Having never read Permutation City, I would find a summary of Dust theory essential to understanding this post, which goal presently eludes me.
SPOILER ALERT
The basic idea is this: If the physical world (including consciousness) is just a succession of states, then why would it matter that these states occur sequentially in time and at the same place? The Dust Theory is the idea that it doesn't matter -- that the same collection of bits that describes the universe we experience also describes some ridiculously large number of other universes.
There's more on Egan's site, although it might be hard to follow if you haven't read the book:
http://gregegan.customer.netspace.net.au/PERMUTATION/FAQ/FAQ.html (edit: linked in TFA, I see now.)
The book is excellent, by the way.
I'm haunted by Solipsism. We should start a support group.
No, seriously. If LW had a forum, this would be one of its sections.
There's something terribly ironic that I can't put my finger on, about a support group for people haunted by solipsism.
I once received a letter from an eminent logician, Mrs. Christine Ladd Franklin, saying that she was a solipsist, and was surprised that there were no others. Coming from a logician, this surprise surprised me.
Note that the problem of "Why do I perceive order instead of disorder?" isn't unique to this metaphysical dust theory business. Given that I expect the universe to eventually settle into thermal equilibrium, why do I believe that I'm not a Boltzmann brain temporarily and randomly formed out of that great chaos?
I'm not sure if it counts as "purely logical", but another problem with Dust theory is that it assumes that conscious states supervene on brain states instantaneously. There is no evidence for that. We seem to be conscious moment-by-moment, but the "moments" in question are rather coarse-grained, corresponding to the specious present of 0.025-0.25 second or so. It's quite compatible with the phenomenology that it requires thousands or millions of neural events or processing steps to achieve a subjective instant of consciousness. Which ...
Isn't this, along with so many other problems, a candidate for our sometime friend the anthropic principle? That is: only in a conscious configuration field which has memories of perceptions of an orderly universe is the dust theory controversial or doubted?
The Anthropic Principle conditions on the fact of our existence. But you seem to be conditioning on the fact that we don't accept dust theory. That makes no sense - you could explain absolutely any observation that way!
Maybe that's not what you meant, but I don't see how the A. P. is relevant here.
Tegmark's level IV multiverse is the only explanation I've ever heard for why there is something rather than nothing. I intuitively lean toward it for that reason. Of course, I don't know how to put a measure on that space that explains my subjective experience, but that seems like a much smaller problem then the most fundamental problem of why anything exists in the first place.
Personally, I'd like to hear alternatives to Tegmark's theory more than I'd like to hear rebuttals.
Tegmark's level IV multiverse is the only explanation I've ever heard for why there is something rather than nothing.
You can tell when something has been explained because it no longer has the same air of mystery that it did at the start. The Level IV hypothesis might very well be true, but it's not an explanation.
I've tried to formalize the Dust argument, though I don't know if it actually succeeds at being deductively valid. FYI, I don't believe the conclusions are true, necessarily, I'm just working through the argument. There is for sure plenty wrong with it.
Subjective experience is found anytime there are mental states where relation K obtains. (K is something like the psychological or memorial continuity relation that gets used in personal identity theory, but I'm not sure I can define it except by appealing to the brain: where m1 and m2 are mental states an
Isn't this, along with so many other problems, a candidate for our sometime friend the anthropic principle? That is: only in a conscious configuration field which has memories of perceptions of an orderly universe is the dust theory controversial or doubted? In the vastly more numerous conscious configuration fields with memories of perceptions of a chaotic and disorderly universe lacking a rational way to support the observer the dust theory could be accepted a priori or at least be a favored theory.
Ahem, this is circular logic. "The vast majority...
I don't think that really works. The problem is "I perceive far more order than would be needed for me to (briefly) exist from this moment"
ie, I observe that my surroundings seem to match my recent memories, etc etc..
QM arguably IS dust theory, just that one adds on a few rules for how the arrangements relate to each other, and then assign to each a complex number and have various rules for those relate to each other, how that changes, etc...
Isn't this, along with so many other problems, a candidate for our sometime friend the anthropic principle? That is: only in a conscious configuration field which has memories of perceptions of an orderly universe is the dust theory controversial or doubted?
How is this not a fully general argument against ever trying to explain anything?
I say we are in a simulation. I'm not sure what the precise definition of 'simulation' is, but it should be a broad enough concept to include the universe, whatever the universe is. The universe may not be a directed simulation, it may not be a simulation that has a beginning and an end, and even the continuity of it may be a complete illusion. But I cannot imagine how anything at a sufficient level of detail could be interpreted as not a simulation; that is, as something that isn't computed or doesn't run with some mix of mechanical and random rules.
In th...
If we take the possibility of dust scenarios as a given, then perhaps our observation of a coherent universe can be explained by some idea of the "measure" of different possible universes/simulations. That is, if all possible universes are some Turing machine, then perhaps the simplest Turing machines have in some sense higher probability/measure, and the simplest machines that contain observers are still on the relatively simple and lawful side.
edit: or perhaps it's that lawful simulations have a higher density of observers.
I tend to ignore the dust theory simply because entities which are implemented as scattered states throughout spacetime can't be interacted with. Even just inverting the order of the states is enough to make interaction impossible - two observers with opposite time directions don't see each other as having any memories of past interactions.
