> No - I read that a few years ago, and couldn't really get Penrose's
> point. He seemed to be postulating some sort of mystical component
> to thought because he couldn't face, philosophically, the idea that
> human brains might be just another Turing machine.
Naw, he's no mystic in that way. He has a speculative hypothesis that the brain is more than a Turing machine due to quantum mechanical effects. And to get quantum mechanical effects in the brain he had to isolate a geometrically small region -- small enough that QM effects would sing.
So he has this idea that microtubules in the brain add non-algorithmic capability to the brain's toolkit.
http://www.u.arizona.edu/~hameroff/or.html
The book however is not concentrated enough on its topic, and winds up being at times a quite readable and interesting layperson's view of QM, general relativity, and cosmology theory.
BTW, there is an email list based in Arizon (i have the URL if anyone is interested) which discusses topics at the edge of, and possible intersection of, QM and brain research. i've followed the list for several years in aggravation, as the S/E ratio (speculation to experiment ratio) is way way way too high.
here's more...
http://psyche.cs.monash.edu.au/v2/psyche-2-03-klein.html
my microtubules are experiencing wave-packet reduction to sleep state, so cant say no mo right now....
les schaffer