1 00:00:10,670 --> 00:00:15,860 So let's suppose that after all this discussion of what knowledge is, we end up saying, well, 2 00:00:15,860 --> 00:00:21,650 actually we do want to use the word knowledge in a way that reflects our use in ordinary language. 3 00:00:21,650 --> 00:00:29,240 We want to allow that. I can know the train is time to leave it 1736, even though I might be dreaming. 4 00:00:29,240 --> 00:00:35,960 Maybe we want to allow the contextual list to apply. Different levels of knowledge and different different circumstances. 5 00:00:35,960 --> 00:00:40,820 And we certainly don't want to insist that only super rational beings who reflect 6 00:00:40,820 --> 00:00:45,770 on all their beliefs and justifications can know things quite the reverse. 7 00:00:45,770 --> 00:00:49,460 We want to accept that dogs and cats can know things. 8 00:00:49,460 --> 00:00:57,230 We're happy to say that ordinary, unreflective people can know things when there are reliable connexions between their faculties and the truth, 9 00:00:57,230 --> 00:01:07,350 even if they can't explain what those connexions are. So this naturally leads us back to externalism as an attractive account of knowledge. 10 00:01:07,350 --> 00:01:12,700 This enables me to claim that I do know this is a hand. 11 00:01:12,700 --> 00:01:19,090 Even if I can't prove it. And even if I can't know that I know it. 12 00:01:19,090 --> 00:01:23,950 Whether I do, in fact, know, it depends on how things stand outside my mind, 13 00:01:23,950 --> 00:01:28,060 the various causal links between the world and my perceptions and so forth. 14 00:01:28,060 --> 00:01:34,270 As long as they're working fine, then I can have knowledge, just as the dog can have knowledge. 15 00:01:34,270 --> 00:01:46,300 I don't have to be an expert, philosopher or an expert in human perception for my perceptual faculties to operate correctly and give me knowledge. 16 00:01:46,300 --> 00:01:52,850 But the sceptic is still lurking in the wings. Let's suppose we accept all I've said. 17 00:01:52,850 --> 00:01:57,500 Suppose we accept that the word knowledge as it's used in ordinary language, 18 00:01:57,500 --> 00:02:06,740 fits with this sort of external list account and can quite properly be used in the various loose waves I've described. 19 00:02:06,740 --> 00:02:18,870 That doesn't actually defeat the sceptic because the sceptic can say, well, look, if what you say is right, if your beliefs are in fact true. 20 00:02:18,870 --> 00:02:24,180 Then I'll accept that, you know, all these things in this ordinary language since. 21 00:02:24,180 --> 00:02:30,940 But I still challenge you that those beliefs might be false. 22 00:02:30,940 --> 00:02:40,390 So even if scepticism can be answered from a God's like, externals point of view, God can look down and say Milliken's faculties are working fine. 23 00:02:40,390 --> 00:02:51,160 So he does, in fact, know that there's a hand there. The question whether they're actually true can still be asked from the internal perspective. 24 00:02:51,160 --> 00:02:59,890 I can't necessarily know that I know. So I can still raise sceptical problems about things that from a God's eye point of view. 25 00:02:59,890 --> 00:03:15,160 I do supposedly know. So is there any answer to this kind of scepticism? 26 00:03:15,160 --> 00:03:24,130 Well, surprisingly, perhaps one rather prominent answer, which aims to show that we can be confident of some of our basic perceptual beliefs, 27 00:03:24,130 --> 00:03:28,930 has come from the direction of the analysis of ordinary language. 28 00:03:28,930 --> 00:03:40,730 So suppose I refer to this and I call it a hand. And I conclude that there are two hands of a really. 29 00:03:40,730 --> 00:03:44,660 Of a really hands. You might think. 30 00:03:44,660 --> 00:03:51,390 No. For all you know, your brain in a VAT, your dreaming, whatever. 31 00:03:51,390 --> 00:03:56,840 Okay, let's suppose I am, in fact, a brain in a vat. 32 00:03:56,840 --> 00:04:02,780 OK. I'm a brain in the VAT. I look at this. I look at this. 33 00:04:02,780 --> 00:04:08,330 I think there's something there. Let's not worry about where there is. 34 00:04:08,330 --> 00:04:19,310 I'm aware of something and I call this a hand. And if these are actually hand images. 35 00:04:19,310 --> 00:04:27,270 Then when I use the word hand to refer to them. I'm referring to hand images. 