00:00:00.000 Today I'm doing chapter 5, the reality of abstractions.
00:00:04.000 Here we learn about the fact that there's not only physical material in the universe,
00:00:09.000 but rather there's also some other kind of part to reality.
00:00:15.000 And these abstractions can have real causal effects on physical things like atoms.
00:00:21.000 The reason why something like that ends up taking the shape that it does
00:00:27.000 has nothing to do with self-organization and physical forces.
00:00:32.000 It cannot be explained purely in terms of the motion of atoms,
00:00:35.000 and it can't be reduced to laws of motion or any kind of law of physics.
00:00:41.000 Instead, the explanation is that a great architect called Gaudi some 100 years ago
00:00:52.000 The idea was originally represented inside of his mind.
00:00:56.000 The idea was originally some kind of neural firings inside of his brain,
00:01:08.000 and then over many, many years it's beginning to take form
00:01:12.000 or beginning to be instancigated in the rock and stone and mortar
00:01:18.000 and other materials that make up an absolutely phenomenal building like this one.
00:01:24.000 It's only partially complete, and apparently it's going to be some decades before it finally is.
00:01:33.000 So with a great building, something like Gaudi's Cathedral,
00:01:37.000 what we have is an idea that is somehow taken physical form.
00:01:50.000 there are two ways of speaking about what exists.
00:02:01.000 Because the material things can be arranged into particular patterns.
00:02:05.000 And in particular, what we can have is kinds of patterns.
00:02:12.000 Ideas are things that can be instantiated within physical substrates.
00:02:17.000 And whether that physical substrate happens to be ink on paper,
00:02:21.000 or electrical signals in the brain, or indeed messages inside of a computer.
00:02:28.000 The point is that these ideas are something over and above the mere atoms,
00:02:37.000 So there really are two kinds of things in reality.
00:02:41.000 There's physical things, stuff made out of atoms,
00:02:50.000 We can have ideas about things like mathematics,
00:02:57.000 So these are abstract concepts about other abstract concepts.
00:03:06.000 The explanation of physical laws is itself an abstract concept.
00:03:11.000 So a realist is committed to the idea that abstract things exist.
00:03:17.000 That there are two kinds of existence in reality.
00:03:25.000 This doesn't commit us to any kind of woo, or supernatural kind of force, or spirituality.
00:03:31.000 All that it says is that the way in which physical things are arranged is not haphazard.
00:03:42.000 And even more profound, the abstract things can cause things to occur in physics.
00:03:54.000 They really are the proximate and indeed ultimate cause of many kinds of events that happen in the universe,
00:04:04.000 So let's read a little from chapter 5, the beginning of infinity, called the reality of abstractions.
00:04:11.000 And we'll see what David has to say about how abstract things cause stuff to happen,
00:04:18.000 and how they are the explanation of things happening in physical reality.
00:04:25.000 The fundamental theories of modern physics explain the world in jarringly counterintuitive ways.
00:04:30.000 For example, most physicists consider itself evident that when you hold your arm out horizontally,
00:04:36.000 you can feel the force of gravity pulling it downwards.
00:04:41.000 The existence of a force of gravity is astonishingly denied by Einstein's general theory of relativity.
00:04:47.000 One of the two deepest theories of physics are paused there.
00:04:57.000 and there's a section there on general relativity, and it speaks about why gravity is indeed not a force.
00:05:06.000 Gravity is not a force, I think is the name of the article.
00:05:11.000 This says that the only force on your arm in that situation is the one which you yourself are exerting upwards
00:05:17.000 to keep it constantly accelerating away from the straightest possible path in a curved region of spacetime.
00:05:23.000 The reality described by our other deepest theory, quantum theory, which I shall describe in chapter 11, is even more counterintuitive.
00:05:32.000 To understand explanations like those, physicists have to learn to think about everyday events in new ways.
00:05:39.000 The guiding principle is, as always, to reject bad explanations in favor of good ones.
00:05:44.000 In regard to what is or is not real, this leads to the requirement that if an entity is referred to by our best explanation in the relevant field,
00:05:56.000 This harks back to a section right at the beginning in one of the early chapters of the fabric of reality, the criteria for existence.
00:06:04.000 And the criteria of existence is said right there.
00:06:06.000 How do we know if something actually exists in reality?
00:06:09.000 Well, the way in which we know it exists is not via our senses.
00:06:13.000 It's not via us being able to detect it by seeing it or hearing it.
00:06:17.000 That's not what we mean by if something actually existing.
00:06:20.000 Because our senses are fallible that we can make mistakes.
00:06:29.000 Things can still go wrong with our explanations.
00:06:31.000 But the best way to decide whether or not something actually exists is whether or not it is referred to by our best explanations is what David says.
00:06:40.000 So our best explanation of how matter works requires us to believe,
00:06:45.000 and I believe requires us to invoke the existence of atoms, of particles.
00:06:51.000 And those particles are made up of protons, neutrons, and electrons.
00:06:55.000 So we're committed to the idea that electrons really do exist.
00:06:58.000 We can't get away with explaining physical reality without referring to electrons.
00:07:07.000 well, none of our best explanations of anything require us to speak in terms of ghosts.
00:07:13.000 People might think they've seen ghosts, but that is not a good explanation.
00:07:18.000 Usually in those situations, what has happened is that people have simply made mistakes.
