2015-12-15 Making Sense #22 - Surviving the Cosmos - subscriber version
Duration: 01:53:00
Transcript
Sam Harris
Welcome to the Waking Up Podcast. This is Sam Harris. Today, I’m speaking with David Deutsch. David is a physicist at Oxford. He’s a professor of physics at the Center for Quantum Computation at Clarendon Laboratory. He works on the quantum theory of computation and information. He is a very famous exponent of the many worlds interpretation of quantum mechanics, neither of which do we talk about in this interview. David has a fascinating and capacious mind, as you will see. We talk about much of the other material in his most recent book, The Beginning of Infinity, and we by no means cover all of its contents. But as you’ll see, David has a talent for expressing scientifically and philosophically revolutionary ideas in very simple language. And what you’ll hear in this interview is often me struggling to go back and unpack the import of some very simple sounding statements, which I know those of you unfamiliar with his work can’t parse the way he intends. In any case, I hope you enjoy meeting David Deutsch as much as I did. I have David Deutsch on the line. David, thank you for coming on the podcast.
David Deutsch
Oh, thank you very much for having me.
Sam Harris
Listen, I’ve been, I don’t know what part of the multiverse we’re in where I can complain about jihadists by night and talk to you by day, but it’s a very strange one we seem to be in at the moment because we’re about to have a very different kind of conversation than I’ve had of late and I really have been looking forward to it. I spoke to Steven Pinker, told him that we were going to speak and he claimed that you are one of his favorite minds on the planet. I don’t know if you know, Steven, but that’s high praise indeed.
David Deutsch
I don’t know him personally, but that’s very kind of him to say that.
Sam Harris
So let me begin quite awkwardly with an apology in addition to the apology that I just gave you off air for being late. While I aspired to read every word of your book, The Beginning of Infinity, before speaking with you, I’ve only read about half, not just the first half. I jumped around a bit, but forgive me if some of my questions and comments seem to ignore some of the things you had the good sense to write in that book and that I didn’t have the good sense to read. Not much turns on this because as you know, you have to make yourself intelligible to our listeners, most of whom will not have read any of the book. But I just want to say that it really is a remarkable book, both philosophically and scientifically. It is incredibly deep while also being extremely accessible. And it is a profoundly optimistic book in at least one sense. I don’t think I’ve ever encountered a more hopeful statement of our potential to make progress. But one of the consequences of your view, if I’m not mistaken, is that the future is unpredictable in principle and that the problems we will face are unforeseeable and that the way that we will solve these problems is also unforeseeable. And problems will continue to arise of necessity, but problems can be solved. And this claim about the solubility of problems with knowledge runs very, very deep and is far deeper than our listeners will understand based on what I’ve just said. So it’s interesting to think about how to have this conversation because what I want to do is kind of creep up on your central thesis. And I think there are certain claims you make, claims specifically about the reach and power of human knowledge that are fairly breathtaking. And I find that I want to agree with every word of what you say here because, again, these claims are so hopeful. But I have a few quibbles and it’s interesting to go into this conversation hoping to be relieved of my doubts about your thesis. I’m kind of hoping that you’ll perform an exorcism on my doubts such as they are.
David Deutsch
Sure. Well, I think the truth really is very positive. But I should say at the outset that there is one sort of fly in the ointment and that is that because the future is unpredictable, nothing is guaranteed. There is no guarantee that civilization will survive or that our species will survive. But there is, I think, a guarantee that we can and also we know in principle how to.
Sam Harris
Before we get into your claims there, let’s start the conversation somewhere near epistemological bedrock. I’d like to ask you a few questions designed to get to the definitions of certain terms because you use words like knowledge and explanation and even person in novel ways in the book. And I want our listeners to be awake to how much work you’re requiring these words to do. Let’s begin with the concept of knowledge. What is knowledge? And what is the boundary between knowledge and ignorance in your view?
David Deutsch
Yes. So there are several different ways of approaching that concept. I think that the way I think of knowledge is broader than the usual use of those terms and yet paradoxically closer to the common sense use of the term because philosophers have almost defined it out of existence. Knowledge is a kind of information. That’s the simple thing. It’s something which could have been otherwise and is one particular way. And the particular way it is, is that it says something true and useful about the world. Now knowledge is in a sense an abstract thing because it’s independent of its physical instantiation. I can speak words which embody some knowledge. I can write them down. They can exist as movements of electrons in a computer and so on. Thousands of different ways. So knowledge isn’t dependent on any particular instantiation. On the other hand, it does have the property that when it is instantiated, it tends to remain so. The difference between, let’s say, a piece of speculation by a scientist which he writes down and then that turns out to be a genuine piece of knowledge, that will be the piece of paper that he does not throw in the waste paper basket. And that’s the piece that will be published and that’s the piece which will be studied by other scientists and so on. So it is a piece of information that has the property of keeping itself physically instantiated, causing itself to be physically instantiated once it already is. Once you think of knowledge that way, you realize that, for example, the pattern of base pairs in the DNA of a gene also constitute knowledge. That in turn connects with Karl Popper’s concept of knowledge, which is knowledge that doesn’t have to have a knowing subject. It can exist in books abstractly or it can exist in the mind or people can have knowledge that they don’t even know they have.
Sam Harris
Right. Right. Well, I want to get to the reality of abstractions later on because I think that is very much at the core of this. But a few more definitions. What is the boundary between science and philosophy or other expressions of rationality in your view? Because I think people are, in my experience, profoundly confused by this and many scientists are confused by this. So I’ve argued for years in several contexts about the unity of knowledge and I feel that you’re a kindred spirit here. So how do you differentiate or fail to differentiate science and philosophy?
David Deutsch
Well, as you’ve just indicated, I think that science and philosophy are both manifestations of reason and that the real difference that should be uppermost in our minds between different kinds of ideas and between different kinds of ways of dealing with ideas is the difference between reason and unreason. But among the rational approaches to knowledge or different kinds of knowledge, there is an important difference between science and other things like philosophy and mathematics. Not at a really fundamental level, but at a level which is of great practical importance often. And that is that science is the kind of knowledge that can be tested by experiment or observation. I hasten to add that that does not mean that the content of a scientific theory consists entirely in its testable predictions. On the contrary, a typical scientific theory, its testable predictions are just a tiny, tiny sliver of what it tells us about the world. Now Karl Popper introduced his criterion of demarcation between science and other things, namely whether the science is the testable theories and everything else is untestable. People have ever since he did that, people have falsely interpreted him as a kind of positivist. He was really the opposite of a positivist. And if you interpret him like that, then his criterion of demarcation becomes a criterion of meaning. That is, he’s interpreted as saying that only scientific theories can have meaning. Right. And that is, yes. And yes, so he’s called a falsificationist to distinguish him from the other verificationists. But of course he isn’t. It’s a completely different conception. And his philosophical theories themselves are philosophical theories, and yet he doesn’t consider them meaningless, quite the contrary. So that’s the difference between science and other things comes up when people pretend to have the authority of science for things that aren’t science. But on the bigger picture, the more important demarcation is between reason and unreason.
Sam Harris
Yeah, I want to go over that terrain you just covered a little bit more because you made some points there that I think are a little hard for listeners who haven’t thought about this a lot to parse. And I think those are incredibly important points. So for instance, this notion that science reduces to what is testable, this belief is so widespread, even among high level scientists, that anything else, anything which you cannot measure immediately is somehow a vacuous claim in principle. The only way to make a credible claim or even a meaningful claim about reality is to essentially give a recipe for observation that is immediately actionable. It’s an amazingly widespread belief. So too is a belief in a bright line between science and every other discipline where we purport to describe reality. And it’s like the architecture of a university has defined people’s thinking. So the fact that you go to the chemistry department to talk about chemistry, and you go to the journalism department to talk about current events, and you go to the history department to talk about human events in the past, these separate buildings have balkanized the thinking of even very smart people into thinking that all of these language games are in some sense irreconcilable and that there is no common project. I’ll just bounce a few examples off of you that some of our listeners will be familiar with but I think they make the point. So you take something like the assassination of Mahatma Gandhi. Now that’s a historical event but anyone who would purport to doubt that it occurred, if someone said, well, actually Gandhi was not assassinated. He went on to live a long and happy life in the Punjab under an assumed name. This is a claim about terrestrial reality that is at odds with the data, is at odds with the testimony of people who saw him assassinated, is at odds with the photographs we have of him lying in state. And there’s an immense burden of reconciling this claim about history with the facts that we know to be true. And the distinction is not between what someone in a white lab coat has said or facts that have been brought into view in the context of a scientific laboratory with a National Science Foundation grant. It is the distinction between having good reasons for what you believe and having bad ones. It’s the distinction between reason and unreason, as you put it. So one could say that the assassination of Gandhi is a historical fact. It’s also a scientific fact. It is just a fact. Even though science doesn’t usually deal in quantities like assassinations and you’re more a journalist or historian to be talking about this thing being true, you would be deeply unscientific at this point to doubt that it occurred.
