WEBVTT 1 00:00:00.000 --> 00:00:05.020 It's a bit like hacking the side engine of the commuter trains, and thank you very much 2 00:00:05.020 --> 00:00:05.540 to the ushers. 3 00:00:05.580 --> 00:00:09.280 It's a terrific job you do at the last minute, squeezing in the extra bums on seats. 4 00:00:11.260 --> 00:00:15.520 Welcome this afternoon, and I'd like to say that my name's David Chalmers, and I'm here 5 00:00:15.520 --> 00:00:16.660 to talk to you about consciousness. 6 00:00:18.180 --> 00:00:22.640 I think if I was 17 or 18 again, I think I would certainly be getting into what I think 7 00:00:22.640 --> 00:00:28.420 is the biggest game in town, and that fascinating nexus between philosophy and neurophysiology 8 00:00:28.420 --> 00:00:29.580 and artificial intelligence. 9 00:00:30.140 --> 00:00:36.260 But no, my name's Peter Goldschild, and it's my privilege to introduce David to you this 10 00:00:36.260 --> 00:00:36.640 afternoon. 11 00:00:36.780 --> 00:00:43.560 I think if you're a materialist, as I usually am, that is, you think everything will one 12 00:00:43.560 --> 00:00:49.160 day be explained in terms of the materials, the quarks, the energy, the atoms, then there 13 00:00:49.160 --> 00:00:52.920 are a couple of mysteries you really have to honestly confront. 14 00:00:53.200 --> 00:00:56.700 I mean, the first one is, the basic one, why is there any material at all? 15 00:00:57.160 --> 00:00:58.780 Why is there something rather than nothing? 16 00:00:58.840 --> 00:00:59.980 And that's pretty mysterious. 17 00:01:00.000 --> 00:01:05.880 But the second one, and even though those things we first debate when we are about 17, 18 00:01:06.100 --> 00:01:12.860 you know, have a flagon of red or a bong or whatever, that doesn't mean that they don't 19 00:01:12.860 --> 00:01:16.700 continue to seek answers later in life. 20 00:01:16.840 --> 00:01:22.520 And that second mystery, I think, is a real mystery, and it's that strange, surprising 21 00:01:22.520 --> 00:01:26.640 thing that the material is slowly becoming conscious of itself, or so it seems, through 22 00:01:27.240 --> 00:01:28.640 agents such as us. 23 00:01:29.020 --> 00:01:29.960 And how is... 24 00:01:30.000 --> 00:01:30.620 How is this possible? 25 00:01:30.680 --> 00:01:31.720 And what is this subjective... 26 00:01:31.720 --> 00:01:39.360 The mystery of subjective consciousness and how it evades and eludes material description? 27 00:01:41.060 --> 00:01:45.400 Now, you know, I'd followed, like a lot of people, I guess, the consciousness wars between 28 00:01:45.400 --> 00:01:51.640 people like Daniel Dennett and John Searle, as fought out, well, various venues, but certainly 29 00:01:51.640 --> 00:01:53.560 in the correspondence pages of the New York Review of Books. 30 00:01:54.140 --> 00:01:59.980 But in 1996, I read a book, The Conscious Mind, by David Chalmers, that really, really, really, 31 00:02:00.000 --> 00:02:02.720 really rattled the bars of my materialism, I think. 32 00:02:02.920 --> 00:02:05.840 And perhaps I've been a bit of a lapsed materialist ever since. 33 00:02:06.420 --> 00:02:15.080 I think David resurrected a dualism, a Cartesian dualism there, that I guess had been out of 34 00:02:15.080 --> 00:02:22.020 favour, buried by the triumphs and triumphalism, I guess, to some extent, of various branches 35 00:02:22.020 --> 00:02:22.660 of the sciences. 36 00:02:23.000 --> 00:02:28.540 And I think it was an important book, and I'm fascinated to hear how far further down that 37 00:02:28.540 --> 00:02:29.200 path we're going. 38 00:02:29.300 --> 00:02:29.740 Yeah. 39 00:02:29.740 --> 00:02:29.920 Yeah. 40 00:02:30.000 --> 00:02:32.160 And how far up that path he's travelled since. 41 00:02:32.460 --> 00:02:34.280 Now, I'm not going to go through his CV. 42 00:02:34.500 --> 00:02:39.740 You wouldn't be here if you didn't know who David Chalmers is, and it's been recited several 43 00:02:39.740 --> 00:02:42.060 times already at the festival, and it's in the program. 44 00:02:43.060 --> 00:02:45.560 Suffice perhaps to say that he's a local boy. 45 00:02:47.100 --> 00:02:52.080 He was a victim for a while, from our point of view, at least, of the brain drain, but 46 00:02:52.080 --> 00:02:53.500 he's clambered back up that drain. 