Sculptor1 wrote: ↑December 13th, 2021, 4:24 pm
No one has fully explained why a physical explanation is not valid...
Probably because no one here has claimed that there a physical explanation does not exist. Our only claim is that none of the particular physical claims are conclusive.
I see competing hypotheses as being like a race, where you will have leading ideas and others trailing behind. The leading idea at this stage is global workspace. While not all guesses are equal, it is still a guess, a hypothesis. The weakness I see in GW is that, being related to key medical fields, it's been far more lavishly funded than the vast majority of disciplines (many of which survive on grants that amount to "starvation rations"). Yet no answer to how the phenomenon of consciousness exists and how prevalent it is. Lots of data on how consciousness can be manipulated and analysed via the brain, though.
To be fair, neuroscience research is funded to be a pragmatic medical discipline. So it doesn't much bother with the hard problem. Rather, it simply assumes that consciousness exists and it can be manipulated via the brain, and the field moves forward based on those assumptions. This is reminiscent of how physicists assume that the big bang happened and start calculating from that base. Until relatively recently, they didn't much bother with what preceded the big bang. As with consciousness, physicists routinely claimed that even asking what was before the big bang was invalid, saying there was 'no before". Now the hard question is being questioned.
As I have said before, if I'm betting my house on it, I'd go with consciousness being generated by the interaction between CNS and the metabolic organs, with the brain shaping these raw sensations into a type of consciousness that facilitates survival, mating and viable offspring. As per that guess, I think a "brain in a vat" would just be a processor without sensation, without qualia.