1 00:00:10,620 --> 00:00:16,080 Today, I'll be finishing off our historical survey by talking about David Hume, 2 00:00:16,080 --> 00:00:21,660 and then I'll be moving on to the first of the topics of general philosophy, 3 00:00:21,660 --> 00:00:32,280 the main topics that form the syllabus and focussing on the topic that's most associated with David Hume, namely induction. 4 00:00:32,280 --> 00:00:39,570 David Hume, known at the time as the Great Infidel by some, was probably the greatest philosopher of this period. 5 00:00:39,570 --> 00:00:45,960 At any rate, in my view, Scottish philosopher unfortunately had nothing whatever to do with Oxford. 6 00:00:45,960 --> 00:00:48,480 Live from 1711 to 1776, 7 00:00:48,480 --> 00:00:59,220 his biggest and in many ways most famous work is the Treatise of Human Nature of 1739 that he went on to write in quite a wide range of fields. 8 00:00:59,220 --> 00:01:05,910 A lot of very interesting essays, which to some extent helped to found the science of economics. 9 00:01:05,910 --> 00:01:12,120 Adam Smith was a younger contemporary of Hume, whom Hume influenced a great deal. 10 00:01:12,120 --> 00:01:14,850 His enquiries, the two enquiries are very famous. 11 00:01:14,850 --> 00:01:22,050 He wrote A History of England, which was for a long time the standard history and published a lot on religion, 12 00:01:22,050 --> 00:01:27,960 including the dialogues concerning natural religion of 1779, published posthumously. 13 00:01:27,960 --> 00:01:30,360 It was such a dangerous work. 14 00:01:30,360 --> 00:01:38,820 If you want to read a truly great work of philosophy that is actually quite funny, then the dialogues is the place to go. 15 00:01:38,820 --> 00:01:48,890 I think certainly the the greatest combination of philosophical originality, erudition and humour to be found in the literature. 16 00:01:48,890 --> 00:01:56,660 Now, in many ways, human can be seen as building on Newton Unlock from Newton. 17 00:01:56,660 --> 00:02:03,710 You get the general idea that the aim of science is not necessarily to aim for ultimate understanding of things, 18 00:02:03,710 --> 00:02:11,930 but rather systematise ation, just as Newton, when it came to gravitation, didn't pretend to understand how gravitation works. 19 00:02:11,930 --> 00:02:18,680 He gave formulae that encapsulate how it works. The effects of it. 20 00:02:18,680 --> 00:02:24,240 So that is a taken by Hume to be a model for how science in general can operate. 21 00:02:24,240 --> 00:02:32,040 And like Locke, in contrast to people like Descartes, he emphasised that the aim of science is not to get certainty. 22 00:02:32,040 --> 00:02:45,940 That is not achievable. We have to make do with probability. Now, take the fundamental case, forget about gravitation and weird things like that. 23 00:02:45,940 --> 00:02:52,240 Think about the motion of billiard balls, one billiard ball bashing into another. 24 00:02:52,240 --> 00:02:56,320 We see a white billiard ball moving towards a red one. The two collide. 25 00:02:56,320 --> 00:03:07,470 Why do we expect the red one to move? And Hume imagines a thought experiment, a thought experiment in which Adam, the first man newly created by God, 26 00:03:07,470 --> 00:03:12,510 sees one billiard ball moving towards another, is asked to predict what's gonna happen. 27 00:03:12,510 --> 00:03:18,420 Could he predict it? Well, according to Hume, he couldn't. He's got no experience to call on. 28 00:03:18,420 --> 00:03:25,200 So there's no way he can know in advance of actually experiencing the impact of balls and similar object. 29 00:03:25,200 --> 00:03:32,870 What's going to happen? So, in fact, not only is gravity unintelligible, as we saw last time, 30 00:03:32,870 --> 00:03:41,000 many philosophers at the time wanted to say actually even mechanical causation is pretty unintelligible, too. 31 00:03:41,000 --> 00:03:46,400 We used to seeing billiard balls bashing into each other. So we think we sort of understand why. 32 00:03:46,400 --> 00:03:54,080 But really, there's no understanding to it. It's just habit. So. 33 00:03:54,080 --> 00:04:01,160 The lesson that Newton drew in the case of gravity and Barkley generalised, 34 00:04:01,160 --> 00:04:09,950 as we saw in his instrumentalism, Hume wanted to draw as a quite general lesson of science. 