David Deutsch’s Four Strands

David DeutschIn a previous post I talked about Roger Penrose’s seven (depending on how you count them) SUPERB theories of science. Now I’d like to give you an alternative view that I think is equally fascinating, though it takes a completely different path.

David Deutsch, being a Popperian Epistemologist (i.e. Epistemology is the theory of how we gain knowledge), believes that what makes a theory one of our best theories is not its range and accuracy, but instead how much it explains. Based on these criteria, Deutsch believes our four deepest theories of science are the following:

  1. Quantum Mechanics
  2. Biological Natural Selection
  3. Popper’s Theory of Knowledge (Epistemology)
  4. Computational Theory

In fact, Deutsch believes that these four strands are the start of what he calls “a theory of everything.”

What’s a Theory of Everything?

Please don’t mistake this ‘theory of everything’ with how a physicist would normally understand that term. Most physicists, if you referred to a ‘theory of everything’ would think you are talking about some heretofore undiscovered theory (well, actually, it might be M-Theory, which is a type of String theory) that combines Einstein’s General Relativity with Quantum Mechanics.

As we saw in my post on Penrose’s SUPERB theories of physics, those two theories (General Relativity and Quantum Mechanics) are known to be in contradiction to each other. So it is believed that if only we could come up with a theory that combines the two together we’d then have a ‘theory of everything.’

But this isn’t really what Deutsch has in mind. Yes, it would be a ‘theory of all physics’ but not really a ‘theory of everything.’ A fully formed theory combining Quantum Mechanics and General Relativity would not, for example, answer questions about philosophy, morality, and beauty. So it can’t really be, from Deutsch’s perspective, a theory of everything.

Now, if you just followed that line of logic, you might be scoffing at the computer screen right now. For what I really just implied is that Deutsch believes that his four strands has the potential to explain beauty, morality, and philosophy. That is to say, he believes his four strands can start to answer the most difficult questions that humans really care about. Questions of meaning, purpose, and human destiny.

Let’s face it. So far, science has really not even touched any of these truly meaningful subjects except in Lovecraftian ways. i.e. Death is the end, there is no meaning of life, your life is truly pointless, we are here by accident, you will live a painful life that ends in premature annihilation, and every thing you do will in the end come to ruin thanks to the second law of thermodynamics. In fact, the more “good” you do, the more “evil” will the created future be — once all is taken into consideration — because every gain at order/good must be offset by even more chaos/evil. [1] So far, that’s what our scientific world view has taught us about the most important questions we human’s have about ourselves. Not exactly a pretty picture.

David Deutsch believes we just haven’t looked hard enough at the implications of our science to realize that there is nothing Lovecraftian about reality. He believes science will finally be ready for prime time when it comes to answering the great of human questions.

Whether or not he’s right, I’m not sure. I can’t help but feel that he’s heading in a good general direction. But at times, it all seems premature to me. If I ever get around to doing an extended review and critical analysis of Deutsch’s latest book, The Beginning of Infinity, I could give you a good feel for how Deutsch believes science (i.e. the four stands above) is starting to answer some of the most profound of questions we as humans have. This is why I find Deutsch to be the only real scientific challenger to religion out there. Consider my previous quote about this:

In a strange sort of way, this makes Deutsch far more challenging to Theists than Dawkins brand of atheism. Let’s face it, Dawkins — at his best — does nothing more that mock religious people. He has yet to come up with a coherent argument for why religious people should care about the materialistic worldview he is advancing. In fact, he seems to have not even come to grips with the fact that this is the key argument his particular worldview owes us. As far as I can tell, Dawkins best answer to this question so far has been an appeal to Truth as its own end – which is, of course, really a hidden appeal to faith in God. This just makes Theism all the more attractive.

Deutsch, by comparison, has no need to mock religion; for his approach (if successful at some distant future date) would effectively supplant religion by engulfing it.

Therefore Deutsch never feels a need to mock religion because his theories very existence presents the only real challenge to religion ever conceived. Whether or not you see this as an ‘attack’ on religion, or ‘proof that religion was basically right all along’ seems to be somewhat subjective. I choose to read him more like the latter and I find him full of incredible gems.

Are the Four Strands Even Science?

Another fair question is, are Deutsch’s four stands even science? Certainly there is no question that we consider Quantum Mechanics and Evolution (i.e. natural selection) to be science. But what about Popper’s Theory of Knowledge? Even Popper didn’t refer to it as science. And the Theory of Computation? That’s math, not science, right? (Okay, I confess, I originally wrote this post prior to the one that’s already published on The Turing Principle. If you’ve already read that post, you already know that Theory of Computation is in fact a science.)

