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I had an extraordinary week because I decided I changed my mind about this quite early on.

2
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And I've virtually rewritten the whole lecture in the last week.

3
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But it's so enjoyable, the subject. I mean, you must be loving it.

4
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I hope you are. I am. Okay.

5
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So let's. If you remember, this is the fifth week of lectures.

6
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So we've done four weeks of looking at various theories of causation.

7
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And we've considered three types of reductive analysis. So we've looked at the regularity theory, which comes from Hume.

8
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So he thinks causation is lawful regularity. And we've looked at the counterfactual theory, which comes from David Lewis.

9
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He thinks causation is counterfactual dependency of some kind.

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We saw that there are few accounts of counterfactual dependency that won't do.

11
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But we saw one that maybe will do. And we've looked at singulars theories where causation is a set of perhaps or a physical process.

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We haven't considered primitivism the idea that causation is so fundamental and central to our thinking that we can't reduce it.

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So it's like truth. It's it is just suy generous one thing in itself.

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And nor have we considered illuminative ism and the idea that causation doesn't exist.

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More than briefly. We'll look at that very briefly today.

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But I think somebody said to me last week that she thought this might be the case.

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Well well, we'll have a look at others who think this.

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So this week, we're going to be looking at the relation between causal asymmetry and temporal asymmetry.

19
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So we're no longer looking at a theory of causation. We're looking at theories of how the causal asymmetry is aligned with the temporal ASEM of God.

20
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I've probably done that the whole way through. Because, of course, these spellcheck doesn't pick that up.

21
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No, not Cashel. Causal. Causal. Whenever you read Casualty, you should read it as causal.

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Okay. So the folk concept of causation. And you remember last week,

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I distinguish the folk concept and the scientific concept and said that any account

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of the scientific concept is only going to be interesting from our point of view,

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if it arguably is or can be seen to be the folk concept.

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Because what we're interested in is causation as we use it in our everyday lives.

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So the folk concept of causation seems to be asymmetric causes come before their effects.

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If we see causes e e does not cause, see, they're asymmetric and this asymmetry seems to align with the direction of time.

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The fact that time itself seems to have a direction from past to future, it doesn't go from future to past.

30
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So it's interesting to ask how these two asymmetries are related.

31
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I mean, the fact that they are aligned so well makes it look as if they might be related.

32
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Well, Hume has theories about this or views on this or other.

33
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He his views aren't very interesting on this. He thinks causation itself is symmetrical.

34
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So he thinks if A and B are constantly conjoined, then A is constantly conjoined with B and B is constantly conjoined to A.

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Of course, has to be. That's the relation of constant conjunction is a symmetrical relation.

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And Hume thinks that causation is constant conjunction. Therefore, Hume thinks the relation of causation is a symmetrical relation.

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So he thinks there's no more to the causal arrow,

38
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to the fact that there appears to be an asymmetry of causation than the semantic convention that causes come before their effects.

39
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So cause is just defined in such a way that causes come before their effects.

40
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An effect is just defined in such a way that effects come off to their causes.

41
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This is surely not very interesting.

42
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I mean, one problem is lots of people have thought that simultaneous causation and backwards causation are possible.

43
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But according to Hume or on Hume story, all these people are conceptually confused.

44
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So anyone who thinks that time travel really might be possible is conceptually confused.

45
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It couldn't be anyone who thinks that there are tachyons.

46
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Particles that move faster than speed of life light are conceptually confused.

47
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So they're there. The objection to them is not just that they're wrong empirically, but that they've got their concepts mixed up.

48
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Same with precognition. And any suggestion that a cause could come at the same time as its effect or after its effect is confused on Hume's story.

49
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And that's got to be a problem for Hume's story, because there.

50
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It seems perfectly reasonable to consider the possibility of simultaneous backwards causation,

51
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even if we don't seem to see it very often or indeed at all.

52
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So the second problem is that it doesn't explain the fact that fact of our practical reason,

53
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which is that we see the past as fixed and the future open.

54
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So when we deliberate to achieve goals.

55
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So we want to achieve some goal or other we deliberate about future goals.

56
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We do not deliberate about past goals because we can't change the past.

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So if we're thinking about what we can do, it's about how to change the future.

58
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And again, a human can't explain this. He just says, well, if you think you can do anything else, you're conceptually confused.

59
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And surely we might think there's a bit more to it than that.

60
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There is a sense we think, don't we, in which the past really is fixed and the future really is open?

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Well, he can't explain that.

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So Hume's account of the alignment of the temporal symbols, a cemetery and the causeless cemetery is unsatisfactory, to say the least.

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What we should like is an account of causal asymmetry that ensures the possibility,

64
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at least in principle, of simultaneous causation and backwards causation.

65
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And explains our deliberative practises. Preferably in terms of some objective asymmetry that ensures that the past is fixed and the future is open.

66
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And David Lewis attempts to offer such an account, the same chap just gave us the counterfactual theories.

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OK. Any questions about Hume's? And the problems with it?

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No, it's pretty straightforward, I think. Okay, so let's have a look at David Louis'.

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Here he is. Lewis thinks that causal asymmetry depends upon the asymmetry of counterfactual dependence.

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Well, that won't surprise you. And that the asymmetry of counterfactual dependence depends on the asymmetry of over determination.

71
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What's that? Okay.

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So to evaluate this claim and to relate it to our hope of understanding the relation between the temporal asymmetry and the causal asymmetry,

73
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we need to ask several questions. And here are the questions that we're going to be asked answering in this lecture.

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So first of all, you want to know, I assume, what they symmetry of over determination is.

75
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Okay. Secondly, you'll want to know how the asymmetry of counterfactual dependence depends on the aim at a cemetery of over determination.

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If if Lewis is using this asymmetry to explain that asymmetry, we've got to know how they're related.

77
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And thirdly, does appeal to a symmetry of over determination.

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Explain the relation between the causal arrow and the temporal arrow.

79
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Because that's what we want to know. So those two are things that we've got to know in order to know this.

80
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But that's the important thing. And I've already said that we've got to desiderata of an account of the alignment of the symmetries.

81
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Does louis' accounts give us the first one? I does it permit the possibility in principle of backwards and simultaneous causation?

82
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And you can imagine what the second one is. Does Louis' account Louis' account to explain are deliberative practises?

83
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And lastly, of course, is Louis' account correct? Are there any objections we can bring to it or should we just reject it and with it

84
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the explanation of the alignment between causal asymmetry and temporal asymmetry.

85
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Okay. And you won't think of any other questions? I hope not.

86
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But if you can think of them afterwards. So what I'm going to do for the rest of this lecture is try and answer these questions.

87
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So let's start with the asymmetry of over determination.

88
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What is the asymmetry of over determination? Lewis says that in this world, though, not in every world.

89
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So we're talking about something contingent here. We're not talking about something necessary in this world.

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It's typically the case. In other words, it can happen in this world that it's not like this.

91
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But typically it is like this. And there are many more future determinants of events than past determinants of events.

92
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I the put of events in there. Okay, so Lewis thinks that there is an asymmetry of over determination because it's typically the

93
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case in this world that events have many more future determinants than past determinants,

94
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and a determinant is a set of minimal conditions such that there are sufficient for the event.

95
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Okay, well, we'll say something more about that in a minute. Okay, so let's have a look at an example.

96
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We say that the campus lighting his campfire started the forest fire because we believe that had the camper not lit his campfire,

97
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there would not have been a forest fire. Okay. Does that make sense?

98
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We think the nearest no camp far possible world to this world is the world in which the forest didn't burn down.

99
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OK, so if you remember, we evaluate counterfactuals by saying in the world where the antecedent history of,

100
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say, is there a world in which the antecedent and the consequence are true?

101
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Is that world a world like that, nearer than any world in which the consequent the antecedent is true and the consequent false?

102
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So looking at had the camper, whereas it had the camp not it is camp father would not have been a forest fire.

103
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We're looking for whether there's a world in which the camper did light its campfire.

104
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Sorry, didn't light his campfire and there wasn't a forest fire.

105
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Is that nearer than any world where he did light his camp fire and there was a forest fire?

106
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Have I got that right? Who is on the ball here?

107
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On let me just in case I've confused you. The come had the camper not lit his father, that would not have been a forest fire.

108
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OK. So we're looking. Which is NERA. Kamper didn't light fire and no fire or camper didn't light fire and far anyway.

109
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You with me? OK. So that's only true if that world is nearer than that world.

110
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Yep. OK. Sorry to confuse you there.

111
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So we think the nearest no campfire possible worlds to this world is one in which the forest didn't burn down.

112
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We don't believe it's a world where there was another condition sufficient to burn the forest down.

113
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Overdetermined of outward determination of future events.

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By past events, it does happen in this world. So if you're facing a firing squad, you may end up with two bullets in your heart.

115
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So if the first bullet hadn't killed you, the second would have done and your death is over determined.

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It undoubtedly happens in this world, but it doesn't happen very often.

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It would be very bad luck in this world. Once we discover there's a link between the camp highlighting the camp fire and the forest fire,

118
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it would be very unlucky if the camp hadn't lit is far and lightning were to strike.

119
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And the FA start anyway. It's not usually the case in this world that the past over determines the future.

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But now consider that the forest fire happened a year ago.

121
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There'll be many traces of the forest fire and in principle, scientists, forensic scientists will be able to discover where and how it started.

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So there'll be many conditions a year off to the fire that could only have come about because the fire started when and how it did.

123
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And that's what forensic science is all about. And what we're seeing when we see that is that there are many future determinants of the fire.

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There are many conditions, sets of minimal conditions such that they are sufficient for the fire having started when and how it did.

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So there's an asymmetry of past to future here.

126
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So typically, there's only one minimal set of conditions such that given the laws of nature as they are,

127
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they were sufficient for the forest fire starting when and how it did.

128
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But again, typically there are many sets of minimal conditions such that given the laws of nature being as they are,

129
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again, they are sufficient for the forest. Forest fires having started having started, I should say, when and how it did.