35 00:04:09,950 --> 00:04:16,550 But intelligibility is not something that we can reasonably aim for in science. 36 00:04:16,550 --> 00:04:25,030 Ultimately, all we have is those systematic laws that codify the way things behave. 37 00:04:25,030 --> 00:04:30,100 It's a bit like Malebranche is theory, except without God. 38 00:04:30,100 --> 00:04:42,220 Which is sort of paradoxical, but Hume wants to say that there is no real glue in nature, or at least nothing at all that we can remotely understand. 39 00:04:42,220 --> 00:04:49,630 All we can do is see how things behave, codify that behaviour and do us our science on that basis. 40 00:04:49,630 --> 00:05:00,650 Ultimate understanding. Forget it. OK, then, if all we have to go on is experience, where does that leave us? 41 00:05:00,650 --> 00:05:05,660 Where does that leave us in respective scepticism? For example? 42 00:05:05,660 --> 00:05:11,300 Suppose I've seen lots of billiard balls impacting with each other, I've got used to the way they behave. 43 00:05:11,300 --> 00:05:18,680 Maybe I've done careful investigations and I've come up with some laws that seem to codify the way they behave. 44 00:05:18,680 --> 00:05:23,120 Conservation of momentum. The law of restitution, that sort of stuff. 45 00:05:23,120 --> 00:05:29,540 So I'm actually able to put this into scientific formulae and work out when one billiard ball moves towards another. 46 00:05:29,540 --> 00:05:33,800 How in the past that collision would have happened. 47 00:05:33,800 --> 00:05:41,560 Does that give me a good reason for supposing that the next collision of billiard balls will work in the same way, 48 00:05:41,560 --> 00:05:48,190 will operate according to the same descriptive rules? Well. 49 00:05:48,190 --> 00:05:55,960 If past experience is to give me a good reason, it seems that I've got to have some reason for extrapolating from the past to the future. 50 00:05:55,960 --> 00:06:04,810 Some reason that will justify taking that past experience as relevant to what's going to happen next? 51 00:06:04,810 --> 00:06:14,330 Well, it's not self-evident that that's true. It's not a lot a matter of logic that what's happened in the past should continue for the future. 52 00:06:14,330 --> 00:06:19,700 My sense is don't tell me anything relevant that I'm seeing the same motion of billiard balls. 53 00:06:19,700 --> 00:06:25,180 But that doesn't tell me what's going to happen after they've collided. 54 00:06:25,180 --> 00:06:33,940 And if I tried to appeal to experience, it seems that I'm begging the question I'm taking for granted, that experience is relevant to the future. 55 00:06:33,940 --> 00:06:42,010 So we seem to get a very sceptical lesson about induction, about inference from past to future. 56 00:06:42,010 --> 00:06:55,780 It seems that we can give no reason at all to justify that. We'll be coming to that in a little bit more detail later. 57 00:06:55,780 --> 00:07:03,880 So Hume's view on induction seems to take us quite a long way beyond lock Lock wanted to say against Descartes that 58 00:07:03,880 --> 00:07:12,280 we have to make do in science with lack of certainty when we reason about things in the world as opposed to logic. 59 00:07:12,280 --> 00:07:19,410 There is no certainty to be had. But now Hume is saying it's worse than that, actually. 60 00:07:19,410 --> 00:07:22,470 We cannot give any good reason, whatever, 61 00:07:22,470 --> 00:07:30,990 for supposing that the laws that we've gleaned from past experience will be applicable to what happens in the future. 62 00:07:30,990 --> 00:07:39,090 It seems that all of our scientific ambitions, everything is based on a brute animal instinct. 63 00:07:39,090 --> 00:07:44,590 We just naturally think that the future will resemble the past. 64 00:07:44,590 --> 00:07:51,700 So in a certain respect, we know in no better position than the dog who when you go for the lead. 65 00:07:51,700 --> 00:07:57,820 Near the front door, starts jumping up and down with anticipation of going for a walk. 66 00:07:57,820 --> 00:08:02,050 Why does it do it? Habit it associates you going for the lead? 67 00:08:02,050 --> 00:08:08,080 We're going for a walk. It doesn't have any rational insight into the connexion between the two. 68 00:08:08,080 --> 00:08:16,300 It's just habit. And we seem to be the same with billiard balls. 