47 00:02:54.800 --> 00:02:59.980 I won't use the obvious metaphor, but he's back in character. 48 00:02:59.980 --> 00:03:04.120 He's been clambered at least for five years, and I think it's terrific to have a philosopher 49 00:03:04.120 --> 00:03:05.300 of his standing back here. 50 00:03:05.820 --> 00:03:13.120 And without any further details, it is a real privilege and a pleasure to meet David finally. 51 00:03:13.180 --> 00:03:18.260 We have corresponded a little bit, and to be able to introduce him to you, David Chalmers. 52 00:03:19.740 --> 00:03:20.740 David Chalmers 53 00:03:22.060 --> 00:03:22.820 David Chalmers 54 00:03:22.820 --> 00:03:23.760 David Chalmers 55 00:03:23.760 --> 00:03:24.560 David Chalmers 56 00:03:24.560 --> 00:03:25.500 David Chalmers 57 00:03:25.500 --> 00:03:25.600 David Chalmers 58 00:03:25.600 --> 00:03:26.520 David Chalmers 59 00:03:26.520 --> 00:03:27.060 David Chalmers 60 00:03:27.060 --> 00:03:28.580 David Chalmers 61 00:03:28.580 --> 00:03:29.580 David Chalmers 62 00:03:29.580 --> 00:03:33.080 And I certainly, of course, will look forward to invigorating a question session. 63 00:03:33.620 --> 00:03:34.060 David Chalmers 64 00:03:34.060 --> 00:03:36.980 Thank you, Peter, and thanks everyone, for coming along. 65 00:03:37.420 --> 00:03:42.660 Particular thanks to all the old friends and family members who I have paid and bribed 66 00:03:42.660 --> 00:03:46.420 and cajoled to come along so that, you know, it wouldn't be a completely empty house. 67 00:03:46.720 --> 00:03:49.440 So, pleasure to see you all. 68 00:03:49.540 --> 00:03:53.540 It's really fantastic to be back here in Adelaide taking part in this really pretty amazing 69 00:03:53.540 --> 00:03:55.480 event, the Festival of Ideas. 70 00:03:55.500 --> 00:03:59.560 I've never seen anything like it anywhere else I've been, so it's a really great, great 71 00:03:59.560 --> 00:04:08.280 thing. A lot of you will know the case of Terry Shiver, the woman in Florida who was in the news 72 00:04:08.280 --> 00:04:17.320 a few months ago. In February of 1990, she suffered a cardiac arrest, followed by a serious 73 00:04:17.320 --> 00:04:22.940 lack of oxygen to the brain, with the result that she had some serious and permanent brain damage. 74 00:04:22.940 --> 00:04:30.340 She spent two and a half months in a coma, came out of the coma, and then spent the next 15 years 75 00:04:30.340 --> 00:04:37.920 in a persistent vegetative state, characterized by apparent wakefulness, her eyes were open, 76 00:04:38.220 --> 00:04:45.340 and maybe apparent appearances of certain kinds of responsiveness, but no real responsiveness, 77 00:04:45.420 --> 00:04:51.840 certainly nothing like a language or interaction with the environment. This is often characterized 78 00:04:52.940 --> 00:04:59.740 wakefulness without consciousness. Over the ensuing years, there were some serious 79 00:04:59.740 --> 00:05:06.680 legal battles over the status of Terry Shiver between her family members and her husband. 80 00:05:06.780 --> 00:05:10.500 Her family members arguing that there was at least perhaps some minimal consciousness 81 00:05:11.400 --> 00:05:17.860 there in Terry Shiver from time to time, brought out by moments of apparent responsiveness. Her 82 00:05:17.860 --> 00:05:22.800 husband arguing that, in fact, and no consciousness there at all. 83 00:05:22.940 --> 00:05:30.840 The experts all sided with the husband on this no sign of consciousness to be seen in Terry Shiver. 84 00:05:30.940 --> 00:05:36.420 And after numerous court battles, a number of, I mean, actually her feeding tube was removed and 85 00:05:36.420 --> 00:05:41.180 reinserted a couple of times on appeal. The governor of Florida got involved. Jeb Bush 86 00:05:41.180 --> 00:05:45.740 passed a new law. Even the Senate majority leader, Bill Frist, got involved with his own 87 00:05:46.380 --> 00:05:52.560 diagnosis of the case. Finally, her feeding tube was removed on March 18th, 2005. 