130
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The future, says Lewis, typically over determines the past, but the past does not typically over determine the future.

131
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And this is the asymmetry of over determination. Okay, anyone want to ask any questions about that before I go on?

132
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Basically, what does it mean when you say that the top line,

133
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the top paragraph differs from the second only word starting is that rather than having staff write.

134
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Starting in other words, there was only one minimal set of conditions before the fire that was sufficient for the fire.

135
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But there are many sets of milling pool conditions off to the fire for the fire.

136
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And it's those conditions that science, that lead science to say that that's where the fire started.

137
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Okay. How are things?

138
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Joint. OK.

139
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Can you imagine a forensic scientist saying, ah, if this were not the case?

140
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If so, given that this is the case and that this is the case, it must be the case that the fire started here before.

141
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Those conditions there off to the fire. It's the fire that caused those conditions, but those conditions are sufficient for the fire having started.

142
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Then. Yeah.

143
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Okay. So. So there's one. This is typically the case.

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Condition sufficient for the fire starting.

145
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And many, again, typically conditions sufficient for the fires having started.

146
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I should say then and there. That's the difference.

147
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That's the asymmetry. So if the camp hadn't lit his fire, the fire, the forest would not have burnt down.

148
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Is one sufficient condition, I should think that you will accept that happily.

149
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Okay. What. You're having trouble with, I assume, is this one.

150
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The idea that there are many conditions in the future sufficient for the fires having started.

151
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Okay, but again, think about forensic science and think about the fact that a forensic scientists would be able to go into

152
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that forest and identify conditions that would only be there if the fire had started then and there.

153
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In other words, they are looking backwards. They determine that that's why the fire started.

154
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Yeah. Then exactly the same way. Uh.

155
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Sufficient evidence. Can I say that? I mean, will that make it easier for you?

156
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So if I say this condition was sufficient, OK, that's got to be causal.

157
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I suppose it's it's causally sufficient for the fire having started.

158
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And here I can use Causley again, because if you're thinking and we are thinking maybe I should have said this before,

159
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that the laws of nature are deterministic in each direction. So the reason the forensic scientists can look at a crime scene.

160
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Forget the far from the reason a forensic scientist can look at a crime scene and say this is the sort of weapon that you're looking for.

161
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This is the sort of height of the person who wielded the weapon.

162
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The person who wielded the weapon is probably right handed. The reason that the forensic scientists can say that is because there are lots of things

163
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about the crime scene that make it the case that this is what must have happened.

164
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Well, you can write improbability if you like. Even if you add the words probability.

165
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That's that's not a problem. I think I'm worried about the determined cause of the fire because as I see it.

166
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There isn't any over determination of the cause of the fire.

167
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There's only one cause of the fire and that's the camper having litters, there could be others.

168
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Yep, you're absolutely right. There could be a lightning strike. Yeah, absolutely.

169
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So we looked back and we see that the fire did start that way.

170
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But of course, it could have started. It could have been that had the camper not lit his campfire, the lightning would have struck.

171
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But in this case, that's not well, nor is it true often in this world, is it?

172
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So if the fire brigade tells us that the fire in the house started because there was a short circuit here,

173
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we tend to think that that was the only sufficient condition for the fire that was around at the time.

174
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And of course, we might be wrong later on, the fire brigade might come to us and say,

175
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oh, hang on, we've also just discovered this oily rag of petrol covered rag.

176
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So maybe it was that. And now we seem to have two potentially sufficient conditions for the fire.

177
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And this is going to throw up. You know, this is really irritating because that's very uncommon.

178
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That would count as if there's more than one condition sufficient for starting something for causing something that's over determination.

179
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So I'm. Yes, that's why the word typically is so important.

180
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Sometimes there's over determination from past to future, but typically in this world that isn't over determination from past future.

181
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There's only one sufficient condition for an effect.

182
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But when it comes to the forensic scientists checking out why it started, there are lots of things that lead back to the fire, to the campfire.

183
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Be instant before the fire starts. You might say one identifiable act is.

184
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That is one of many. No, no. You looking the other way is the many factors that tell you.

185
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There was one. I think you could have an equal number of determinants.

186
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Going in each direction you go, you go with the fire.

187
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Yes, I see what you're saying. Okay. I did say, but I didn't make a lot of the fact that it has to be a minimal set of sufficient conditions.

188
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There's so have I said it here? Okay. There's only one minimal set of conditions such that given the laws of nature,

189
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the camp fire was a necessary part of that minimal set of sufficient conditions.

190
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That being said, after a. The forced fall of camp for you would be a.

191
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Minimal sets of conditions looking backwards. Well. OK, so this is this what you're saying here is the campfire.

192
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And you're saying there are many things that lead to that, just as there are many things that lead away away.

193
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The more you have. Yep.

194
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Okay. And we're saying that this is the cause because had this not occurred, the forest fire would not have occurred.

195
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So. I want the word necessary in there somewhere, don't I?

196
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Because it's the NSA's necessity of this one. That's important because it's the it's everything looks back at this one.

197
00:25:27,310 --> 00:25:32,670
Not at the others. Just before the fire.

198
00:25:32,670 --> 00:25:39,030
So it's typically there's only one minimal set of conditions such that given the laws of nature,

199
00:25:39,030 --> 00:25:45,870
they were sufficient for the forest fires starting and the camp fire was what was a necessary part of those.

200
00:25:45,870 --> 00:25:54,520
I think you're quite right that that needs to be in the. But what happened in.

201
00:25:54,520 --> 00:26:06,010
Will that happen in the future is a necessary condition of the sufficiency of the condition with the one condition in the past five?

202
00:26:06,010 --> 00:26:18,310
I think so, yes. Sorry, I'm looking at that one person behind you.

203
00:26:18,310 --> 00:26:27,700
Good past. Yes, I have already introduced explanation.

204
00:26:27,700 --> 00:26:40,720
Yes. And think of it like this.

205
00:26:40,720 --> 00:26:46,780
The camp fire, as you said, has many different causes and many different effects.

206
00:26:46,780 --> 00:26:55,090
But we explain it. We do remember when I talked about we we only learnt what the difference explanation is, is we talk about the cause.

207
00:26:55,090 --> 00:27:05,030
In other words, it's the one that makes it intelligible to us. Explanation.

208
00:27:05,030 --> 00:27:13,930
Well, because when we identify that condition, the forest fire makes sense to us.

209
00:27:13,930 --> 00:27:22,240
So I could just as easily say, had the camper not been born, the forest fire would not have started.

210
00:27:22,240 --> 00:27:30,700
And that's true because the the campers birth was a necessary condition of the fire starting.

211
00:27:30,700 --> 00:27:42,530
But it doesn't give us an explanation, does it? It's it doesn't make the fire intelligible to us, whereas if I pick out this cause the camp fire.

212
00:27:42,530 --> 00:27:48,770
It's an explanation because it does make the fire intelligible.

213
00:27:48,770 --> 00:27:53,460
The normally intelligent person would choose and that would not be affected.

214
00:27:53,460 --> 00:28:01,200
But. I take it.

215
00:28:01,200 --> 00:28:12,340
That's what I just said. So so there are lots of different causes, most of which wouldn't be cited in an explanation.

216
00:28:12,340 --> 00:28:20,600
The only causes that can be cited in an explanation are the ones that make intelligible to us the effect.

217
00:28:20,600 --> 00:28:30,760
There's no there there can be I mean, there are lots of conditions necessary for the minimal set of sufficient conditions,

218
00:28:30,760 --> 00:28:36,980
but some of them won't be cited in explanations. OK.

219
00:28:36,980 --> 00:28:46,310
I'm going to move on. You know, I mean, just the right direction.

220
00:28:46,310 --> 00:28:55,220
Well, do you remember it's always the case that that's any one event has many things that contribute to the cause.

221
00:28:55,220 --> 00:29:03,090
But if we're wanting to explain it, we'll pick it will say had the camper not lit the campfire, the fire would not have started.

222
00:29:03,090 --> 00:29:09,710
It's also true that had the winds not been in the right direction, the fire would not have started.

223
00:29:09,710 --> 00:29:18,590
And we might use that as an explanation if we're particularly interested in why the fire went that way instead of that way or whatever.

224
00:29:18,590 --> 00:29:27,140
So what we pick out is the explanation tends to be relevant to our interest in an explanation.

225
00:29:27,140 --> 00:29:31,610
What it is we want, if we only want to know whether it's why it started.

226
00:29:31,610 --> 00:29:40,640
The camp fire is the one. If we want to know the direction it went in, probably the wind's direction would be.

227
00:29:40,640 --> 00:29:46,130
But I want I just want to go back because I'd hate to lose you at this point.

228
00:29:46,130 --> 00:29:53,060
So let's just. OK.

229
00:29:53,060 --> 00:30:03,140
Lewis says that the asymmetry of over determination is the result of its typically being the case, that events have more future determinants.

230
00:30:03,140 --> 00:30:10,670
There are more things in the future that determine that this fire started with a campfire that will tell us,

231
00:30:10,670 --> 00:30:21,050
if you like, that this thing started with the campfire. Then there are things in the past that ensure that the forest fires started.

232
00:30:21,050 --> 00:30:24,580
Good, this I'm good, think I'm getting myself confused here.

233
00:30:24,580 --> 00:30:33,100
So we say that the campers lighting his campfire started the forest fire and we say that because we believe that had the camper not lit his campfire,

234
00:30:33,100 --> 00:30:44,340
there would not have been a forest fire. And that's because the possible worlds.

235
00:30:44,340 --> 00:30:49,520
So we ask, which is an era where the camper didn't like the fort, his campfire.

236
00:30:49,520 --> 00:30:56,910
And there was no forest fire or the one where he didn't lighter's camp fire and there was a fire anyway.

237
00:30:56,910 --> 00:31:09,510
If that world's close closer than the forest fire is overdetermined, which it might be similar, more similar to.

238
00:31:09,510 --> 00:31:13,260
I know. I'll be looking at that in a minute. Okay.

