The great free will debate | Bill Nye, Michio Kaku, Robert Sapolsky, Steven Pinker & more — Transcript

Full transcript

1. 0:00- Well, you ask one of the deepest philosophical  questions of physics. The question of free will.
2. 0:05- For billions of years on this planet,  there was life, but no free will.
3. 0:10Physics hasn't changed, but now we have free will.
4. 0:13- The brains are automatic, but people are free.
5. 0:15- Our ability to choose is often confused.
6. 0:19- Human choices will not be  predictable in any simple way.
7. 0:24- In reality, I don't think  there's any free will at all.
8. 0:39DANIEL DENNETT:  For billions of years on this planet there was life, but no free will. Physics hasn't changed,
9. 0:46but now we have free will. The difference is  not in physics. It has to do with, ultimately,
10. 0:54with biology. Particularly evolutionary biology.  What has happened over those billions of years,
11. 1:00is that greater and greater competences  have been designed and have evolved.
12. 1:07And the competence of a dolphin, or of  a chimpanzee, the cognitive competence,
13. 1:13the sort of mental competence, is hugely superior  to the competence of a lobster, or a starfish. But
14. 1:22ours dwarfs the competence of a dolphin or a  chimpanzee, perhaps to an even greater extent.
15. 1:30And there's an entirely naturalistic story to say,  to tell about how we came to have that competence,
16. 1:36or those competences. And it's that, "Can do."  It's that power that we have which is natural,
17. 1:44but it's that power which sets us aside from  every other species. And the key to it is that we
18. 1:52don't just act for reasons.  We represent our reasons
19. 1:56to ourselves and to others. The business  of asking somebody, "Why did you do that?"
20. 2:04And the person being able to answer, it is the  key to responsibility. And in fact, the word,
21. 2:11"responsibility," sort of wears its meaning on its  sleeve. We are responsible because we can respond
22. 2:19to challenges to our reasons. Why?  Because we don't just act for reasons,
23. 2:25we act for reasons that we consciously represent  to ourselves. And this is what gives us the power
24. 2:32and the obligation to think ahead, to anticipate,  to see the consequences of our action.
25. 2:39To be able to evaluate those consequences  in the light of what other people tell us.
26. 2:43To share our wisdom with each other. No  other species can do anything like it.
27. 2:48And it's because we can share our wisdom  that we have a special responsibility.
28. 2:54That's what makes us free in a way that no bird  is free, for instance. There's a very sharp
29. 3:02limit to the depth that we as conscious agents can  probe our own activities. This sort of superficial
30. 3:14access that we have to what's going on,  that's what consciousness is. Now, when I say,
31. 3:21who's this, "we," who's got this access? That's  itself part of the illusion because there isn't
32. 3:28a, sort of, boss part of the brain that's sitting  there with this limited access. That itself
33. 3:36is part of the illusion. What it is, is a  bunch of different subsystems, which have
34. 3:43varying access to varying things and that  conspire in a sort of competitive way to
35. 3:51execute whatever projects it is that they're,  in their, sort of, mindless way executing.
36. 3:56STEVEN PINKER: I don't believe there's such a  thing as free will in the sense of a ghost in
37. 4:02the machine, a spirit, or soul that somehow reads  the TV screen of the senses and pushes buttons
38. 4:10and pulls levers of behavior. There's no sense  that we can make of that. I think we are...our
39. 4:17behavior is the product of physical processes  in the brain. On the other hand, when you
40. 4:23have a brain that consists of a hundred billion  neurons, connected by a hundred trillion synapses,
41. 4:29there is a vast amount of complexity. That means  that human choices will not be predictable in any
42. 4:36simple way from the stimuli that have impinged  on it beforehand. We also know that that brain
43. 4:44is set up so that there are at least two  kinds of behavior. There's what happens when
44. 4:49I shine a light in your eye and your iris  contracts, or I hit your knee with a hammer
45. 4:53and your leg jerks upward. We also know that  there's a part of the brain that does things like
46. 5:00choose what to have for dinner, whether  to order chocolate, or vanilla ice cream.