00:07:26.000 Furthermore, every day events are stupidly complex when expressed in terms of fundamental physics.
00:07:32.000 If you feel a kettle with water and switch it on, all the supercomputers on earth,
00:07:36.000 working for the age of the universe could not solve the equations that predict what all those water molecules will do.
00:07:42.000 Even if we could somehow determine their initial state,
00:07:45.000 and that of all the outside influences on them,
00:07:51.000 So I just had to move my camera there a little bit.
00:07:56.000 Fortunately, some of that complexity resolves itself into a higher level simplicity.
00:08:01.000 For example, we can predict with some accuracy how long the water will take to boil.
00:08:06.000 To do so, we need only a few physical quantities that are quite easy to measure,
00:08:10.000 such as mass, the power of the heating element and so on.
00:08:13.000 For greater accuracy, we may also need information about subtler properties,
00:08:18.000 such as the number and type of nucleation sites for bubbles.
00:08:21.000 But these are still relatively high-level phenomena,
00:08:25.000 composed of intractively large numbers of interacting atomic level phenomena.
00:08:29.000 Thus, there is a class of high-level phenomena,
00:08:32.000 including the liquidity of the water and the relationship between containers, heating elements,
00:08:40.000 that can be well explained in terms of each other alone,
00:08:43.000 with no direct reference to anything at the atomic level or below.
00:08:47.000 In other words, the behavior of that whole class of high-level phenomena
00:08:56.000 This resolution into applicability at a higher, quasi-autonomous level is known as emergence.
00:09:03.000 So we just pause there, introduces the concept of emergence,
00:09:09.000 which many science popularizers and many scientists have written about over the years,
00:09:15.000 often in the quite confused way, but this is exceptionally clear.
00:09:20.000 There's nothing particularly mysterious about emergent phenomena,
00:09:28.000 That somehow, the laws of physics are such that particles arrange themselves in ways
00:09:41.000 And that higher level simplicity obeys its own laws.
00:09:47.000 It doesn't violate, it's not possible for it to violate the laws of physics.
00:09:51.000 So when we say it obeys its own laws, that doesn't mean in contradiction to the laws of physics,
00:09:56.000 it simply means these higher-level laws themselves emerge,
00:10:00.000 and govern the behavior of those higher-level simple structures.
00:10:15.000 but if you wanted to predict where each bubble will go,
00:10:18.000 or to be precise what the probabilities of its various possible motions are,
00:10:24.000 Still less, it is feasible to predict the countless microscopically defined properties of the water,
00:10:30.000 such as weather and odd or even number of its electrons,
00:10:33.000 will be affected by the heating during any given period.
00:10:40.000 and just refer you to this little self-indulgent,
00:10:44.000 to another one of my articles, this one about free will.
00:10:46.000 And I think it's important to note here that I regard free will,
00:10:57.000 because the laws of physics are already mandate what is going to happen in the universe,
00:11:03.000 in other words, everything is already determined.
00:11:05.000 It simply ignores the fact that there is such a thing as really existing emergent phenomena.
00:11:13.000 So we cannot escape from the fact that the laws of physics govern all things that happen in the universe.
00:11:19.000 But that doesn't mean that you can't have higher order simplicity.
00:11:28.000 And so this is my attempt to explain free will in terms of this higher level,
00:11:45.000 The behavior of high level physical quantities consists of nothing but the behavior of their low level constituents,
00:11:53.000 This has given rise to a widespread misconception about emergence and explanation,
00:12:00.000 The doctrine that science always explains and predicts things reductively,
00:12:06.000 Often it does, as we will use the fact that interatomic forces are
00:12:10.000 by the law of conservation of energy to make and explain a high level prediction
00:12:15.000 that the kettle cannot boil water without a power supply.
00:12:18.000 But reductionism requires that the relationship between different levels of exclamation
00:12:25.000 For example, as I wrote in the fabric of reality,
00:12:28.000 consider one particular copper atom at the tip of the nose of the statue of Sir Winston Churchill
00:12:37.000 Now, I'm not going to read that passage. I would just encourage everyone to grab the fabric of reality
00:12:42.000 or grab the beginning of any and read that for themselves.
00:12:45.000 It's not saying my running that I'm reading passages,
00:12:47.000 and I'm not going to read one of my favorite passages in both books.
00:12:52.000 And it's a brilliant passage because it articulates in a very profound way
00:12:59.000 the difference between reductionism as a dogma and how we go about actually
00:13:12.000 Not everything is explicable in terms of the laws of physics.
00:13:17.000 And I'm not going to read the passage, but I'll give you a flavor of what the passage is.
00:13:21.000 It's this idea that if you want to explain where a particular copper atom is,
00:13:26.000 but if it's at the nose of the statue of Winston Churchill,
00:13:29.000 then trying to explain the position of that copper atom in terms of laws of motion
00:13:34.000 and initial conditions stretching back to the big bang
00:13:38.000 in order to try and predict that the copper atom is being bumped
00:13:42.000 in sequence over and again until such time as it arrives at the tip of the nose of Winston Churchill.
00:13:48.000 You don't explain anything. However, if instead you talk about the copper atom as being part of a brass statue
00:13:55.000 and statues are made out of brass so that they don't corrode away.
00:13:58.000 And we like to make statues of important people like Winston Churchill,
00:14:02.000 who prevented the Second World War from being a victory for the Nazis.
