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.
It sounds like I should clarify that I don't actually endorse the argument. I'm just trying to make the argument explicit so that we can stop all the hand-waving.
Objection 1:..What is the discussion of 'subjective experience' needed for? What is the problem with discarding the entire concept? (I'm aware there are some problems, but I'm interested in your take on it because I think most of them can be explained away.)
I successfully referred to something with the phrase. I know I did because your response wasn't "Huh? What does that word mean?" I'm more than open to the suggestion that subjective experience is a illusion or an error-- but it is the constitutive feature of our existence. Curious people aren't going to just stop talking about it without a very good reason. The burden is on those who don't think it should not be discussed, to explain why.
Objection 2, to your item 3: the mapping of a 'mental state' to the configuration of some physical system is purely a matter of interpretation. The problem here is that you ascribe to physical configurations, some properties that are normally reserved for causal sequences of physical states, i.e. outright simulations.
Agreed. This is a good line of attack. Egan's response in the FAQ is:
some people have suggested that a sequence of states could only experience consciousness if there was a genuine causal relationship between them. The whole point of the Dust Theory, though, is that there is nothing more to causality than the correlations between states.
I don't really know where he is coming from. If that is "the point" of Dust theory I don't see how he as made that argument. It looks to me like brains and genuine simulations are indeed causal but arbitrary patterns are not. That said, it isn't obvious to me why causation would be necessary for consciousness. Say we simulate your brain and record the simulation. We then divide the recording into 100,000 pieces, scramble them, and put them back together. Then we play the recording. The Dust theory says that the recording will be conscious just in no way proceeding along the arrow of time the way we are. Is the recording still a causal system?
Regarding the rest of the objection: First, Obviously the argument is counter-intuitive. Second, as I understand the argument, your mental intention has nothing to do with it. What matters is that there be multiple structural patterns that relate to one another as sequential mental states do. Thats it. If happiness are suffering are symmetrical it might ever be the case that every time you experience suffering there is another you that is happy and vice versa. You definitely can't just say of some set of patterns "These are Jack suffering" and make them that way. With patterns that we are sure are sufficiently complex that they include a series of mental states those patterns will also include infinitely many other mental states (I think infinite, anyway). No is going to be able to alter the structure such that it only represents mental states where I am suffering. With less complex patterns we will be less sure any minds are included. To be sure there is a mind and to specify a particular experience of me suffering I suspect you would have to actually simulate me suffering. The sentence "Jack is suffering" isn't complex enough to support mental states. Neither would the simulation written out in a programming language. Does that make any sense?
Objection 3, to your C2: your logic is invalid. Compare: "somewhere in the universe are mental states which correspond to someone mentally identical to yourself experiencing eternal torture. Therefore you will experience eternal torture, starting a moment from now."
My logic isn't invalid. I addition to their being mental states with relation K to your final mental state there are some such states where you are happy and others in which you experience eternal torture. That is also a consequence of the argument.
The problem is that you have not defined what 'you' means in this context.
My position on this is basically that our concept of personhood confuses types and tokens because it was developed in a world where every person had only one token. The fact that our concept of personal identity isn't equipped to deal with the Dust argument isn't really a point against it.
This would be the Subjective Dust Theory
Clarifying: Is the "Subjective Dust Theory" different from some other Dust theory as you understand it? I'm trying to describe Egan's Dust theory.
Also, I agree. Based on our experiences we can conclude that we are not dust-minds.
That said, it isn't obvious to me why causation would be necessary for consciousness.
How about "consciousness is computation, and causation is necesary for computation".
Say we simulate your brain and record the simulation. We then divide the recording into 100,000 pieces, scramble them, and put them back together. Then we play the recording. The Dust theory says that the recording will be conscious just in no way proceeding along the arrow of time the way we are. Is the recording still a causal system?
Yes. But who ever said that any old ca...
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.