88 00:05:53.240 --> 00:06:02.280 And she died on March 31st this year. That's one case. Another case that some of you may know, 89 00:06:02.400 --> 00:06:09.080 the case of Jean-Dominique Boby. He was in Paris. He was the editor of Elle magazine 90 00:06:09.080 --> 00:06:18.100 for some time. In December 1995, he suffered a stroke. His entire body was paralyzed. He had no 91 00:06:18.100 --> 00:06:22.920 control over his body, with the exception of control over his legs. 92 00:06:22.940 --> 00:06:29.440 He had a left eyelid. This is called locked-in syndrome. There is apparently every reason 93 00:06:29.440 --> 00:06:34.240 to believe there's a conscious being in there, but they've lost almost all control over their 94 00:06:34.240 --> 00:06:37.420 body. However, he did have control over his eyelid, and he could use this to communicate. 95 00:06:38.420 --> 00:06:42.760 For example, to spell out words of the alphabet, someone would sit there with him, counting 96 00:06:42.760 --> 00:06:49.380 his eye blinks, going A, B, C, D, E, F, G, H, I, J, K, L, L. And eventually he could say 97 00:06:49.380 --> 00:06:52.660 a sentence, a paragraph, a page. He wrote an entire book this way. 98 00:06:52.940 --> 00:06:58.900 You can imagine how long that took to write. It can't have been a really engaging job to be a 99 00:06:58.900 --> 00:07:05.680 transcriber. He wrote a truly amazing book, The Diving Bell and the Butterfly, which some of you 100 00:07:05.680 --> 00:07:11.960 may have seen, all about this state of being in locked-in syndrome. It was published on March 9, 101 00:07:13.140 --> 00:07:20.980 1997, and he died three days later. So these are two pretty extraordinary and contrasting 102 00:07:20.980 --> 00:07:21.820 cases. 103 00:07:22.940 --> 00:07:26.760 They're mirrored by cases that people find all the time. These are two particularly well-known 104 00:07:26.760 --> 00:07:32.940 cases of patients in various states of coma, vegetative state, paralysis. And the question 105 00:07:32.940 --> 00:07:40.040 is, how do we treat these people? Should they be treated as regular, conscious human beings with 106 00:07:40.040 --> 00:07:44.760 full moral status, or should they be treated some other way? The question that came up for Terry 107 00:07:44.760 --> 00:07:51.580 Shivo is, when is it okay, in fact, to remove the feeding tube? And in all of these questions, 108 00:07:51.700 --> 00:07:52.760 the central question comes to me. 109 00:07:52.940 --> 00:07:56.700 What do we care about and how we should treat these people? I mean, the central question isn't 110 00:07:56.700 --> 00:08:00.740 directly, the thing that's of ultimate concern here isn't directly, you know, how are they behaving 111 00:08:00.740 --> 00:08:06.340 or what is their brain doing? Those things are of indirect importance to us in diagnosing what 112 00:08:06.340 --> 00:08:11.400 their mind is doing. The question of ultimate concern to us in dealing with patients in these 113 00:08:11.400 --> 00:08:18.860 cases is, are they conscious? Could they be conscious? What's going on with them in their 114 00:08:18.860 --> 00:08:22.860 inner lives? Now, in the case of Terry Shivo, it turned out, I think, in the end, 115 00:08:22.940 --> 00:08:27.600 to be a reasonably clear case. Her brain was half the weight of a normal brain. It was mostly 116 00:08:28.320 --> 00:08:34.240 cerebrospinal fluid. The pyramidal neurons in her cortex, which normally, which play the central 117 00:08:34.240 --> 00:08:39.620 role in cognition, were all destroyed. Likewise, Bobi was a reasonably clear case the other way, 118 00:08:39.640 --> 00:08:45.200 because he had that control over his eyelid. But you can imagine somebody in the situation, 119 00:08:45.300 --> 00:08:52.500 just like Bobi, but without that control over his eyelid. Completely locked in syndrome. 120 00:08:52.940 --> 00:08:58.420 From the outside, no behavioral control. From the outside, perhaps not all that distinguishable 121 00:08:58.420 --> 00:09:03.060 from Terry Shivo, at least where behavioral measures are concerned. And the fact is, 122 00:09:03.060 --> 00:09:10.020 nobody knows exactly who might be in situations like that today. So what we really need here, 123 00:09:10.060 --> 00:09:16.100 you know, is a way to figure out how to treat these people and how to diagnose and measure 124 00:09:16.100 --> 00:09:20.820 their states of consciousness. Because here, it's consciousness. It's their subjective inner lives 125 00:09:20.820 --> 00:09:22.080 that makes all the difference. 