00:14:07.000 That is an explanation. Why is the copper atom there?
00:14:10.000 Or the copper atom is there because it's part of brass.
00:14:13.000 And brass is there because we make statues out of it.
00:14:15.000 We make statues out of it because we'd like to remember important historical figures.
00:14:19.000 That's the explanation of why the copper atom is there.
00:14:26.000 But you won't get the why if you say, oh, it's the laws of physics.
00:14:30.000 It is just determined that the copper atom was going to be there.
00:14:39.000 if you attempt to explain it in terms of deterministic laws,
00:14:43.000 then you ignore the high level causative structure that exists in the universe, namely emergence.
00:14:50.000 And one of the most parsimonious ways to explain why people choose to do one thing or the other is freewill.
00:14:57.000 If you try and say what they were compelled to do that in the first place,
00:15:02.000 be they laws of neuroscience or neurobiology or even deeper the laws of physics,
00:15:07.000 you're missing the difference between explanation and prediction.
00:15:13.000 And although an oracle who has access to the perfect laws of physics and initial conditions
00:15:21.000 In other words, their behavior is perfectly determined in the same way that the copper atom was perfectly determined to end up where it was.
00:15:33.000 There's a difference. There's a really important difference.
00:15:36.000 So I'm skipping a bit and David goes through arguments against reductionism.
00:15:41.000 And then arguments against its mirror image called holism.
00:15:45.000 This holism idea is something that you often hear from natural therapies type people.
00:15:51.000 This idea that we should treat diseases of the body by looking at the entire body as a whole,
00:15:56.000 rather than focusing on a specific problem with the body.
00:16:04.000 all those doctrines are irrational from the same reason.
00:16:07.000 They advocate accepting or rejecting theories on grounds other than whether they are good explanations.
00:16:12.000 Whenever a high-level explanation does follow logically from low-level ones,
00:16:16.000 that also means that the high-level one implies something about the low-level ones.
00:16:20.000 Thus, additional high-level theories provided that they were all consistent would place more and more constraints on what the low-level theories could be.
00:16:29.000 So it could be that all the high-level explanations that exist taken together imply all the low-level ones,
00:16:36.000 Or it could be that some low-level, some intermediate level,
00:16:39.000 and some high-level explanations taken together imply all explanations.
00:16:48.000 So this is an interesting way of speaking about explanations and laws, if you like.
00:16:59.000 but in a sense, they're constrained by what we learn about the way in which high-level explanations work.
00:17:05.000 The high-level explanations, what we know about them, constrains what actually happens at the lower-level,
00:17:10.000 or what we know about what happens at the lower-level.
00:17:16.000 but we also can't go violating just any old high-level explanation as well.
00:17:31.000 You're right. In any case, the emergent phenomena are essential to the applicability of the world.
00:17:36.000 Long before humans had much explanatory knowledge,
00:17:39.000 they were able to control nature by using rules of thumb.
00:17:42.000 Rules of thumb have explanations, and those explanations were about high-level regularities among emergent phenomena,
00:17:50.000 Long before that, it was only genes that were encoding rules of thumb.
00:17:54.000 And the knowledge in them, too, was about emergent phenomena.
00:17:57.000 Thus, emergence is another beginning of an affinity.
00:18:01.000 All knowledge creation depends on, and physically consists of, emergent phenomena.
00:18:06.000 Emergence is also responsible for the fact that discoveries can be made in successive steps,
00:18:12.000 thus providing scope for the scientific method.
00:18:15.000 The partial success of each theory, in a sequence of improving theories,
00:18:19.000 is tantamount to the existence of a layer of phenomena,
00:18:23.000 that each theory explains successfully, though, as it then turns out, partly mistakenly.
00:18:30.000 Successive scientific explanations are occasionally dissimilar in the way they explain their predictions,
00:18:36.000 even in a domain where the predictions themselves are similar or identical.
00:18:40.000 For instance, Einstein's explanation of planetary motion does not merely correct Newtons.
00:18:46.000 It is radically different, denying, among other things, the very existence of central elements of the Newtons explanation,
00:18:52.000 such as the gravitational force and the uniformly flowing time with respect to which Newton defined motion.
00:18:58.000 Likewise, the astronomer Johannes Kepler's theory, which said that the planets move in ellipses,
00:19:03.000 did not merely correct the celestial sphere theory.
00:19:09.000 And Newtons did not substitute a new shape for Kepler's ellipses,
00:19:12.000 but a whole new way for laws to specify motions, through infinitesimally defined quantities
00:19:21.000 Thus, each of those theories of planetary motion was ignoring or denying its predecessors' basic means of explaining what was happening out there.
00:19:31.000 This has been used as an argument for instrumentalism, as follows.
00:19:36.000 Each successive theory made small but accurate corrections to what its predecessor predicted,
00:19:42.000 and was therefore a better theory in that sense.
00:19:44.000 But since each theory's explanation swept away that of the previous theory, the previous theory's explanation was never true in the first place,
00:19:52.000 and so one cannot regard those successive explanations as constituting a growth of knowledge about reality.
00:19:59.000 From Kepler to Newton to Einstein, we have, successfully, no force needed to explain orbit,
00:20:05.000 and inverse square law needed to be responsible for every orbit, and again, no force needed.
