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 successfully referred to something with the phrase. I know I did because your response wasn't "Huh? What does that word mean?"
That's also true of things like the Christian Trinity and immortal souls and consciousness and acausal free will. All these words refer to things that are untestable and unobservable, or are described in internally inconsistent ways (logical impossibilities); those of them that could potentially exist, don't exist as a matter of fact; and some of them are just meaningless strings of words.
The real referent in these cases is just the sum of everything people tend to say or feel about these supposed concepts.
I'm more that open to the suggestion that subject 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 be discussed, to explain why.
I certainly agree that experience exists - I know I have mine, everyone else says the same about themselves. But if we insist on treating it as purely subjective experience, then we'll never be able to say anything about it, pretty much by definition. In my experience all those curious people are talking about badly-understood notions deriving from beliefs of body-mind duality. No matter how much we learn about objective experience, even if we can manipulate somebody's experience in any way we like, people can still say they don't understand subjective experience.
It's easy to think that because we experience things (as a verb), there must be some subjective experience to talk about. But my position is that if we can't formulate a question about subjective experience - a question that will make us behave differently depending on the answer - then there's nothing to talk about. We can go searching for answers, but there's no such thing as searching for a question. Are we supposed to one day think of a question and be enlightened? But that question exists in its own right, and can be answered if we ever think it's important in the way that any question may be important. Meanwhile, if we have some kind of psychological drive to look for The Question, we might as well ignore that drive or look for a way to suppress it - just as we do with other unprofitable, un-fullfillable drives.
That's my position, anyway...
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.
In a timeless view, causality is just (regular) correlation in spacetime, as Egan says. I'm not sure what you are saying, though.
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?
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?
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.
Regarding the rest of the objection...
You don't address my central claim: that the mapping of 'mental states' to the physical representation used is arbitrary. If I can build a physics-simulator as a state machine encoding complete rules of physical evolution, then by the principles of Turing equivalence, I can build some other machine that uses any mapping I like from physical states to numbers (each number representing the simulator's state). Does it then generate subjective experience in "someone", and is it morally significant, to feed that machine some given number - even the number 1 for instance - because I built the machine to represent torture with that number?
You say of this,
You definitely can't just say of some set of patterns "These are Jack suffering" and make them that way.
But why not? I can choose the mapping as I like.
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.
Do you mean that it's difficult to get the information needed to build a machine that correctly maps the number 1 to your suffering?
I can do this, for instance, by observing you in a normal state - recording what your brain looks like - then applying my understanding of nervous systems pain signals to build a description of your brain suffering pain. It's not difficult in principle.
Or do you mean I might simulate your brain suffering without thereby creating a suffering mind? Why? And why would this be anything more than a matter of arbitrary definition?
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.
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" :-)
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.
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"?
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.
I coined the term "subjective Dust theory" to mean Dust theory as applied to me and my subjective experience (producing conclusions such as "I'm necessarily immortal"), as opposed to Dust theory applied to other minds.
Also, I agree. Based on our experiences we can conclude that we are not dust-minds.
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, which include:
Arguably, each of these theories is much more specific than the idea that you're a dust-mind. That is, Dust theory predicts that there will be (infinitely many?) versions of you, some of which are being simulated, others have faulty memory, yet others are having their minds messed with by aliens, and still others are genuine Boltzmann brains. So in the absence of evidence to choose one of these, we should stick with the most general applicable theory - Dust theory.
On the other hand, the classes of all simulations and of all Boltzmann-brains also include all dust-minds... (You can simulate a universe containing a dust mind, and a a dust mind's states can come about by Boltzmann chance.) So it's not conclusive.
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 ...
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.