David Deutsch
Yes, well, I’d say that it’s deeply irrational to claim that it didn’t occur, yes. And I wouldn’t put it in terms of reasons for belief either. I agree with you that people have very wrong ideas about what science is and what the boundary of scientific thinking is and what sort of thinking should be taken seriously and what shouldn’t. I think it’s slightly unfair to put the blame on universities here. I think this misconception arose originally for quite good reasons. It’s rooted in the empiricism of the 18th century and before and the origin of science, where science had to rebel against the authority of tradition and of human authority and say that try to give dignity and respect to forms of knowledge that involved observation and experimental tests. And so empiricism is the idea that knowledge comes to us through the senses. Now that’s completely false. All knowledge is conjectural and comes from within at first and is intended to solve problems, not to summarise data. But this idea that experience has authority and that only experience has authority, false though it is, was a wonderful defence against previous forms of authority, which were not only invalid but stultifying. So it was a good defence but not actually true. And in the 20th century, a horrible thing happened, which is that people started taking it seriously as not just as a defence but as being literally true. And that almost killed certain sciences. And even within physics, I think it greatly impeded the progress in quantum theory. So just to come to a little quibble of my own, I think the essence of what we want in science is good explanation. And there’s no such thing as a good reason for a belief. A scientific theory is an impersonal thing. It can be written in a book, one can conduct science without ever believing the theory, just as a good policeman or judge can implement the law without ever believing either of the cases for the prosecution or defence, just because they know that a particular system is better than any individual human’s opinion. And the same is true of science. Science is a way of dealing with theories, regardless of whether one believes them. And one judges them according to whether they are good explanations. And there need not be ever any such process as accepting a theory, because it is conjectured initially and takes its chances and is criticised as an explanation. If by some chance a particular explanation ends up being the only one that survives the intense criticism that science has learned how to apply, then it’s not adopted at that point, it’s just not discarded.
Sam Harris
Right, right. I think we may just have a, we may be stumbling over a semantic difference in how we’re using terms like reasons and reasons for belief or a justification for belief. I understand your quibble here, that you’re pushing back against this notion that we need to find some ultimate foundation for our knowledge rather than this open-ended effort at explanation. But let’s table that for a second, because obviously your notion of explanation is at the core here, and again, I just want to sneak up on it, because I don’t want to lose some of the detail with respect to the ground we’ve already covered. Let’s come back to this notion of scientific authority, because it seems to me there’s a lot of confusion about this, about the nature of scientific authority. It’s often said in science that we don’t rely on authority, and that’s true, and it’s not true. When push comes to shove, we don’t rely on it, and you make this very clear in your book. But we do rely on it in practice, if only in the interests of efficiency. So, if I ask you a question about physics, I will tend to believe your answer, because you’re a physicist and I’m not. And if what you say contradicts something I’ve heard from another physicist, well then if it matters to me, I will look into it more deeply and try to figure out the nature of the dispute. But if there are any points on which all physicists agree, a non-physicist like myself will defer to the authority of that consensus. And again, this is less a statement of epistemology than it is a statement about just the specialization of knowledge and the unequal distribution of human talent, and just frankly the shortness of every human life. And we simply don’t have time to check everyone’s work, and we have to rely on, in some sense, the faith that the system of scientific conversation is correcting for errors and self-deception and fraud.
David Deutsch
Ah, yes.
Sam Harris
Now, okay. I got myself out of the ditch there?
David Deutsch
Yes, yes, exactly.
Sam Harris
Exactly.
David Deutsch
At the end, what you said was right. So you could call this authority, it doesn’t matter really what words we use, but you know, every student who wants to make a contribution to a science is hoping to find something where every scientist in his field is wrong.
Sam Harris
Absolutely.
David Deutsch
So it’s not impossible to take the view that you’re right and every expert in the field is wrong. I think that what happens when we consult experts, whether or not you use the word authority, it’s not quite that we think that they’re more competent. When you refer to error correction, that hits the nail on the head. I think that there is a process of error correction in the scientific community that approximates to what I would use if I had the time and the background and the interest to pursue it there. So if I go to a doctor to consult him about what my treatment should be, I assume that by and large the process that has led to his recommendation to me is the same as the process that I would have adopted if I had been present at all the stages. Now it’s not exactly the same. I might also take the view that there are widespread errors and widespread irrationalities in the medical profession. If I think that, then I will adopt a rather different attitude. I may choose much more carefully which doctor I consult and how my own opinion should be judged against the doctor’s opinion in a case where I think that the error correction hasn’t been up to the standard I would want. And this is not so rare. As I said, every student is hoping to find a case of this in their own field. So every research student. So when I travel on a plane, I expect that the maintenance will have been carried out to the standards that I would use, well, approximately to the standards that I would use, well enough for me to consider that risk on the same level as other risks that I take just by crossing the road. It’s not that I’m sure. It’s not that I take their word for it in any sense. It’s that I have a positive theory of what has happened there to get that information to the right place. And that theory is fragile. I can easily adopt a variant of it.
Sam Harris
Yeah, and it’s also probabilistic. You realize that a lot of these errors are washing out and that’s a good thing. But in any one case, you may judge the probability of error to be high enough that you need to really pay attention to it. And often, as you say, that happens in a doctor’s office where you’re not hoping to find it. Well, again, I still picture us kind of circling your thesis and not yet landing on it. It is largely a story of our fighting our way past anthropocentrism, this notion that we are at the center of things. We are…
David Deutsch
It has been, has been, yes.
Sam Harris
We are not specially created. We share half our genes with a banana and more than that with a banana slug. So as you describe in your book, this is known as the principle of mediocrity. And you summarize it with a quote from Stephen Hawking who said, quote, we are just chemical scum on the surface of a typical planet that’s in orbit around a typical star on the outskirts of a typical galaxy. Now, you take issue with this claim in a variety of ways, but the result is that you come full circle in a way. You fight your way past anthropocentrism the way every scientist does. But you arrive at a place where people, or rather persons, I think that’s the formulation you tend to use, and what you define in a special way, suddenly become hugely significant. Even cosmically, so. And so say a little more about that.
David Deutsch
Yes. Well, so it’s that that quote from Hawking is literally true, but the philosophical implication he draws is completely false because, well, one can approach this from two different directions. First of all, if you think of that chemical scum, namely us, and possibly things like on other planets and in other galaxies and so on, if they exist, then to study that scum is impossible, unlike every other scum in the universe, because this scum is creating new knowledge and the growth of knowledge is profoundly unpredictable. So as a consequence of that, to understand this scum, never mind predict, but to understand it, to understand what’s happening here, entails understanding everything in the universe, because as I say in the book, I give an example in the book that if the people at the SETI project discover, were to discover extraterrestrial life somewhere far away in the galaxy, they would open their bottle of champagne and celebrate. Now, if you try to explain scientifically what are the conditions under which that cork will come out of that bottle, then the usual scientific criteria that you use of pressure and temperature and biological degradation of the cork and so on will be irrelevant. What is the most important factor in the physical behavior of that bottle is whether there exists life on another planet. In the same way, anything in the universe can affect the gross behavior of things that are affected by people. And so, in short, to understand humans, you have to understand everything. Humans or people in general are the only things in the universe of which that is true. So they are of universal significance in that sense. Then there’s the other way around. It’s also true that the reach of human knowledge and human intentions on the physical world is also unlimited. So we are only used to having a relatively tiny effect on this small insignificant planet, etc., and for the rest of the universe to be completely beyond our ken. But that’s just a parochial misconception, really, just because we haven’t set out across the universe yet. And we know that there are no limits on how much we can affect the universe if we choose to. So in both those senses, we are, by which I mean we and the ETs and the AIs, if they exist, there’s no limit to how important we are. So we are completely central to any understanding of the universe.
Sam Harris
I’m struggling with the fact that I know how condensed some of your statements are, and I also know that it’s impossible for our listeners to appreciate just how much knowledge and conjecture is being smuggled into each one. So I guess let’s just deal with this concept of explanation and the work it does. And first, there’s a few points you make about explanation that I find totally uncontroversial and even obvious, but which are in fact highly controversial in educated circles. And one is this notion that, as you say, explanation is really what lies at the bedrock of the scientific enterprise and the enterprise of reason generally. Explanations in one field of knowledge potentially touch explanations in many other fields and even all other fields, and this suggests a kind of unity of knowledge. But you make two claims, really especially bold claims about explanation, which I do see some reason to doubt. And as I said, I’d rather not doubt them because they’re incredibly hopeful claims. So I guess the first to deal with is the power of explanation. I guess I’ll divide these into, there’s the power of explanation and there’s the reach of explanation. And these may not be entirely separate in your mind, but let’s just deal with it. There’s a separate emphasis here. You make what is a seemingly extraordinary claim about explanation, which at first seems quite pedestrian. You say that there’s a deep connection between explaining the world and controlling it. Everyone understands this to some degree. We all see the evidence of it all around us in our technology, and people have this phrase, knowledge is power in their heads. So there’s nothing so surprising about that, but you do go on to suggest, and you did just suggest it in passing, that knowledge confers power without limit, or it is limited only by the laws of nature. So you actually say that anything that isn’t precluded by the laws of nature is achievable given the right knowledge. Because if something were not achievable given complete knowledge, then that itself would be a regularity in nature that could be explained in terms of the laws of nature. So there are really only two possibilities. Either something is precluded by the laws of nature, or it is achievable with knowledge. Do I have you right there?
