Science Saturday: A Plan to Dye One's Whiskers Green | John Horgan & David Deutsch
Hello, David Deutsch, are you on the other end there?
It's great to have you here on Blogging Heads, David.
Let me just introduce myself and then I'll let you do the same.
I am John Horgon, I'm a science journalist and occasional science correspondent for Blogging
Heads TV and I have a really special guest with me today.
The physicist, British physicist, David Deutsch, who is now in your end Oxford right now.
So, David, could you just give us a little background on yourself and then we'll start
talking about your wonderful new book?
So, my name is David Deutsch and I'm a physicist at Oxford University and I'm the author
of two books, the fabric of reality and recently the beginning of infinity.
David, you were often described as a pioneer of or even the father of quantum computation.
And that's been a theme in both of your books.
Can you just describe a little bit about how you got into that field?
I wish I think was quite a while ago, a couple of decades ago.
Yes, it was actually, I actually began thinking about quantum computers in the 1970s, although
I didn't call them that then because I didn't think of them as being anything to do with
the foundations of computation.
The context there was the so-called parallel universes or many universes interpretation
of quantum mechanics and I had realized that the consensus view that both the proponents
and the opponents of this rather controversial interpretation had been taking, namely that
it is just a matter of interpretation and that there are no possible experimental tests
of it, was actually false and that this idea that it can't be tested was simply due to
some poor thinking about what would happen when an observer did a measurement on another
observer and so on.
And so I was trying to clarify this issue of what an observer is in quantum mechanics.
And so I thought, well, the simplest way to clarify that is to imagine an artificial observer
and what would be called an AI or an AGI, an artificial general intelligence, but running
on the hardware that obeys quantum mechanics.
Of course, all hardware obeys quantum mechanics, but I was thinking of hardware that obeys
it in a way that can be tested in the laboratory.
And so I imagined an AI program running on this quantum hardware and then I added a few extra
elementary operations to this computer, which would be, sorry, that was okay, they'll have
to cut out this bit.
It's okay, it's those little glitches that make blogging head so charming to some people.
So I had to add a couple of extra operations to this computer because that's what made
the difference between doing this experiment with a computer that obeys quantum mechanics
and an ordinary computer, the kind of computer that we know that we're familiar with.
And given those extra operations, it was possible to perform an experiment whose outcome
would be one way if there was only one universe, if something like the Copenhagen interpretation,
the way function collapse interpretation, or any single universe interpretation of quantum
mechanics were true.
It would go another way if the many universes interpretation was true.
And so as a sort of side effect of this, I realized that quantum mechanical computers would
be inherently more powerful than they could perform more qualitatively different computations
than classical ones.
And then later, yes, maybe you should just back up and we can't assume that our listeners
are completely familiar with all the different interpretations of quantum mechanics.
Just remind us of what the many worlds or many universes interpretation of quantum mechanics
is and how it differs from, say, I don't know, the Copenhagen interpretation, if that's
kind of the more mainstream view of what quantum mechanics means.
To explain what quantum computers are, I have to explain what quantum mechanics is from my
point of view.
And I adhere to what's called the parallel universes or many universes interpretation proposed
by Hugh Everett in 1957, it says that the universe we see around us is just a tiny facet
of the whole of physical reality, which, and so if we want to retain the same word for
universe, we have to invent another word for the whole thing and I favor the word multiverse
for the whole of reality.
In my view, and in the view of its proponent, its other proponents, this is an incontrovertible
implication of quantum theory, which is almost fundamental theory in physics.
But I always have to warn the viewer immediately that this view is shared by perhaps fewer
than 10% of theoretical physicists at any rate, that's what I take quantum theory to say.
And quantum computers are computers that harness quantum theory to perform a different mode
of computation, something that cannot be performed by existing classical computers at all.
I see, okay, I want to come back to multiverse theories and the multiple universe interpretation.
But let's talk about your book.
Now I'm holding up the galleys that I got from the Wall Street Journal when I reviewed
your book, the beginning of infinity, and I should say that the journal, I think, asked
me to review your book because it is almost the antithesis of a book that I wrote in 1996,
the end of science.
And in fact, at the very end of your book, you mentioned my book and reject its claim
that science might be approaching its limits very forcefully.
I think the journal expected me to lay waste to your book, they thought that that would
be entertaining, and I fully expected to do that when I started reading you, but I ended
up really loving your book.
I think it wasn't what I expected at all, it's a really grand vision of human possibility
and it got me questioning my own pessimism about the future of science and even technological
So could you just tell us, where did the idea for this, first of all, say give us a nutshell
version of the book's theme and then and also say give us some sense of where the ideas
Yes, the basic theme of the book is that all human progress in the past has been fundamentally
caused by a single kind of activity, which I call the quest for good explanations, explanations
being accounts of some kind of reality and how it works and why.
