Dear Alan,

 

One more thing RE: non-physical mental properties. I attach my view on the issue.  I acknowledge that the issue is not resolved, but I provide a view, "subjective realism" that shows how I try to navigate the explanatory gap, etc.

 

I do think THE BIG PROBLEM with advocating non-physical mental properties has to do with Epiphenomenalist Implications.  There is NO explanation for how non-physical properties could be causally efficacious (one can make this point without entering into the debate about causal closure). And if they are not causally efficacious then it's the end of the world as we know it. Self-transformation is impossible, etc.  Alan has said that the burden of proof is on the physicalist.  But the physicalist can at least explain how mental causation is possible.  There is no credible non-physicalist account of causal efficacy on offer.

 

A separate point about recent attempts to explain consciousness via exotic physics.  Stuart Hameroff and his colleagues at Arizona along with Roger Penrose in the UK suggest that "quantum gravitational effects" in the microtubules of neurons might be the mechanism.  Two points: First, we don't know if there is quantum gravity. If there is it is approx. 40 orders of magnitude weaker than ordinary gravity!  I still prefer global oscillations in the 40Hz gamma range as part of how it happens (see W. Singer & Marburg; Lutz et al.).  Second, quantum physical explanations of consciousness are just not a very plausible route to go—quantum effects cancel out at our body temperature.  Find a part of brains at absolute zero and I'll reconsider.