126 00:09:22.940 --> 00:09:29.360 Whether these treat these people as conscious human beings, to be loved, to be respected, 127 00:09:29.600 --> 00:09:34.020 to be, you know, his lives to be continued, or if there's no consciousness and no potential 128 00:09:34.020 --> 00:09:39.580 for consciousness, then as was argued in the Terry Shivo case, then it's completely appropriate then 129 00:09:39.580 --> 00:09:45.060 to, you know, to terminate their lives. And basically, the moral status of that decision, 130 00:09:45.180 --> 00:09:51.180 although wrenching, is no, perhaps no more morally significant than, say, cutting down a tree, 131 00:09:51.280 --> 00:09:52.920 let's say, or, you know, or burying a tree. So, you know, it's a very, 132 00:10:22.920 --> 00:10:24.360 consciousness meter. 133 00:10:25.780 --> 00:10:26.780 The thing which you could 134 00:10:26.780 --> 00:10:28.920 pick up, point it at someone's head, 135 00:10:29.440 --> 00:10:30.440 searching for consciousness, 136 00:10:31.340 --> 00:10:32.340 searching for consciousness, 137 00:10:32.860 --> 00:10:34.800 searching for consciousness, and here, up on the screen, 138 00:10:34.940 --> 00:10:36.680 we'd get a readout of Peter's consciousness. 139 00:10:36.980 --> 00:10:38.960 Hopefully, with all the embarrassing bits and all. 140 00:10:41.740 --> 00:10:43.340 I once pointed one at, 141 00:10:43.440 --> 00:10:45.100 Peter mentioned Dan Dennett, 142 00:10:45.160 --> 00:10:46.240 once pointed at Dan Dennett. 143 00:10:46.560 --> 00:10:48.180 Not much of a readout to be seen. 144 00:10:50.440 --> 00:10:51.820 John Searle was on life support. 145 00:10:54.920 --> 00:10:56.440 Actually, if you go to my website, 146 00:10:56.520 --> 00:10:58.620 you'll see there's a picture of a consciousness meter there. 147 00:10:59.260 --> 00:11:01.320 I unveiled it at a conference back in 1996. 148 00:11:02.240 --> 00:11:03.440 Constructed with a combination of 149 00:11:05.020 --> 00:11:05.620 transpersonal psychology, 150 00:11:06.280 --> 00:11:06.880 neuromorphic engineering, 151 00:11:07.080 --> 00:11:07.940 and quantum gravity. 152 00:11:09.000 --> 00:11:10.300 Looks a little bit like a hair dryer, 153 00:11:10.380 --> 00:11:11.320 but you shouldn't let that fool you. 154 00:11:12.860 --> 00:11:14.480 Actually, I gave a talk about some of this stuff 155 00:11:14.480 --> 00:11:16.100 a few years ago, 156 00:11:16.140 --> 00:11:18.720 at, of all places, the Central Intelligence Agency 157 00:11:18.720 --> 00:11:19.380 in the US. 158 00:11:19.820 --> 00:11:22.740 I don't know why they wanted to hear about consciousness. 159 00:11:22.920 --> 00:11:24.800 But I started off talking about the philosophical issues 160 00:11:24.800 --> 00:11:25.980 and the scientific issues 161 00:11:25.980 --> 00:11:27.860 tied to consciousness. 162 00:11:28.200 --> 00:11:29.060 And I think the fact is, 163 00:11:29.120 --> 00:11:30.080 they were mostly falling asleep. 164 00:11:30.440 --> 00:11:31.580 Boring, boring, boring. 165 00:11:32.340 --> 00:11:33.840 Then I got to the consciousness meter. 166 00:11:34.100 --> 00:11:36.160 And suddenly, they perked up. 167 00:11:36.180 --> 00:11:38.500 I was like, yeah, we could really use one of those. 168 00:11:42.120 --> 00:11:42.980 Alas, the fact is, 169 00:11:43.040 --> 00:11:44.700 there is no consciousness meter. 170 00:11:44.800 --> 00:11:45.000 Why? 171 00:11:45.180 --> 00:11:48.000 Because consciousness is private, subjective state, 172 00:11:48.120 --> 00:11:50.740 known to each of us intimately and directly, 173 00:11:50.980 --> 00:11:52.500 but known to the outside world 174 00:11:52.500 --> 00:11:52.820 only. 175 00:11:52.920 --> 00:11:53.280 And I think it's happening at best 176 00:11:53.280 --> 00:11:56.680 very indirectly and imperfectly. 