36 00:04:27,270 --> 00:04:34,710 OK. But if when I say hand, I mean a hand image, then this is a hand after all. 37 00:04:34,710 --> 00:04:37,400 Even if I'm a brain in a VAT. 38 00:04:37,400 --> 00:04:46,790 This, which I call a hand, is a hand good, maybe from a God's eye point of view that just hand images from my point of view. 39 00:04:46,790 --> 00:04:59,440 That's what I call a hand. So if even if I am a brain in a vat, I can say with Gillmore there's a hand, there's another. 40 00:04:59,440 --> 00:05:07,660 If the meaning of hand is determined by what we're actually referring to, it looks like the sceptic can be defeated. 41 00:05:07,660 --> 00:05:15,670 Or at least I need not worry about whether this is really a hand. This must be a hand, because that's what I mean by hand. 42 00:05:15,670 --> 00:05:24,450 And that's the kind of approach that Putnam suggests. Now, you might well think that's a little bit too quick. 43 00:05:24,450 --> 00:05:28,980 It's not really a very satisfactory answer to the sceptic. I think that worries. 44 00:05:28,980 --> 00:05:40,110 Right. Here's how I might spell it out. When I look at this thing, I think there's an object there which is actually moving in space. 45 00:05:40,110 --> 00:05:44,850 And whose movement is systematically correlated with my perception in such a 46 00:05:44,850 --> 00:05:51,730 way that my perceptions give a directly reliable indicator of where it is. 47 00:05:51,730 --> 00:06:00,730 I have an idea of the sort of causal interaction which is responsible for these perceptions in terms of light shining on my hand bouncing off. 48 00:06:00,730 --> 00:06:03,920 I see it with my eyes and so forth. 49 00:06:03,920 --> 00:06:12,350 And that's a very different picture from the picture of some mad scientists manipulating electrodes or running some computer programme, 50 00:06:12,350 --> 00:06:19,570 which is bringing it about my perceptions correlate as though they were an object, their. 51 00:06:19,570 --> 00:06:25,030 So maybe I can make some sense of God's eye point of view from which it would turn 52 00:06:25,030 --> 00:06:31,530 out that what I call a hand is really nothing like what I take to be a hand. 53 00:06:31,530 --> 00:06:40,860 In that case, the Puttnam approach can be challenged. It won't follow that when I say there's a hand, I can be utterly sure that that's true. 54 00:06:40,860 --> 00:06:54,680 If what's really there is nothing that bears any systematic correlation to what I'm perceiving except through the manipulation of some mad scientist. 55 00:06:54,680 --> 00:07:03,110 And there's another problem with Putnam's approach. Let's step back from the vet for a moment and return me to real life, okay. 56 00:07:03,110 --> 00:07:13,490 I know what a hand is. There's a hand. I'm walking along in Oxford one day on my way to a lecture and I get kidnapped and invited. 57 00:07:13,490 --> 00:07:19,050 Some mad scientist extracts my brain and puts it in a vat. 58 00:07:19,050 --> 00:07:23,320 Forget about all this, of course, I'm given the illusion of coming to a lecture. 59 00:07:23,320 --> 00:07:29,230 I look at this and I say he has a hand. But actually, it's just a hand image. 60 00:07:29,230 --> 00:07:38,710 And now it looks like Putnam's approach isn't going to work because I learnt the use of the word hand by referring to real hands. 61 00:07:38,710 --> 00:07:42,490 So when I say hand, I mean a real hand. 62 00:07:42,490 --> 00:07:48,970 I don't mean a hand image, in which case I can raise the sceptical worry. 63 00:07:48,970 --> 00:07:55,840 Maybe this isn't a real hand. Maybe I am a brain in a vat. 64 00:07:55,840 --> 00:08:01,630 So needless to say, the bogey of scepticism comes back, as indeed it usually does. 65 00:08:01,630 --> 00:08:10,980 There's no magic bullet to defeat the sceptic, and at least Putnam hasn't given us one. 66 00:08:10,980 --> 00:08:19,370 Finally, I want to go back to induction. The Puttnam approach might lead you to the following thought. 67 00:08:19,370 --> 00:08:25,580 Leaving aside the worry about being kidnapped and invested, 68 00:08:25,580 --> 00:08:33,680 suppose we worried that our whole life is lived in a VAT or in the Matrix or something like that. 69 00:08:33,680 --> 00:08:38,150 It's tempting to think, well, suppose I am a brain in a vat. 70 00:08:38,150 --> 00:08:45,030 Suppose I am in a matrix. Why should I care? 71 00:08:45,030 --> 00:08:53,090 I'm living my life perfectly well. Maybe it is in The Matrix, but that doesn't stop me enjoying the things that I enjoy. 