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.