69 00:08:16,300 --> 00:08:28,740 Now, think about this in the context of the philosophy of the time we've seen how much of the thinking of the time was imbued with religious thinking. 70 00:08:28,740 --> 00:08:33,280 We were seen seen at the time as creatures made in God's image. 71 00:08:33,280 --> 00:08:40,960 Man is the image of God. And the primary instance of that is human reason. 72 00:08:40,960 --> 00:08:51,160 Human reason was supposed to be a sort of think image of God's reason, just as God can see everything by immediate insight. 73 00:08:51,160 --> 00:08:59,440 So we, through mathematics and through science, are supposed to be able to acquire insight into the way the world works. 74 00:08:59,440 --> 00:09:09,950 Something in the same sort of way as God does. We're up there intermediate between the animals and the angels. 75 00:09:09,950 --> 00:09:13,130 We're not merely part of the animal creation. 76 00:09:13,130 --> 00:09:22,430 Our bodies may be physical, but our minds are made of immaterial substance, which is quite different in nature. 77 00:09:22,430 --> 00:09:31,080 So we have this view of man as privileged and Hume's attack on our rational faculties. 78 00:09:31,080 --> 00:09:35,190 Strongly counters that it puts us back with the animals. 79 00:09:35,190 --> 00:09:39,520 It suggests that for all our cleverness. 80 00:09:39,520 --> 00:09:50,020 Ultimately, our rational faculties have a very earthy foundation in brute animal instinct rather than insight. 81 00:09:50,020 --> 00:10:01,240 So if we want to find out about the way human beings behave, the right way to do it is not by thinking of us as specially rational creatures. 82 00:10:01,240 --> 00:10:05,140 Rather, one should find out about the way humans behave. 83 00:10:05,140 --> 00:10:13,510 By observation, experiment, systematise Asian generalisation, you treat us as part of the natural world. 84 00:10:13,510 --> 00:10:19,300 One might suggest that modern day economists would do well to learn this lesson. 85 00:10:19,300 --> 00:10:28,450 A lot of economic models are based on the assumption of perfect rationality. We've seen recently where that leads us humans. 86 00:10:28,450 --> 00:10:35,530 Lesson is that actually humans in their behaviour are far less rational than they like to pretend. 87 00:10:35,530 --> 00:10:48,980 Empirical investigation of how people actually work is likely to yield much better results than the assumption that we are perfectly rational. 88 00:10:48,980 --> 00:10:53,420 This lesson goes through to the human free will. 89 00:10:53,420 --> 00:11:02,390 Hume, in many ways follows Hobbs. He's a compatibles. He thinks freewill is compatible with determinism. 90 00:11:02,390 --> 00:11:07,130 As part of nature, human action is causally determined. 91 00:11:07,130 --> 00:11:12,470 Hume thinks exactly the same way as billiard balls. 92 00:11:12,470 --> 00:11:20,900 Someone who knew all the laws that govern the way we behave would be able to predict reliably what we would do. 93 00:11:20,900 --> 00:11:26,660 Free will is simply having the power to do as our will dictates. 94 00:11:26,660 --> 00:11:34,310 Now, you might think that that is going to undermine morality if we are ultimately causal parts of nature, 95 00:11:34,310 --> 00:11:39,510 working according to causal laws in the same sort of way as billiard balls. 96 00:11:39,510 --> 00:11:51,800 How does morality get any purchase? We'll Hume's answer to that is to found morality on sentiment, on fellow feeling, empathy for other people. 97 00:11:51,800 --> 00:11:56,810 His idea is that we naturally identify with others. 98 00:11:56,810 --> 00:12:02,450 When we think about another person's pain, to some extent, we share the pain. 99 00:12:02,450 --> 00:12:08,110 Therefore, we have an interest in relieving it. We grow up in families. 100 00:12:08,110 --> 00:12:14,590 Families get wider into social groups by mixing together, we learn to care for each other. 101 00:12:14,590 --> 00:12:23,560 And we find that codifying rules of behaviour makes sense on that basis because we actually feel a passion to do good to others. 102 00:12:23,560 --> 00:12:28,630 We are not purely selfish creatures in the way that Hobson thought. 103 00:12:28,630 --> 00:12:46,208 So Hume gives morality a basis in our bruit, human nature.