Great chat indeed! Sorry I couldn’t watch it live, but I did have some notes/questions for all three of you. Probably Tom won’t see this, but anyway…

——

An analogy for Keith as to why there could be an epistemic wall even if we knew all the objective facts: subjective facts could plausibly be cast as something like indexical facts. Even if you know all the objective facts, you don't necessarily know where you are, because there could be more than one centred world consistent with your observations.

There could similarly be different physical states of affairs which lead to different subjective experiences, but not in a way you are equipped to distinguish until you have that experience yourself and learn which of the objective states of affairs you were previously acquainted with it is. Mary seeing red for the first time, if the Ability Hypothesis is right.

——-

For Philip: I don't think that panpsychism is simpler than panprotopsychism or neutral monism, as I conceive of them. It's the other way around.

On my interpretation of neutral monism, the idea is that there is some essential intrinsic nature to physical stuff, and that this nature happens to be such that consciousness can exist. Personally, I do not take it to be committed to the view that the intrinsic nature is not consciousness itself (though I think that is implausible, because I'm inclined to reserve the word "consciousness" for beings at least a little like us). It's just positing that the intrinsic nature is somehow responsible. That's relatively parsimonious because it's not going out on a limb any more than necessary.

The insistence that the intrinsic nature just is consciousness is strictly less parsimonious because it's making an unwarranted further assumption. On this view, panpsychism is like a more specific variety of neutral monism. Panprotopsychism seems to be in the same boat. It insists that the basic stuff is not consicousness. Either way, both views are adding an additional unwarranted assumption. I don’t think that counting kinds of stuff is really the best way to look at parsimony. Of the two, I’m going to give panprotopsychism the edge because of phenomenal conservatism. It seems crazy to suggest that electrons are conscious: QED (Quod Erat Demonstrandum, or Quantum Electrodynamics, take your pick).

Also, you suggest there could be strong emergence in biological systems. But why not simulate the strongly emergent behaviour? Then we're back to square one. Maybe these simulations are conscious and maybe they're not.

——

For Tom: like Keith, I'm an illusionist. But I agree with you that we're not going to solve the Hard Problem by doing more science, so I don’t agree that you should see yourself as on Philip’s side against Keith on this.

I think the Hard Problem is a conceptual confusion, and it has already been "solved" by Daniel Dennett. It's just that, because it is a conceptual confusion, it's not a solution that we can test empirically, and so skepticism of the solution is difficult to eliminate. So it's going to persist indefinitely because of the nature of the problem, even though it has already been solved. If I'm right, it's a bit like the Monty Hall problem, to borrow an analogy from probability theory. It's a problem that has been solved, but even experts found or find the resolution difficult to accept. Paul Erdos (famous mathematician) refused to accept the proof until he saw the results of numerical simulations. Unfortunately, simulations won't help us with the Hard Problem.