177 00:11:56.720 --> 00:11:57.900 My own conscious state right now 178 00:11:57.900 --> 00:12:00.760 consists of this rich panoply of visual images, 179 00:12:00.920 --> 00:12:02.940 of sounds, of bodily feelings, 180 00:12:03.200 --> 00:12:05.100 of emotions, of images, of thoughts, 181 00:12:05.200 --> 00:12:06.140 and memories. 182 00:12:06.280 --> 00:12:08.960 This is part of this internal movie stream of my mind. 183 00:12:09.080 --> 00:12:09.680 Each of you, 184 00:12:10.480 --> 00:12:11.160 I presume, 185 00:12:12.320 --> 00:12:13.880 has one of these as well. 186 00:12:14.000 --> 00:12:15.460 I don't know. I'm not certain. I presume. 187 00:12:15.720 --> 00:12:18.720 You know for sure. You don't know for sure about me. 188 00:12:18.760 --> 00:12:20.280 How can we know about 189 00:12:20.280 --> 00:12:22.140 another being's state of consciousness? 190 00:12:22.140 --> 00:12:22.980 We can't know directly. 191 00:12:24.020 --> 00:12:26.400 The way to know, I think, is to know indirectly. 192 00:12:26.680 --> 00:12:28.220 In the easy cases, through language. 193 00:12:28.400 --> 00:12:29.280 In the hard cases, 194 00:12:30.380 --> 00:12:32.220 through, perhaps, the indicators 195 00:12:32.220 --> 00:12:33.880 that we might get from a science of consciousness 196 00:12:33.880 --> 00:12:35.120 that we don't yet have. 197 00:12:35.260 --> 00:12:37.580 So what we need to diagnose the hard cases, 198 00:12:37.700 --> 00:12:39.900 to know exactly how to treat the people like 199 00:12:39.900 --> 00:12:42.100 Terry Schiavo, John Dominic Bobey, 200 00:12:42.160 --> 00:12:44.020 and the wide penumbra 201 00:12:44.020 --> 00:12:45.120 of cases in between, 202 00:12:45.260 --> 00:12:47.740 is some way of constructing 203 00:12:47.740 --> 00:12:49.940 indirectly a consciousness meter 204 00:12:49.940 --> 00:12:52.120 to know about another being's 205 00:12:52.140 --> 00:12:52.820 state of consciousness. 206 00:12:52.960 --> 00:12:54.480 We're not yet in that position, 207 00:12:54.640 --> 00:12:56.560 but the question is, how can we get there? 208 00:12:56.620 --> 00:12:58.020 That's a task for this new, 209 00:12:58.680 --> 00:13:00.520 but now ongoing and thriving, 210 00:13:00.520 --> 00:13:02.680 science of consciousness. 211 00:13:03.040 --> 00:13:04.540 Now for some people, science of consciousness 212 00:13:04.540 --> 00:13:07.000 is a contradiction, 213 00:13:07.520 --> 00:13:08.740 somehow, in terms. Why? 214 00:13:10.200 --> 00:13:11.820 Science is meant to be completely objective. 215 00:13:12.960 --> 00:13:13.800 Objective, measurable, 216 00:13:14.480 --> 00:13:14.920 intersubjective. 217 00:13:15.220 --> 00:13:16.280 Consciousness, by its nature, 218 00:13:16.380 --> 00:13:17.920 is entirely subjective 219 00:13:18.480 --> 00:13:20.440 and private. Therefore, some people 220 00:13:20.440 --> 00:13:22.060 say science can't study. 221 00:13:22.140 --> 00:13:22.700 Consciousness. 222 00:13:23.400 --> 00:13:25.780 Psychology got started as a science of consciousness 223 00:13:25.780 --> 00:13:27.260 150 years ago. 224 00:13:28.880 --> 00:13:30.480 But 50 odd years later, 225 00:13:31.160 --> 00:13:32.260 consciousness proved too hard 226 00:13:32.260 --> 00:13:32.680 to measure. 227 00:13:33.700 --> 00:13:35.880 Psychology turned into the science of behavior. 228 00:13:37.280 --> 00:13:38.320 And behaviorism 229 00:13:38.320 --> 00:13:39.660 was in the ascendant for decades. 230 00:13:40.360 --> 00:13:41.860 The cognitive science revolution 231 00:13:41.860 --> 00:13:43.920 came along a few decades later, but still 232 00:13:43.920 --> 00:13:45.340 consciousness was left out. 233 00:13:45.440 --> 00:13:48.080 It's really only in the last 10, 15, 234 00:13:48.080 --> 00:13:50.180 20 years that consciousness has seen 235 00:13:50.180 --> 00:13:51.880 a real return to the scientific, 236 00:13:51.880 --> 00:13:52.180 scientific agenda. 237 00:13:52.400 --> 00:13:55.180 And there's been a real flux of activity here, 238 00:13:55.240 --> 00:13:57.240 not just in philosophy, but in neuroscience, 239 00:13:57.600 --> 00:14:00.320 in psychology, in physics, in medicine, and so on. 240 00:14:00.380 --> 00:14:03.260 People trying to bring together data from all fields 241 00:14:03.260 --> 00:14:05.780 to bear on this big central question 242 00:14:05.780 --> 00:14:08.700 of the construction of a theory of consciousness. 