> The idealists claim is a genetic fallacy: that since the product of the objective, the subjective, has a property P so must its origin. ie., the objective is Ideal because the subjective is Ideal.

No, the idealists claim there is no objective, and that we only know the world subjectively via our senses. This is an unfalsifiable claim, because any attack on it can be written off by arguing that any experience of investigating the claim is coloured by the subjectivity of the senses.

The only viable "attack" on idealism is to accept that while it is possible, unless there is direct evidence - e.g. you observe things that would not be possible in a physical world - it is pointless to consider the idea because it is unfalsifiable.

This is much the same with simulation arguments - they're nothing but "digital versions" of idealism. What simulation arguments (any varianet, not just Bostrom's) gives us is a constraint that gives us something that could become worth investigating if we specific things. E.g. if we were to observe telltale signs of possible compression in physical reality

> This claim is false, and is basically just a restatement of the same genetic fallacy. Language describes the objective (eg., "I am in a room"), not the subjective. It is just asserted that since the objective = subjective, then this language is "ontologically neutral" -- ie., it "avoids metaphysics".

That languages seeks to make claims about the objective does not mean the claims are true.

A simple description of idealism in "physical terms" is to imagine three rooms connected in a series with a data feed A <-> B <-> C, where rooms A and C are minds, and B is physical reality, and where none of the rooms have any other ability to obtain information about what is outside the room. Idealism states that only A and C exists, and that B is an illusion produced by A and C or by as a product of their connection. Any statement you make "about the objective" is meaningless because you have no way of talking about an objective outside your room that is not based on the information obtained from the data feed.

If you are A you don't know if B exists or if C exists for that matter, because you have no source of information about them that you can prove is objective. Your data feed might be purely fake, it may come from you yourself, or it may be manipulated in all kinds of ways, or it may come from outside the rooms entirely. But there's a further problem: You only observe A as well through a stream of data that you believe to be internal to A, but you have no way of verifying that either. You can't prove A exists, have existed, or will exist. You can at most assert that in the given moment, something has an experience that gives an experience of time and space and consciousness. There is no way for you to independently verify the existence of time even.

You may not have existed before you read this and you may cease to exist after having read this, and I might not exist at all.

Now, if I were to assert that this is definitely true, that would be unjustified and idiotic. I can't even say if it is possible. I can say, however, that we have no means of falsifying it, and so any assertion - like the one that started this discussion - that anything we observe falsifies simulation, is unjustified.

> The idealists need there to be a "neutral language of the subjective" to avoid the challenge of scepticism -- ie., that all our claims are false.

The only viable attack on idealism is that it is unfalisifiable, and so not worth spending time on the unconstrained form of idealism.

That does not mean all forms of idealism are necessarily unfalsifiable; one can imagine constrained forms that set out further propositions that would make it detectable; e.g. in the subset of idealist philosophies of simulation theories, a simulation theory that posits specific constraints on computability or posits "escapes", those specific subsets could possibly be falsified if they're concrete enough.

> So what? Well then there is no reply to scepticism. If you believe all our claims are false then there is no "neutral language" to translate them into for the sake of "practical reasoning". To be sincere in this belief, you cannot reason.

This does not hold at all. All you need to do to reason is to argue that even if you believe idealism (or a simulation) to be true, you accept that this idealist world / simulation at a minimum appears to adhere to certain rules, and to constrain your reasoning to add an implicit "assuming the observed apparent rules hold and continue to hold then within this subjective space / simulation ....". We don't need this to be true. If it's not true, then the reasoning doesn't hold, but that's fine.

Put another way: We can reason about fantasy worlds within the rules that hold in those fantasy worlds all we want. We do it all the time. If the rules for those fantasy worlds are sufficiently well defined, we can do complicated reasoning about them. E.g. we can reason about a game of chess to a great level of fidelity. Whether that world has a physical existence or is simulation has no bearing on our ability to reason about it. We just can't claim that the reasoning is about an objective reality.

So we can continue to act as if we are in objective reality, and reason as if we are, whether or not we are or whether or not we believe we're in a simulation or not, because we can reason with implicit caveats that what we believe we observe continues to hold.

Even assuming we are in an objective reality we do exactly that anyway. We keep extrapolating and assuming that things will continue mostly the way it always has, because that is the best we can do. We don't know if there's some unknown natural law that causes the speed of light to halve tomorrow. It makes no sense to assume there is, and so we reason on the basis there isn't until there is evidence to the contrary.

> To connect this with the simulation point: to believe we are actually in a total simulation you are either (1)incapable of reasoning; or (2) asserting a contrary metaphysics without any justification whatsoever.

Certainly, this I agree with.

But what I addressed initially was your claim that non-determinism falsifies simulation, and it does not.

That does not translate into believing we are, only in believing that it may be possible.

The two are different - we have no evidence that we are. We do however have a number of theories that set out in various level of detail and seriousness ways in which a simulated reality might be possible or even likely, and some of those theories are at least in theory falsifiable. E.g. Bostroms Simulation Argument is falsifiable (but falsifying it falsifies just his set of propositions, not simulation in general, and it's reasonable to argue if one wishes that the conditions required to falsify his argument makes it unfalsifiable in any meaningful way - e.g. the ways to falsify it either for humanity to go extinct prior to creating simulations, or for us to prove that simulations of sufficient fidelity are impossible within our perceived reality; while the former is possible and the latter might be, they're not exactly practical)

The point being that even though we absolutely agree that there is no justification for claiming we can currently claim to know we are in a simulation, that does not mean it's a subject we can't investigate or reason about. It just means for us to be able to get somewhere meaningful we need to investigate sets of propositions about these concepts that are actually falsifiable, and outside of that narrow scope people should just reason on the same basis as we always have: On the assumption that the laws of nature will continue to hold.