72 00:08:53,090 --> 00:08:59,210 Doesn't stop me getting satisfaction from the company of Matrix, people eating night. 73 00:08:59,210 --> 00:09:08,850 Nice matrix food or whatever. You might, however, wonder where this leaves issues about moral obligation to those matrixx people. 74 00:09:08,850 --> 00:09:16,650 But let's put that to one side. All these matrix things, they may not be real, but they bring me the same pleasure. 75 00:09:16,650 --> 00:09:21,300 So why worry about it? Why not just go on as before? 76 00:09:21,300 --> 00:09:23,310 Even if I am a brain in a vat, 77 00:09:23,310 --> 00:09:32,040 even if I am living in the Matrix now seem like this vertical scepticism that is worrying about inference from one level, 78 00:09:32,040 --> 00:09:37,470 the level of perception to some deeper level, the level of objects. 79 00:09:37,470 --> 00:09:41,030 Can seem not so worrying after all. 80 00:09:41,030 --> 00:09:49,270 And there's a contrast here with horizontal tunnel scepticism, the kind of scepticism that you get in the problem of induction. 81 00:09:49,270 --> 00:10:01,130 And that will remain even if you're happy with living in the Matrix or as a brain in a VAT, everything so far might have gotten gone on fine. 82 00:10:01,130 --> 00:10:04,970 But how can I be confident that it will carry on going on? 83 00:10:04,970 --> 00:10:14,090 Fine. This problem, the problem of induction arises whether I'm in the real world or in a matrix or a brain in a VAT. 84 00:10:14,090 --> 00:10:21,200 So there's a sense in which horizontal scepticism, that is scepticism about inferring more of the same, 85 00:10:21,200 --> 00:10:27,080 though it seems less radical, is actually potentially more worrying than vertical scepticism. 86 00:10:27,080 --> 00:10:30,620 And this gives me an excuse, having gone back to human induction, 87 00:10:30,620 --> 00:10:37,010 to look at the kind of response that he gave and is commonly given now to these kinds of sceptical worries. 88 00:10:37,010 --> 00:10:45,660 And that is to focus on the ethics of belief. What should we believe? 89 00:10:45,660 --> 00:10:52,650 Descartes started out his scepticism, saying that he shouldn't believe anything that is less than certain. 90 00:10:52,650 --> 00:11:01,200 The message of all the discussion about scepticism is that if we do determine ourselves not to believe anything that is less than certain, 91 00:11:01,200 --> 00:11:06,860 we might end up believing virtually nothing at all. But is that possible? 92 00:11:06,860 --> 00:11:12,530 Are we able to believe nothing at all? And should we even go along with it? 93 00:11:12,530 --> 00:11:18,730 Why should we condemn ourselves to believing nothing that is less than certain? 94 00:11:18,730 --> 00:11:25,870 Well, I think most philosophers would agree with Hume that suspension of all belief is just impossible for us the way we're made. 95 00:11:25,870 --> 00:11:28,840 We just cannot help believing certain things. 96 00:11:28,840 --> 00:11:36,520 And it's probably a good thing that we're made that way, because if we weren't, then we'd be in serious trouble. 97 00:11:36,520 --> 00:11:40,870 Notice also that this approach goes well with contemporary externalism. 98 00:11:40,870 --> 00:11:47,080 The thought is that we shouldn't aim for all our beliefs to be such that we can justify them internally. 99 00:11:47,080 --> 00:11:54,070 We shouldn't expect to be able to work out internally the justification for everything we believe. 100 00:11:54,070 --> 00:11:57,310 Perhaps we have to rely on our animal nature. 101 00:11:57,310 --> 00:12:07,340 That leads us inevitably to believe certain things and to trust in general that our faculties are thankfully more or less reliable. 102 00:12:07,340 --> 00:12:12,460 Course, that doesn't mean that we should become undiscriminating and remain big questions 103 00:12:12,460 --> 00:12:18,070 about how to distinguish between things that remain justified and things that aren't. 104 00:12:18,070 --> 00:12:32,938 But if we want to hold out against the sceptic, we probably have to be prepared to accept standards that are less than absolute.