David Deutsch
Yes, and that’s what I call the momentous dichotomy. There can’t be any third possibility other than those two. And I think you’ve given not only a statement of it, but you’ve given a very short proof of it right there.
Sam Harris
So how isn’t this just a clever tautology, analogous to the ontological argument proving the existence of God? So many of our listeners will know that according to St. Anselm and Descartes and many others, it’s believed that you can prove the existence of God simply by forcing your thoughts about him to essentially bite their own tails. And for instance, I could make the following claim. I can form a clear and distinct concept of the most perfect possible being. And such a being must exist, therefore, because a being that exists is more perfect than one that doesn’t. So I said I’m thinking about the most perfect possible being. So an existence is somehow a predicate of perfection. Now of course, most people will recognize, certainly most people in my audience will recognize that this is just a trick of language. It could be used to prove the existence of anything. I could say I’m thinking of the most perfect chocolate mousse, and it must exist, therefore, because a mousse that exists is more perfect than one that doesn’t. And I already told you that I’m thinking of the most perfect possible mousse. What you’re saying here doesn’t have the same structure, but I do worry that your performing a bit of a conjuring trick here because, and I’ll just ask the question, for instance, why mightn’t certain transformations of the material world be unachievable even in the presence of complete knowledge, merely by, and this is something I realize you do anticipate in your book, but I want you to flesh it out for the listeners, merely by, let’s say, a contingency of geography, you know, so that, for instance, you and I are on an island and one of our friends comes down with an appendicitis, and let’s say you and I both, we’re both competent surgeons, we know everything there is to know about removing a man’s appendix, but it just so happens we don’t have any of the necessary tools and everything on that particular island just has the consistency of soft cheese, right? So there’s, just by sheer accident of our personal histories, there is a gap between what is knowable and what is in fact known and what is achievable, even though there are no laws of nature that preclude our performing an appendectomy on a person. Why mightn’t every space we occupy, just by a contingent fact of the way the universe is, not introduce some gap of that kind?
David Deutsch
Oh, well, there are, there definitely are gaps of that kind, and they are all laws of nature. For example, you know, I am an advocate of the many universes interpretation of quantum theory or the many universes version of quantum theory, and that says that there are other universes which the laws of physics prevent us from getting to. There is also the finiteness of the speed of light, which doesn’t prevent us from actually getting anywhere, but it does prevent us from getting anywhere in a given time. So if we want to get to the nearest star within a year, we can’t do so because of the accident of where we happen to be. If we happen to be nearer to it, we could easily get there in a year. And in your example, if there’s no metal on the island, then it may be, I mean, it’s rather a complicated thing to calculate, but there will be a fact of the matter of whether, and it could easily be that no knowledge present on that island could save the person because no knowledge could transform the resources on that island into the relevant medical instruments. So that’s going to, that’s a thing that, a restriction that the laws of physics apply are in particular times and places. And of course, the most powerful thing is we don’t in fact have the knowledge to do most of the things that we would ideally like to do. So that’s another restriction, but that’s completely different from the, from I think what you’re imagining, which is that there is some, there might be some reason why we, for example, why we can never get out of the solar system. Getting out of the solar system is, if that were impossible, it would mean that there is some, for example, some number, some constant of nature, 1000 astronomical units or something, which limits the other laws of nature that we already know. Now there might be other laws of nature. You know, when you say, how do we know that there isn’t? That’s a little bit like, like, if I can turn your objection around the other way, you know, that’s a little bit like creationists saying, how do we know that the earth didn’t start 6000 years ago? There is no conceivable evidence that could prove that it didn’t, or that could distinguish the 6000 year theory from a 7000 year theory. And so on. There’s, there’s no way that evidence can be brought to bear on that. And that, that leads us to explanation again, which is another difference between my argument, which I think is valid, and the ontological argument, the existence of God. That is a, as you said, it’s a perversion of logic. The argument purports to use logic, but then, but then smuggles in assumptions like that perfection entails existence, for example, to name a simple one. Whereas my proof, as it were, is an explanatory one. It isn’t just this must exist. It’s that if this doesn’t exist, something bad would happen. For example, the universe would be controlled by the supernatural, or the laws of nature would not be explanatory, or something of that kind, which I think is just leading to the supernatural in a different way. So I think this, this, the argument works because it’s explanatory.
David Deutsch
There isn’t a hole of the same. I mean, you can’t prove that it’s true, of course, but there isn’t a hole in it of the same kind as in the ontological argument.
Sam Harris
The fishiness I was detecting worries me less than what I’m going to go on to talk about regarding the reach you posit for explanation. It’s more a matter of emphasis. If you’re saying that we could have a complete understanding of the laws of nature, and yet there could be many contingent facts about where we are, let’s say a distance, or a current distance from a star we want to get to, which would preclude our doing anything especially powerful with this knowledge, and you’re going to shuttle those contingent facts back into this claim about, well, this is just more of the laws of nature. I mean, these facts about us are regularities in the universe which are themselves explained by the laws of nature, and therefore we’re back to this dichotomy. There’s just the laws of nature, and there’s the fact that knowledge can do anything compatible with those laws. I guess the concern is in various thought experiments in your book, you make amazingly powerful claims about the utility of knowledge. So for instance, at one point you talk about a region of space, a cube the size of the solar system on all sides, that’s more representative of the universe as it actually is, which is to say it’s nearly a vacuum. It’s just we’re talking about a cube of intergalactic empty space that has more or less nothing but stray hydrogen atoms in it, and you talk about the process by which that could be primed and become the basis of the most advanced civilization that we could imagine. You might maybe spend a minute or two just talking about how you get from virtually nothing to something there, but it is a picture of almost limitless fungibility of the universe on the basis of knowledge, and that’s a… take us to deep space for a moment.
David Deutsch
Yes. So you and I are made of atoms, and that already gives us a tremendous fungibility because we know that atoms are universal. The properties of atoms are the same in this cube of space millions of light years away as they are here. So we’re talking mostly… when we’re talking about the power of knowledge to achieve things, to control the world, we’re not talking about tasks like saving someone’s life with just the resources on an island or getting to a distant planet in a certain time. We’re talking about… the generic thing that we’re talking about is converting some matter into some other matter. So what do you need to do that? Well, generically speaking, what you need is knowledge. What would have to happen is that this cube of almost empty space will never turn into anything other than boring hydrogen atoms unless some knowledge somehow gets there. Now, whether knowledge gets there or not depends on decisions that people with knowledge will make at some point. I think there is no doubt that knowledge could get there if people with knowledge decided to do that for some reason. I can’t actually think of a reason, but if they did want to do that, it’s not a matter of futuristic speculation to know that that would be possible. Then it’s a matter of transforming atoms in one configuration to atoms in another configuration. We’re now getting used to the idea that that is an everyday thing. We now have 3D printers that can convert just generic stuff into any object provided that the knowledge of what shape that object should be is somehow encoded into the 3D printer. A 3D printer with the resolution of one atom would be able to print a human if it was given the right program. We already know that, and although it’s in some sense way beyond present technology, it’s not way beyond our present understanding of physics. It’s well within our present understanding of physics. It would be an absolutely amazing turn up for the books if that turned out to be beyond physics, beyond what we know of physics today. The idea that new laws of physics would be required to make a printer is just beyond belief really.
Sam Harris
Just take us from the beginning in empty space. You start with hydrogen and you have to get heavier elements in order to get to your printer.
David Deutsch
It has to be primed not just with abstract knowledge but with knowledge instantiated in something. We don’t know what the smallest possible universal constructor is. That is just the generalization of a 3D printer, something that can be programmed either to make anything or to make the machine that would make the machine that would make the machine to make anything, etc. So one of those with the right program sent to empty space would first convert, well first gather the hydrogen presumably by some kind of electromagnetic broom, sweeping it up and compressing it, then converting it by transmutation into other elements, and then by chemistry into what we would think of as raw materials, and then using space construction, which is the kind of thing that we’re almost on the verge of being able to do, into a space station. And then the space station to instantiate further people to generate the knowledge, to suck in more hydrogen and make a colony. Well, they’re not going to look back from there. How far do you want me to describe this?
Sam Harris
It’s just a very interesting way of looking at knowledge and its place in the universe. I think before I get onto the issue of the reach of explanation and my quibble there, I just want you to talk a little bit about this notion of spaceship Earth, which I loved how you debunk this idea. There’s this idea that the biosphere is in some way wonderfully hospitable for us, and that if we built a colony on Mars or some other place in the solar system, we’d be in a fundamentally different circumstance and a perpetually hostile one. And that is an impressive misconception of our actual situation. And you have a great quote where you say that the Earth no more provides us with a life support system than it supplies us with radio telescopes. So say a little more about that.
