I think the fact that an objective external reality is indistinguishable from a simulated virtual reality is no mere inference that cannot be understated. Often, this inference is used to prop up skepticism of an external reality, but in fact, this inference gives way to an esoteric argument that needs to be brought to light:
Premise 1. If reality is a simulation, then it has a simulator.
Premise 2. If reality is a simulation, then it has a logical foundation to explain its existence.
Premise 3. If reality is a simulation, then it is grounded by an absolute reality which is logical.
Premise 4. If our objective external reality is indistinguishable from a simulation, then by the Law of Identity, our objective external reality must also have a simulator, a logical foundation for its existence, and is also grounded by an absolute reality which is logical.
Conclusion. That absolute reality is God.
I wrote an essay to flesh out this argument, if you're interested. I think it's a fairly strong argument for the existence of God vis-a-vis philosophy (not theism), because you can't knock down the first three premises without making other metaphysical claims.
Has anyone pointed out yet that your conclusion does not follow from the premises? You need a premise that affirms the antecedent of P1-3, and that would get you a simulator, logical foundation, etc. Also, you need to specify what you mean by "indistinguishable" in P4 - is it epistemological or ontological? If the former, then the law of identity isn't going to help you, because a simulation and non-simulation are not identical by definition. Not saying it can't be done, but you have a few steps to make explicit.
Oh for sure. I should have been a little more precise, because in the essay I don't use that argument wholly, rather it's initial premise of "the mere plausibility that physical reality is indistinguishable from a virtual one could not be the case if we did not think there wasn’t some fundamental design to reality itself (both simulations and physical objects obey rules)" that needs to be stated.
It's an implicit argument that comes from asking: "why do you think reality could be a simulation/illusion/hallucination?" Followed by: "how can you tell the difference between what is real and illusion if you don't know?" I think there are two responses that could undermine one's external world skepticism:
(1) I can't tell the difference.
(2) It's possible an illusion could be the case.
On accounting of (1), their doubts are defeated because if you can't tell the difference, whence the doubt? Why ask the question if you can't possibly know the answer to it? If you can't tell the difference between what is real and illusion, then it doesn't matter if you're actually sitting down on a chair or dreaming of sitting down on a chair. In both instances, you're sitting down on a chair. In this case, skepticism is defeated with pragmatism.
On accounting of (2), if you're asserting that possibility, you need an epistemic antecedent for illusions/simulations. This is where my argument comes in, because you can't have simulations without a simulator, or illusions without projectors, or hallucinations without minds. In each of those cases, you have a Contingency Problem to deal with. If you pick the hallucinations + minds option, then you have to circle back to response (1)... which leads to pragmatism.