00:20:10.000 So how could Newton's force of gravity, as distinct from his equations predicting its effects,
00:20:18.000 It could, and was, because sweeping away the entities through which a theory makes its explanation,
00:20:23.000 is not the same as sweeping away the whole of the explanation.
00:20:26.000 Although there is no force of gravity, it is true that something real, the curvature of space-time,
00:20:32.000 caused by the sun, has a strength that varies approximately according to Newton's inverse square law,
00:20:38.000 and affects the motion of objects seen and unseen.
00:20:41.000 Newton's theory also correctly explained that laws of gravitation are the same for terrestrial and celestial objects.
00:20:47.000 It made a novel distinction between mass, the measure of an object's resistance to being accelerated,
00:20:52.000 and weight, the force required to prevent an object from falling under gravity.
00:20:56.000 And it said that the gravitational effect of an object depends on its mass and not other attributes,
00:21:04.000 Later, Einstein's theory not only endorsed all those features, but explained in turn why they are so.
00:21:10.000 Newton's theory too had been able to make more accurate prediction-centered predecessors,
00:21:14.000 precisely because it was more right than they were about what was really happening.
00:21:18.000 Before that, even Kepler's explanation had included important elements of the true explanation.
00:21:23.000 Planetary orbits, and indeed determined by laws of nature.
00:21:26.000 Those laws of nature are indeed the same for all planets, including Earth.
00:21:30.000 They do invoke the sun, they are mathematical, angiometrical, and character, and so on.
00:21:34.000 With the hindsight provided by each successive theory, we can see not only where the previous theory made false predictions,
00:21:40.000 but also that wherever it made true predictions, this was because it had expressed some truth about reality.
00:21:50.000 As Einstein remarked, there could be no fairer destiny for any physical theory,
00:21:55.000 and then it should point the way to a more comprehensive theory in which it lives on as a limiting case.
00:22:03.000 I've been engaged in some discussions recently about the existence of truth, and whether or not it can be found.
00:22:08.000 There's a school of philosophy called skepticism, and the skeptics seem to believe that we cannot attain truth,
00:22:20.000 And this is why fallibleists don't agree insofar as we cannot get to the final truth.
00:22:29.000 But this doesn't mean we can't find any truth at all.
00:22:35.000 And the reason we know we can have access to provisional truth is for the reasons articulated in the passage right there.
00:22:41.000 So let me just reread a little bit where David said, wherever it, the previous theory, made true predictions,
00:22:54.000 this was because it had expressed some truth about reality.
00:22:59.000 So true predictions, in other words, the prediction worked, but why did the prediction work?
00:23:05.000 Well, the prediction worked because there must have been something about reality that the theory got correct.
00:23:12.000 It doesn't mean it got the whole lot correct, but the fact that it did get correct means it got something right, something true was stated.
00:23:21.000 These things are synonyms as far as I'm concerned.
00:23:24.000 We're just talking about the same thing. There's a reality out there.
00:23:28.000 And when we make statements about that reality, that work, we've said something true.
00:23:34.000 We might not know precisely which part of the theory is true until sometime later in retrospect.
00:23:42.000 But we are able to get some of this truth sometimes, not the final truth, not ultimate truth, provisional truth.
00:23:51.000 Truth that works, truth that enables us to make progress.
00:23:55.000 And the reason we make progress is because we are improving by objective standards our theories.
00:24:01.000 We're going to skip a little more and then read a little more.
00:24:06.000 David writes, and this is a sort of esoteric thing that philosophers of science like to talk about, but I will mention it.
00:24:14.000 So he writes, by the way, it is something of a misconception that the predictions of successive theories of planetary emotions were all that similar.
00:24:22.000 Newton's predictions are indeed excellent in the context of bridge building, and only slightly inadequate when running the global positioning system.
00:24:29.000 But they are hopelessly wrong when explaining a pulsar or quasar, or the universe as a whole, to get all those right, one needs Einstein's radically different explanations.
00:24:39.000 Such large discontinuities in the meanings of successive scientific theories have no biological analogue.
00:24:46.000 In an evolving species, the dominant strain of each generation differs only slightly from that in the previous generation.
00:24:52.000 Nevertheless, scientific discovery is a gradual process too. It is just that, in science, all the gradualness, and nearly all the criticism and rejection of bad explanations takes place inside the scientists' minds.
00:25:05.000 As Papa put it, we can let our theories die in our place.
00:25:10.000 I'm skipping forward to the place where he gets to the meat of the matter, namely abstractions, and he writes.
00:25:18.000 That brings me to the main subject of this chapter, abstractions.
00:25:22.000 In Chapter 4, I remark that pieces of knowledge or abstract replicators that use, hence effect, organisms and brains to get themselves replicated.
00:25:31.000 That is a higher level of explanation than the emergent levels I have mentioned so far.
00:25:35.000 It is a claim that something abstract, something non-physical, such as knowledge in a gene or a theory, is affecting something physical.
00:25:45.000 Again, this is one of those profound passages where it's no good just reading it once.
00:25:51.000 You really have to meditate on that for a moment, so I just want to read that last sentence again.
00:25:57.000 It is a claim that something abstract, something non-physical, such as the knowledge in a gene or a theory, is affecting something physical.
00:26:10.000 He continues. Physically, nothing is happening in such a situation other than that one set of emergent entities such as genes or computers, is affecting others, which is already anathema to reductionism.
