I can not say that Penrose does not know Douglas Hofstadter, but Penrose apparently never (as of 1989) read Godel, Escher, Bach (1979). If we are in need of a clear example of the dangers of philosophizing about the meaning of mathematics in the mind/brain debate, we need look no further than a comparison of Penrose's and Hofstadter's ideas. Covering much the same ground, (Turing Machines, Truth, Proof, Godel's proof that formal mathematical systems are incomplete, computation) they come to entirely different conclusions: the mental equivalents of two complementary antiparticles. The main problem is that Penrose believes in a world of Platonic Ideals and suffers a severe case of the standard physicist's disease: free will envy. The second problem is that Penrose places consciousness itself into his Platonic dream land. Down 2 strikes, Penfield wiffs by not mentioning brains until 4 fifths of the way through his book and then devoting only about 5% of the book to brains, neurons, and synaptic plasticity.
Most of this book is a very clear demonstration of the frustration of physicists who know by introspection that consciousness is wonderful, feeling every second of every day that they have free will, but who grew up being told that the equations of physics theories are deterministic. It is now clear that the new science of complex systems is a royal road out of this valley of despair, and molecular and cellular neurobiology is the empiracle science that is identifying the physical mechanisms of biological consciousness. It is impossible to strongly condemn the wondering physicists for their heroic attempts to deal with consciousness in terms of quantum physics. To see a mature scientist reduced to saying "Perhapse our minds are qualities rooted in some strange and wonderful feature of those physical laws which actually govern the world we inhabit" is touching. Indeed, perhapse mind is a physicist's quality like charge or charm. Why would we want to have to bust our asses to figure out how a brain works when we can just discover mind floating in the Platonic wilderness, pluck it like a plum, and publish the equations in the next Pys. Rev. Lett.?
Daniel C. Dennett's review.
Go to John's Book Page.
Go to John's