239
00:31:13,260 --> 00:31:19,530
So we think that the nearest no camp fire possible world to this one is the one where the well, the forest didn't burn down.

240
00:31:19,530 --> 00:31:26,250
If the camp hadn't lost as far, the forest would not have burned down. And we don't believe there was another condition similar.

241
00:31:26,250 --> 00:31:31,080
We know that had the campfire not. Sorry, I can't put it that way.

242
00:31:31,080 --> 00:31:35,700
If we see that there's a link between the camper lighting his fire and the forest fire,

243
00:31:35,700 --> 00:31:44,280
we tend to discount the possibility that there was another condition that was sufficient, although there might have been.

244
00:31:44,280 --> 00:31:52,110
And so, although overdetermined, a future event over determination of future events by past events does happen.

245
00:31:52,110 --> 00:31:57,810
So do you remember you might be shot and you have two bullets in your heart if one hadn't killed you.

246
00:31:57,810 --> 00:32:05,700
The other would have done. And if the camp fire, if the camp hadn't lit his camp fire, the lightning would have struck.

247
00:32:05,700 --> 00:32:10,170
And the forest burned down any way might be true, but it's not true.

248
00:32:10,170 --> 00:32:21,540
Very often in this world, there tends to be one thing that will pick out as the minimally sufficient condition for the starting of a fire.

249
00:32:21,540 --> 00:32:27,030
And then I wanted you to get it OK, so that, I think should be fairly straightforward.

250
00:32:27,030 --> 00:32:31,470
But now I'm asking you to consider that it happened a year ago.

251
00:32:31,470 --> 00:32:39,150
And I'm pointing to the truth that they are going to be many traces of the forest fire at this point.

252
00:32:39,150 --> 00:32:47,670
And scientists are in principle able to follow those back to identify the cause of the fire.

253
00:32:47,670 --> 00:32:52,050
The thing we're picking out is the cause of the fire.

254
00:32:52,050 --> 00:33:02,610
So many conditions that could only have come about because the fires started when and how it did.

255
00:33:02,610 --> 00:33:11,250
And what that is, says Lewis, is it shows us that there are many future determinants of the FA if we're looking backwards.

256
00:33:11,250 --> 00:33:20,570
There are many ways of telling it that it was the FA. If we're looking forwards, the forest fire started because of the campfire.

257
00:33:20,570 --> 00:33:31,620
Okay, so that's the asymmetry of over determination, and I hope that they'll be a bit of time left at the end of the session.

258
00:33:31,620 --> 00:33:35,340
For those who who would still like to ask about this.

259
00:33:35,340 --> 00:33:47,220
But let's go on to look at how the asymmetry of counterfactual dependence depends on the asymmetry of over determination.

260
00:33:47,220 --> 00:33:53,280
My throat is not going to hold out. I think so.

261
00:33:53,280 --> 00:34:00,180
Lewis says that when we evaluate counterfactuals, we rely on determining the overall similarities,

262
00:34:00,180 --> 00:34:09,110
said this, Lance, to the question that you wanted to ask. Just then, the overlap all similarity to the actual world.

263
00:34:09,110 --> 00:34:16,460
Various possible worlds, and in determining this, we've got two things that we've got to consider.

264
00:34:16,460 --> 00:34:25,220
Firstly, we've got to consider the laws of nature of that world and how, like the laws of nature of this world, they are.

265
00:34:25,220 --> 00:34:35,030
And secondly, we've got to consider particular matters of fact at that world and how similar they are to the particular matters of fact at this world.

266
00:34:35,030 --> 00:34:39,080
So you might have world worlds where the particular matters.

267
00:34:39,080 --> 00:34:42,890
Well, where the laws of nature are very different from our world.

268
00:34:42,890 --> 00:34:53,540
I mean, perhaps these are worlds where things water looks like this and tastes like this and behaves like this, but is X, Y, Z.

269
00:34:53,540 --> 00:34:58,700
So they're not our world are our laws. They're very different from our laws.

270
00:34:58,700 --> 00:35:03,620
And there are other worlds where I male.

271
00:35:03,620 --> 00:35:07,950
Let's say, actually, whether that is a possible world is a different, difficult question.

272
00:35:07,950 --> 00:35:13,780
So, OK, so we've got to determine we've got to look at the both these two things.

273
00:35:13,780 --> 00:35:23,430
And the counterfactual is going to be true or false, depending on how we weigh these two things with each other.

274
00:35:23,430 --> 00:35:32,640
And I'm going to illustrate this claim to you by bringing to Lewis's claim an objection called the future similarity.

275
00:35:32,640 --> 00:35:40,890
Objection. That I think you might find interesting as well.

276
00:35:40,890 --> 00:35:45,790
OK, if Nick Nixon had pressed the button, they would have been a nuclear holocaust.

277
00:35:45,790 --> 00:35:58,010
OK, who believes that? If Nixon had pressed the button, that would have been a nuclear holocaust.

278
00:35:58,010 --> 00:36:06,800
And you will not believe it. Why? All right.

279
00:36:06,800 --> 00:36:10,820
Okay. But we sort of think that in this world,

280
00:36:10,820 --> 00:36:19,870
things were such in the Cold War that everything was set up in such a way that if either side had actually pressed the bloody button,

281
00:36:19,870 --> 00:36:25,880
we would have been in trouble. Okay. So usually would consider that to be true.

282
00:36:25,880 --> 00:36:30,240
We'll just ignore Mike and anyone else who thinks that maybe not.

283
00:36:30,240 --> 00:36:36,920
Okay. But surely, says Kit Fine, who brought this objection originally.

284
00:36:36,920 --> 00:36:43,640
Any world in which a nuclear holocaust didn't happen should be nera taken as nearer to our world,

285
00:36:43,640 --> 00:36:51,170
more similar to closer to our world than any world in which a nuclear holocaust did happen.

286
00:36:51,170 --> 00:36:55,400
And you can see why says that, you know, a world in which a nuclear holocaust.

287
00:36:55,400 --> 00:37:04,580
I mean, given that this is a world in which though there was so far no nuclear, I'm touching wood, no nuclear holocaust and any world,

288
00:37:04,580 --> 00:37:14,400
any other world in which there wasn't a nuclear holocaust is going to be more like this world than any world in which there was a nuclear holocaust.

289
00:37:14,400 --> 00:37:21,370
And so surely this is a problem for louis' accounts of counterfactuals.

290
00:37:21,370 --> 00:37:30,820
Whoops. I didn't realise that was going to. Do you see why that is a problem for Louis' account of counterfactuals?

291
00:37:30,820 --> 00:37:40,450
Lewis says that what we look for is the worlds closest to our own and what we're thinking here is in the world in which Nixon did press the button,

292
00:37:40,450 --> 00:37:44,560
which is not our worlds, of course, because in our world, thankfully, he didn't press the button.

293
00:37:44,560 --> 00:37:50,320
But in the world in which he did press the button, there would have been a nuclear holocaust.

294
00:37:50,320 --> 00:37:55,420
Now, intuitively, we think that that's true.

295
00:37:55,420 --> 00:38:07,000
But what Kit Fine is saying is it's actually not true if what we're looking for is the world that's more similar to ours.

296
00:38:07,000 --> 00:38:10,480
So this is a black mark for Louis' theory.

297
00:38:10,480 --> 00:38:20,800
Let me go on to how Lewis responds to this, and that might help you understand if you haven't understood the problem here.

298
00:38:20,800 --> 00:38:26,230
So Lewis responds by taking us through the procedure of identifying possible

299
00:38:26,230 --> 00:38:33,070
worlds and judging their relative similarity to ours and their two things,

300
00:38:33,070 --> 00:38:38,050
we've got to note before considering this rebuttal of this objection.

301
00:38:38,050 --> 00:38:43,150
And this is the one that I should have said earlier, perhaps for ease of exposition.

302
00:38:43,150 --> 00:38:48,700
Lewis considers the laws of nature to be everywhere and always deterministic.

303
00:38:48,700 --> 00:38:53,080
He explicitly says, and I put the reference in the notes for all these things,

304
00:38:53,080 --> 00:38:56,560
by the way, he is missing and says that this is necessary for his claim.

305
00:38:56,560 --> 00:39:04,780
But it does just make it a lot easier to think about. And he's going to talk about miracles in a minute.

306
00:39:04,780 --> 00:39:13,150
So you need to know what a miracle is and what a miracle is, is a violation in our laws of nature.

307
00:39:13,150 --> 00:39:17,890
But importantly, it expresses a relation between this world and another world.

308
00:39:17,890 --> 00:39:24,270
So if we're thinking about a world in which Nixon did press the button.

309
00:39:24,270 --> 00:39:31,360
OK. There is a violation of our laws. There must be, because in this world, he didn't press the button.

310
00:39:31,360 --> 00:39:35,890
But it's not a violation of the will of the laws in that world.

311
00:39:35,890 --> 00:39:41,140
How could it be? There can't be violations of the laws of nature.

312
00:39:41,140 --> 00:39:48,400
So the laws of nature of this other world, the world where he didn't press the button, are not the same as ours.

313
00:39:48,400 --> 00:39:51,790
They may be like ours, but they're not the same as ours.

314
00:39:51,790 --> 00:39:57,790
They couldn't be. Again, let me continue.

315
00:39:57,790 --> 00:40:07,730
Okay, so we surveyed the possible worlds. So we're looking for the nearest world where Nixon did press the button.

316
00:40:07,730 --> 00:40:15,990
Sorry, you're gonna have to put up with my stopping for. The nearest well, where Nixon did press the button.

317
00:40:15,990 --> 00:40:23,760
Well, there are worlds that we discount as being so dissimilar to ours where they're not even candidates.

318
00:40:23,760 --> 00:40:29,160
So the world where Nixon presses the button and there is this great spray of confetti comes

319
00:40:29,160 --> 00:40:37,980
out or the missiles go off and shower Moscow and Leningrad and so on with with confetti.