00:26:23.000 But abstractions are essential to a fuller explanation.
00:26:26.000 You know that if your computer beats you at chess, it really is the program that is beaten you, not the silicon atoms or the computer is such.
00:26:33.000 The abstract program is instantiated physically, as a high level behaviour of vast numbers of atoms, but the explanation of why it is beaten you cannot be expressed without also referring to the program in its own right.
00:26:46.000 That program has also been instantiated, unchanged, in a long chain of different physical substrates, including neurons in the brains of the programmers, and radio waves when you download the program via wireless networking,
00:27:00.000 and finally, as states have long and short-term memory banks in your computer.
00:27:05.000 The specifics of that chain of instantiations may be relevant to explaining how the program reached you, but it is irrelevant to why it beats you.
00:27:13.000 There, the content of the knowledge in it and in you is the whole story.
00:27:19.000 That story is an explanation that refers in electrically to abstractions, and therefore those abstractions exist.
00:27:27.000 And really do affect physical objects in a way required by the explanation.
00:27:33.000 The next section is a section that summarizes part of Douglas Hofstadter's work.
00:27:40.000 And I think it is a powerful, excuse the pun, knockdown argument about the reality of abstractions.
00:27:56.000 The computer scientist Douglas Hofstadter has a nice argument that this sort of explanation is essential in understanding certain phenomena.
00:28:02.000 In his book, I am a strange loop, 2007, he imagines a special purpose computer built of millions of dominoes.
00:28:10.000 They are set up as dominoes often are for fun, standing on end close together.
00:28:14.000 So if one of them is knocked over, it strikes its neighbour, and so a whole stretch of dominoes falls one after another.
00:28:20.000 But Hofstadter's dominoes are spring-loaded in such a way that, whenever one is knocked over, it pops back up after a fixed time.
00:28:27.000 Hence, when a domino falls, a way of a signal of falling dominoes propagates along the stretching the direction in which it fell, until it reaches either a dead end, or a currently fallen domino.
00:28:39.000 By arranging these dominoes in a network with looping, bifurocating, and rejoining stretchers, one can make these signals combine and interact.
00:28:48.000 In a sufficiently rich repertoire of ways, to make a whole, to make the whole construction into a computer.
00:28:55.000 A signal travelling down a stretch can be interpreted as a binary one, and the lack of a signal as a binary zero.
00:29:01.000 And the interactions between such signals can implement a repertoire of operations such as and, or, and not.
00:29:08.000 Out of which arbitrary computations can be composed.
00:29:12.000 One domino is designated as the on switch. When it is knocked over, the domino computer begins to execute the program that is instantiated in its loops and stretchers.
00:29:23.000 The program in Hofstadter's thought experiment computes whether a given number is a prime or not.
00:29:29.000 One inputs that number by placing a stretch of exactly that many dominoes at a specified position before tripping the on switch.
00:29:37.000 Elsewhere in the network, a particular domino will deliver the output of the computation.
00:29:42.000 It will fall only if a divisor is found, indicating that the input was not prime.
00:29:49.000 Hofstadter sets the input to number 641, which is a prime, and trips the on switch.
00:29:56.000 Flourries of motion begin to sweep back and forth across the network.
00:29:59.000 All 641 of the input dominoes soon fall as the computation reads its input and snap back up and participate in further intricate patterns.
00:30:08.000 It is a lengthy process because this is a rather inefficient way to perform computations, but it does the job.
00:30:14.000 Now Hofstadter imagines that an observer who does not know the purpose of the domino network, what just the dominoes performing, and notices that one particular domino remains resolutely standing.
00:30:26.000 Never affected by any of the waves of downs and ups sweeping by.
00:30:31.000 He David quotes a part of Iron Strange Loop where Hofstadter writes.
00:30:36.000 The observer points at that domino and asks with curiosity, how come that domino there is never falling?
00:30:48.000 We know that that is the output domino, but the observer does not.
00:30:54.000 Let me contrast two different types of answer that someone might give.
00:30:58.000 The first type of answer, myopic to the point of silliness would be because it is predecessor never falls, you dummy.
00:31:07.000 Or if it has two or more neighbours, because none of its neighbours ever fall.
00:31:13.000 To be sure, this is as correct as far as it goes, but it does not go very far.
00:31:22.000 In fact, one could keep passing the buck from domino to domino to provide ever more detailed answers that were silly, but correct as far as they go.
00:31:31.000 Eventually, one had passed the buck billions of times, many more times than there are dominoes because the program loops.
00:31:38.000 One would arrive at the first domino, the on-switch.
00:31:41.000 At that point, the reductive to high-level physics explanation would be in summary.
00:31:46.000 That domino did not fall, because none of the patterns of motion initiated by knocking over the on-switch ever included.
00:31:56.000 We can reach that conclusion, as we just have, without going through that laborious process.
00:32:03.000 But it is not the explanation we were looking for, because it is addressing a different question.
00:32:10.000 Mainly, if the first domino falls, will the output domino ever fall.
00:32:15.000 And it is asking at the wrong level of emergence.
00:32:21.000 To answer that, Hofstadter then adopts a different mode of explanation at the right level of emergence, where Hofstadter writes.
00:32:28.000 The second type of answer would be, because 641 is prime.