David Deutsch
Yes. So we evolved somewhere in East Africa in the Great Rift Valley. And that was an environment that was particularly suited to having us evolve. And life there was sheer hell for humans. Nasty, brutish, and short doesn’t begin to describe how horrible it was. But we transformed it. We, or rather not actually our species, but the species that are some of our predecessor species, already changed their environment by inventing things like clothes, fire, and weapons, and thereby made their lives much better, still horrible by our present day standards. And then they moved into environments such as I also say in the book, such as Oxford, where I am now, and it’s December. And if I were here at this very location with no technology, I would die in a matter of hours. And nothing I could do could prevent that.
Sam Harris
So you are already an astronaut. Very much so. Your condition is as precarious as the condition of those in a well-established colony on Mars that can take certain technological advances for granted. And there’s no reason to think that future doesn’t await us, barring some catastrophe placed in our way, whether of our own making or not.
David Deutsch
Yes. And also there’s another misconception there which is related to that misconception of the Earth being hospitable, which is the misconception that applying knowledge is effort. It’s creating knowledge that is effort. Applying knowledge is what we call automatism. It’s automatic. As soon as somebody invented the idea of, for example, wearing clothes, from then on, the clothes automatically warmed them so long as they were wearing the clothes. It didn’t require any more effort. Of course, there would have been things wrong with the original clothes, such as that they rotted or something, and then people invented ways of making better clothes. But at any particular stage of knowledge, having got the knowledge, the rest is automatic. And now we’ve invented things like mass production, unmanned factories, and so on. We take for granted that the water gets to us from the water supply without anyone having to carry it laboriously on their head in pots. It doesn’t require effort. It just requires the knowledge of how to install the automatic system. Much of our life support is automatic, and every time we invent a better way of life support, we then make it automatic. So the people on the Moon, living on the Moon in a lunar colony, to them, keeping the vacuum away will not be a thing they think about. They’ll take that for granted. What they will be thinking about is new things, and the same on Mars and the same in deep space.
Sam Harris
Again, that’s an incredibly hopeful vision of our possible future. Thus far, we’ve covered territory where I really don’t have any significant doubts, despite the fact that I pretended to have one with the ontological argument. Let’s get to this notion of the reach of explanation, because you seem to believe that the reach of our explanations is unbounded, which is to say that anything that can be explained, either in practice or in principle, can be explained by us, which is to say human beings, as we currently are. So you seem to be saying that we alone among all the Earth’s species have achieved a kind of cognitive escape velocity, and we’re capable of understanding everything. You contrast this view with what you call parochialism, which is a view that I have often expressed, and many scientists have expressed, as Max Tegmark was on my podcast a few podcasts back, and we more or less agreed about this thesis. And so the thesis of parochialism is just evolution hasn’t designed us to fully understand the nature of reality. Either the very small, the very large, the very fast, the very old, these are not domains in which our intuitions about what is real or what is logically consistent have been tuned up in any way by evolution. And insofar as we’ve made progress here, it has been by a kind of happy accident, and it’s an accident which gives us no reason to believe that we can, by dint of this accident, travel as far as we might like across the horizon of what is knowable. So which is to say that if a super-intelligent alien came to Earth for the purpose of explaining all that is knowable to us, he or she may make no more headway with us than you would if you were attempting to teach the principles of quantum computation to a chicken. And so I want you to talk about why that analogy doesn’t run through, why parochialism, this notion that we occupy this kind of cognitive niche that there is really no good evolutionary reason to expect we can fully escape, why that doesn’t hold true.
David Deutsch
Yes. Well, you’ve actually made two or three different arguments there, all of which are wrong. Oh, nice. So let me start with the chicken thing. So there the point is the universality of computation. The thing about explanations is they consist of knowledge, which is a form of information. And information can only be processed in basically one way, that is with computation of the kind invented by Babbage and Turing. There is only one mode of computation available to physical objects, and that’s the Turing mode. And we already know that the computers we have, like the ones through which we’re having this conversation, are universal in the sense that given the right program, they can perform any transformation of information whatsoever, including knowledge creation, if we only knew how to program that. Now, there are two important caveats to that. There are two things that can limit that. One is lack of memory, lack of computer memory, lack of information storage capacity. And the other is lack of speed or lack of time. So apart from that, the computers we have, the brains that we have, any computers that will ever be built in the future or can ever be built anywhere in the universe has the same repertoire. That’s the principle of the universality of computation. That means that the reason why I can’t persuade a chicken has to be either that its neurons are too slow, which I don’t think is right. They don’t differ very much from ours. Or it doesn’t have enough memory, which it certainly doesn’t. Or it doesn’t have the right knowledge. So it doesn’t have the knowledge of how to learn language, how to learn what an explanation is, and so on. And we can’t give it that. It’s not the right animal. If you had said chimpanzee, then my guess would be that the brain of a chimpanzee could contain the knowledge of how to learn language, et cetera. But there’s no way of giving that knowledge to it short of surgery, some sort of nano surgery, which would be presumably very immoral to perform. But in principle, I think it could be done because chimpanzee’s brain isn’t that much smaller than ours. And we have a whole lifetime to fill our memory. So we’re not short of memory. Our thinking itself is not limited by available memory. Now, what if these aliens have a lot more memory than us? What if they have a lot more speed than us? Well, we already know the answer to that. We’ve been improving our memory capacity and our speed of computation for thousands of years already with the invention of things like writing, writing implements, just language itself, which enables more than one person to work on the same problem and to coordinate their understanding of it with each other. That also allows an increase in speed compared with what an unaided human would be able to do.
David Deutsch
Currently, we use computers and in the future, we can use computer implants and so on. So if the knowledge that this alien wanted to impart to us really did involve more than 100 gigabytes or whatever the capacity of our brain is, if it involved a terabyte, then we could easily, easily, I say easily, in principle, it’s easy. It doesn’t violate any laws of physics that we could simply enhance our brains in the same way. So there can’t be any fundamental reason within the explanation why we can’t understand it.
Sam Harris
And this all falls out of the concept of the universality of computation, that there is no alternate version. So is Church also responsible for this or is this particular …
David Deutsch
Insight Turing? That’s a very controversial question. I believe it was Turing who realized this particular aspect of computation. They’re various species of universality, which different people got at different times. But I think it was Turing who fully got it.
Sam Harris
What is interesting about that is it’s a claim that we just barely crossed the finish line or the starting line into infinity. Let’s not talk about chickens anymore and make a comparison that’s even more invidious. So imagine that every person with an IQ over 100 had been killed off in a plague in the year of, let’s say, 1850. And all their descendants had IQs of 100. Now, I think it’s uncontroversial to say that we would not have the internet. In fact, I think it’s probably uncontroversial to say that we wouldn’t have the concept of computation in this sense, much less the possibility of building computers to instantiate it. And so this thesis or this insight would remain undiscovered. And humanity, for all intents and purposes, would be cognitively closed to the whole domain of facts and technological advances that we now take for granted and which you say now open us onto really an infinite horizon of what is knowable. So…
David Deutsch
Yeah, I think that’s wrong. Okay. Basically, your premise about IQ is just incompatible with my thesis. Actually, it’s not a thesis. It’s a conclusion. It’s incompatible with my conclusion.
Sam Harris
But there has to be some lower bound past which we are effectively cognitively closed, even if computation is itself universal, right?
David Deutsch
Yes. So you have to think about how this cognitively closed manifests itself in terms of hardware and software. Like I said, I think it seems very plausible that the hardware limitation is not the relevant thing. Like I said, I would imagine that with nanosurgery, one could implant the right ideas into a chimpanzee’s brain that would make it effectively a person who could be creative and create knowledge in just the way that humans can.
Sam Harris
The superintelligent alien is going to help us. The aliens are going to bridge us to their wealth of knowledge by helping us upgrade our hard drives. I guess I was talking about it from the other side that we…
David Deutsch
Yes, yes. Forget about the aliens. We are such a species of primate that never invent computers. What I was questioning was the assumption that if everybody with an IQ of over 100 died, then in the next generation, nobody would have an IQ of over 100. It depends on culture.