47. 5:04How to move the next chess piece. Whether  to pick up the paper, or put it down. That
48. 5:10is very different from your iris closing when  I shine a light in your eye. It's that second
49. 5:16kind of behavior, one that engages vast amounts  of the brain, particularly the frontal lobes,
50. 5:22that incorporates an enormous amount of  information in the causation of the behavior,
51. 5:28that has some mental model of the world, that  can predict the consequences of possible behavior
52. 5:35and select them on the basis of those  consequences. All of those things carve
53. 5:41out the realm of behavior that we call free  will. Which it is useful to distinguish from
54. 5:48brute involuntary reflexes, but which doesn't  necessarily have to involve some mysterious soul.
55. 5:54ROBERT SAPOLSKY: The polite thing that I've sort  of said for decades, is that, well, if there's
56. 6:00free will, it's in all the boring places and  those places were getting more and more cramped.
57. 6:06If you want to insist that today you decided to  floss your teeth starting on your upper teeth,
58. 6:12rather than your lower teeth, rather than the  other way around, that that was an act of free
59. 6:17will, whatever, I'll grant that one to you, that's  where the free will is. In reality, I don't think
60. 6:24there's any free will at all. If you look at the  things that come into account as to whether or not
61. 6:30someone is going to do the right thing in the next  two seconds amid a temptation to do otherwise,
62. 6:37and the variables in there reflect everything  from whether they are having gas pains that day,
63. 6:44because of something unpleasant  they ate that morning that makes us
64. 6:48more selfish, more impulsive, et cetera, to what  epigenetic effects occurred to them than when they
65. 6:54were a first trimester fetus. When you look at  the number of things we recognize now that are
66. 7:01biological organic, where 500  years ago, or five years ago,
67. 7:06we would have had a harsh moral judgment about it.  And instead we now know, "Oh, that's a biological
68. 7:12phenomenon." And when we're we gonna get to the  point is recognizing, "Yeah, we're biological
69. 7:16organisms." This notion of free will, for want of  a less provocative word, is nothing but a myth.
70. 7:23NYE: Our brains are complicated and they got  this big, or as big as they are organically
71. 7:30through evolution, with layer being added  upon layer. So our ability to choose
72. 7:36is often confused. Our ability to make  choices and is often affected by the
73. 7:43environment, by our experiences and by  biochemistry. The shape of our brain.
74. 7:48MICHIO KAKU:
75. 7:54Well, you ask one of the deepest philosophical  questions of physics. The question of free will.
76. 8:00First of all, there's something called, Newtonian  determinism. Newtonian determinism says that the
77. 8:05universe is a clock. A gigantic clock that's wound  up at the beginning of time and it's been ticking
78. 8:10ever since, according to Newton's laws of motion.  So, what you're gonna eat 10 years from now on
79. 8:16January 1st has already been fixed. It's already  known using Newton's laws of motion. Einstein
80. 8:23believed in that. Einstein was a determinist. And  some people asked Einstein, "Well, does that mean
81. 8:28"that a murderer, a horrible mass murderer "isn't  really guilty of his works "'cause it was already
82. 8:34preordained billions of years ago?" And Einstein  said, "Well, yeah, in some sense, that's true.
83. 8:41"That even mass murderers were predetermined.  "But," he said, "They should still be placed
84. 8:47in jail," okay? Heisenberg then comes along and  proposes the Heisenberg uncertainty principle.
85. 8:53And says, "Nonsense. "There's uncertainty. "You  don't know where the electron is. "It could be
86. 8:58here, here, or many places simultaneously." And  this of course, Einstein hated because he said,
87. 9:04"God doesn't play dice with the universe."  Well, hey, get used to it. Einstein was wrong.
88. 9:12God does play dice. Every time we look at an  electron, it moves. There's uncertainty with
89. 9:17regards to the position of the electron. So what  does that mean for free will? It means, in some
90. 9:22sense, we do have some kind of free will. In the  sense that no one can determine your future events
91. 9:30given your past history. There's always the  wild card. There's always the possibility
92. 9:35of uncertainty in whatever we do. So this  means that free will, determining the future?
