Earlier quoted context omitted.
The point is that that in one hypothesis you have two conditions and you must determine the boundary between them. In the other you have only one. You have no evidence to prove that there are two conditions that need to be distinguished; some boundary between them needs to be defined. The emergent phenomenon hypothesis requires this. Panpsychism doesn't.
Panpsychism only superficially looks as if it does not have boundaries because it literally says next to nothing about consciousness. Once one gets into the combination problem, or even the difference between how consciousness presents itself a living brain and the same brain dead, we can confidently expect there will be boundaries. This is entirely moot, however, until you have a hypothesis that offers something in…
> Panpsychism only superficially looks as if it does not have boundaries because it literally says next to nothing about consciousness.
But what does the theory of emergent consciousness say? It is a theory about how consciousness comes to be presupposing there is an opposite state. But we have no evidence of the opposite state. We have evidence of consciousness. We posit the existence of unconsciousness (not the state of anesthesia or immobility, but the state of existing absent qualia).
The whole problem is that we can't get grips on what it is we are explaining. We can't even start. How do other theories improve on this? They posit a difference to explain without having observed this difference.
> I doubt Occam's razor has ever been relevant in choosing between worked-out hypotheses about natural phenomena, as it would require them to be indistinguishable except in the number of premises. If you can think of an exception, I would be happy to discuss it.
Occam's Razor says this: only seek an explanation for things for which have evidence. Does this rock exist, or does this rock and a ghost exist? I have evidence for the rock. I have no evidence for the ghost. The ghost is unnecessary. I will assume it does not exist. The simpler model is one which contains only the rock. In the absence of evidence otherwise we prefer the simpler model.
Here is a point completely separate from anything I said before, but which I wish I had said before.
In olden times -- the 19th century, say -- we didn't speak of consciousness; we spoke of souls. Some things had souls. Other things lacked souls. You could do what you wished with things that lacked souls. They were zombies. They could not suffer, however much they simulated suffering. This was like how a poster of someone being tortured simulating suffering, or a splat of mud which by some mad, impossible chance looked like a depiction of someone being tortured. There was no actual suffering. No soul: no suffering.
Then we became scientists. This talk of souls was religious dogma! What evidence is there for souls? Science requires evidence! But we recreated this scenario by positing the opposite of a soul: unconsciousness. This is scientific! Instead of asking why some things have souls and others don't we ask why some things have consciousness and others don't. We recreate exactly the same ethical results, but now we sound scientific!
We have no evidence for souls. By the same logic, we have no evidence for the absence of souls. We do have evidence for consciousness. We have no evidence for unconsciousness.