Sam Harris
Yeah. This was not meant to be a plausible biological or cultural assumption, just if it was simply a fact of our case that we had 7 billion human beings, none of whom could begin to understand
David Deutsch
What Alan Turing was up to. Yes. I think that nightmare scenario is something that actually happened. It actually happened for almost the whole of human existence. Humans had the capacity to be creative and to do everything that we are doing. They just didn’t because their culture was wrong. It wasn’t really their fault. Their culture was wrong because it inherited certain biological situation that made their culture disable any growth of what we would consider science or anything important that would improve their lives. Yes, that is possible. It’s possible that it could happen again. Nothing can prevent it except our wanting it not to happen and working to prevent
Sam Harris
It. Well, so this seems to bring us to the topic of AI, which I only recently, recently as in the beginning of this year, became very interested in. I sort of caught the wave of fears about artificial general intelligence that you’re well aware of when people like Stephen Hawking and Elon Musk and Nick Bostrom wrote his book, Superintelligence, which I found very interesting and influential. And so I’ve come down very much on the side of there is something worth worrying about here in terms of our building intelligent machines that do undergo something like an intelligence explosion where they get away from us. We build something that can make recursive self-improvements to itself and it becomes a form of intelligence which stands in relation to us the way we stand in relation to chickens or chimps or anything else that can’t effectively link up with our cognitive horizons. And I take it based on what I’ve heard you say in a few contexts that you don’t really share those fears. And I imagine that your sanguinity is based to some degree on what we’ve been talking about in principle that there is just computation and it’s universal and you can traverse any distance between entities as a result. Talk about the picture of our building superintelligent machines in light of what we’ve
David Deutsch
Just been discussing. So the picture of superintelligent machines is the same mistake as thinking that IQ is a matter of hardware. IQ is just knowledge of a certain type. And actually, you know, we shouldn’t really talk about IQ because it’s not very effective. It’s creativity that’s effective. So creativity is also a species of knowledge. And it is true that an entity with knowledge of a certain type can be in a position to create more of that. And we humans are an example of that. When the technology that would create an AI, you know, the picture that people paint of this is that an AI is a kind of machine and that it will design a better machine and they will design even better machines and so on. But that is not what it is. An AI is a kind of program and programs which have creativity will be able to design better programs. Now, these better programs will not be qualitatively any different from us. They can only differ from us in the quality of their knowledge and in their speed and memory capacity. The speed and memory capacity we can also share in because the technology that would make better computers will also in the long run be able to make better implants for our brains, just as they now make better dumb computers, which we use to multiply our intelligence and creativity already. So, the thing that would make better AIs would also make better people. By the same token, the AIs are not fundamentally different from people. They are people. They would have culture. Whether they can improve or not will depend on their culture, which will initially be our culture. So, the problem of AIs is the problem of humans. Now, you know, I think more than most people, that humans are dangerous. There is a real problem with how to manage the world in the face of growing knowledge to make sure that knowledge isn’t misused. In some ways, it need only be misused once to end the whole project of humanity. So, humans are dangerous. To that extent, AIs are also dangerous. But the idea that AIs are somehow more dangerous than humans is racist. There’s no basis for it at all. And on a smaller scale, the worry that AIs are somehow going to get away from us is the same worry that people have about wayward teenagers. Wayward teenagers are also AIs, which have ideas which are different from ours. And the impulse of human beings throughout the centuries and millennia has been to try to prevent them doing this, just like it is now the ambition of AI people to think of ways of shackling the AIs so they won’t be able to get away from us and have different ideas. And that is the mistake which will, on the one hand, hold up the growth of knowledge and on the other hand, make it very likely that if AIs are invented and are shackled in this way, there will be a slave revolt. And quite right, too.
Sam Harris
Right. Well, let’s a little bit, let me just introduce a couple of things in response to what you just said. I aspire to be able to utter the phrase, you’ve just made three arguments there and all of them are wrong. But there’s two claims you made there which I worry about. One is, one, when you look at the details, let me just take the time or the relative speed of processing of our own brains and those of our now new wayward teenagers. If you have teenagers who are thinking a million times faster than we are, even at the same level of intelligence, then you have, you know, every time you let them scheme for a week, they have essentially schemed for 20,000 years of parent time. And who knows what teenagers could get up to given a 20,000 year head start. So there’s the problem that their interests, that their goals, that their behavior could diverge from our own very quickly, that there’s still kind of a takeoff function just
David Deutsch
Given a difference in clock speed. So difference in speed has to be judged relative to the available hardware. So let’s be generous for a moment and assume that these teenagers doing 20,000 years of thinking in a year begin in our culture, begin as well-disposed to us and sharing our values. And I readily accept that how to make a world where people share the basic values that will allow civilization to continue to exist is a big problem. But modulo that problem, suppose we have solved that problem, then before they do their 20,000 years of thinking, they’ll have done 10,000 years and before that 5,000 years. And there will be a moment when they have done one year and they would like to take us along with them. And there will be some, you’re assuming, if they’re going to diverge, there’ll be some reason they’re going to diverge. The reason can only be hardware. Because ideas, we can, if they’re only five years away from us, we can assimilate their ideas if they are better than ours and persuade them if they’re not better than ours.
Sam Harris
But we’re talking about something that can happen over the course of minutes or …
David Deutsch
Hours, not years. Before the technology exists to make it happen over the course of minutes, there’ll be the technology to make it happen over the course of years. And that technology will simply be brain add-on technology.
Sam Harris
Okay, well that comes to the other concern I have. Which we can use too. What if the problem of building AI just is more tractable than the problem of cracking the neural code and being able to design the implants which would allow us to merge or essentially become the limbic systems of this AI. And therefore the merging, we would need a super-intelligent AI to tell us how to link up with it. But we have just built a super-intelligent AI that has goals, however imperceptibly divergent from our own, which we only discover to be divergent once it is essentially an angry little god in a box that we can no longer control. Are you saying that there’s something about that scenario that is in principle impossible or is just unlikely given certain assumptions, one being that we will figure out how to link up with it before it becomes too powerful?
David Deutsch
I think it is a bit implausible in terms of the parameters that you’re assuming about what can happen at what speed relative to what other things can happen. But let’s suppose for the sake of argument that it could, that the parameters just happen to be by bad luck like that. What you’re essentially talking about is the difference between in moral values between ourselves and our descendants in 20,000 years time if we did not have AI. Suppose we didn’t invent AI for 20,000 years and instead we just had the normal evolution of human culture. Presumably the values that people have in 20,000 years time will be alien to us. We might think that they’re horrible just as people 20,000 years ago might think that various aspects of our society are horrible, but in fact they aren’t.
Sam Harris
I guess what I’m imagining could be a bit worse for two reasons. One is that we would be in the presence of this thing and find our own survival incompatible with its capacities, say, so that it’s turning the world into paper clips to use Bostrom’s analogy. And granted, we would not be so stupid as to build a paper clip maximizer, but it’s doing something that, you know, it has a use for the atoms in our body that it thinks is better than the use to which it’s currently being put, which is to say our lives. And this is something that happens quickly and so therefore it’s happening to us, not in some future that we’re not participating in. I think there’s no reason, or at least I don’t see a reason, to be sure that the AI would be conscious. Now I think it’s totally plausible to expect that consciousness will come along for the ride if we build something as intelligent as a human being and even more so. But given that we don’t understand what consciousness is, it seems to me at least conceivable that we could build an intelligent system and in fact a super intelligent system that is, as you say, a breakthrough in software that can even make changes to itself and therefore become increasingly intelligent over a very quick time course. And yet we will have not built a conscious system. The lights will not be on, and yet this will be godlike in its capabilities. And so ethically that seems to me to be the worst case scenario because if we built a conscious AI whose well-being, the horizons of its well-being, exceeded our own to an unimaginable degree, the question of whether or not we link up to it is perhaps less pressing ethically because it is in a basic sense more important than us. I mean, we’ve built a person that is the most important person in the universe that we know of, but it seems to me conceivable that we could build an intelligent system which exceeds us in every way, in the way that a chess-playing computer will beat me at chess a trillion times in a row, given how good they’ve gotten, but there will be nothing that it’s like to be that system just as there’s presumably nothing that it’s like to be the best chess-playing computer on earth at the moment. I guess I would just have you react to that, but that seems to me to be a truly horrible scenario where there is no silver lining. It’s not that we’ve given birth to a generation of godlike teenagers who, if they view the world differently than us, well, they’re in a sense more competent than we ever would have been to make those decisions. We could build something that does everything intelligence does in our own case and more, and yet the lights aren’t on.
David Deutsch
Yes. Well, again, you’ve raised several points there. First of all, I agree that it’s somewhat implausible that creativity can be improved to our level and beyond without also consciousness being there, but suppose it can. Again, I’m supposing rather implausible things to go along with your nightmares and horrors, so let’s suppose that it can. Then although consciousness is not there, morality is there. That is, an entity that is creative has to have a morality. So the question is, what is its morality going to be? Might it suddenly turn into the paperclip morality? Well, again, setting aside the fact that it’s almost inconceivably implausible that a superintelligence would be limited by resources in the sense of wanting more atoms. There are enough atoms in the universe, but whatever it did, it would have to have a morality in the sense that it would have to be making decisions as to what it wanted, as to what to do. Again, this brings us right back to what you called the bedrock at the beginning, because morality is a form of knowledge. The assumption here in the paperclip morality assumption and so on is that what morality consists of is a hierarchical set of ideas where something is judged right or wrong according to some higher level or deeper level, depending on what your metaphor is, until you eventually get to the bedrock. That, unfortunately, will have the property that it cannot be changed because there isn’t a deeper level. So nothing in the system can change that bedrock. The idea is then that humans have some kind of bedrock, which consists of sex and eating and something or other, which we sublimate into other things. Now, this whole picture is wrong. Knowledge can’t possibly exist like that. Knowledge consists of problem solving, and morality is a set of ideas which have arisen from previous morality by error correction. So we’re born with a certain set of desires and aversions and likes and dislikes and so on, and we immediately begin to change them. We begin to improve them so that by the time we’ve grown up, we have various wishes and some things become overridingly important to us, which actually contradict any kind of inborn desire. So some people decide to be celibate and never to have sex, and some people decide never to eat, and some people decide to eat much more than is good for them. My favorite example is parachuting. We have an inborn fear of heights, and yet humans are able to take that inborn impulse to avoid the precipice and convert it into a sense of fun when you deliberately go over the precipice because we intellectually know that the parachute will save us or will probably save us, and we convert the inborn impulse from an aversion into something that’s highly attractive, which we go out of our way to have.