00:32:34.000 Now this answer, while just as correct, indeed in some sense it is far more on the mark, has the curious property of not talking about anything physical at all.
00:32:44.000 Not only has the focus moved upwards to collective properties, these properties somehow transcend the physical, and have to do with pure abstractions, such as primality.
00:33:01.000 The point of this example is that 641's primality is the best explanation, perhaps even the only explanation, for why certain dominoes did fall, and certain others did not fall.
00:33:17.000 The physics-based explanation is true as well, and the physics of the dominoes is also essential to explaining why prime numbers are relevant to that particular arrangement of them.
00:33:26.000 But Hofstadter's argument does show that primality must be part of any full explanation of why the dominoes did or did not fall.
00:33:35.000 Hence, it is a refutation of reductionism in regards to abstractions, for the theory of prime numbers is not part of physics.
00:33:43.000 It refers not to physical objects, but to abstract entities, such as numbers of which there is an infinite set.
00:34:02.000 This was the idea that spinodes are had. There is one reality.
00:34:06.000 However, there are two kinds of real existing objects within that reality.
00:34:13.000 There is stuff made of atoms, the physical world, and then there's stuff that's not made of atoms, the abstract world.
00:34:20.000 There's nothing spiritual or spooky about the abstract world.
00:34:23.000 It consists of things like numbers, and those numbers have properties.
00:34:29.000 Those properties include things like whether they have multiple factors or not.
00:34:34.000 If they don't, and they only have themselves in one as factors, then they have the property that they are prime numbers.
00:34:40.000 In which case, we have this rich class of structures out there in abstract reality that have relations among themselves, but more profoundly, the abstract entities can have causal effects on the physical world.
00:34:54.000 How do they have causal effects on the physical world?
00:34:59.000 Because the physical world is organized in patterns in such a way that the abstract entities are instantiated within that physical reality.
00:35:05.000 And the relationships between the abstract entities are represented within the physical world.
00:35:10.000 There's nothing mysterious here. There's no extra forces that are required in order to push things around.
00:35:15.000 We still have the same forces we do in physics.
00:35:18.000 And the next part that David talks about is a little bit within the wheelhouse of Sam Harris.
00:35:24.000 And a little bit within the wheelhouse of Buddhists, and sort of an interest of people who interested in this question of personhood, which I certainly am.
00:35:33.000 David writes, unfortunately, speaking about how Hofstadter has just distinguished between two kinds of really existing things,
00:35:43.000 namely the physical and the abstract, David writes,
00:35:46.000 unfortunately Hofstadter goes on to disown his own argument and to embrace reductionism.
00:35:53.000 His book is primarily about one particular emergent phenomenon, the mind, or as he puts it, the eye.
00:35:59.000 He asks whether the mind can be consistently thought of as affecting the body, causing it to do one thing rather than another,
00:36:06.000 given the all embracing nature of the laws of physics.
00:36:11.000 For instance, we often explain our actions in terms of choosing one action rather than another,
00:36:15.000 but our bodies, including our brains, are completely controlled by the laws of physics,
00:36:18.000 leaving no physical variable free for an eye to affect in order to make such a choice.
00:36:25.000 Well, Paul said, that's the determinism argument against free will.
00:36:29.000 People who think that determinism is incompatible with free will.
00:36:33.000 These people who think determinism is incompatible with free will,
00:36:36.000 tend to also think that determinism is incompatible with abstract entities.
00:36:39.000 If abstract entities can have causal effects in the world,
00:36:42.000 then the eye, being an abstract entity, also cannot have causal effects in the world,
00:36:49.000 But that's not possible, as we have seen, the dominoes fall down,
00:36:51.000 because the abstract concept of primality is the explanation as to why a particular domino did or did not fall.
00:37:04.000 Hofsteder eventually concludes that the eye is an illusion.
00:37:08.000 Minds, he concludes, can't push material stuff around,
00:37:12.000 because physical law alone would not suffice to determine its behaviour,
00:37:18.000 And now David writes something very, very important.
00:37:21.000 He writes, but first of all, physical laws can't push anything either.
00:37:28.000 They only explain and predict, and they are not our only explanations.
00:37:33.000 The theory that the domino stands because 641 is prime,
00:37:38.000 and because the domino network instantiates a primality testing algorithm,
00:37:47.000 and explains more than any explanation purely in terms of those laws.
00:37:50.000 And no known variant of it can do the same job.
00:37:53.000 Second, that reductionist argument would deny that an atom can push in the sense of cause to move,
00:38:00.000 Since the initial state of the universe, together with the laws of motion,
00:38:03.000 has already determined the state at every other time.
00:38:07.000 Third, the very idea of cause is emergent and abstract.
00:38:10.000 It is mentioned, nowhere in the laws of motion about elementary particles,
00:38:17.000 we cannot perceive causation, only a succession of events.
00:38:27.000 That means that, just as they determine the final state of any motion,
00:38:29.000 given the initial state, they also determine the initial state,
00:38:35.000 And this state at any time, from the state at any other time.
00:38:39.000 So at that level of explanation, cause and effect are interchangeable.
00:38:43.000 And not what we mean when we say that a program causes a computer to win at chess,
00:38:47.000 or that a domino remains standing because 641 is prime.
