counterexamples set then becomes if it's Friday, Marianne's wearing jeans.
37
00:03:50,870 --> 00:03:57,080
Marianne Wear is wearing jeans. It's not the case.
38
00:03:57,080 --> 00:04:02,240
It's not what the premising inclusion will eat.
39
00:04:02,240 --> 00:04:07,250
It is Friday. It's not the case that Marianne's wearing jeans. That's the counterexample set.
40
00:04:07,250 --> 00:04:12,350
Now, listen again. Is that consistent? Could all these sentences be true together?
41
00:04:12,350 --> 00:04:16,880
If it's Friday, Marianne's wearing jeans. It is Friday.
42
00:04:16,880 --> 00:04:24,490
It's not the case that Marianne's wearing jeans. Could those be true together?
43
00:04:24,490 --> 00:04:29,560
They couldn't. Could they? And that shows that the original argument is valid.
44
00:04:29,560 --> 00:04:34,030
It shows there is no possible situation where the premises are true.
45
00:04:34,030 --> 00:04:43,510
And the conclusion is false because the set consisting of the premises and the negation of the conclusion is inconsistent.
46
00:04:43,510 --> 00:04:47,860
In other words, there's no possible situation where they're all true together.
47
00:04:47,860 --> 00:04:51,400
That's why that test works. So, OK.
48
00:04:51,400 --> 00:04:55,660
And I said too, though, to test, you will have understood the concept of validity.
49
00:04:55,660 --> 00:05:02,290
Once you've understood, firstly, the paradoxes of entailment and secondly, why this works.
50
00:05:02,290 --> 00:05:05,380
If you understand why this works. You're getting there.
51
00:05:05,380 --> 00:05:12,520
If you understand why the paradoxes of entailment are valid arguments, you will see why you've.
52
00:05:12,520
Load full transcript
--> 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.