I think this is another area where Deutsch is trying to get us to change our thinking. We’re so used to certain categories being separate, like say math, science, and philosophy, that we can’t seem to ‘think outside the box’ enough to realize that an explanation is an explanation. If we have a theory that explains something and that something is far-reaching, profound, and important, it doesn’t really matter if we slap the label of “science” on it or not.

Further, I think Deutsch would argue that without a doubt Popper’s Theory of Knowledge and the Theory of Computation are physical theories. For example, biological evolution is actually just a special case of how knowledge grows and improves via natural selection. In reality, biological natural selection is really just one part of a larger concept of natural selection of knowledge that extends right into Popper’s theory of knowledge. (i.e. memes and genes)

And for the Theory of Computation: what could be more physical than the fact that we actually can build real computers and compute with them? Computation is a fundamental part of the nature of physical reality. Computation works because we live in a physical reality where everything that happens follows the laws of computation. And, Deutsch would add, because all of reality follows the laws of computation, we know that all of reality is comprehensible to us. (See also my discussion about the deep tie between comprehension and computation.)

The Four Strands

I’ve actually done various posts on each of the four strands mixed into various other topics of interest. For those interested in Deutsch’s four strands, see the following links.

Quantum Mechanics

Biological Natural Selection

Popper’s Theory of Knowledge

The Theory of Computation

Regardless of whether or not Deutsch is correct that these four ‘sciences’ can together begin to answer the deepest of human questions, there is no doubt that these four strands are all deep theories that have profound philosophical implications. I, for one, am not convinced that Deutsch has enough observational evidence to support his claims – yet. But I’m hopeful that one day we will find that it’s possible to explain the most important of human questions via the power of scientific explanation.

Notes

[1]  In fact, the more “good” you do, the more “evil” will the created future be — once all is taken into consideration — because every gain at order/good must be offset by even more chaos/evil. For example, if you build a far flung starfaring golden civilization through the universe, that just means that the vast majority of people will be alive when the Second Law “flips” and the entire civilation — the vast majority of people to ever live — must watch in horror as all hope of a brighter future ends in horrific ways. Thus your attempts to create a better future actually created a worse future where far more people are hurt than would have been had you just not bothered. I wrote a post about how this would feel to us now if we knew this was the future for our great grandchildren. Just throw on a more greats and you’ve got the current scientific worldview of humankind’s destiny!

7 thoughts on “David Deutsch’s Four Strands

  1. *Further, I think Deutsch would argue that without a doubt Popper’s Theory of Knowledge and the Theory of Computation are physical theories. For example, biological evolution is actually just a special case of how knowledge grows and improves via natural selection. In reality, biological natural selection is really just one part of a larger concept of natural selection of knowledge that extends right into Popper’s theory of knowledge. (i.e. memes and genes)*

    This makes no sense. It sounds like you are saying that Popper’s Theory and Computation Theory are physical because natural selection, which appears to be physical, really isn’t.

  2. Adam says: “This makes no sense. It sounds like you are saying that Popper’s Theory and Computation Theory are physical because natural selection, which appears to be physical, really isn’t.”

    I’m saying that knowledge comes from natural selection — two kinds being biological natural selection and scientific progress through selection of higher verisimilitude theories over lower verisimiltude theories. Both are types of “natural selection.” And natural selection (both types) are physical processes that generate knowledge.

    I seem to have lost you because I’m assuming it’s obvious that biological natural selection is a physical process. If you disagree with that assumption, then I guess I can see why using it as an example confused you.

    But isn’t it obvious that biological natural selection is simultaneously a) a physical process, b) the source of knowledge found in our genes? If that is the case, then why is it so hard to also accept that our selection of better scientific theories over lower verisimilutide theories is also therefore a physical process? (One that plays out inside our brains, and through criticism of one brain against another fighting over conversion of the most brains.) From this Popperian point of view, biological natural selection and ‘scientific natural selection’ are both special cases of a single physical process that we might just generically call “natural selection” or maybe even just “selection.”

    The point of both theories [selection and computation] as they are conceived — whether you agree with them or not — are that knowledge is solely generated through a physical process and also computation is always performed on physical mediums that use the laws of physics to perform the computations. (And the reason computers work is precisely because physical reality in some sense ‘performs something equivalent to a compuptation.’ An electronic computer just takes advantage of this fact to perform it’s own chosen computations instead.) So both are in fact profoundly physical theories.

    So something (i.e. knowledge) that intially appears otherworldly and non-physical ends up having a deep tie to physical reality after all.

    Or that is what I meant to explain. I do not necessarily expect you to agree (I’m just explaining the theory as Deutsch conceives it) and if you weren’t assuming biological natural selection is both a physical process and a source of ‘knowledge’ (or maybe I should say ‘data’) found in genes — as I was assuming was obviously — then I can see why my example would fall flat on you.

Leave a Reply

Your email address will not be published. Required fields are marked *

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>