320
00:40:37,980 --> 00:40:41,700
Okay. The confetti worlds are not worlds. This is similar to us.

321
00:40:41,700 --> 00:40:47,100
There are such worlds, but they're not ones that are going to be counted for the purpose of this.

322
00:40:47,100 --> 00:40:52,800
And another world which doesn't count is the world in which Nixon presses a button.

323
00:40:52,800 --> 00:41:01,830
But where the laws are identical to our own. In other words, where particular matters of fact are so completely different to our own.

324
00:41:01,830 --> 00:41:07,740
But the laws determine that he presses the button.

325
00:41:07,740 --> 00:41:13,530
So that's what Lewis says, is that either laws are similar to our own or they're not.

326
00:41:13,530 --> 00:41:17,640
Sorry, either worlds are similar to our own or they're not.

327
00:41:17,640 --> 00:41:24,600
And this world just clearly isn't. We don't take any account of this world.

328
00:41:24,600 --> 00:41:29,110
So let's have a look at the worlds that we do count.

329
00:41:29,110 --> 00:41:35,410
Firstly, we're going to look at worlds of type one and then lots of worlds here, not just one world.

330
00:41:35,410 --> 00:41:41,110
And so there are worlds that are just like ours until a tiny miracle.

331
00:41:41,110 --> 00:41:49,540
So tiny change in the laws of nature causes just enough divergence from our world for Nixon to press the button.

332
00:41:49,540 --> 00:41:55,630
And so what Lewis says, perhaps a couple of extra neurones fire in his brain or something like that.

333
00:41:55,630 --> 00:41:59,980
But anyway, you know, there he is. He's sitting there thinking about pressing the button in our world.

334
00:41:59,980 --> 00:42:07,120
He doesn't press it. But in this world, he does. God, maybe it's an accident.

335
00:42:07,120 --> 00:42:15,130
But once he's pressed the button, worlds of type one evolve in accordance with their own laws.

336
00:42:15,130 --> 00:42:23,230
And we know that these laws are very like ours because up until the point of pressing the button, the worlds have been identical.

337
00:42:23,230 --> 00:42:33,910
All we've got is a tiny miracle. So they're a perfect match with respect to matters of fact, up until the divergence miracle.

338
00:42:33,910 --> 00:42:37,450
And they're an almost match with respect to the laws.

339
00:42:37,450 --> 00:42:43,870
We only had a tiny, divergent miracle in order to get Nixon pressing the button.

340
00:42:43,870 --> 00:42:48,820
But the future of these worlds radically diverges from our own.

341
00:42:48,820 --> 00:42:56,590
There's a nuclear holocaust. So and this is why Fine thinks they can't be like our own.

342
00:42:56,590 --> 00:43:03,790
But what Lewis is arguing is that they can be, even though they're so unalike.

343
00:43:03,790 --> 00:43:06,370
So let's look at type two worlds.

344
00:43:06,370 --> 00:43:14,770
So these are worlds again, just like Harz, until there's a tiny divergence miracle which causes Nixon's press the button.

345
00:43:14,770 --> 00:43:19,870
But then there a convergence miracle. And so he presses the button.

346
00:43:19,870 --> 00:43:24,400
But there's no nuclear holocaust. Okay.

347
00:43:24,400 --> 00:43:33,940
So they're a perfect match with respect to the past until the divergence miracle, which causes Nixon to press the button.

348
00:43:33,940 --> 00:43:40,120
And although the Holocaust didn't happen, it's because there was a little convergence.

349
00:43:40,120 --> 00:43:45,370
Miracle. A little miracle that brought the world back.

350
00:43:45,370 --> 00:43:53,770
So there wasn't a Holocaust. And 10 years at Lewis says, 10 years after this convergence miracle.

351
00:43:53,770 --> 00:44:01,520
This world is going to be very different from our own. And that's because Nixon press the button.

352
00:44:01,520 --> 00:44:08,590
And the Holocaust didn't happen, so Nixon's, huh? Wiping the sweat from his brow is having a large gin.

353
00:44:08,590 --> 00:44:12,460
He's writing his memoirs. He gets the Nobel Peace prise.

354
00:44:12,460 --> 00:44:21,190
He, you know, et cetera, et cetera. And each of these little divergences of matters of fact, adds up to a big divergence.

355
00:44:21,190 --> 00:44:35,650
Ten years later. So, again, that world is like.

356
00:44:35,650 --> 00:44:41,500
So it's like [INAUDIBLE] up to the first miracle.

357
00:44:41,500 --> 00:44:50,500
Nixon presses the button. Here's another miracle, and there's no Holocaust.

358
00:44:50,500 --> 00:44:58,990
And you might think that this world is more like ours than so world one.

359
00:44:58,990 --> 00:45:05,500
It's like Harz until there's a first miracle. And then Nixon presses a button.

360
00:45:05,500 --> 00:45:13,270
And then there's a Holocaust. So this is not like us.

361
00:45:13,270 --> 00:45:19,540
And this is like ours. But increasingly divergent.

362
00:45:19,540 --> 00:45:29,910
And then. We've got type three worlds, which, again, just like us, till there's a tiny, divergent miracle which causes him to press the button.

363
00:45:29,910 --> 00:45:41,940
But then there's a convergence miracle that doesn't just prevent the Holocaust happening, but it also wipes out all traces.

364
00:45:41,940 --> 00:45:50,220
Of Nixon having pressed the button. Okay, so here we've got this just like us.

365
00:45:50,220 --> 00:45:56,280
And then there's a small divergence miracle. Nixon presses a button.

366
00:45:56,280 --> 00:46:03,810
And then there's another miracle. But where is this miracle just wiped out?

367
00:46:03,810 --> 00:46:10,770
He's pressing the button and left everything else the same. This wipes out.

368
00:46:10,770 --> 00:46:16,740
Every trace of button pressing.

369
00:46:16,740 --> 00:46:21,660
So he doesn't need a large gin. He doesn't write his memoirs.

370
00:46:21,660 --> 00:46:26,940
He doesn't know the light waves that would have gone from the button. Don't go.

371
00:46:26,940 --> 00:46:34,020
Everything goes back to how it was. So we've got this world like yours till Nixon presses the button.

372
00:46:34,020 --> 00:46:40,890
And then there's a holocaust. Not like ours at all after that. This one like ours till Nixon presses the button.

373
00:46:40,890 --> 00:46:48,720
And then, although there's a no holocaust, there have been a lot of little changes which will become bigger changes later on.

374
00:46:48,720 --> 00:46:52,800
And then this world, which is like us, till Nixon presses a button.

375
00:46:52,800 --> 00:46:58,660
And then because of another miracle exactly like ours from then on.

376
00:46:58,660 --> 00:47:06,920
OK. Lewis says.

377
00:47:06,920 --> 00:47:14,570
That these worlds. OK. What I've just said, these are a perfect match with respect to matters of fact, until the divergence miracle.

378
00:47:14,570 --> 00:47:22,940
And then they're a perfect match again, because the convergence miracle wipes out all traces.

379
00:47:22,940 --> 00:47:32,730
But the miracle required here, says Lewis, is huge. It's huge and it's diverse and it's complex.

380
00:47:32,730 --> 00:47:39,210
And that's because there are so many traces of Nixon pressing the button that have to be wiped out.

381
00:47:39,210 --> 00:47:42,960
And that you you can't just call that a small miracle.

382
00:47:42,960 --> 00:47:49,110
You can't just change a couple of neurones and have that.

383
00:47:49,110 --> 00:47:56,430
Do what you want. So the laws of nature in this world are very different from our own,

384
00:47:56,430 --> 00:48:01,530
and the need to postulate huge miracles means that these worlds are further from our

385
00:48:01,530 --> 00:48:06,540
world than the worlds in which we don't need to postulate a huge conversion miracle.

386
00:48:06,540 --> 00:48:12,930
So here these worlds, which is the outcome we wanted.

387
00:48:12,930 --> 00:48:18,390
We think that it's true that had Nixon not pressed the button, there would have been a holocaust.

388
00:48:18,390 --> 00:48:22,770
What we've got to rule out is these two sets of worlds.

389
00:48:22,770 --> 00:48:28,410
But Lewis thinks it's quite easy to rule out these sets of worlds as being more similar to our own.

390
00:48:28,410 --> 00:48:36,350
This one, because actually, if everything had been up till then as it was.

391
00:48:36,350 --> 00:48:42,960
And you don't introduce any more miracles. But that tiny little divergence, miracle, you'd get the Holocaust.

392
00:48:42,960 --> 00:48:49,750
You wouldn't get the no Holocaust world. Surely a free world.

393
00:48:49,750 --> 00:49:03,330
Is. I'd rather not introduce epistemological problems here.

394
00:49:03,330 --> 00:49:07,590
We're looking at it from a metaphysical point of view here. You're absolutely right.

395
00:49:07,590 --> 00:49:11,870
The only person who would know the difference. Well, actually, even Nixon wouldn't know the difference.

396
00:49:11,870 --> 00:49:17,090
Why is it because it's wiped out his memory? Exactly. So nobody would know the difference here.

397
00:49:17,090 --> 00:49:21,840
But but this is a this is a metaphysical thought experiment. It's not epistemological.

398
00:49:21,840 --> 00:49:29,950
You're absolutely right that the epistemologically we couldn't tell the difference between Major.

399
00:49:29,950 --> 00:49:37,170
Plus, why what sorry? Why would you say that would have been against the laws of nature?

400
00:49:37,170 --> 00:49:42,660
If he had pressed the button. Well, remember that we're thinking of the laws as deterministic.

401
00:49:42,660 --> 00:49:48,780
So in this world, the laws determine him not to press the button.

402
00:49:48,780 --> 00:49:54,340
Therefore, if he did press the button, there must have been a different set of laws.

403
00:49:54,340 --> 00:50:01,310
And or different matters of fact. So that's based on the idea that everything is.

404
00:50:01,310 --> 00:50:11,120
Yes. All these experiments are based on that, on the thought that they're determined into the future and indeed from the future into the past.

