IMHO, though, Penrose's argument is a have-your-cake-and-eat-it kind of thing. His claimed scientific basis for non-algorithmic computation in the mind relies

IMHO, though, Penrose's argument is a have-your-cake-and-eat-it kind of thing. His claimed scientific basis for non-algorithmic computation in the mind relies on science which is tantalizingly out of reach (yet somehow has definable end-point when our understanding of QM reaches point X). But that's the same as claiming that he knows that the science of pixie-dust will be well understood one day, therefore pixie-dust is scientific, and pixie-dust itself makes the brain problem tractable. Personally, I don't think that there is a special mechanism (or pixie-dust) that separates my brain function from that of my cat. Of course, there are some qualitative differences which I clearly don't understand. But, blaming the fact that I don't understand the differences on the lack of some scientific breakthrough doesn't seem to clear the whole problem up : It's passing the buck. IMHO, when the 'trick' to consciousness is found, people will look back and see that what seemed like pixie-dust was just a change in Order() of the system as a brain gets more complex. And there's nothing to suggest that there couldn't be another similar 'upshift' in consciousness beyond that which regulation-sized human brains can do...