243 00:14:08.860 --> 00:14:10.000 So here I'm just gonna say a few things briefly 244 00:14:10.000 --> 00:14:13.520 about how the problems look from the broad overview 245 00:14:14.100 --> 00:14:16.480 of a philosopher and what some of the challenges are 246 00:14:17.160 --> 00:14:18.720 that are ahead of us. 247 00:14:19.580 --> 00:14:21.720 One way to see the science, I mean, I'm ultimately not 248 00:14:21.720 --> 00:14:23.060 an optimist about the science of consciousness, 249 00:14:23.240 --> 00:14:25.280 but I do see some pretty serious obstacles. 250 00:14:25.760 --> 00:14:27.720 As I see it, the science of consciousness is all about 251 00:14:27.720 --> 00:14:30.900 relating two classes of data that we have about 252 00:14:31.380 --> 00:14:32.280 the human being. 253 00:14:32.680 --> 00:14:35.200 What we might call the standard third person data, 254 00:14:35.960 --> 00:14:38.860 what's observable and measurable about a human being 255 00:14:39.380 --> 00:14:40.060 from the outside. 256 00:14:40.340 --> 00:14:42.560 In particular, data about their behavior, 257 00:14:42.720 --> 00:14:44.920 the way they respond, the things they say, 258 00:14:45.040 --> 00:14:47.800 the things they do, data about their brain, 259 00:14:47.940 --> 00:14:50.180 the kind of thing you might get from brain scanners, 260 00:14:50.260 --> 00:14:51.700 from probing their brains with a laser, 261 00:14:51.700 --> 00:14:52.800 electrodes, and so on. 262 00:14:52.840 --> 00:14:53.960 Call those the third person data. 263 00:14:54.280 --> 00:14:57.580 In most fields, third person data about a subject 264 00:14:59.000 --> 00:15:01.500 exhausts the data we have about that subject. 265 00:15:01.680 --> 00:15:03.760 Not so when it comes to consciousness. 266 00:15:04.160 --> 00:15:05.820 In the case of consciousness, uniquely, 267 00:15:06.040 --> 00:15:07.840 we have first person data. 268 00:15:08.300 --> 00:15:11.180 The data of our own subjective experience 269 00:15:11.740 --> 00:15:14.680 about our own states of consciousness. 270 00:15:14.960 --> 00:15:17.260 I know about consciousness in the first instance 271 00:15:17.260 --> 00:15:20.500 from my own case through introspection I experience, 272 00:15:20.500 --> 00:15:21.680 the flow of consciousness. 273 00:15:21.680 --> 00:15:24.000 I know of colors and shapes before me, 274 00:15:24.040 --> 00:15:28.360 of sounds around me, of emotions going through my mind. 275 00:15:28.400 --> 00:15:30.060 That's how each of us knows about consciousness. 276 00:15:30.240 --> 00:15:33.220 And this is a source of data for each of us. 277 00:15:33.940 --> 00:15:35.880 If a science of consciousness was to give a list 278 00:15:35.880 --> 00:15:37.700 of all the data that needs to be explained 279 00:15:37.700 --> 00:15:40.520 and list only the brain and the behavior and so on, 280 00:15:40.580 --> 00:15:43.600 leave off the first person data of subjective experience, 281 00:15:44.040 --> 00:15:45.740 that would be an incomplete catalog 282 00:15:45.740 --> 00:15:47.860 of what needs to be explained. 283 00:15:48.100 --> 00:15:51.660 That would be inadequate I think, as I said. 284 00:15:51.660 --> 00:15:53.440 Because science, it simply wouldn't cover, 285 00:15:54.120 --> 00:15:56.260 it wouldn't catalog the phenomena. 286 00:15:56.660 --> 00:15:58.800 So as good scientists, as good naturalists, 287 00:15:58.840 --> 00:16:00.380 we have to admit first person data. 288 00:16:00.580 --> 00:16:02.320 Now the question is how can we explain 289 00:16:02.320 --> 00:16:04.380 the distinctively first person data 290 00:16:05.180 --> 00:16:08.480 of conscious experience within a scientific framework? 291 00:16:08.880 --> 00:16:11.440 And here's where we come up against an obstacle. 292 00:16:11.700 --> 00:16:15.160 The standard methods we have of scientific explanation 293 00:16:15.160 --> 00:16:19.360 seem to be well developed for explaining third person data. 294 00:16:19.580 --> 00:16:21.420 You know, when it comes to explaining, say, 295 00:16:21.420 --> 00:16:25.140 biologically genetic processes of reproduction, 296 00:16:25.980 --> 00:16:27.560 of transmission of information, 297 00:16:27.820 --> 00:16:29.800 of metabolism, adaptation and so on, 298 00:16:29.840 --> 00:16:32.200 all you need to do is explain the objective functioning 299 00:16:32.920 --> 00:16:33.420 of a system. 