405
00:50:11,120 --> 00:50:16,760
OK, do you see why this is a rebuttal of the future similarities?

406
00:50:16,760 --> 00:50:20,630
Objection. Why we would choose that world as big.

407
00:50:20,630 --> 00:50:29,000
So even a world in which a holocaust has happened is going to be more similar to our world than than these other worlds,

408
00:50:29,000 --> 00:50:37,490
because you've got to change the laws of nature just too much to get those other worlds as being similar to our own.

409
00:50:37,490 --> 00:50:42,290
And as Chris quite helpfully pointed out, this is not an epistemological thought experiment.

410
00:50:42,290 --> 00:50:47,660
It's a metaphysical one. We've got to adopt a God Sci. view of this.

411
00:50:47,660 --> 00:50:53,090
We can't look at how what we would have thought if we had been there.

412
00:50:53,090 --> 00:51:03,110
Okay, so according to Lewis, there's an asymmetry of the miracles needed to change the past and those needed to change the future.

413
00:51:03,110 --> 00:51:13,100
So the four small, divergent miracles, those that change the future need only change a few neurones in Nixon's brain.

414
00:51:13,100 --> 00:51:18,770
But the huge convergent miracles, those that wipe out those that change the past,

415
00:51:18,770 --> 00:51:28,460
have got to wipe out the many diverse and widespread changes of the traces of Nixon's pressing the button.

416
00:51:28,460 --> 00:51:37,820
So not just Nixon's neurones at Nixon's brain, but also his sweat on his finger has got to gather up from the button and leap back to his finger,

417
00:51:37,820 --> 00:51:45,030
and he stops looking at the gin bottle and and so on.

418
00:51:45,030 --> 00:51:55,730
And according to Lewis, this justifies our thinking that Type one worlds are closer to our worlds than type two or three worlds.

419
00:51:55,730 --> 00:52:01,340
And that's the end of the future. Similarity. Objection.

420
00:52:01,340 --> 00:52:14,930
And the asymmetry of over determination explains the asymmetry of counterfactual dependence because it generates this asymmetry of miracles.

421
00:52:14,930 --> 00:52:19,610
So there'll always be an asymmetry of miracles that you need to change the future.

422
00:52:19,610 --> 00:52:28,600
And miracles, you need to change the past, says Lewis. And that asymmetry of miracles.

423
00:52:28,600 --> 00:52:33,940
Generates counterfactual. The asymmetry is some counterfactual dependence because it depends on that.

424
00:52:33,940 --> 00:52:39,780
Or maybe the other way round. I can't remember which way I'm thinking. Okay.

425
00:52:39,780 --> 00:52:46,290
So let's just have a look. Justice explain the relation between the causal arrow and the temporal, Larry.

426
00:52:46,290 --> 00:52:54,330
Now, this is the place where the physicists in the audience can watch me and wonder if I get it right.

427
00:52:54,330 --> 00:53:02,220
So the asymmetry of over determination is a contingent empirical asymmetry.

428
00:53:02,220 --> 00:53:06,360
It's contingent. Nobody is saying it's an oh, sorry.

429
00:53:06,360 --> 00:53:12,390
Okay, it's an objective feature of the world. Okay. It's not something that we're projecting onto the world.

430
00:53:12,390 --> 00:53:20,100
It's an objective feature of the world. And according to Lewis explains both the arrow of time and the causal arrow.

431
00:53:20,100 --> 00:53:25,650
And therefore, the fact that they're aligned with each other.

432
00:53:25,650 --> 00:53:33,270
And if the eight, he says at the end of his piece that I I'm using relying on quite heavily here.

433
00:53:33,270 --> 00:53:41,670
And which, of course, is referenced in your hand out. If the asymmetry of over to termination could be related to the asymmetry of entropy.

434
00:53:41,670 --> 00:53:51,870
He says he doesn't know how to do this. It would ensure that his account is respectable from a physicalist point of view as well.

435
00:53:51,870 --> 00:53:59,580
But other people have done this. I mean, it was many years ago that he said he didn't know how to do this.

436
00:53:59,580 --> 00:54:03,200
So the laws of fundamental physics, as we saw, I think either last week,

437
00:54:03,200 --> 00:54:10,950
all the time before our time symmetric and they run forwards, they run backwards, symmetrical.

438
00:54:10,950 --> 00:54:17,490
There's no a symmetry that couldn't come in there, except, I mean, apparently,

439
00:54:17,490 --> 00:54:23,900
I'm told there are a few particles which that might not be true, which I assume are tachyons.

440
00:54:23,900 --> 00:54:32,610
Okay. Well, so we might think if we think this that time can't be asymmetric and there are physicists who

441
00:54:32,610 --> 00:54:39,390
think that time can't be asymmetric because all that time doesn't exist because of this.

442
00:54:39,390 --> 00:54:44,750
But there is a part of physics that does permit temporal asymmetry.

443
00:54:44,750 --> 00:54:49,290
And it's Thurm Ajin thermodynamics. Okay.

444
00:54:49,290 --> 00:54:53,940
It's that branch of physics. So this is physics one oh one. Right, for the rest of you.

445
00:54:53,940 --> 00:55:04,360
And for me, it's that branch of physics that is concerned with heat and temperature and their relation to energy and work.

446
00:55:04,360 --> 00:55:08,210
And therefore, laws of thermodynamics. And the one that concerns us.

447
00:55:08,210 --> 00:55:14,000
Oh, OK. So all these laws express constraints on macroscopic variables.

448
00:55:14,000 --> 00:55:23,240
OK. They're not the microscopic variables, but the macroscopic ones pressure entropy, an internal energy, the energy within a system.

449
00:55:23,240 --> 00:55:30,200
And these are common to all materials rather than just particular to particular materials.

450
00:55:30,200 --> 00:55:38,900
It's the second law of thermodynamics that tells us that entropy always increases, that unconstrained energy and matter will spread.

451
00:55:38,900 --> 00:55:47,180
So if you look at the picture that's rather ghostly behind this here, you've got something being contained.

452
00:55:47,180 --> 00:55:57,080
But when you remove the constraints, it expands into the area that's available to it.

453
00:55:57,080 --> 00:56:03,030
So entropy always increases, is unconstrained energy and matto will spread.

454
00:56:03,030 --> 00:56:06,650
And entropy is the only quantity in physics,

455
00:56:06,650 --> 00:56:14,240
the measurement of which requires us to postulate a particular direction of time as we go forward in time.

456
00:56:14,240 --> 00:56:23,270
The entropy of an unconstrained system will increase. And that's why if you don't drink your coffee quickly enough, it'll go cold.

457
00:56:23,270 --> 00:56:29,080
The heat will disperse.

458
00:56:29,080 --> 00:56:41,120
So if we can if we can link the asymmetry of over determination with the asymmetry of entropy, we'll have a contingent empirically and physical,

459
00:56:41,120 --> 00:56:56,670
distinctly respectable asymmetry that in underlying the temporal and causal asymmetries explains why the two asymmetries align.

460
00:56:56,670 --> 00:57:04,620
I'm going to say sorry. I'm going to say something later about whether this is possible, because there are people who think that this isn't possible.

461
00:57:04,620 --> 00:57:09,060
And there are other people who think that it is possible, but only under certain conditions.

462
00:57:09,060 --> 00:57:12,180
And I'll say something about that in a minute. But at the moment,

463
00:57:12,180 --> 00:57:18,000
I just want to say that this the link between entropy and the asymmetry of over determination

464
00:57:18,000 --> 00:57:26,940
would give us just what we want as long as it solves the two problems that we looked at earlier.

465
00:57:26,940 --> 00:57:36,600
So let's look at the first problem. Does it permit the possible permit, the possibility in principle of simultaneous and backwards causation?

466
00:57:36,600 --> 00:57:44,300
Well. It's it is a contingent, a cemetery.

467
00:57:44,300 --> 00:57:49,840
There is nothing necessary about it. So that allows that they're all worlds.

468
00:57:49,840 --> 00:57:58,390
Not this world maybe, but there are worlds in which causation is simultaneous or backwards or both.

469
00:57:58,390 --> 00:58:06,760
And it also allows that there might even this world be cases of simultaneous or backwards causation.

470
00:58:06,760 --> 00:58:11,050
So it is just saying this is typically the case.

471
00:58:11,050 --> 00:58:17,350
It's typically the case in this world and it's a contentions matter.

472
00:58:17,350 --> 00:58:22,720
So it allows there to be in this world simultaneous and backwards causation.

473
00:58:22,720 --> 00:58:30,620
And it allows there to be plenty of other worlds in which they're similar to. So it certainly meets that constraint.

474
00:58:30,620 --> 00:58:34,190
And. OK.

475
00:58:34,190 --> 00:58:43,740
Does it explain our deliberative practises? Well, it explains our common refusal to backtrack.

476
00:58:43,740 --> 00:58:50,160
So imagine that Joanna and Jayne had a really bad quarrel yesterday.

477
00:58:50,160 --> 00:58:58,050
Lewis has Jim and Jack, but I think that it's quite important to knowledge that there are women in the world.

478
00:58:58,050 --> 00:59:02,730
So imagine that Joanna and Jane had a quarrel yesterday.

479
00:59:02,730 --> 00:59:08,070
You might think that if John asked Jane for help today, Jane would say no.

480
00:59:08,070 --> 00:59:15,420
Would you usually think that that's the counterfactual that would tell us what would happen if John asked Jane for help.

481
00:59:15,420 --> 00:59:22,620
But why don't we reason that if John asked Jane for help today, it would be because there hadn't been a quarrel yesterday.

482
00:59:22,620 --> 00:59:28,160
So she'd say yes. Well, we don't not reason like that.

483
00:59:28,160 --> 00:59:31,970
And one of the reasons we don't reason like that, according to Lewis,

484
00:59:31,970 --> 00:59:41,870
is because of the asymmetry of over determination, because of our belief that we can't change the past.