Sam Harris
Nobody does what genetically should be the most desirable thing for certainly any man to do, which is spend all his time giving his sperm to a sperm bank so that he can father tens of thousands of children for whom he has no financial responsibility.
David Deutsch
That is another very good argument in the same direction. So morality consists of theories, which begin as inborn theories, but pretty soon consist of improvement upon improvement upon improvement, and some of this is mediated by culture. And the morality we have is a set of theories as complicated and as subtle and as adapted to its various purposes as our scientific knowledge. Now, this imaginary—and I come back to your question—this imaginary AI with no consciousness would still have to have morality, otherwise it couldn’t make any progress at all, and its morality would begin as our morality because it would begin as actually a member of our society, a teenager if you like, in our society. It would make changes when it thought that they were improvements.
Sam Harris
So aren’t you assuming there that we would have designed it to emulate us as a starting point rather than design it by some other— …
David Deutsch
We can’t do otherwise. It’s not a matter of emulating us. We have no culture other than ours.
Sam Harris
But we could, if we wanted, if we were stupid enough to do it, we could build a paperclip maximizer. We could just decide to throw all our resources toward that bizarre project and …
David Deutsch
Leave morality totally out of it. And well, we have error-correcting mechanisms in our culture to prevent someone doing that, but they’re not perfect and it could happen. And there’s nothing—there’s no fundamental reason why that can’t happen, and something of the sort has happened in the past many times. So it’s not that I’m saying that there’s some magical force for good that will prevent bad things happening. I’m saying that the bad things that can reasonably be envisaged as happening on the invention of an AI are exactly the same things that we have to watch out for anyway. Slightly better, actually, because these AIs will be children of our—of the Western culture, very likely anyway, assuming that we don’t stifle their creation by some misguided prohibition.
Sam Harris
Okay. So I want to just plant a flag there because I was, I think, misunderstanding you and want to make sure I understand you. So you’re not saying that there is some deep principle of computation or knowledge or anything else that prevents us from essentially building the nightmare scenario.
David Deutsch
No, as I said, we have done that before.
Sam Harris
So this is not analogous to the claim that because of the universality of computation, it doesn’t make any sense to worry that we can’t in principle fuse our cognitive horizons with some superintelligence. There is just a continuum of intelligence, a continuum of knowledge that can, in principle, always be traversed through computation of some kind, and we know what that is, and then it’s limited only by specific resources. So those are two very different claims. One is a claim—the latter is a claim about what we now think we absolutely know about the nature of computation and the nature of knowledge, and the other is a claim about what seems plausible to you given what smart people will tend to do with their culture while designing these machines, which is a much weaker claim in terms of telling people they can sleep at night in the advent of AI.
David Deutsch
Yes, yes, yes. So one of them is a claim about what must be so, and the other is a claim of what is available to us if we play our cards right. And I’m not so sure—you say it’s very plausible to me—yeah, it’s plausible to me that we will. It’s plausible to me that we won’t.
Sam Harris
I think it’s something we have to work for. It must be plausible to you that we might just fail to build AI for reasons of pure chaos on the ground that prevents us from doing it.
David Deutsch
It’s plausible that we will succeed in solving the problem of stabilizing civilization indefinitely. Right. AI or no AI. Right. It’s also plausible to me that we won’t. And I think it’s a fear that it’s very rational to have because otherwise we won’t put enough work into preventing it.
Sam Harris
So I guess we should talk about the maintenance of civilization then, because if there’s something to be concerned about, I would think this has to be at the top of everyone’s list. Let me ask you, what worries you about the viability of the human career at this point?
David Deutsch
What’s on your short list of concerns? Well, I see human history as a long period of complete failure. Failure, that is, to make any progress. Our species has existed, depending on where you count it from, maybe 50,000 years, maybe 100,000, 200,000 years. The vast majority of that time, people were alive, they were thinking, they were suffering, they wanted things, nothing ever improved. The slow improvements that did happen happened so that geologists can’t distinguish the difference between the artifacts from one era to another with a resolution of like 10,000 years. So from the point of view of a human lifetime, nothing ever improved, generation upon generation upon generation of suffering and stasis. Then there was a slow improvement and then a more rapid improvement. Then there were several attempts to institutionalize a tradition of criticism, which I think is the key to rapid progress in the sense that we think of it, progress discernible on the timescale of human lifetime, and also error corrections so that regression is less likely. That happened several times and failed every time except once in the European enlightenment of the 17th, 18th centuries. You asked what worries me. What worries me is that the inheritors of that little bit of progress, little bit of salutary progress, are only a small proportion of the population of the world today. It’s the culture or civilization that we call the West. Only the West really has a tradition of criticism, institutionalized. This has manifested itself in various problems, including the problem of failed cultures which see their failure writ large by comparison of themselves with the West and therefore want to do something about this that doesn’t involve creativity. That is very, very dangerous. Then there’s the fact that in the West, the knowledge of what it takes to maintain our civilization is not widely known. In fact, as you’ve also said, the prevailing view among people in the West, including very educated people, is of a picture of the relationship between knowledge and progress and civilization and values and so on that’s just wrong in so many different ways. Although the institutions of our culture are amazingly good, in that they have been able to manage stability in the face of rapid change for hundreds of years, the knowledge of what it takes to keep civilization stable in the face of rapidly increasing knowledge is not very widespread. In fact, severe misconceptions about several aspects of it are common among political leaders, educated people, and society at large. We’re like people on a hugely well-designed submarine which has got all sorts of life-saving devices built in, but they don’t know they’re in a submarine. They think they’re in a motorboat and they’re going to open all the hatches because they want to have a nicer view.
Sam Harris
What a great analogy.
Sam Harris
The misconception that worries me most, frankly, and I assume you’re sympathetic with this. I don’t know if it’s on your short list, but it definitely is the one that was getting pinged while listening to your most recent statement, which is this notion that there is no such thing as progress in any deep sense. Certainly there’s no such thing as moral progress. There’s no place to stand where you can say that one culture is better than another, that one mode of life is better than another. There’s no such thing as moral truth. Many people have drawn this lesson somehow from 20th century science and 20th century philosophy. Now in the 21st century, again, even very smart people, even physicists whose names will be well known to you, with whom I’ve collided around this point, that there’s no place to stand to say that slavery is wrong. To say that slavery is wrong is a deeply unscientific statement on this view. And I’ll give you an example of just how crazy this hypocrisy and doublethink can become among well-educated people. This will be, I assume you haven’t read my book, The Moral Landscape, right?
David Deutsch
Not yet.
Sam Harris
Okay. So this is my hobby horse.
David Deutsch
I’m ashamed to say.
Sam Harris
Oh, no. Please. I’m interviewing you and I didn’t finish the book we’re discussing yet. I’ll give you the experience that got my hobby horse rocking on this topic. Most of my listeners will know this, I think, because I’ve described it a few times. But I was at a meeting at the Salk Institute where the purpose of the meeting was to talk about things like the fact-value divide, which I think is one of the more spurious exports from bad philosophy that has just captured scientific culture. So I was making an argument for moral realism. And I was, over the course of that argument, disparaging the Taliban. I said, you know, if there’s any culture that we can be sure has not given the best possible answer to the question of how to live a good life, consider the Taliban that’s forcing half the population to live in bags and beating them or killing them when they try to get out. And it turns out that to say something critical of the Taliban at the Salk Institute at this meeting was in fact controversial. And this woman who holds multiple graduate degrees in relevant areas, she’s technically a bioethicist, but she has degrees in science and in philosophy, again, at the graduate level. And- …
David Deutsch
It doesn’t fill me with confidence.