300 00:16:33.520 --> 00:16:35.960 Explain how it is that a system can transfer 301 00:16:36.560 --> 00:16:39.120 hereditary characteristics from one generation to the next 302 00:16:39.120 --> 00:16:40.820 via a process of information transmission, 303 00:16:41.160 --> 00:16:43.620 leading to development, adaptation and so on. 304 00:16:43.680 --> 00:16:45.440 You've explained what needs to be explained. 305 00:16:45.700 --> 00:16:47.700 This is the research program that's been followed 306 00:16:47.700 --> 00:16:50.600 very well, for example, in molecular biology, 307 00:16:50.760 --> 00:16:51.400 in the science of genetic transformation. 308 00:16:51.420 --> 00:16:54.220 In the science of genetics, people found a mechanism, 309 00:16:55.180 --> 00:17:01.320 DNA, performs a function of underlying these functions 310 00:17:01.320 --> 00:17:03.060 of adaptation, metabolism, transmission. 311 00:17:03.660 --> 00:17:05.160 Explain those third person data. 312 00:17:05.360 --> 00:17:07.340 Explain that you've explained everything. 313 00:17:07.640 --> 00:17:09.160 And indeed, in much of the cognitive sciences, 314 00:17:09.380 --> 00:17:10.720 the sciences of the mind and the brain, 315 00:17:10.800 --> 00:17:11.340 it works that way. 316 00:17:11.400 --> 00:17:12.820 When it comes to explaining, say, 317 00:17:13.780 --> 00:17:19.160 behavior, language, response, perceptual stimulation, 318 00:17:20.380 --> 00:17:21.400 integration of information, 319 00:17:22.000 --> 00:17:25.700 control, all of these are essentially third person 320 00:17:25.700 --> 00:17:27.300 objectively characterizable functions 321 00:17:27.300 --> 00:17:28.060 of the cognitive system. 322 00:17:28.420 --> 00:17:30.620 And here, the standard methods seem to work quite well. 323 00:17:30.800 --> 00:17:32.420 These are the problems which I've sometimes called 324 00:17:32.420 --> 00:17:34.280 the easy problems of consciousness, 325 00:17:34.440 --> 00:17:35.940 not because they're by any means trivial. 326 00:17:36.040 --> 00:17:39.320 They're as hard as most standard problems in science 327 00:17:39.320 --> 00:17:40.780 because they don't get to the central mystery. 328 00:17:40.940 --> 00:17:42.060 The hard problem is this problem 329 00:17:42.060 --> 00:17:43.740 of explaining the first person data. 330 00:17:44.040 --> 00:17:48.100 Why is it that any number of neurons gathered up 331 00:17:48.100 --> 00:17:51.080 in a brain interacting by all these complex processes, 332 00:17:51.400 --> 00:17:53.320 of perception, integration, stimulus, response, 333 00:17:54.060 --> 00:17:56.340 should produce a subjective experience, which 334 00:17:56.340 --> 00:17:58.000 feels like something from the inside? 335 00:17:58.220 --> 00:17:59.460 That's the hard problem of consciousness. 336 00:17:59.780 --> 00:18:02.740 And at this moment, nobody knows the answer to that question. 337 00:18:02.960 --> 00:18:04.480 Now, in the book that Peter mentioned, 338 00:18:04.720 --> 00:18:10.620 I argued that, in fact, no completely objective science 339 00:18:11.160 --> 00:18:13.240 of consciousness is going to, on its own, 340 00:18:13.280 --> 00:18:15.900 solve the hard problem of consciousness. 341 00:18:16.060 --> 00:18:18.760 That is, no purely physical explanation 342 00:18:19.580 --> 00:18:21.280 will ever, on its own, explain why 343 00:18:21.280 --> 00:18:24.380 there is the subjective experience of consciousness. 344 00:18:24.580 --> 00:18:25.540 Now, the reasons for that are complicated, 345 00:18:25.660 --> 00:18:29.000 and I'm not going to go into all of them today. 346 00:18:29.100 --> 00:18:31.560 It's clear that consciousness arises in some way, 347 00:18:31.580 --> 00:18:33.920 is associated in some way with the brain. 348 00:18:34.060 --> 00:18:38.720 The question is, what is it that looking at the brain will explain? 