I certainly agree that experience exists - I know I have mine, everyone else says the same about themselves.
I was actually going to remark in the original comment and my previous one that I thought "subjective experience" was redundant. I truly have no idea what non-subjective experience could possibly be. "Subjective experience" isn't something that is contrasted from other kinds of experience. It isn't my coinage, as far as I know it is a legacy term but helpful in that it combines 'the subject' with 'experiencing'. If that makes you uncomfortable by all means replace every instance of 'subjective experience' with 'experience'. I think you can safely do the same with 'consciousness' or 'qualia' but I imagine you don't like those terms either.
In a timeless view, causality is just (regular) correlation in spacetime, as Egan says. I'm not sure what you are saying, though.
The mercury in my barometer always drops before a thunderstorm. My barometer has never caused a thunderstorm. Thus, I prefer a counterfactual theory of causation. If you think Egan is right then how is a dust mind different from "causal sequences of physical states, i.e. outright simulations">
I also asked if simulating one or just a few mental states, instead of the whole evolution of your mental state over time, created some kind of subjective experience? In that case, would it be morally wrong to keep a highly detailed scan of your brain taken when you were feeling sad?
I think the argument requires that there be more than one mental state, though one can skip mental states. But lets say you had three detailed scans from a period of sadness. Whether or not it is immoral would depend on whether or not we distinguish identical and simultaneous copies of persons in our utility function. But if you do care about such copies then yeah, it wouldn't be the nicest thing to do.
That's entirely a matter of definition - the definitions of "consciousness" and of "causality". You can define them any way you like, but what do you actually learn about reality from this? This part of Dust theory strikes me as leading up to the conclusion that "there are many conscious states!" without defining what consciousness means, and so not actually saying anything.
The concepts of 'consciousness' and 'causality' describe features of the way we relate to the external world. I would like a coherent picture of this relation. Cause and effect, in particular is a huge part of how we experience the world. How this concept relates to what is actually going on is a really interesting question. If a system needs to be the kind of system we recognize as a causal system in order to produce a subject that experiences the world that would be something interesting to know. Getting a really precise definition about what consciousness is would be really cool. I know there are a lot of people working on it but that isn't me. I don't at all think that one needs a really precise analytic definition of a concept in order to employ it or say meaningful things about it.
You don't address my central claim: that the mapping of 'mental states' to the physical representation used is arbitrary.
I just meant that something can't just be labelled "Jack suffering". There has to actually be a set of patterns that represent it. The set of real numbers, for example, is sufficiently complex that if it is represented in the universe (say by an infinite number of particles) then according to the dust theory that representation includes a pattern that is Jack suffering. But it also includes a pattern that is Jack really happy. And it includes lots of other patterns. You saying "This is Jack suffering" doesn't change that. The information is there even if you aren't reading it that way./*
Now what you might be able to do is build a really well determined structure such that only the states of me suffering are represented. I don't really know. If you can though, I'm inclined to say that what you end up being will just be a run-of-the-mill simulation of me suffering, something we'd all recognize as bad. The only way to determine that you've created a pattern that is exactly as you want it to be is to run a regular old person-simulation-- I think.
But I might not be responding to your concern, I'm still pretty confused about what that is.
That means there are (infinitely) many entities you are, with many different experiences. And all of them are you. That sounds like an... unorthodox use of the word "you" :-)
Yeah, I put it more delicately in the undergraduate thesis proposal I just turned in. But yeah it is unorthodox. :-) But the alternative is to give up a coherent account of personal identity altogether, as far as I'm concerned.
Why call this hypothetical collection of persons "you" (or indeed "me") if it contains many different persons and doesn't match our existing use of the word "you"?
Long answer, I'll come back to it.
Obligatory question: given what observations would you assign high probability to the possibility that you are a dust-mind? Why would you privilege it over competing theories.
I'm not sure we can distinguish skeptical hypotheses by empirical evidence-- I'm pretty sure we can't by definition. But we might find empirical evidence that alters our estimations of the premises of those positions (our understanding of entropy could change, our understanding of brain simulations will surely change once we actually succeed, etc. Also we might be able to distinguish them according to a priori criteria like parsimony.
It has been well over a year since I first read Permutation City and relating writings on the internet on Greg Egan's dust theory. It still haunts me. The theory has been discussed tangentially in this community, but I haven't found an article that directly addresses the rationality of Egan's own dismissal of the theory.
In the FAQ, Egan says things like:
and:
Isn't this, along with so many other problems, a candidate for our sometime friend the anthropic principle? That is: only in a conscious configuration field which has memories of perceptions of an orderly universe is the dust theory controversial or doubted? In the vastly more numerous conscious configuration fields with memories of perceptions of a chaotic and disorderly universe lacking a rational way to support the observer the dust theory could be accepted a priori or at least be a favored theory.
It is fine to dismiss dust theory because it simply isn't very helpful and because it has no predictions, testable or otherwise. I suppose it is also fine never to question the nature of consciousness as the answers don't seem to lead anywhere helpful either; though the question of it will continue to vex some instances of these configuration states.