93. 9:41Hey, these are philosophical questions that seem  to indicate that we have some kind of free will.
94. 9:49JOSCHA BACH: Like consciousness, free will  is often misunderstood because we know it
95. 9:56by reference. But it's difficult to know it by  content, what you really mean by free will. A lot
96. 10:01of people will immediately feel that free will is  related to whether the universe is deterministic,
97. 10:06or probabilistic. And while physics has some  ideas about that, which change every now and then,
98. 10:13it's not part of our experience. And I don't think  it makes a difference if the universe forces you
99. 10:17randomly to do things, or deterministically.  The important thing seems to me that in free
100. 10:23will you are responsible for your actions.  And responsibility is a social interface.
101. 10:28For instance, if I am told that if I do X I  go to prison and this changes my decision to
102. 10:37whether or not to do X, I'm obviously responsible  for my decision because it was an appeal to my
103. 10:42responsibility, in some sense. Or likewise, if I  do a certain thing that it causes harm to other
104. 10:47people and I don't want that harm to happen,  that influences my decision. This is a discourse
105. 10:51of decision-making that I would call it's a free  will decision. Will is the representation that my
106. 10:58nervous system, at any level of its functioning,  has raised a motive to an intention. It has
107. 11:04committed to a particular kind of goal and it gets  integrated into the story of myself. This protocol
108. 11:09that I experience as myself in this world. And  that was what I experienced as well, as a real
109. 11:15decision. And this decision is free in as much  as this decision can be influenced by discourse.
110. 11:21MICHAEL GAZZANIGA: The essential part of free  will that people wanna hold on to is the sense
111. 11:25that that therefore makes you responsible for  your actions. So, there is the idea of personal
112. 11:31responsibility. And I think that's very important.  And I don't think that all this mechanistic
113. 11:37work on the brain in any way threatens  that. You learn that responsibility is to
114. 11:41be understood at the social level. The deal,  the rules that we work out, living together.
115. 11:48So the metaphor I like to use is cars and  traffic. We can study cars and all their physical
116. 11:54relationships and know exactly how that works.  It in no way prepares us to understand traffic
117. 11:59when they all get together and start interacting.  That's another level of organization and
118. 12:03description of these elements interacting. So the  same is with brains. That we can understand brains
119. 12:11to the nth degree and that's fine and that's what  we're doing, but it's not going to, in any way,
120. 12:18interfere with the fact that taking responsibility  in a social network is done at that level.
121. 12:26So, the way I sum it up is that brains  are automatic, but people are free
122. 12:30because people are gonna be...are joining the  social group and in that group are laws to live
123. 12:40by. And it's interesting, every social network,  whether it's artifactual, internet, or people,
124. 12:48that accountability is essential,  or the whole thing just falls apart.
125. 12:56DENNETT:
126. 12:57Intuition pumps are sometimes called thought  experiments. More often, they're called thought
127. 13:01experiments. But they're not really formal  arguments. Typically, they're stories. They're
128. 13:07little fables. In fact, I think they're similar  to Aesop's fables in that they they're supposed
129. 13:13to have a moral. They're supposed to teach us  something. And what they do, is they lead the
130. 13:19audience to an intuition, a conclusion, where you  sort of pound your fist on the table and you say,
131. 13:25"Oh yeah, it's gotta be that way, doesn't  it?" And if it achieves that, then it's
132. 13:30pumped the intuition that was designed to pump.  These are persuasion machines. They're little
133. 13:35persuasion machines that philosophers have  been using for several thousand years.
134. 13:39One of my recent favorites, which I devised to  jangle the nerves of neuroscientists who've been
135. 13:48going around saying that neuroscience  shows that we don't have free will.