And pursuing this theme of what an explanation is, why the quest for good explanations
can work and so on.
It makes contact with the whole lot of other bits of science and philosophy and so on,
which together imply that this process need never come to an end.
That is, we could bring it to an end if we destroy ourselves or decide not to or whatever,
but there are no inherent limits to the growth of knowledge and therefore to progress.
And by the way, you mentioned your review of my book, I thought it was exceptionally nice,
generous review, but it's funny, you should mention your feelings on reading it because
they were exactly mirrored in my feeling on reading your book.
I was expecting to hate everything in it, but instead, I merely disagreed with the conclusion.
It seemed to me, correct me if I'm wrong about this, but it seemed to me that in every argument
in your book, there is a sort of reluctance, there is a wish that it will otherwise and
that your arguments about these limits, you are forced to them because you think that
that is the logic of the situation, but you would rather that it will otherwise.
And that's what I got from your book.
Well, of course, I mean, I became a science writer because I see science as I think you
do as by far our most powerful way of understanding ourselves and understanding all of reality.
And as we got into science journalism in the early 80s, when there was talk of a theory
of everything, Stephen Hawking had predicted the end of physics, there would be this great
revelation at the end of our quest to understand everything.
And I was enormously disappointed when I went after a period of time, I started suspecting
that maybe science was already bumping into walls and we wouldn't get these great
revelations in the future.
So you're absolutely right.
But I think these walls of our own making, they're not inherent in the subject of, I mean,
this is my subject, the book covers all subjects and by the way, not only science, I think
this thing about the quest for good explanations has been responsible for all progress
such as moral progress, political progress, artistic progress, every kind.
But science is my field in physics in particular and it is true that progress in fundamental
physics was reached an all-time high in the early 20th century.
And although it hasn't, it by no means gone to zero now, it is lower now than it has been
at the time in the past.
And this is caused some people to think that we may be running out of either, we may
be reaching the end as you, I mean, in your book, you give both possibilities, either
we're reaching the end of knowledge so that we'll understand everything or we're reaching
the end of the capacity of science to create knowledge.
And either way, we're heading for a brick wall.
Now, I think this apparent brick wall, as always in the history of knowledge, was not caused
by anything in the subject, it was caused by what people have chosen to do.
And you mentioned the theory of everything, to me, which is the theory of all, a proposed
or hoped for theory of all elementary particles, space, time, and gravity, that theory,
to me, it should not be called the theory of everything.
That is a very tiny facet of physics from my perspective, let alone everything.
It's just the theory of how objects behave, but beneath all such theories are formulated
within a certain profoundly significant language and conceptual framework, namely quantum
theory, and the theory of everything just assumed that quantum theory would survive would
be exactly the same theory after we have discovered this great unification.
And also that, essentially, the theory of gravity also would, and that unifying them would
simply be finding a way of writing either of them in the language of the other.
And that has been the technique of elementary particle physics for the past several decades.
And to me, that is simply what they're doing is they're trying to formulate a classical theory,
not counting quantum mechanics, as if it was all in one universe, as if they weren't interference
phenomena and tunneling and all those things, just a classical theory, and then they apply
a process that physicists call quantization, which is a way of transforming a classical theory
into a quantum theory. And so you turn the handle, it's just a mechanical process.
And this worked for electro dynamics. That was the great achievement of Richard Feynman
and Julian Schwinger and others. And it really hasn't worked since. And I don't think
there's any reason to believe that this process will ever work. Again, it was just a stroke
of luck that quantum electro dynamics can be obtained from classical electro dynamics by
a mechanical process of quantization, plus a whole load of cleverness. But I don't see
I assume that that would lead you to be skeptical of string theory and even loop space
theory and some of the main contenders for a theory that could unify relativity and quantum
Unfortunately, although I wouldn't say these things aren't worth doing that because if
nothing else, we learn from them even when they fail. But it seems to me that progress,
because progress comes from good explanations, it has to come from problems because an explanation
is an explanation of something like how a thing can possibly be. And that means that the
prevailing way of trying to find fundamental theories in physics is unlikely to succeed
because it is looking for mathematical models and then trying to understand what that could
possibly mean if it were a theory in physics.