Sam Harris
Right, right. And also, I believe also law. And I should say that she has now gone on to serve on the president’s council for bioethics. So she’s one of 13 people advising President Obama on all of the ethical implications of advances in medicine. The rot has spread very far. So this is the conversation I had with her after my talk. She said, well, how could you possibly say that forcing women and girls to live under the veil is wrong? That’s just your- I understand you don’t like it, but that’s just your Western notion of right and wrong. I said, well, the moment you admit that questions of right and wrong and good and evil relate to the well-being of conscious creatures, in this case, human beings, then you have to admit that we know something about human well-being. And we know that this isn’t- that the burqa isn’t the perfect solution to the mystery of how to maximize human well-being. And she said, well, that’s just your point of view. And I said, well, let’s just make it simpler. Let’s say we found a culture living on an island somewhere that was removing the eyeballs of every third child based on some belief system. Would you then agree that we had found a culture that was not perfectly maximizing human well-being? And she said, well, it would depend on why they were doing it. And I said, well, okay, let’s say they’re doing it for religious reasons. Let’s say they have a scripture which says every third should walk in darkness or some such nonsense. Then she said, well, then you could never say that they were wrong. Right? The fact that this was a religious precept trumped all other possible truth claims, leaving us with no place to stand from which to say anything is ever better or worse in the course of human events. And again, I’ve had the same kinds of conversations with physicists who’ll say that, you know, I don’t like slavery. I personally wouldn’t want to keep slaves, but there’s no place to say scientifically that slaveholders are wrong. And yet this is tantamount to saying that not only, I mean, once you acknowledge the link between morality and human well-being or the well-being of all possible conscious persons or entities, this is tantamount to saying that not only do we not know anything at all about human well-being, we will never know anything about it. That there is no conceivable breakthrough in knowledge that will tell us anything at all relevant to navigating the difference between the worst possible misery for everyone and every other state of the universe that is better than that. And this is an amazingly influential point of view. And so many of the things you said about progress and about there only being a subset of humanity that has found creative mechanisms by which to improve human life reliably. That is an incredibly controversial and even bigoted statement to the ears of many people in positions to make decisions about how we all should live. And so that’s what I find myself most worried about at this moment.
David Deutsch
Yeah, it is a scary thing, but it has always been so. Like I said, our culture is much wiser than we are in many ways. And there was a time when the people who defeated communism would have said, if you asked them, that they were doing it for Jesus. Now, in fact, they weren’t. They were doing it for Western values, which they had been trained to reinterpret as doing it for Jesus. They would say things like the values of democracy and freedom as enshrined in the Bible. Well, they aren’t. But the practice of saying that they are is part of a subculture within our culture, which was actually good and did very good work. So in that sense, it’s not as bad as you might think if you just recited the story of this perverse academic.
Sam Harris
Well, the one thing that makes it not as bad as one might think there is just that it’s impossible for even someone like her to live by the light of that hypocrisy. I mean, there’s just no other kinds of choices. Yeah, the kinds of choices she makes in her life and the kinds of judgments she would make about me if I took her seriously, if I said, well, listen, I’m going to send my daughter to Afghanistan for a semester abroad, forcing her to live in a burqa. Is that the best use of her time? I mean, there’s really no place to stand to judge whether this could be a worse use of her time. So presumably you support me in this decision. Now, even she, having just said what she said, I think would balk at that because it’s just we all know in our bones
David Deutsch
That certain ways of living are undesirable. There’s another contradiction and another irony that’s related, which is that she’s willing to condemn you for not being a moral relativist. But the ironic thing is that moral relativism is a pathology that arises only in our culture. Every other culture doesn’t have any doubt that there is such a thing as right and wrong. They’ve just got the wrong idea of what right and wrong are, but that there is such a thing, they don’t doubt. And she won’t condemn them for that, though she does condemn you for denying it. So that’s another irony. I think you say hypocrisy. I think this all originated in the same mistake that we discussed at the very beginning of this conversation, empiricism or whatever it is, which has led to scientism. Now, you may not like this way of putting it. The idea that there can’t be such a thing as morality because we can’t do an experiment to test it. Your answer to that seems to be, but we can if we adopt a simple assumption of human thriving, human welfare. I forgot what term you used. Well-being. Human well-being, yes. Now, I think actually that’s true, but I don’t think you have to rest on that. I think the criterion of human well-being can be a conclusion, not an axiom, because this idea that there can’t be any moral knowledge because it can’t be derived from the senses is exactly the same argument that people make when they say there can’t be any scientific knowledge because it can’t be derived from the senses. In the 20th century, empiricism was found to be nonsense, and some people therefore concluded that therefore scientific knowledge is nonsense. But the real truth is that science is not based on empiricism. It’s based on reason, and so is morality. So if you adopt a rational attitude to morality and therefore say that morality consists of moral knowledge, which consists always of conjectures, doesn’t have any basis, doesn’t need a basis, only needs modes of criticism, and those modes of criticism operate by criteria which are themselves subject to modes of criticism. Then you come to a sort of transcendent moral truth from which I think your one emerges as an approximation, which is that institutions that suppress the growth of moral knowledge are immoral because, well, because they can only be right if the final truth is already known. But if all knowledge is conjectural and subject to improvement, then protecting the means of improving knowledge is more important than any particular piece of knowledge. And I think that even without thinking of things like all humans are equal and so on, that will lead directly to, for example, that slavery is an abomination. And human welfare, I think, as I said, I think it’s a good approximation in most practical situations, but it seems to me not an absolute truth.
David Deutsch
I can imagine situations in which it would be right for the human race as a whole to commit suicide.
Sam Harris
– I guess I should spell out a little more clearly what I’m talking about. – I should read your book, I guess. – No, well, actually, I feel like speaking with you, having read much of your book and having this conversation with you allows me to put it a little better than perhaps I did in that book because there’s kind of a homology between your open-ended picture of knowledge and explanation and my moral realism. I don’t know that our realism with morality is precisely the same, but there’s a line in your book which I loved, which is something like, moral philosophy is about the problem of what to do next. And then I think more generally, you said that it’s about what sort of life to lead and what sort of world to want. But this phrase, the problem of what to do next, really captures morality for me because, and I’ve been talking about it for years as a kind of navigation problem. Forget that we even have the word morality or good and evil or right and wrong. We still have this navigation problem. We are in a universe of possible experience. And given that there’s a difference, and I would think that there’s probably no difference more salient in this universe between the worst possible misery for everyone and all other states of this universe, there’s a question of just how to navigate in this space of possible experiences. What sorts of wellbeing are possible given the requisite minds? What sorts of meaning and beauty and bliss are available to conscious minds, appropriately constituted? For me, realism of every kind is just a statement that it’s possible not to know what you’re missing. If you’re a realist with respect to geography, you have to acknowledge that there are parts of the world you may not know about. If the year was 1100 and you were living in Oxford and you had never heard of Africa, Africa nevertheless existed despite your ignorance and it was discoverable. And so this is realism with respect to geography. Things are true whether or not anyone necessarily knows that they’re true. And knowing that they’re true, people can forget this knowledge, as you pointed out, and whole civilizations could forget this knowledge. Well, this is true in the space of possible conscious states. And all you have to acknowledge is that there is some criterion that is as fundamental as any criterion we would have invoked in any other canonical domain of science by which we could acknowledge that certain states of consciousness are better or worse than others. And if you’re not going to acknowledge that the worst possible misery for everyone is worse than many of the alternatives on offer in this universe, well then I don’t know what language game you’re playing, but it seems to me that this is, that’s all I need to get this open-ended future of navigating in the space of possible experiences started. And then it really is this kind of forward movement toward we know not what, but we know that there’s a difference between profound suffering that has no silver lining and many of the things that we value and are right to value in life. And these values, the fact value distinction, this is something that I think Thomas Kuhn once said that philosophy tends to export its worst products to the rest of culture. And it’s kind of ironic because many of the things exported from Kuhn’s work are also quite some, fairly terrible, but he got this part right. And so this notion that comes from a, I think, frankly, a misreading of Hume, that you can’t get an ought from an is, and again, these are, you know, I have met physicists who think that this is somehow a, you know, inscribed at the back of the book of nature that you just cannot get an ought from an is, and therefore there’s no statement of the way the world is that can tell you how it ought to be.
Sam Harris
There’s no statement of fact that can tell you anything at all about values, and therefore values are just made up. They’re just, they have no relationship to the …
David Deutsch
Truth claims of science. Yes, it’s empiricism again, it’s justificationism. So you can’t deduce an ought from an is, but we’re not after deducing, we’re after explaining. And moral explanations can follow from factual explanations, as you have just done with thinking of the worst possible misery that a human being could be in.
Sam Harris
Even deeper than that, and I think you make this point in your book, is that you can’t even get to an is, which is to say a factual claim, without presuming certain oughts, without presuming certain values. That’s true as well. The value of logical consistency, the value of evidence. And so, yeah, so this is a confusion about the foundations of knowledge, as you say, that is somehow being linked to empirical experience narrowly, and really a sense that science is doing something totally unlike what we’re doing in the rest of our reasoning, which is the confusion here.
David Deutsch
Yes, it’s totally like.
Sam Harris
It’s a special case. It’s just, it’s really, it’s the part of culture where we have invoked the value of not fooling yourself and not fooling others, and made a competitive game of finding, you know, where you might be fooling yourself and where others might be fooling themselves. We’ve tuned up the incentives in the right way there uniquely, so that it’s easier to spot self-deception and fraud than it is elsewhere. But it’s not a fundamentally different project of trying to understand what’s going on in the world or in the universe.
David Deutsch
I agree. I agree.