485
00:59:41,870 --> 00:59:46,550
So it explains are reluctance to backtrack.

486
00:59:46,550 --> 00:59:49,010
Actually, we will backtrack.

487
00:59:49,010 --> 00:59:58,610
I mean, if if we were talking about Johna and Jane's quarrel and you suggest, well, if John asked Jane for help, Jane would say no.

488
00:59:58,610 --> 01:00:06,830
I might jokingly say, well, actually, if John Ross Jane felt today, it would be because there hadn't been a quarrel and you would laugh, wouldn't you?

489
01:00:06,830 --> 01:00:17,750
But you wouldn't take it seriously, because we can all imagine situations where it was true that despite the quarrel, Joanna had asked Jane for help.

490
01:00:17,750 --> 01:00:23,090
But they all involve situations that are so emotionally tearing or, you know,

491
01:00:23,090 --> 01:00:31,820
if something had happened that meant that John's child was her life was hanging on a thread and the only person who could help would be Jane.

492
01:00:31,820 --> 01:00:37,660
She would ask John the fact, Jane, for help, wouldn't she? Despite the quarrel.

493
01:00:37,660 --> 01:00:45,180
But so none of these situations involve the quarrels not having happened.

494
01:00:45,180 --> 01:00:46,860
But others have asked why?

495
01:00:46,860 --> 01:00:55,860
The fact of a asymmetry of over determination should lead to our determining it's not rational to act with past ends in mind.

496
01:00:55,860 --> 01:01:00,420
So I thought you'd like to do this little Newcome problem.

497
01:01:00,420 --> 01:01:06,000
Some of you may know it, but the rest of you, OK.

498
01:01:06,000 --> 01:01:12,480
There are two boxes and this one is transparent. I know it doesn't look it, but it is.

499
01:01:12,480 --> 01:01:18,930
And that's why you can see that inside it. There's a thousand dollars. This one is opaque.

500
01:01:18,930 --> 01:01:26,880
You can't see what's inside that. But luckily, I can tell you that.

501
01:01:26,880 --> 01:01:34,570
In a minute, you're going to be asked to choose whether to take just one of these boxes or to take both of them.

502
01:01:34,570 --> 01:01:39,100
And that and an infallible predictor.

503
01:01:39,100 --> 01:01:46,930
Somebody who knew which you were, which choice you are going to make has put either nothing in that box.

504
01:01:46,930 --> 01:01:57,740
If he reckons you were going to choose both boxes or a million dollars, if you thought you were just going to choose that box.

505
01:01:57,740 --> 01:02:01,520
So which is going to choose. Both boxes. Put your hand up if you're going to choose.

506
01:02:01,520 --> 01:02:11,190
Both boxes. So shall I go over that again or is it clear?

507
01:02:11,190 --> 01:02:17,650
Yes, I will. OK. So you've got two boxes, one transparent. You can see there's a thousand dollars in it, one opaque,

508
01:02:17,650 --> 01:02:26,810
which is either empty or half a million dollars in it, depending on weather and into an infallible predictor.

509
01:02:26,810 --> 01:02:32,440
Reckons you would choose just this box or the two boxes.

510
01:02:32,440 --> 01:02:37,360
And he thought, okay. So looking at Mike, isn't it?

511
01:02:37,360 --> 01:02:41,140
Mike's going to choose one box that just this box.

512
01:02:41,140 --> 01:02:46,840
I'm going to put a million pounds in it. But what's your name?

513
01:02:46,840 --> 01:02:51,400
Adrian is going to choose both boxes. I'm going to put nothing in here.

514
01:02:51,400 --> 01:03:00,100
Okay, who's going to pick both boxes? Hands up so I can see.

515
01:03:00,100 --> 01:03:04,640
OK, who's going to pick just the one box? Just the opaque box.

516
01:03:04,640 --> 01:03:13,300
I'm the one box or two. OK. So, so relatively easily, evenly divided.

517
01:03:13,300 --> 01:03:18,850
Those who would pick the two boxes. Why would you pick the two?

518
01:03:18,850 --> 01:03:28,870
What's your justification for picking the two? Can anyone tell me. Mm hmm.

519
01:03:28,870 --> 01:03:34,750
OK. So you're going to if you buy picking two, you get a thousand dollars, whatever happens.

520
01:03:34,750 --> 01:03:41,430
And if there's a million pounds in here, you're doing even better. OK, minus.

521
01:03:41,430 --> 01:03:46,300
So you take my money. No, no.

522
01:03:46,300 --> 01:03:53,330
That one's going to have a thousand dollars in it, whatever you do. Say that was that you must pay about.

523
01:03:53,330 --> 01:03:58,310
No, no, that's not. In this one, there's either nothing or there's a million pounds.

524
01:03:58,310 --> 01:04:03,820
Oh, I see. You're changing the experiment. I'd have to think about that.

525
01:04:03,820 --> 01:04:08,390
OK. Those of you who say that, you would only pick one.

526
01:04:08,390 --> 01:04:18,060
What's your reason there? Because I notice that if I it must be predicted.

527
01:04:18,060 --> 01:04:20,680
It's okay,

528
01:04:20,680 --> 01:04:30,310
because you your what do you want to do is provide evidence to yourself that the infallible predictor didn't predict that you would pick the only one.

529
01:04:30,310 --> 01:04:34,360
In which case they'll be a million pounds in it. Why the two boxes?

530
01:04:34,360 --> 01:04:38,920
Why didn't you go along with that? What makes you think that in picking both.

531
01:04:38,920 --> 01:04:47,350
There might be a million pounds in there rather than nothing. Oh, right.

532
01:04:47,350 --> 01:04:56,260
Well, forget you. Are you saying the invalid. If you want a million dollars.

533
01:04:56,260 --> 01:05:03,160
If he thought you would pick only that box, he would have put a million pounds in that box.

534
01:05:03,160 --> 01:05:11,090
Whereas if he thought that you'd pick both, he would put you trust the concept.

535
01:05:11,090 --> 01:05:17,980
Yes. Because, I mean, the interesting thing about this is, that's all.

536
01:05:17,980 --> 01:05:24,710
So you'd you'd have both. Okay, so you have both boxes, your two Bokser.

537
01:05:24,710 --> 01:05:35,980
Okay. The thought is here that when you're actually making your choice, it's too late, isn't it, that whatever has happened has already happened.

538
01:05:35,980 --> 01:05:41,410
So you should. If we're right that we never think of doing anything to affect the past,

539
01:05:41,410 --> 01:05:47,390
there's nothing we can do at this point, in which case we may as well take both.

540
01:05:47,390 --> 01:05:52,150
That's the thinking. And that's why Lewis says he would take both.

541
01:05:52,150 --> 01:06:00,310
But the rest of us, those of us who won boxes, have a slight sneaking suspicion that actually by taking this box,

542
01:06:00,310 --> 01:06:10,210
we can make it to have been the case, that the infallible predictor will have predicted that we would choose that one.

543
01:06:10,210 --> 01:06:15,310
And so he would have put a million pounds in it anyway.

544
01:06:15,310 --> 01:06:22,330
Possibly you might. So you're free.

545
01:06:22,330 --> 01:06:35,010
I don't need to bring free will into it. Yes, she took up the whole point of.

546
01:06:35,010 --> 01:06:44,560
My prediction is infallible. And there's probably 10 pounds in there.

547
01:06:44,560 --> 01:06:56,030
Yes, that's why you would choose two boxes, presumably, so you don't lose anything by choosing two boxes through your speech.

548
01:06:56,030 --> 01:07:04,300
Yeah, but I assumed that's what you were thinking because that's what a two boxes would think.

549
01:07:04,300 --> 01:07:14,230
Assuming your table say sorry. So Soskin experiments are.

550
01:07:14,230 --> 01:07:24,500
No, I don't think they're grounded in reality, it's. Yes, actually, I have one.

551
01:07:24,500 --> 01:07:35,300
I mean, you there's some description's is this experiment to have an almost infallible predictor and others have an infallible predictor,

552
01:07:35,300 --> 01:07:43,020
but almost infallible is probably better for the reason that you're saying.

553
01:07:43,020 --> 01:07:47,860
OK. Because if it's infallible, he would have known that you would choose only that one.

554
01:07:47,860 --> 01:07:52,060
Yep. OK. So. Oh, sorry.

555
01:07:52,060 --> 01:07:57,290
Got not done that. So Lewis says that you should take both boxes.

556
01:07:57,290 --> 01:08:04,040
And then he believes that our rational deliberations are determined by the asymmetry of over determination.

557
01:08:04,040 --> 01:08:11,740
But if we realise the infallible predictor would have known that we would choose the single box, then.

558
01:08:11,740 --> 01:08:20,070
Those of us who would choose the one box would say it's not irrational to choose the one box, there's a good reason for doing so.

559
01:08:20,070 --> 01:08:28,480
So all rational deliberations are not guided solely by the asymmetry of over determination.

560
01:08:28,480 --> 01:08:38,160
Now, I'm happy if you ask lots of questions about that later, because I'm not sure I entirely understand how the how it works here.

561
01:08:38,160 --> 01:08:44,070
And I'm still I'd like to have given a lot more thought to that before doing the essays.

562
01:08:44,070 --> 01:08:47,790
So if you want to ask questions about that, we can work it out together.

563
01:08:47,790 --> 01:08:54,390
But let's go on to the sixth question, which is, should we accept Lewis's account?

564
01:08:54,390 --> 01:08:59,820
So we've looked at what Lewis's account is. So he says that the reason,

565
01:08:59,820 --> 01:09:06,600
the causal asymmetry and the temporal symmetry are aligned is because both are determined by the asymmetry

566
01:09:06,600 --> 01:09:14,640
of over determination and that the asymmetry of over determination is a contingent empirical asymmetry,

567
01:09:14,640 --> 01:09:24,120
possibly relatable to the asymmetry of entropy, which is an objective fact about the world in which we live.

568
01:09:24,120 --> 01:09:28,860
And it's quite consistent with there being simultaneous and backwards causation.