And I mean, even if you found the right theory that way, I think there are chances of fairly
low that you'd recognize it because how do you know which of those mathematical objects
correspond to which objects in nature? We're assuming that the future theory is going
to still be based on things like particles, space, time, fields, and so on. But why should
Fundamental progress in the past has always involved new kinds of entity, new modes of explanation
that weren't thought of before. So yes, I'm skeptical that these approaches, any of
these approaches can work. And I think that's why there hasn't been this fundamental
David, let me raise an objection to your optimistic vision of the future of science, which
is actually based on my reading of what quantum mechanics is done in physics. You have a
passage in your book where you recall, I think it's Niels Bohr saying that anybody who
thinks he understands quantum mechanics obviously doesn't. And you reject that as a kind
of no-nothing-ness, which is surprising for something like Bohr. But it seems to me that
if you look at sort of in a sociological sense, all the different competing attempts to
understand what the hell quantum mechanics means, that you'd have to grant that even for
the experts, the theory is quite confusing. On the other hand, it's powerful. It doesn't
anything that you could want from a theory in terms of being able to predict experiments
and leads to all sorts of amazing applications and so forth. And so it seems to me that
you're getting a split between science as giving us power over nature and science as
a mode of understanding. And the understanding, and especially then, if you look at the
rest of physics as well, which has become for the average person extremely difficult
to understand, very esoteric, I see science as really beginning in the 20th century becoming
more and more distant from the comprehension of the average person. And I just wonder where
your optimism comes from that somehow in the future, I don't know, as a result of new ideas
and physics, new ideas about how unification should take place or whatever, why we should
get the comprehension that seems to be received now in the past.
Yes. In my view, this split that you talk about between quantum theory as a powerful technique
for building things and making predictions and quantum theory as a way of understanding
nature. This split is not a feature of quantum theory. It is a feature of the sociology
of science during the 20th century. The split was introduced as a matter of philosophical
dogma in order to protect from criticism the bad explanations that the founders of the theory
and subsequent physicists have favored for quantum theory, which by the way from the
many universities point of view, they are all equivalent to saying, well, at some point
when we're not looking, all the universes but one suddenly disappear. And we can't notice
this because we're not looking. And that sort of thing. And when the response to careful
considered criticism of this view is to say, oh, well, you don't understand quantum
theories. Now, the thing is we've been here before that as the, however, the founder
of the many universities theory pointed out in a famous letter, we have been here before
the a radical change in worldview was occasioned by the discovery of the heliocentric theory
that the son and not the earth is the center of the solar system, what we now call the
solar system. And Galileo championed this theory and in a famous conflict between him and
the inquisition, they tried to force him to renounce the theory. But if you look in more detail,
what they were asking him to renounce was not the power of the theory, not its ability
to predict that they were quite willing to allow him to, to espouse and to teach and
and so on. What they wanted him to reject was the claim that this described reality,
that this described the solar system. And the new vision of the solar system that was
entailed by the heliocentric theory was a jarring change from what had gone before,
because for example, it meant that the earth beneath our feet, which is the paradigm of
something fixed in common sense, is actually moving very fast. It's moving at a thousand
miles an hour around the earth's axis and also moving around the sun. And we can't
feel this because the laws of physics are constructed in precisely such a way as to cancel
out any feeling that we might have about this motion. And people who were at first sight,
this is a ridiculous idea, because it's like what Lewis Carroll said. I was thinking
of a plan to die one's whiskers green and always use so large a fan that they could not
be seen. It was accepting one thing just in order to make it invisible and then explain
something else and so on. And it's only when you look very carefully at what the theory
says that you see how much and how enormously better an explanation it is of the observed
motion of the planets and so on. And then it allowed further unification by Newton of celestial
mechanics and terrestrial mechanics and so on. And so this split at that time was an invention
of the Inquisition. The split in quantum mechanics regrettably was an invention of its
very founders. They didn't want to take the theory seriously as a description of reality.
Do you think that Einstein, if he was alive today or had lived long enough to see you
ever its theory, would have been embraced it or would have made it even more frustrated
with quantum mechanics and convinced that it had to be incomplete or wrong in some way?
It's hard to predict what an actual person would have said. But if we look at what Einstein
wrote about quantum theory and wrote about his famous criticism and his great debate with
Neil's Law about quantum theory, all his criticisms are straightforwardly met by the
many universities interpretation. So he only missed it by two years and it's very very
frustrating. The bristy wit in his famous article introducing the many universities interpretation
in a footnote he says that Albert Einstein would surely have liked this.