349 00:18:40.700 --> 00:18:43.480 I'd argue that looking at the brain will give you 350 00:18:43.480 --> 00:18:45.900 an understanding of the mechanisms that perform 351 00:18:45.900 --> 00:18:49.360 the functions associated with the third person data of consciousness, 352 00:18:49.580 --> 00:18:50.780 how it is that the brain 353 00:18:50.780 --> 00:18:53.560 responds to inputs, how information is integrated, 354 00:18:53.900 --> 00:18:57.200 how this produces behavior, how this produces verbal report. 355 00:18:57.560 --> 00:18:59.660 That will explain all the third person data. 356 00:19:00.200 --> 00:19:02.620 No matter which of the third person data you explain, 357 00:19:02.840 --> 00:19:05.560 third person brain processes will always 358 00:19:05.560 --> 00:19:06.820 explain third person data. 359 00:19:07.080 --> 00:19:08.560 There will always be a further question. 360 00:19:08.820 --> 00:19:11.700 Why is all this accompanied by consciousness? 361 00:19:11.960 --> 00:19:14.240 Why is all this accompanied by a subjective experience? 362 00:19:14.580 --> 00:19:18.080 Why doesn't all this go on in the dark, so to speak, 363 00:19:18.100 --> 00:19:18.720 without consciousness? 364 00:19:19.040 --> 00:19:20.760 Sometimes philosophers put this forward, 365 00:19:20.760 --> 00:19:24.840 fancifully, by saying, why is it that we're not zombies? 366 00:19:26.980 --> 00:19:30.300 Creatures physically identical to normal human beings, 367 00:19:30.380 --> 00:19:32.020 but without consciousness at all. 368 00:19:32.740 --> 00:19:35.240 For all I know, strictly speaking, for all I know, 369 00:19:35.320 --> 00:19:37.800 each of you might be a zombie. 370 00:19:38.520 --> 00:19:39.720 Even my brother over there. 371 00:19:40.620 --> 00:19:42.580 I have my doubts from time to time. 372 00:19:44.340 --> 00:19:50.140 Walking, talking, getting around, and so on, but with nothing going on inside. 373 00:19:50.200 --> 00:19:50.520 Now. 374 00:19:50.760 --> 00:19:54.060 I don't believe that any of you are zombies, not even my brother. 375 00:19:55.240 --> 00:19:58.420 But the point is, the hypothesis makes sense. 376 00:19:58.620 --> 00:19:59.340 We're not zombies. 377 00:19:59.460 --> 00:20:00.100 I'm not a zombie. 378 00:20:00.160 --> 00:20:01.020 I believe you're not a zombie. 379 00:20:01.060 --> 00:20:02.040 Why are we not zombies? 380 00:20:02.120 --> 00:20:04.000 Why didn't evolution create zombies? 381 00:20:04.060 --> 00:20:07.660 Nothing in the physical story, I think, distinguishes the two. 382 00:20:07.800 --> 00:20:10.800 So I've argued, though, that this, so consciousness, I think, 383 00:20:10.800 --> 00:20:14.180 involves something that's not quite reducible to a physical process. 384 00:20:14.360 --> 00:20:18.980 Nonetheless, closely connected to a physical process. 385 00:20:22.480 --> 00:20:24.620 So at this point, two possibilities. 386 00:20:25.300 --> 00:20:28.240 I mean, you could either say, either reduce consciousness to a physical process 387 00:20:28.240 --> 00:20:32.540 or give up on science, or we can say, look for a slightly different kind of science. 388 00:20:33.060 --> 00:20:38.580 And the approach which I take is to admit consciousness as a natural datum of the natural 389 00:20:38.580 --> 00:20:39.040 world. 390 00:20:39.260 --> 00:20:40.520 It's a first person datum. 391 00:20:40.540 --> 00:20:41.420 It's part of our world. 392 00:20:41.500 --> 00:20:46.080 But it's not something that we should try to reduce to something that it's not. 393 00:20:46.180 --> 00:20:48.640 We shouldn't try to reduce it to a physical process. 394 00:20:49.320 --> 00:20:50.680 And this has... this has... 395 00:20:50.680 --> 00:20:53.240 you know, precedence throughout the history of science. 396 00:20:53.360 --> 00:20:55.900 We don't try to... we don't try to explain space and time. 397 00:20:56.580 --> 00:21:00.380 Physicists don't explain those things in terms of processes more basic than themselves. 398 00:21:00.560 --> 00:21:04.480 They admit them as part of the natural world and develop theories of them as irreducible 399 00:21:04.480 --> 00:21:05.560 properties of the world. 400 00:21:05.640 --> 00:21:07.300 Space-time, mass charge. 401 00:21:07.500 --> 00:21:11.500