569
01:09:28,860 --> 01:09:38,280
And it's it explains at least some of our rational choices.

570
01:09:38,280 --> 01:09:43,680
So. Well, Adam Elgar and all the references are, again, on your handouts.

571
01:09:43,680 --> 01:09:53,360
Where are your handouts? Are they. Have you gotten Doug? Oh, no, well, wait until the end.

572
01:09:53,360 --> 01:10:01,550
So Adam Elga thinks that convergence miracles needn't be large and diverse.

573
01:10:01,550 --> 01:10:09,110
So if you remember, Lewis's account depends upon an asymmetry of miracles.

574
01:10:09,110 --> 01:10:17,090
It depends upon the idea that miracles that caused a divergence can be small, very small.

575
01:10:17,090 --> 01:10:24,860
Whereas miracles that cause a convergence must be big and diverse and wide spread.

576
01:10:24,860 --> 01:10:37,070
Well, Adam Algorithm, in a rather very interesting paper, argues that actually they needn't be large and diverse at all.

577
01:10:37,070 --> 01:10:40,400
It depends upon the boundary conditions.

578
01:10:40,400 --> 01:10:48,250
And if the boundary if the boundary conditions change just slightly, you could actually get a reconversion miracle.

579
01:10:48,250 --> 01:10:52,490
That's very small as well. I recommend you to read that paper.

580
01:10:52,490 --> 01:10:59,720
If you're a physicist and really want to know what I'm talking about here, because that will tell you what I'm talking about.

581
01:10:59,720 --> 01:11:06,980
But Price and Westlake show that that just needs to shows that we need to set boundary conditions.

582
01:11:06,980 --> 01:11:14,510
If we relate the asymmetry of over determination with the asymmetry of entropy,

583
01:11:14,510 --> 01:11:20,390
and we need to say that we should only consider those possible worlds in which the

584
01:11:20,390 --> 01:11:27,050
boundary conditions are as we think the boundary conditions must be in this world,

585
01:11:27,050 --> 01:11:34,730
i.e., we started off many, many years ago at the beginning of our universe with a state of very low entropy.

586
01:11:34,730 --> 01:11:40,770
And this is called the past hypothesis. And.

587
01:11:40,770 --> 01:11:49,440
According to Price in Westlake, if you assume that the asymmetry of over determination is constrained by the past hypothesis,

588
01:11:49,440 --> 01:11:55,770
as the asymmetry of entropy must be constrained by the half past hypothesis,

589
01:11:55,770 --> 01:12:07,230
if it's to deliver our experiences, then you get a very nice link between entropy and over determination.

590
01:12:07,230 --> 01:12:15,420
They also think, however, that unless we build in the asymmetry for a rational of rational deliberation from the beginning,

591
01:12:15,420 --> 01:12:24,560
we'll never succeed in getting it. They actually think that all these asymmetries are subjective.

592
01:12:24,560 --> 01:12:33,090
In fact, that fundamental physics is absolutely right. There is no asymmetry at a fundamental level in the world.

593
01:12:33,090 --> 01:12:42,090
And the symmetry sorry, the asymmetry at the macro level is entirely subjective.

594
01:12:42,090 --> 01:12:44,610
And there are physicists. This is for you.

595
01:12:44,610 --> 01:12:55,470
There are physicists and philosophers and there are references on the sheet who believe that time isn't real and perhaps at the micro level it isn't.

596
01:12:55,470 --> 01:12:59,250
What does this tell us about its reality at the micro level?

597
01:12:59,250 --> 01:13:11,630
Perhaps these two are right to think that actually all these asymmetries are entirely the result of our perspective as rational agents on the world.

598
01:13:11,630 --> 01:13:15,080
Okay. Oh, sorry. There's someone else.

599
01:13:15,080 --> 01:13:22,760
So Matthias Frist, Fresh, believes that temporal asymmetry depends on causal asymmetry rather than the other way round.

600
01:13:22,760 --> 01:13:28,380
So, again, you can have a look at that. I haven't considered his view at all.

601
01:13:28,380 --> 01:13:33,640
So. We've got courtroom now, which you can tell me what you think.

602
01:13:33,640 --> 01:13:38,390
And just to say we've examined the alignment of the course, Laro and the Temporal Arrow.

603
01:13:38,390 --> 01:13:46,480
Next week is the last week of these lectures. And we're going to be looking at mental causation and whether causation when

604
01:13:46,480 --> 01:13:53,360
it comes to mental states is different from causation in the physical world.

605
01:13:53,360 --> 01:14:03,180
Oh, I still give voice. Just.

606
01:14:03,180 --> 01:14:11,530
Bob. Right. I'm go back to the forest for better.

607
01:14:11,530 --> 01:14:25,390
I can see the good lighting, the camper, lighting the fire, causes the forest fire and causes loads of pieces of evidence to be around a year later.

608
01:14:25,390 --> 01:14:29,410
Yeah. Which are caused by those we might call the effects.

609
01:14:29,410 --> 01:14:37,900
I can see the forensic scientists will be able to focus on any number of events independently without

610
01:14:37,900 --> 01:14:45,620
the others and say this effect shows conclusively that the fire started when and where it did.

611
01:14:45,620 --> 01:14:51,770
But I don't think anybody in normal English. Would say that those effects.

612
01:14:51,770 --> 01:14:55,670
Were the cause? No, nobody's saying that the cause, see?

613
01:14:55,670 --> 01:15:00,180
In that case, let me say. Well, that's a purely yes.

614
01:15:00,180 --> 01:15:07,230
OK. Well, perhaps you could say they were the. I why wouldn't you say it's the cause.

615
01:15:07,230 --> 01:15:13,380
Answer because you think causes come before effects. Because I think it's just not the use of the word cause.

616
01:15:13,380 --> 01:15:25,810
We would say that there is. There's absolutely no doubt that you wouldn't say cause you'd say that they are they are the reason why I believe.

617
01:15:25,810 --> 01:15:37,730
Whereas the writing was. Was the reason why it happened, not the reasons the police.

618
01:15:37,730 --> 01:15:43,930
And it's not only because the word cause you you would use cause here.

619
01:15:43,930 --> 01:15:48,080
So. Sorry, I should have two things here.

620
01:15:48,080 --> 01:15:55,470
I'm going to run out of paper. Crosswords getting.

621
01:15:55,470 --> 01:16:10,220
Hang on, let me just draw things as I want to draw them. OK.

622
01:16:10,220 --> 01:16:17,020
The camp fire cause is a sufficient condition of the forest fire caused the forest fire

623
01:16:17,020 --> 01:16:25,300
and the forest fire caused the traces that the forensic scientist is able to trace back.

624
01:16:25,300 --> 01:16:33,450
And what you're saying is that you're happy to use the word cause here and indeed here.

625
01:16:33,450 --> 01:16:39,130
Yeah, but what you won't use is cause here.

626
01:16:39,130 --> 01:16:44,630
Not. I mean, so the traces of the fire didn't cause the fire.

627
01:16:44,630 --> 01:16:55,990
And you you assume that that's what I'm saying. Bearing in mind that the laws are deterministic.

628
01:16:55,990 --> 01:16:59,620
You could say this caused it to be the case that that.

629
01:16:59,620 --> 01:17:22,900
But I agree we wouldn't usually do that. But can I say that Trace A is a necessary part of a minimal sufficient condition for there having been a far.

630
01:17:22,900 --> 01:17:35,790
So I'm not using the word cause. It's a minimal a sufficient condition for there to have been a fire.

631
01:17:35,790 --> 01:17:47,830
Sorry. It's. Who should have put is a necessary part of a minimal sufficient condition for there to have been a fire.

632
01:17:47,830 --> 01:17:52,940
None. What, it's a minimum, yes, it is. It's a minimal whatever you just said.

633
01:17:52,940 --> 01:17:59,400
Compassion for empathy for our believing that there was a fight.

634
01:17:59,400 --> 01:18:09,960
Well, possibly FXE. It's. I mean, I'm trying to keep our beliefs out of this, if you like.

635
01:18:09,960 --> 01:18:16,960
I mean. I'm looking at the relation between this trace trace, a underfire,

636
01:18:16,960 --> 01:18:28,570
and I'm saying that trace is a necessary part of a minimal sufficient condition for there having been the fire or for that to have been the fire.

637
01:18:28,570 --> 01:18:33,160
So I agree that we are using the word cause here.

638
01:18:33,160 --> 01:18:40,300
It feels all wrong. One condition. Well, can I leave you to think about that?

639
01:18:40,300 --> 01:18:44,920
Because obviously you don't find nothis as worrying.

640
01:18:44,920 --> 01:19:03,050
And you might ask yourself, why is the secondary?

641
01:19:03,050 --> 01:19:05,780
They would call these the initial and secondary causes,

642
01:19:05,780 --> 01:19:16,750
it could have caused the initial cause and those others going to traces as the secondary causes of the campfire.

643
01:19:16,750 --> 01:19:25,360
Yes. The fire, not the. Oh. Would have been the initial cause.

644
01:19:25,360 --> 01:19:34,960
But if my should be more low to have the camp fire not spread to, say, containers of, I don't know,

645
01:19:34,960 --> 01:19:44,400
butane gas that he got for cooking, that would then have blown the thing much wider and actually caused the total forest.

646
01:19:44,400 --> 01:19:50,670
So forensic scientist would look at them as initial primary causes.

647
01:19:50,670 --> 01:19:59,230
This is where they were caused. And then second coastline, but maybe yes.

648
01:19:59,230 --> 01:20:09,620
But but that doesn't response to Bob's point because he is happy to allow that causes can be in the past and have effects in the future.

649
01:20:09,620 --> 01:20:12,260
That causes in the past can have effects in the future.

650
01:20:12,260 --> 01:20:22,610
What he's unhappy about is what he saw as my surge, suggesting that there are causes in the in the future of things in the past.

651
01:20:22,610 --> 01:20:28,340
And I hope that I've put in slightly at ease by saying that we don't have to use the word causes here.