So I think he would as well because what was driving Einstein both in theory of relativity
and in his critique of quantum theory as it was in his day was realism. He understood
science and physics as being the study of what reality is like. And these equivocations
that the quantum theory appeared to bring namely, well what do you really mean by real
and we can't really say well it's real, we can only say what we observe about the reality
and so on in which case science becomes the study of us, it becomes the study of our perceptions
and everything else is just a sort of fiction. That he rejected rightly. Having, by the
way, believed stuff like that in his youth and rejected it in order to make progress with
relativity. He then applied that idea of realism to the whole of science and insisted on
that and rejected the quantum theory of the time as not being realistic whereas the
ever theory is entirely realistic. In fact, you can define many universe quantum theory
as just the statement that the equations of quantum mechanics describe reality. That's
all it is. Let me bring up another possible objection that Einstein might have had. Einstein
has this wonderful phrase. I have no idea when he said it but that the goal of physics
is to determine whether God had any choice in making the universe. It's a way of getting
up the question of why do we, okay even after we figure out the laws of the universe
in its history and so forth, we still have to ask why this universe? Why do we find ourselves
living in a universe that allowed our existence and so forth? It seems to me that, and there
is a hope, Stephen Weinberg has also talked about this, that there would be a theory at
some point that would be kind of logically inevitable or necessary and if you tried to tweak
it, it would fall apart and it would make this universe that we live in also necessary
or inevitable in some sense and what has happened over the last couple of decades is that
things have gone completely in the opposite direction and now you have theories that predict
basically an infinite number of other universes. So you're sort of back to the arbitrariness
of this one and the problem as far as I can tell, it's gotten even worse. So I wonder
how you respond to that issue. So first of all, if one interprets Einstein's view as
that quote of Einstein as saying that we need an ultimate explanation, then I think that that
is a chimera. I think that that will never be found and can never be found and if such a thing
could be found it would be a catastrophe because it would be the end of progress. The progress
in science is intimately connected with all the other kinds of progress so it would also lead
to the end of progress in the other ways that we like such as morality, politics and so on.
But I think there is nevertheless a truth in it which is the truth about good explanations.
What we want from a good explanation in the way I describe in the book is that it be hard to vary.
That is, if you displace one note as Sharper said in the play Amadeus, then there's diminishment
and if you displace a phrase then the whole structure falls apart. So in that sense we want the
theory to have a good theory must have a certain inevitability about it with hindsight of course.
So with hindsight you see there couldn't have been any other way. But what saves us from the evil
implications of an ultimate explanation is that good explanations solve the problems that they address
but they always raise new and better problems. So the problems that we have today for example
in cosmology about what the dark energy is that's making the universe expanded in accelerating
rate and one of the most startling discoveries of science in recent times,
that discovery depended on the previous discovery of the general theory of relativity
and cosmological models in that theory and so on. It's only in the light of those theories
that we can even know that the expansion of the universe is accelerating and know that that's
amazing. So in solving the problems that Einstein solved, namely how things like the motion of
light and the existence of gravity could be reconciled in his general theory of relativity,
that opened up problems that were simply inconceivable before and one couldn't have expressed
them even in the language of of physics or in the language of common sense. There were problems
whose that opened up because of the solution of previous problems and that is
that's the solution to the conundrum. How we can get our hard to vary good explanations
without grinding to a halt as a result. It's because good explanations open up new problems.
Let me bring up another figure he's very prominent in your work, the philosopher Karl Popper,
who I was fortunate enough to interview a few years before he he died. Obviously he's been
a very big influence on you. I just wonder how Popper would have reacted or did react. I
don't know if he ever wrote on multi-verse theories, but wouldn't I would suspect that Popper
would have been a skeptic of multi-verse theories because he was so insistent on
testability and it seems to me that multi-verse theories are at the very least extremely
difficult to test and that any kind of evidence you would have of their existence would be
circumstantial at best. Okay, yes, two issues there. One about the testability of the many
universe interpretation and the other one about Popper. I was also privileged to meet Popper on one
occasion when I was a student and I was lucky enough to be invited along to a meeting between
Popper and my mentor Bryce Dewitt, my physics boss, Bryce Dewitt and basically at that meeting,
Dewitt told Popper that he had misunderstood what the fundamental problem is in quantum theory.
The Popper thought it was to give a meaning to probability statements and he'd kind of missed
the deeper problem of things like entanglement and interference and the measurement problem.
And Popper said that he had realized that he had an inadequate understanding and had held up
publication of one of his books in order to try to improve it. Now, I've looked at his subsequent
books and they all contain the same misunderstanding of quantum theory, unfortunately.