136. 13:53I think their reasons for saying that are  ill-considered and moreover that what they're
137. 13:59doing is apt to be mischievous and doing some real  harm. So, I concocted a little thought experiment,
138. 14:06a little intuition pump to suggest that. So  this is the case of the nefarious neurosurgeon,
139. 14:13who treats a patient who has obsessive compulsive  disorder by inserting a little microchip in his
140. 14:22brain, which controls the OCD, the obsessive  compulsive disorder. Now, there is such a chip.
141. 14:30It's been developed in the Netherlands and it  works really quite well. That's science fact,
142. 14:36but now here comes science fiction. So the  neurosurgeon, after she's operated on the guy,
143. 14:43sewed him all up, say, "Okay, your OCD is  under control now you'll be happy to learn,
144. 14:48but moreover our team here will be monitoring  you 24/7 and we're going to be controlling
145. 14:56everything you do from now on. You will think  you have free will. You'll think you're making
146. 15:01your own decisions, but really you won't have  free will at all. Free will is an illusion that
147. 15:05we will maintain while controlling you. Goodbye,  have a nice life." Sends him out the door. Well,
148. 15:13he believes her. She has a shiny lab and, you  know, lots of degrees and diplomas and all that.
149. 15:20So, what does he do? Well, he, thinking he  doesn't have free will anymore, he gets a little
150. 15:26self-indulgent, a little bit aggressive, little  negligent in how he decides what to do. And pretty
151. 15:33soon, by indulging some of his worst features,  he's got himself in trouble with the law. And he's
152. 15:40arrested and he's put on trial. And at the trial  he says, "But your honor, I don't have free will.
153. 15:48I'm under the control of the team at  the neurosurgery clinic." They say,
154. 15:53"What's this?" And they call the neurosurgeon to  the stand. And say, "Did you tell this man that
155. 15:59you are controlling his every move, he didn't  have free will?" She says, "Yeah, I did, yeah,
156. 16:04but I was just messing with his head. That was  just a joke. I didn't think he'd believe me."
157. 16:09Now, right there, I think we can stop, take a  deep breath and say, well she did something really
158. 16:14bad. That was...that was really, she really  harmed that man. In fact, her little "joke,"
159. 16:23telling him that, actually accomplished  non-surgically pretty much what she claimed to
160. 16:28accomplish surgically. She disabled him by  telling him he didn't have free will. She
161. 16:35pretty much turned his free will off and  turned him into a morally incompetent person.
162. 16:44Now, if we agree that she did a bad thing, if  nobody recommends people play jokes like this,
163. 16:52what are we to say about the neuroscientists who  are telling the public every day, "We've shown in
164. 16:57our neuroscience labs that nobody has free will."  I think if the neuroscientists recognize that what
165. 17:06my imaginary neurosurgeon did was irresponsible,  they should think seriously about whether it's
166. 17:13irresponsible of them to make these claims  about free will. And it's not just a fantasy.
167. 17:21Vohs and Schooler, in an important paper, which  has been replicated in several different ways,
168. 17:27set up an experiment, really to test  this with college students, who were
169. 17:35given two texts to read. One was a text. They  were both from Francis Crick's book, "The
170. 17:41Astonishing Hypothesis," and one was not about  free will. And the other was about free will. And
171. 17:48basically it said, "Free will is an illusion.  All your decisions are actually determined by
172. 17:56causes that neuroscience is investigating. You  don't have free will. That's just an illusion."
173. 18:02All right, so there we have two groups. The group  that read that passage and the group that read
174. 18:06another passage from that book of the same length.  After they've read the passage, they are given a
175. 18:14puzzle to solve where they can earn some money  by solving it. And the experimenters cleverly
176. 18:21made the puzzles slightly defective, so there  was a way of cheating on the puzzle. That was,
177. 18:29oops, inadvertently revealed to the subjects. And  guess what? The subjects who'd read the passage
178. 18:39where Crick says, "Free will is an illusion,"  cheated at a much higher rate than the other ones.
179. 18:46In other words, just reading that passage  did have the effect of making them
180. 18:53less concerned about the implications of their  actions and they became, as it were, negligent,
181. 19:02or worse, in their own decision-making.