652
01:20:28,340 --> 01:20:43,210
We. It's certainly true that the camp fire would have itself had lots of effect that combines to produce the forest fire.

653
01:20:43,210 --> 01:20:51,640
And those would be secondary causes on your yeah, because the ninety five with the primary indignation.

654
01:20:51,640 --> 01:20:57,970
Yeah. Yeah. But then several other things happened.

655
01:20:57,970 --> 01:21:01,920
Yeah. And the fire was no longer contained.

656
01:21:01,920 --> 01:21:05,470
It went wider and went into a forest fire.

657
01:21:05,470 --> 01:21:12,350
Yeah. The fire started. It was just a campfire. Yeah, yeah, yeah, no, I see exactly what I mean.

658
01:21:12,350 --> 01:21:16,820
But something you just say. Yeah.

659
01:21:16,820 --> 01:21:24,170
I mean, what's your job? The secondary causes are in here, aren't they? Yeah.

660
01:21:24,170 --> 01:21:33,710
Well, the camp fire caused the secondary causes. And then the secondary causes combines to to cause the forest fire.

661
01:21:33,710 --> 01:21:43,200
Yes. Sorry, say again this.

662
01:21:43,200 --> 01:21:49,970
The secondary causes your meaning. The factors that contributed.

663
01:21:49,970 --> 01:21:54,310
Oh, OK. So things like the butane gasping there.

664
01:21:54,310 --> 01:22:03,050
Okay. So so they were just okay. There was a whole context within which the campfire led to the forest fire.

665
01:22:03,050 --> 01:22:09,590
I mean, that doesn't go against anything I've said here. I mean, we've always allowed that when you strike the match.

666
01:22:09,590 --> 01:22:13,670
The match only causes the lighting of the flame if there is oxygen around.

667
01:22:13,670 --> 01:22:18,060
There's always a context within which, of course, has its effect.

668
01:22:18,060 --> 01:22:27,870
The tree friendly fire also means many conditions.

669
01:22:27,870 --> 01:22:36,120
Yeah. I guess you can say asymmetrical because there are trees not just to the fire.

670
01:22:36,120 --> 01:22:40,970
Okay. There's no easy. Well, if you don't think there's any asymmetry,

671
01:22:40,970 --> 01:22:52,750
then you will agree with Elgar and you might read his paper because he he also disagrees with Lewis that there is an asymmetry of well,

672
01:22:52,750 --> 01:22:57,050
that there's an asymmetry in miracles and therefore an asymmetry of over determination.

673
01:22:57,050 --> 01:23:11,620
Chris, very. In fact, physics may well require as a condition.

674
01:23:11,620 --> 01:23:21,230
Quantum mechanics, however, are much less happy about the suggestion that, as I understand, the effects occurred before the cause.

675
01:23:21,230 --> 01:23:30,740
But could causation? Well, nobody's saying that it can. All we're doing is is leaving the possibility open.

676
01:23:30,740 --> 01:23:35,310
If we. So if I'm going to tell me.

677
01:23:35,310 --> 01:23:41,150
But the man in the street believes that can't happen.

678
01:23:41,150 --> 01:23:49,860
We need to take and Louis' Count does take account of that, what what he's saying is that there typically.

679
01:23:49,860 --> 01:24:03,310
So if I go back to the slides where I'm considering that.

680
01:24:03,310 --> 01:24:12,370
OK. So does he permit the possibility in principle of simultaneous and backwards causation?

681
01:24:12,370 --> 01:24:18,640
All he's saying is that it's typically the case that causes come before their effects.

682
01:24:18,640 --> 01:24:22,440
There might be cases in this world. He's not saying there are cases in this world.

683
01:24:22,440 --> 01:24:28,620
There might be cases of simultaneous and backwards causation in this world and there might not.

684
01:24:28,620 --> 01:24:33,570
And there are worlds in which there is cases of simultaneous causation.

685
01:24:33,570 --> 01:24:39,170
There are also worlds in which there are cases of backwards causation right from the very beginning.

686
01:24:39,170 --> 01:24:49,330
It is human that's given us the idea that the word cause means comes before in effect.

687
01:24:49,330 --> 01:24:53,110
Well, well, no, because the thing is you do.

688
01:24:53,110 --> 01:25:02,070
It's certainly true that our experience tells us the causes come before effects, but that's consistent with everything that everybody said.

689
01:25:02,070 --> 01:25:07,420
But we do wonder about time travel. We do wonder about.

690
01:25:07,420 --> 01:25:14,490
And I'm wondering about time travel, where we're postulating backwards causation.

691
01:25:14,490 --> 01:25:19,950
But I'm right. I'm not like a philosophical argument that denies.

692
01:25:19,950 --> 01:25:34,430
Backward causation. You're not getting this you could all this argument is saying is that in principle then might be worlds out there and it might not

693
01:25:34,430 --> 01:25:45,860
be this one in which there is backwards causation in which an an egg might sort of uncork itself and leap back into its shell.

694
01:25:45,860 --> 01:25:58,930
But they're not saying it's this world. Do you see, I mean, there's a very it's a very important point here where what Lewis is doing, I think,

695
01:25:58,930 --> 01:26:08,500
is making sense of the eye of why lots of people have thought the backwards causation might be possible.

696
01:26:08,500 --> 01:26:12,550
Another people of thought, simultaneous causation might be possible.

697
01:26:12,550 --> 01:26:20,170
And he's allowed us to do that, whereas Hume doesn't. Hume just rules it out a priori.

698
01:26:20,170 --> 01:26:28,570
David, we see lots of things niggled me about it.

699
01:26:28,570 --> 01:26:32,670
Gone is the verdict rational?

700
01:26:32,670 --> 01:26:38,260
Was he just omniscient? What presumably is rational as well.

701
01:26:38,260 --> 01:26:42,690
Because he said he was acting for reasons, isn't he? He's easy.

702
01:26:42,690 --> 01:26:51,940
He's just the sort of peculiar machine whose actions are determined by the position of it goes through the slit.

703
01:26:51,940 --> 01:26:59,860
Well, we've got to right into the thought experiment that he puts a thousand pounds of sorry, a million pounds into the opaque box.

704
01:26:59,860 --> 01:27:04,840
If he believes that you're going to choose. Just so he's acting for a reason,

705
01:27:04,840 --> 01:27:14,550
he's put the thousand million pounds in there because he believes that you're going to choose that box only applies to charities.

706
01:27:14,550 --> 01:27:19,960
You. I'm not sure I'd call it a principle of charity.

707
01:27:19,960 --> 01:27:28,290
He has views on the choices that you will make in the future.

708
01:27:28,290 --> 01:27:33,780
He believes that you will choose two boxes, but you will choose only one.

709
01:27:33,780 --> 01:27:39,300
And on the basis of his belief that you will choose two boxes, he's going gonna put nothing in the second box.

710
01:27:39,300 --> 01:27:42,900
And on the basis of the fact that you against choose both boxes, No.

711
01:27:42,900 --> 01:27:46,570
One box, he's going to put a million pounds in there. Is he generous?

712
01:27:46,570 --> 01:27:56,640
Was he trying to make it? He's trying to confound you all on me.

713
01:27:56,640 --> 01:28:06,480
He's probably quite predictable on an individual basis, but he's making this individual prediction.

714
01:28:06,480 --> 01:28:15,090
Oh, it would have to you know, it would have to be for for one particular person, one choice and one choice of that person.

715
01:28:15,090 --> 01:28:19,970
Because, I mean, you might having chosen one way the first time might think something solid.

716
01:28:19,970 --> 01:28:25,430
Going to choose the other way the next time. Because I know.

717
01:28:25,430 --> 01:28:29,700
Do got it. Oh I see what you mean.

718
01:28:29,700 --> 01:28:35,970
I'm sorry. I shouldn't either. By choosing the box I'm trying.

719
01:28:35,970 --> 01:28:39,550
You can't influence sets. No, you can't influence it.

720
01:28:39,550 --> 01:28:45,630
It's already done. The choices already be made as to whether there's a million pounds in there or nothing.

721
01:28:45,630 --> 01:28:50,440
But what you're trying to do is provide evidence for his having chosen.

722
01:28:50,440 --> 01:28:54,490
Yes. To put a million pounds in there.

723
01:28:54,490 --> 01:29:00,060
Doesn't your rationality determine how he's going? Yes. Yep.

724
01:29:00,060 --> 01:29:10,740
Yep. I mean, that's why it's a game theory problem. But he knew what you were going to choose.

725
01:29:10,740 --> 01:29:19,790
I mean, when you write that in, you've immediately got a situation that isn't like any situation you're actually going to have.

726
01:29:19,790 --> 01:29:26,040
Well, he's omniscient and rational, isn't he? I'm not convinced he's not just on this.

727
01:29:26,040 --> 01:29:31,410
OK, so you think it's what?

728
01:29:31,410 --> 01:29:38,310
I'm just not convinced that it isn't a case of an exercise in risk on both sides.

729
01:29:38,310 --> 01:29:45,000
Well, it is your risk. I mean, if you choose one box, you're risking losing the thousand pounds thousand pounds.

730
01:29:45,000 --> 01:29:50,390
If you choose both boxes, you're risking losing a million pounds. I.

731
01:29:50,390 --> 01:29:55,380
I mean, how can he. Sad. Oh, I see.

732
01:29:55,380 --> 01:30:01,950
Well we've just written that in the game.

733
01:30:01,950 --> 01:30:06,690
Well yes, of course. Because you're allowed to do that. The thought experiment.

734
01:30:06,690 --> 01:30:10,680
I said there is a question of whether he is infallible or almost infallible.

735
01:30:10,680 --> 01:30:15,590
I'm saying that I think it's a risk assessment.

736
01:30:15,590 --> 01:30:22,740
So why I don't think we'll have to assume that it's not his million pounds.

737
01:30:22,740 --> 01:30:37,858
Unlike your assumption that it is his million pounds, maybe he's spending other people's money.