When he does, he does occasionally mention the many universe interpretation but only to dismiss it
for kind of non philosophical reasons just to say, well, you know, we can't have that and therefore
I'm going to concentrate on this other thing. So Popper unfortunately like Einstein died too soon
but not too soon chronologically. He just died too soon for the right understanding to have reached
him. I suppose that is not a coincidence either because 90% of the physicists whom he might have
asked about the foundations of quantum theory would have given him nonsensical answers. Now,
as for the testability of the many universe interpretation, this is, as I said, there are
in principle tests that would test it against the rival theory that there is only one universe.
But really that is grossly understating the scientific status of the theory. The reason that one
doesn't normally test an interpretation, normally in science, one says that yes, indeed,
the equations of the theory do describe reality and it's really only in the case of quantum theory
within physics that somebody has said, how can we test the interpretation by itself? Namely,
how can we test the statement that these equations, though we're not disputing that they correctly
predict experiments, how can we test the statement that in fact they represent reality rather than
just what we see in reality. As I said, we've been here before in physics, namely at the time
of Galileo and the Inquisition, but in the present day there is a very close analog of this and
that is the creationists who say that fossils, no one's ever seen a dinosaur, just like
no one's ever seen in parallel universes, all we have is the circumstantial evidence of fossils
and the interpretation of fossils as being the remains of dinosaurs. Similarly,
we have no one's ever seen parallel universes, but what we have seen is interference phenomena
and the interpretation of interference phenomena as being due to the interaction of different universes
and there's no other explanation. So if you want to say the other universes don't exist,
you have to do it by fear rather than rather like the people who say that the world was created
6,000 years ago with fossils. So similarly, the conventional interpretations of quantum mechanics
say that at the moment of a measurement, all the universes except one disappear, don't exist
and no one can contradict this because no one can see them. David, I'll just tell you,
I think that's a stretch to compare doubters of parallel universes to, and I count myself one,
not a doubter, but more an agnostic if someone who thinks that it's kind of a mood issue
because we'll never have good evidence, doubters of these things to creationists who are sure
that dinosaurs really exist. But listen, I want to get onto another really big topic that you
raised in a book. By the way, I was only saying that the logic is the same. The psychological
motivation is not the same, but the logic is the same because of the existence of good
explanations in both cases, but okay, continue. All right, a really wonderful theme that emerged
at a number of places through your book was, and I'll put it in my own words and you can tell
me if I've gotten it wrong, was a kind of critique of simple reductionism or materialism,
which obviously is the kind of prevailing philosophy of physics that good answers will come
from going to smaller and smaller scales and also focusing on things, on objects, on particles
and so forth. Yes. And you seem to be, you are, to my mind, saying that that is a much too
restrictive form of explanation and that we have to recognize that what we might even call
immaterial phenomena that aren't reducible to specific physical objects or processes
can have a profound impact and have had a profound impact on reality, particularly our human
reality, human history, the world of politics and culture and so forth. And it seems to me,
you're almost, it's almost a rebuke of physics as kind of the really the best mode of understanding
the world. And you're emphasizing how important mind is and ideas are and thoughts and so forth.
So I'll talk about that a little bit. Yes, of course I am a physicist and I'm profoundly
opposed to any idea of non-physical explanations that contradict physics. So that's a no-no
and really doesn't make sense. However, there are ways in which both emergent properties,
such as minds and life and so on have an effect. And as you said, also abstractions.
Now this, this, the fact that the theory of good explanations led to the idea that abstractions
are real things was slightly surprising to me. I wasn't expecting the link, at least,
wasn't expecting it to be so strong as it is. But the thing is if you think about how to explain
events, physical events, like a footprint on the moon, how do you explain how that happened? Well,
it happened because of human ideas, of science. And human ideas, you could say in this reduction
it's sense that as you rightly say is the prevailing mode of explanation and the prevailing
idea is to look down on other modes of explanation that those ideas are nothing more than
configurations of atoms. So some physicists, some rocket scientists put their brain into certain
configurations of atoms and those atoms then acted on other atoms, which acted on other atoms,
which then ended up making a footprint on the moon. Now what that misses is the explanation of
why certain configurations of atoms put footprints on the moon, while others, the overwhelming
majority of configurations that human brains, even human brains have been put into in history,
do not have that effect. And it's because of, it's a certain type of information. And this
information can't, in my view, be reduced to statements about atoms, because if you think about
what that information does, it is in brains, but it's the same information then gets transferred
into, let's say, sound waves in air and then it gets transferred into
ink and ink on paper and then it gets transferred into magnetic domains inside a computer,
which then control the machine that instantiates those ideas in bits of steel and silicon and
so on. And so on, there's an immense chain of instantiations of the same information.