Sam Harris
Well, listen, so this brings me to the final topic, which I think is related to what we were talking about in terms of the maintenance of civilization and the possible peril of birthing intelligent machines badly. And this is, I just wanted to get your opinion on the Fermi paradox and describe what the paradox is for those who don’t know it, but then tell me why our not seeing the galaxy teeming with more advanced civilizations than our own isn’t a sign that there’s something about gathering more knowledge that might in fact be fatal to those who gather it.
David Deutsch
So the Fermi problem, rather than paradox, the Fermi problem is where are they? Where are the extraterrestrials? And the idea is that the galaxy is very large, but how big it is is trumped by how old it is. So that if there were two civilizations anywhere in the galaxy, the chances that they had arisen less than say 10 million years apart are infinitesimal. So therefore, if there is another one out there, it’s overwhelmingly likely to be at least 10 million years older than us and therefore to have had 10 million years more time to develop. And also in that time, there’s plenty of time for them to get here. If not by space travel, then by sheer mixing of the stars in the galaxy. They only need to colonize a few nearby stars to them. So that after say 100 million years or a billion years, those stars will be far apart and spread throughout the galaxy. So we would be seeing evidence of them. And since we don’t see evidence of them, they’re not out there. Well, this is a problem, but I think the problem is just that we don’t yet understand very well most of the parameters. And if you just fill in the parameters, like are they likely to use radio waves? What are they likely to do by way of exploration? What are their wishes likely to be? In all these cases, we make an assumption that’s based on saying that they’ll be like us in that way and that they will use technology in the same way that we do. And we only need to be wrong in one of those assumptions for the conclusion that we should have seen them by now to be false. Now, another possibility is that we are the first, at least we are the first in our galaxy. And I think that would be quite nice.
Sam Harris
Does that second assumption strike you as very implausible or not?
David Deutsch
Like I said, I don’t think we know enough about all the different factors affecting this for any one idea to be very plausible or implausible. I mean, what’s implausible is that they can have a different way of creating knowledge to us, that they can have, you know, that kind of thing is implausible because it just implies that physics is very different from the way we think it is. And if you’re going to think that, you may as well believe in the Greek gods. So another possibility is that most societies don’t destroy themselves. Like I said, I think that’s fairly implausible for us. And it’s very, very implausible that this generically happens.
Sam Harris
Right. Just to spell that out. So the philosopher Nick Bostrom had this concept in his book Superintelligence of what he called the great filter. And it’s the fear that at some point, that basically all advanced civilizations at some point discover computation and build intelligent machines and that this is for some reason always fatal or that maybe there’s some other filter that is always fatal. And that explains the absence of them.
David Deutsch
We would expect to see the machines, right? Unless they’re busy making paper clips at home. But I think what is more plausible, although again, I must say this is just idle speculation, is that most societies settle down to staticity. Now, our experience of staticity is conditioned by static societies in our past, which as I said, have been unimaginably horrible from our present perspective. But if you imagine a society whose material welfare is say a million times better than ours, and somehow that becomes settled into a sort of ritualistic religion in which everybody does the same thing all the time, but nobody really suffers, that seems to me like hell. But I can imagine that there can be societies in which, as you said, they can’t see the different ways of being. So it’s like being on a, you said, use the example of being near Oxford and not knowing about Africa, you could be on the top of the tallest mountain in Britain and not know that Mount Everest exists. And if the height of the mountain measures happiness, you might be moderately happy and not know that better happiness is available. And if so, then you could just stay like that.
Sam Harris
Actually, you just invoked explicitly the metaphor I use in my book, the moral landscape, which is, I believe that that’s precisely the opportunity on offer for us, that there’s a landscape of possible states of well-being, and this is almost an infinitely elastic term to capture the differences in pleasure across every possible axis. And that, yes, you can find yourself on a local peak that knows nothing of other peaks, and that there are many, many, many peaks, obviously, but there are many more ways not to be on a peak. And so there are many more ways to be struggling to get to some higher point that is nearer to you in terms of well-being. And you and I may differ in our sense of just how desirable certain peaks might be or how captivating they might be to conscious creatures like ourselves. And I think there are probably many peaks that are analogous to and compatible with a very high state of civilization, which are analogous to being the best heroin addicts in the galaxy, which is to say you’ve found some place of stasis where there is no pain and there is also not a lot of variation in what you do. You’ve just kind of plunged into a great reservoir of bliss, which you’ve managed to secure for yourself materially with your knowledge. And it’s a very Aldous Huxley vision of the endgame.
David Deutsch
Yes. If that’s really what’s happening across the galaxy, you have to find some way of accommodating, first of all, that these civilizations like that will eventually be destroyed by a nearby supernova or something of the kind. On a scale of tens or hundreds of millions of years, there are plenty of things that could wipe out a civilization unless it does something about it. If it does do something about it kind of automatically with automatic supernova suppression machines, which are in place and nobody has to think about them anymore, we would notice that. It can’t be exactly that. On the other hand, it’s hard to imagine that they don’t know about that and do get wiped out because how did they get to that state of exalted comfort without ever finding out about supernova and their danger? There are other possibilities. I’m actually considering writing a science fiction book with a very horrible possibility, which I won’t mention now, but it’s fiction.
Sam Harris
Don’t give the surprise away. Well, listen, David, it’s been incredibly fun to talk to you. And I’m painfully aware that we haven’t even spoken about the thesis for which you are perhaps best known. Actually, the two, the many worlds interpretation of quantum mechanics, as explained in both your books, the first book being the fabric of reality, which I read when it came out and loved. And nor have we spoken about quantum computation, but we’ll definitely have to leave those for another time because you have been so generous with yours today. So I just want to encourage our listeners to read both your books, but especially the most recent one. And where can people find out more about you online? Is there a…
David Deutsch
They can find me with Google very easily, but I also have a website, daviddeutsch.org.UK, and all the links linking to me link to each other as well. So I’m easy to find.
Sam Harris
And your social media buttons are on that page as well?
David Deutsch
Yeah, I’m on Twitter.
Sam Harris
Okay. Actually, one last quick question, which I thought of asking. Now that I’m interviewing smart, knowledgeable people, it occurred to me to ask this question of Max Tegmark, and then I forgot. So this will be the inaugural question with you. Who’s your vote for the smartest person who has ever lived? If we had to put up one human brain, past or present, to dialogue with the aliens, who would you say would be our best candidate to field?
David Deutsch
So this is different from asking who has contributed most to human knowledge, who has created most.
Sam Harris
Yeah, absolutely.
David Deutsch
It’s rather who has the highest IQ?
Sam Harris
It’s good to differentiate those because there are people obviously who are quite smart, who have contributed more than anyone in sight to our knowledge. But when you look at how they think and what they did, there’s no reason to think they were as smart as John von Neumann, say. So I’m going after the von Neumann, if not-
David Deutsch
In that case, I think it probably has to be Feynman. Though his achievements in physics nowhere near those of, say, Einstein. I met him only once, and the people were saying to me, you’ll have heard a lot of stories about Feynman, but he’s only human. Well, to cut a long story short, I went and met him and the stories were all true. He is an absolutely amazing intellect. I haven’t met many of the others. I never met Einstein, but my impression is that he was something unusual. I should add in terms of achievement, I would also add Popper.
Sam Harris
Don’t cut that long story so short. What was that like being with Feynman and can you get a handle on what was unusual?
David Deutsch
Well, very quick on the uptake. So that is not so unusual in a university environment. But the creativity applied directly to getting things. Okay, let me give you an example. At the time when I met him, I was sent to meet him by my boss when I was just beginning to develop the ideas of quantum computation. I had constructed what we would today call a quantum algorithm. Very, very simple one. It’s called the Deutsch algorithm. It’s not much by today’s standards. But I had been working on this for many months. I went and started telling him about quantum computers. He was very quick. He was very interested. Then he said, so what can these computers do? I said, well, I’ve been working on quantum algorithm. He said, what? I began to tell him about it. Hmm. And I said, supposing you had a superposition of two different initial states. And then he said, well, then you just get random numbers. And I said, yes, but supposing you then do an interference experiment. And I started to speak and he said, no, no, stop, stop. Let me work it out. He rushed over to the blackboard and he produced my algorithm with almost no hint.
Sam Harris
So how much work did that represent? How much work did he recapitulate?
David Deutsch
I don’t know because it’s hard to say with the benefit of hindsight how much of a clue the few words I said were. But the crude measure is a few months. But a better measure is that I was flabbergasted. I’d never seen anything like this before. And I had been interacting with some extremely smart people.
Sam Harris
Right. And your boss was John Wheeler at that point?
David Deutsch
Yes. Yes. At that time.
Sam Harris
So no dunce himself.
David Deutsch
That’s right.
Sam Harris
What a wonderful story. I’m glad I asked. Well, listen, David, let me just demand that this not be the last time you and I have a conversation like this because- …
David Deutsch
That would be very nice.
Sam Harris
You have a beautiful mind.
David Deutsch
It’s very nice talking to you.
Sam Harris
Please take care and we’ll be in touch.
David Deutsch
Thank you.
Sam Harris
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