00:38:52.000 There is no inconsistency in having multiple explanations of the same phenomenon,
00:38:56.000 at different levels of emergence, regarding micro-physical explanations as more fundamental in emerging ones,
00:39:03.000 There is no escape from Hofstra to 641 argument, no reason to want one.
00:39:07.000 The world may or may not be as we wish it to be,
00:39:10.000 and to reject good explanations on that account is to imprison oneself in parochial error.
00:39:16.000 So the answer, because 641 is prime, does explain the immunity of that domino.
00:39:22.000 The theory of prime numbers on which that answer depends
00:39:25.000 as not a law of physics, nor an approximation to one.
00:39:29.000 It is about abstractions and infinite sets of them at that,
00:39:32.000 such as the set of natural numbers, 1, 2, 3, etc., etc.
00:39:37.000 There is no mystery how we can have knowledge of infinitely large things,
00:39:45.000 Versions of number theory that can find themselves to small natural numbers
00:39:48.000 would have to be so full of arbitrary qualifiers, workarounds and unanswered questions
00:39:52.000 that they will be very bad explanations, until they would generalise
00:39:55.000 to the case that makes sense without such ad hoc restrictions, the infinite case.
00:40:00.000 I shall discuss various sorts of infinity in chapter 8.
00:40:04.000 Skipping just a short paragraph now, and David Wright's.
00:40:08.000 Our own brains are computers, which we can use to learn about things
00:40:11.000 beyond the physical world, including pure mathematical abstractions.
00:40:16.000 This ability to understand abstractions is an emergent property of people,
00:40:20.000 which greatly puzzled the ancient Athenian philosopher Plato.
00:40:25.000 such as Pythagoras' Theorem, are about entities that are never experienced,
00:40:32.000 intersecting each other on a perfect plane to make a perfect triangle.
00:40:36.000 These are not possible objects of any observation,
00:40:39.000 and yet people knew about them, and not just superficially at the time,
00:40:42.000 such knowledge was the deepest knowledge of anything that human beings had ever had,
00:40:46.000 where did it come from? Plato concluded that it,
00:40:50.000 and all human knowledge must come from the supernatural.
00:40:54.000 He was right that it could not have come from observation,
00:40:57.000 but then it could not have, even if people had been able to observe perfect triangles,
00:41:02.000 as arguably they could today using virtual reality.
00:41:05.000 As I explained in chapter 1, empiricism has multiple fatal flaws,
00:41:09.000 but it is no mystery where our knowledge of abstractions comes from.
00:41:13.000 It comes from conjecture like all our knowledge, and through criticism and seeking good explanations.
00:41:18.000 It is only empiricism that made it seem plausible that knowledge outside of science is inaccessible,
00:41:24.000 and it is only the justified true-belief misconception
00:41:27.000 that makes such knowledge seem less justified than scientific theories.
00:41:35.000 almost all rejected theories are rejected for being bad explanations,
00:41:39.000 without ever being tested. Experimental testing is only one of many methods of criticism used in science,
00:41:45.000 and the Enlightenment has made progress by bringing those other methods to bear in non-scientific fields as well.
00:41:52.000 The basic reason that such progress is possible is the good explanations about philosophical issues
00:41:57.000 are as hard to find as in science, and criticism is correspondingly effective.
00:42:03.000 I'm skipping a little here and then he gets into a different class of abstract entities.
00:42:08.000 Moral entities, so let's have a read about what he says there.
00:42:13.000 In the case of moral philosophy, the empiricist and justificationist misconceptions are often expressed in the maxim
00:42:20.000 that you can't derive and ought from an is a paraphrase of a remark by the Enlightenment philosopher David Hume.
00:42:27.000 It means that moral theories cannot be deduced from factual knowledge.
00:42:31.000 This has become conventional wisdom, and has resulted in a kind of dogmatic despair about morality.
00:42:36.000 You can't derive and ought from an is, therefore morality cannot be justified by reason.
00:42:41.000 That leaves only two options either to embrace unreason, or to try living without ever making moral judgment.
00:42:47.000 Both are liable to lead to morally wrong choices just as embracing unreason,
00:42:52.000 and never attempting to explain the physical world, leads to factually false theories and not just ignorance.
00:42:57.000 I'll pause there, so this has been part of the recent uptick in philosophical interest about morality
00:43:07.000 We hear Jordan Peterson and Sam Harris talking about exactly the same issue.
00:43:12.000 This idea that because we can't derive and ought from an is, many people choose one of two paths.
00:43:18.000 The first is to head towards unreason, and I think that what we're hinting at here when we come to unreason is a kind of dogma.
00:43:25.000 So you give up trying to improve your theories, you settle on a particular idea, moral code, religious or otherwise, and you refuse to change it.
00:43:34.000 It's a form of unreason, or you move into relativism, where you simply say, I cannot make any moral judgments.
00:43:41.000 And this all stems from this justificationist mistake or imperial system mistake that you can't derive and ought from an is.
00:43:51.000 Certainly, you can't derive an ought from an is, but you can't derive a factual theory from an is either.
00:44:00.000 The growth of knowledge does not consist of finding ways to justify one's beliefs.
00:44:06.000 And although factual evidence and moral maximally independent, factual and moral explanations are not.
00:44:12.000 Thus, factual knowledge can be useful in criticizing moral explanations.
00:44:17.000 For example, in the 19th century of an American slave had written a bestselling book,
00:44:21.000 that event would not logically have ruled out the proposition Negroes are intended by providence to be slaves.