And it's only special kinds of information that have this property that they are preserved and
instantiated in successive physical modes. So what is being transmitted, what is having the causal
effect is not the atoms, but the fact that the atoms are in certain instantiate certain kinds
of information and not other kinds. So therefore, it is the information that is having the causal
effect. If a particular instantiation of that information were damaged, then processes would come
along to fix it, whether or not they could fix the physical instantiation. For example,
if the computer goes wrong, then we don't use the corrupted information. We go back and rescue the
information from a different computer and we throw away the atoms that at one point instantiated
it. So the information causes itself to remain in existence. Now, I think there's no way out
of that mode of explanation. And if explanation is going to be the fundamental thing about
our criterion, for example, about what is or isn't real, then we have to say that information
and this particular kind, which we call knowledge, is real and really does cause things.
It seems to me, you've got you bring up the word choice at a number of places in your book and you
emphasize the power of human choice. It seems to me that what you were really doing is defending
the concept of free will. Maybe you can tell me if I'm wrong here. And as some of the listeners
out there know, I am a free will fanatic. I'm very upset that some prominent scientists recently
have said that free will probably doesn't exist. It's an illusion. Stephen Hawking
has said as much Einstein in a couple of his quotes suggest that free will probably doesn't
exist. So you believe in free will, I take it. I certainly do. And I think that the argument
against free will from reductionism is just a mistake. It's a fundamental mistake. It's the idea
that all explanation must be in terms of microscopic things. There's no philosophical for
argument in favor of that, that I'm aware of. It's just an assumption. It has historical roots
in how science centuries ago escaped from the clutches of the supernatural. And as I said earlier,
certainly I'm opposed to any kind of modes of explanation in terms of things like, in terms of
immaterial things, in terms of abstractions that contradict physics. But the idea that all such
explanations by their very nature contradict physics is simply false. I just gave an explanation of
footprints on the moon in terms of the ability of certain types of information to preserve
themselves in existence and so on, whereas other kinds don't. That I defy anyone to reproduce
in terms of atoms. And I also define anyone to show how that contradicts an explanation in terms
of atoms. So we have to accept the physical world as we find it. We have to find the best
explanations that explain it rather than impose by dogma a criterion that explanations have to
meet other than that they explain reality. So I think this, this reductionism, the fashionable
reductionism is just a mistake. I'm sure that free will exists. However, I think free will is one
of a constellation of emergent abstract. We're not sure exactly what proportion the free will is
abstract or emergent properties that are not yet understood. Things like consciousness,
creativity, choice, free will and so on. We do have good explanations about them at the emergent
level, but we don't understand them well enough to make artificial ones. And I say in the book
that my criterion for judging any theory of consciousness, free will and so on is can you program it?
And if you can't program it, then I cannot take seriously your theory of it. Now, I don't have a
theory of it. I only have a theory that it exists. Now, if someone says that it doesn't exist
because we can explain everything without invoking it, I want to see those explanations.
Roger Pedros, I assume that you know him has proposed a solution to the mind-body problem
involving quantum mechanics working in some way. To me, this is the mind-body problem and free will,
which is obviously a big part of it, is the biggest, the biggest unsolved problem in
in science. And people are just grasses on right now. So I just wonder if you see any even blue sky
ideas that might provide a kind of framework for understanding it. Maybe also information theory,
which some people have also tried to bring into physics. Well, as you said, Roger Pedros is
looking for a new theory to replace quantum theory, which would not only
be a better theory in physics than quantum theory is, but would also solve problems like
the existence of free will and creativity and so on. I'm pretty skeptical for the same reason
that I'm skeptical of the mathematical approaches that are currently fashionable in fundamental
physics. I think that one solves problems in physics by addressing problems that are in physics,
rather than hoping that they have certain attributes, finding a theory with those attributes,
and then hoping that it applies to physics. But you know, I could be wrong, but at present,
there are no such theories. I think existing approaches to AI, artificial general intelligence,
are all philosophically flawed. And I think that's why they haven't succeeded for decades
because a philosophical advance is needed. And they are trying to get the answer without making
any philosophical advance. And that leads them essentially to sort of behaviorist models of what
and behaviorist models are non-explanatory models. They are models that just try to relate output
to input without explaining why the output comes from the input and so on. And I think that
that approach can't succeed. And it's the reason that the quest for AI has not got anywhere
during the last decades. What we need is first philosophical progress in understanding
how creativity, I think that's the key thing that relates all these unsolved problems about free
will, consciousness, and so on, how creativity is implemented. And it has to be implemented,
we know a few things. It has to be in the broadest sense, an evolutionary process. It has to
work by variation and selection, or as publicals it in the case of science, conjecture and
refutation or conjecture and criticism. But we need to know the details and devil will be in
the details. My guess is that once we understand what it is, we will be able to program it.
