>Then how do we explain the double slit experiment,

Question: why do panpsychists always want to flip from a philosophical consideration of consciousness that admits no existence of anything objective except their own mind to the conundrum of wave-partice duality which necessarily presupposes the existence of all of the objective apparatus that demonstrations of quantum physics requires, as soon as their philosophical hypothesis is shown to be incoherent? Answer: because their philosophical hypothesis is incoherent.

>as if what might have occurred--but we understand not to have occurred-

Because the reliance of your description on "as if" and the limits of our understanding reinforces rather than refutes my position, that's why. If you took your own position seriously, there would be no need to refer to the double slit experiment, it would simply be a mundane an unsurprising result that whatever we wish to be is what happens, even when it needs to reverse chronology and change what happened, in order to make what is match our desires. But your position cannot be taken seriously in that way, instead it is incoherent, because this phenomena can only be demonstrated by the double slit experiment, and panpsychism has no cogent explanation for why that is the only circumstance that conforms to this expectation of yours that objectivity is subjective.

Realists don't need to explain quantum weirdness, we need merely annotate it as weird, and not currently explained. But fantasists can't explain why everything else except carefully and rigorously defined demonstrations like the double slit experiment doesn't exhibit the same kind of weirdness. That alone is not an insurmountable task: if an idealist worldview could coherently describe how, when, and why quantum decoherence results reliably (very reliably) in the deterministic objective behavior of non-quantum systems, that would be interesting and informative. But that doesn't seem likely, since idealist philosophies such as panpsychism reject the notion any such description is necessary, and are incompatible with scientific results because science is realist rather than anti-realist.

>The implication being, observation causes change in the observed.

Your implication is simple-minded and mistaken. For the purposes of physical experiments (including quantum mechanics) "observation" is interaction with any other system, not limited in any way to conscious perception. The double slit demonstration carefully excludes all other interactions in order to make the effect obvious, but all it proves is that quantum weirdness (including the measurement problem, heisenberg's uncertainty principle, wave-particle duality, and other related but not necessarily identical artifacts) is an objective phenonemon, independent of any subjective "belief system" of the scientist performing the empirical experiment or philosopher proclaiming its implications, despite being surprising based on intuitions honed by classical objective phenomena.

Since the basic premise of panpsychism is that mind is more fundamental than matter, quantum physics doesn't actually support your premise any more than classical physics does. It just opens the door to epistemic and metaphysical confusion, which fantasists can then take advantage of to pretend their hypothesis is coherent.

>Except, on the quantum level we abandon many of our physical and metaphysical presumptions and assumptions about causation itself.

LOL. Nobody abandoned any assumptions, we are simply forced to do without certain familiar prevarication and posturing. Since the quantum world still conforms to an extreme degree with mathematical predictability (it simply does so probabalistically rather than deterministically) causation itself still favors the realist side rather than the fantasist side, despite the adjustment that must be made in understanding what causation is. I've developed a philosophy which does so adequately, without the need to resort to anti-realism.

>Again, we cannot have an experience of lacking consciousness. > Hallucinations are experiences, even if they are not shared. >But here we contemplate objectivity itself, not just any conjecture.

Your declarations lead to confused rhetoric and pointless insistences, so I reject your semantics and instead attempt to clarify discussions of very difficult topics by using better ideas about the proper usage of these words. "Experience" excludes false perceptions such as dreams and hallucinations. "Objectivity" does not exclude subjectivity. These aren't perfect allowances; the nature of epistemology and ontology ensure that no terminology can be perfect. But mine is more practical than yours, more consistent and productive. Yours simply revels in being mired in ignorance so that you can maintain a fantasist's outlook.

>We were encouraged to discard the theory as nonsense, just as you have.

I have read extensively on it. My dismissal is not based on a mere paragraph, but grows ever more certain with every paragraph I read about it. My philosophy actually explains the underlying problem (related to the connection, necessarily but generally inconsequentially ignored by scientific realism, between self-determination, consciousness, and the nature of teleologies, causation) that fantasists believe justifies panpsychism, but without all the fantasizing panpsychism requires. And the fact that even after all that anti-realist effort, panpsychism still doesn't provide a coherent explanation seems, to me, to bring the matter to a conclusion. No, I cannot disprove idealism, but that's okay, because I don't need to, I only need to recognize why it can't be disproven.

Thanks for your time. Hope it helps.