When I said Roger Penrose is a "raving nutter", what I meant is that he is a bit of a crank (not at all unusual for brilliant scientists or mathematicians). I do not dispute his competence at physics and related works, as that is what he is excellent at. However, his competence in one field does not translate to competence in another (Carl Sagan syndrome). His work on consciousness, intelligence, and similar is quite simply, crap. He was writing stuff on that topic in his books that had already been rigorously refuted by the experts in the field before he had even published that garbage. None of the real experts in that field of mathematics take him seriously, and for good reason. His positions on this topic are essentially religious in nature, as he refuses to even address the numerous solid criticisms of his positions (and in some cases outright proofs that his premises are false). He defends his positions when attacked by making even more obtuse and/or unfalsifiable assertions. In other words, his work on the matter is seriously lacking scientific and mathematical integrity, and does not belong in any serious discussion of it. The mathematics he uses for physics is totally unrelated to the mathematics used for fields actually relevant to consciousness and intelligence, so it is ridiculous to think that his expertise in theoretical physics translates into expertise in the other topics. There is no such thing as a universal genius. Einstein was the same way, a real genius in his area of expertise but essentially a crank in others.
Fair enough Tortoise. But a few comments. First, he is an indisputably brilliant man, and a very talented mathematician (his work in twistor theory is now being adopted by many in string theory, and may be a precursor and foundational building block to string theory). I have read his two books (the second of which was written to refute his critics) on this topic, and found his arguments (though I am NOT an expert in the field) to be compelling. I know that he has been attacked incessantly by those in the artificial intelligence field, because there it is politically incorrect to assert that computers won't lead to consciousness. So, I'm left with what I do know about Penrose vs. what you tell me you know. If you have good cites relating to refutations of his work in this area(and even better, to unbiased and professional syntheses of pro and con), please Freep-mail them to me. I'd be interested in reading them. You say "he was writing stuff.. that had already been rigously refuted by the experts in his field..." Well, a prior refutation of the argument that algorithmic calculation cannot be foundational for consciousness would be something like a proof that it can be. To my knowledge, such does not exist. Lastly, though this is not my area, I freely acknowledge, I have personally always been skeptical of the idea that computational algorithms can give rise to consciousness - and like Penrose, I do believe that there will be a quantum mechanical component involved (for reasons outside of what Penrose was talking about). Notably, I have read of many AI people over the years who claim that we just need bigger computing machines, better algorithms and more complex neural networks before consciousness spontaneously arises in machines. I personally think this is hogwash, and note that now that we have those powerful machines, nothing of the sort has happened. One of us is wrong about Penrose's assertion. Time will tell who is right!