I think there's an analogy here with Darwin's theory of evolution that Darwin's great contribution
in my view is not his scientific theory of evolution. It is the philosophical progress that he made
in inventing a new mode of explanation, just not just a new explanation, but a new mode. Previously,
everyone who addressed the question, why are animals the way they are? Why are they, why are
they adaptations there? Everyone who, people try to address this by supernatural explanations and
also by scientific explanations, but all of them took for granted that what you had to do
is find a reason why there are elephants, why elephants have long trunks, that kind of thing.
And Darwin realized that that is a bad way of approaching the problem. To understand why
elephants have long trunks, you must not ask why they have them as your initial question,
you must ask what kind of process could give rise to trunks. And then that they have purposes and
some biological features have purposes, some have anti-purposes like the peacock's tail and so on,
that all comes out in the sophisticated elaboration of the basic theory of how it could possibly
happen by variation and selection, by random variation that is undirected variation and then directed
selection. Now, free will, consciousness and so on, definitely involves that as well,
but it involves something else that we don't get to understand, which it will take a new Darwin
to realize. And once the new Darwin has realized it, it will be, well, it took many decades
between Darwin and DNA. I think it will be much faster. It will be in between the person who
discovers the correct philosophy of AI and the programming of AI will be a matter of months
not decades. I hope I live long enough to see that. And I also, it would be very exciting.
And then limited time we have left, I want to make sure that we touch on some of the
political themes that you raise in your book. I mean, it really is part of the,
what I enjoyed about the book was that it was so broad and you had these very powerful ideas,
especially about accepting our fallibility as kind of a mode to constant self
improvement and applying that in all these different fields, science, culture, and politics.
So when it comes to politics, I wanted to ask you whether or not you think that, you know,
Francis Fukuyama had this, I had a book called The End of History where he's saying that in a very
broad sense, democracy plus free market capitalism represents the best we can do as far as finding
a way of organizing ourselves. And I just wonder, although, you know, of course there's a lot
of tweaking we can do. I just wonder if you agree with that or if you think that there could also
be infinite progress in the realm of politics. The same arguments that I use in the book for
everything else apply automatically to politics and imply that that infinite improvement, unlimited
improvement is better word, is possible there too. The liberal democracy plus free market capitalism
is the best known, the best existing knowledge of this. And so I would guess that Fukuyama,
despite recent hiccups in his predictions, is right that the ideas that had been the main
rivals to those ideas, during let's say the early 20th century, such as totalitarianism, communism,
and so on, that those are going into the dustbin of history. I think that is very different
from saying that our best guess as to how to create new political knowledge is going to be
just our current institutions. I'm sure that unlimited improvement is possible there too.
For one thing, we haven't solved the enormously important problem of how to transmit
this knowledge to political cultures that don't yet have it. And it seems that there's something
about our existing political culture that is actually antagonistic to transmitting it outside its
natural home. So that will be a major improvement because as Martin Reiss said in his recent
book in which he predicts that there's only a 50% chance of civilization surviving the next
century, progress in other areas, especially technological areas, mean that smaller and smaller
numbers of people are going to be able to do larger and larger amounts of damage. And so unless the
means of promoting the resolution of agreements without violence can be propagated to basically
the whole world, we're going to be an increasing danger from things like weapons of mass destruction
in the hands of terrorists. By the way, I think this is not just a political, a problem with
improving our political system. It's a general problem to do with technology and everything else
because apart from trying to, I should say that that our civilization, the civilization of the
west of liberal democracy and capitalism and so on, is within itself, inside itself, it is by far
the most peaceful as well as the most rapidly progressing civilization that's ever existed.
But I think that apart from having to improve it further in order to allow it to survive,
there's another thing we have to do and this is a big theme of my book as well.
We have to continue to make rapid progress and it's not just for its own sake, but in this
context of, in this political context, it's because rapid progress is the basic means
by which the good guys can defend themselves against the bad guys. I've said that technology
makes a smaller and smaller number of people able to cause larger and larger effects. Well that
has to be offset by the larger number of people, the good guys, making at least as much progress
as that in order to be able to cause even larger effects in self-defense. So it's a rapid
progress that is our major means of self-defense against the instabilities caused by small numbers
of bad people. Okay, I've got to stop you there. That sounds to me like more arms races in the
future. We've already been down that path and produced nuclear arsenals capable of destroying
all life on earth. Yes, that's not the implication of what I was saying. That's to interpret it
in terms of the technology of the past. It's a sort of reductionist interpretation, if I may say so.