00:44:26.000 No experience could because that is a philosophical theory.
00:44:29.000 But it might have ruined the explanations through which many people understood that proposition.
00:44:32.000 And if, as a result, such people had found themselves unable to explain to their own satisfaction why it would be providential if that author would have been forced back into slavery,
00:44:41.000 then they might have questioned the account that they had formally accepted of what a black person really is.
00:44:46.000 And what a person in general is, and then a good person, a good society, and so on.
00:44:51.000 Conversely, advocates of highly immoral doctrines, almost invariably believe associated factual falsehoods as well.
00:44:58.000 For instance, ever since the attack on the United States on 11 September 2001, millions of people worldwide have believed it was carried out by the US government or the Israeli Secret Service.
00:45:08.000 Those are purely factual misconceptions. Yet they bear the imprint of moral wrongness, just as clearly as a fossil, made of purely an organic material, bear the imprint of ancient life.
00:45:22.000 To correct a moral explanation for why Westerners deserve to be killed indiscriminately, one needs to explain factually that the West is not what it pretends to be.
00:45:29.000 And that requires uncritical acceptance of conspiracy theories denial of history and so on.
00:45:34.000 So there we have this concept about derivation and people are fixated on the idea, especially morality, about trying to derive moral theories from a set of facts about the real world.
00:45:53.000 derivation is very much a logical and mathematical process. If you stay within the domain, within the domain of mathematics, then you can derive the conclusion from the premises, given a certain set of rules, given a certain set of rules of inference.
00:46:09.000 That's what mathematics is about. That's what philosophical logic is about.
00:46:14.000 But observing stuff in the world and then deciding what to do about it isn't a straight line using derivation. You need explanation.
00:46:28.000 Next paragraph has a telling phrase, David writes, quite generally, in order to understand the moral landscape in terms of a given set of values, one needs to understand some facts being a certain way as well.
00:46:42.000 And the converse is also true. For example, as the philosopher Jacob Brunowski pointed out, success at making factual scientific discoveries entails a commitment to all sorts of values that are necessary for making progress.
00:46:54.000 The individual scientist has to value truth and good explanations and to be open to ideas and to change, the scientific community and to some extent the civilization as a whole has to value tolerance, integrity and openness of debate.
00:47:07.000 We should not be surprised at these connections. The truth has structural unity as well as logical consistency.
00:47:13.000 And I guess that no true explanation is entirely disconnected from any other.
00:47:17.000 Since the universe is explicable, it must be that morally right values are connected in this way with true factual theories and morally wrong values with false theories.
00:47:26.000 Moral philosophy is basically about the problem of what to do next. And more generally, what sort of life to lead and what sort of world to want.
00:47:36.000 Some philosophers can find the term moral to problems about how one should treat other people. But such problems are continuous with problems of individuals.
00:47:43.000 Choosing what sort of life to lead, which is why I adopt the more inclusive definition.
00:47:47.000 Terminology aside, if you were suddenly the last human on earth, you would be wondering what sort of life to want. Deciding, I should do whatever pleased me most, would give you very little clue.
00:47:57.000 Because what pleases you depends on your moral judgement of what constitutes a good life and not vice versa.
00:48:03.000 So that's profound. There's a few moral philosophies going around today, or codes of behaviour one might say, such as effective altruism.
00:48:12.000 These purport to be explanations of morality that are able to provide a foundation or a framework within which to decide what we should do next.
00:48:26.000 Now, useful as they might be, for many situations, the problem is they cannot be an all-encompassing moral philosophy, because moral philosophy can't be about how to treat other people.
00:48:38.000 That might be a very small part of moral philosophy, but essentially, as David is saying here, if there were no other people, there'd still be a lot of moral questions.
00:48:49.000 If you, with the last person earth, you'd want to know what you should do next. It wouldn't have anything to do with other people, because by definition there are no other people there.
00:48:58.000 And moral philosophy is also about what kind of life to want. If you're not sure about what to do next, then simply saying that you should do whatever your preferences are, is not much use.
00:49:09.000 If you don't know what you want to do, and so therefore you can't know what your preferences are.
00:49:13.000 Now, so let's continue. This also illustrates the emptiness of reductionism in philosophy, for if I ask you for advice about what objectives to pursue in life, it is no good telling me to do what the laws of physics mandate.
00:49:25.000 I shall do that in any case. Nor is it any good to tell me what I prefer, because I don't know what I prefer to do until I have decided what sort of life I want to lead or how I should want the world to be.
00:49:34.000 Since our preferences are shaped in this way, at least in part by our moral explanations, it does not make sense to define right and wrong entirely in terms of the utility in meeting people's preferences.
00:49:43.000 Trying to do so is the project of the influential moral philosophy known as utilitarianism, which played much the same role as empiricism did in the philosophy of science.
00:49:52.000 It acted as a liberating focus for the rebellion against traditional dogmas, while its own positive content contained very little truth.
00:50:01.000 So there is no avoiding what to do next problems. And since the distinction between right and wrong appears in our best explanations that address such problems, we must regard that distinction as real.
00:50:10.000 In other words, there is an objective difference between right and wrong. Those are real attributes of objectives and behaviour. In chapter 14, I shall argue that the same is true in the field of aesthetics.