The kind of, for example, protecting ourselves against nuclear attack during the Cold War
was done and rather imperfectly done by developing ways of nuclear attack ourselves. But protecting
against, let's say, biological warfare attacks has got nothing to do with, well, perhaps it also
involves developing weapons as a means of developing antidotes against them, but it's basically
what we need in the case of biological warfare is antidotes, not weapons, and antidotes are,
and this is going to be increasingly so as the complexity and knowledge in society becomes the
thing that we need to protect. Once we have, for example, once we are able to download our brains
into our minds, from our brains into computers and so on, then physical protection of them
will become much less important compared with protection of them from bad ideas which would use
creativity to destroy all backups. I'm talking about the ultimate extreme of the process,
which is already there in the fact that defending against biological weapons involves not
biological weapons, but antidotes. That kind of rapid progress is essential to the future of
civilization. One other, okay, boy, you're just popping open cans of worms all over the place here,
David, and we're basically out of time, but I just wanted to make sure that we touched on,
at the very end here, you refuse on our environmental problems on global warming, the question of
sustainability, you're quite critical of the concept of sustainability, and also of what you might
call, I don't know, environmental alarmism, you recall hearing Paul Erlich give one of his
gloom and doom speeches decades ago, and you were pretty dismissive because you thought that
Erlich wasn't anticipating any technological progress that might help us overcome these problems.
So give us a quick picture of your view on our sustainable or not sustainable future.
So I think it's a great pity that the issue of how to manage the environment has become a
political issue, because as a political issue, it has become dogmatic, and the dogmas on all
sides are simply false. They contradict the arguments of my book that, I mean, what more can I
say? On the one side, we have the people who say that the only way of ensuring our survival in
the long run is in damping down our impact on the environment. Now damping down our impact on the
environment is itself an impact on the environment. There's no fundamental difference between
changes that we cause, changes that it causes, or changes that we cause by trying to undo
things that we have done. All those things require knowledge, all of them require technology,
all of them are going to give rise to unknown problems in the future. And on the other hand,
there are people who try to deny that physics is relevant if it contradicts the political dogma.
And that's not true either. It's a rather unfortunate that in the case of global warming,
the exact details of how soon this is going to become a major problem depend on supercomputer
simulations. The thing is that it is going to become a problem eventually doesn't need
supercomputer simulations. It's politically important whether the tipping point is likely to
come in 50 years or 150 years. The difference between those is enormously important politically,
but it's not at all important technologically it seems to me. It seems to me that in both cases,
we need a very rapid progress and we need to assume that the solution is going to come from this
rapid scientific and technological progress and that this won't be the last problem that
ever faces us. What strange arrogance it is among the opponents of arrogance in technology
to assume that global warming is going to be the last major problem that will ever face our
species. That seems to me ridiculous and the task of technology is not to optimize the entire planet
to solve one particular problem that we happen to know about, but to give us the means of
first of all addressing problems that we do not yet know about and secondly,
the means to recover from disasters that will also inevitably happen when we make mistakes.
And both those things dealing with unforeseen problems and recovering,
both those things require knowledge and that's why we need to increase knowledge as far
as we can. One final question and I'm sorry about your answer has to be fairly brief.
I just wonder where your optimism comes from. I hope you don't mind my saying. I don't mean
this as an insult, but it approaches a kind of faith and I wonder if that faith has anything to
do with a kind of spirituality on your part, a belief and I don't know God or something.
So, well first of all, I deny it. I deny that I have any faith, religious or otherwise,
and I deny that I have any spirituality and I also deny that this optimism is an attribute of me.
It's as if you were saying what kind of predisposition to multiplicity led you to become
a defender of the parallel universes interpretation. That's not how it happened. The reach
comes from the ideas, not from what I want them to say. So, I can no more deny the links between
the theory of evolution in biology and in, let's say, human ideas than I can deny that they
apply to one particular animal. If the theory of evolution is true, then all animals evolved
and if somebody wants to say all animals accept elephants or as historically happened,
all animals accept humans evolved, then that doesn't make sense as an explanation and what
I'm about, what my books are both about, is taking explanation seriously and requiring them to be
good explanations, not requiring them to meet predetermined implications. Listen, there are a lot
of pessimists out there. As you know, I'm sure you've gotten some pushback against your vision
of the future. So, I urge them all to read your book and give your ideas a chance and it might
even make some of those pessimists out there a little less gloomy. Well, that's great and I'm
glad that you're not one. I'm working on it. Thank you very much, David. It was really a pleasure.
Okay. Nice talking to you. All right, same here.