Thought I'd post up this:
" ....it is worth noting that Descartes said he derived his ambition of designing a new philosophical and scientific system not from rational, lucid, thought but from a series of dreams...On the one hand, he developed philosophical and scientific theories that were rooted in rigid mathematics and the material and scientific world. On the other, his system was posited on the existence of a divine, benevolent, Creator. Out of this contradiction grew his well known "Cartesian dualism" that proposes the existence of two radically different kinds of substance: material substance ( rocks, trees, animals and the human body ) and thinking substance ( the human mind, thoughts, desires ) . From this duality arises a notion that the self. ( consciousness ) is something non-material, rather as a puppeteer manipulates a puppet. The English philosopher Gilbert Ryle summed up this in the famous phrase "Ghost in the Machine."
Descartes idea persists in what is now called attributive dualism, the doctrine that psychological phenomena cannot be reduced to a physical foundation. Whilst there is some sense in the kind of opposition to a recductionist explanation of the mind, I believe any persusasive explanation must refer to the form and functioning of the brain, the matter of the mind. The ghost hidden in the machine is a cognitive illusion created by the electro-chemical functioning of the brain."
The Mind In the Cave: Consciousness and the Origins of Art.
Quite apart from the fact Descartes "dreamed" up the system that serves much of the basis of the contemporary Western mind; much like a Southern African San shaman "dreams" the cures necessary for his tribe; I think what Lewis-Williams ( who Im quoting ) is saying is very interesting here. Not just because its critical of Cartianism but because it segues with those scientists looking for a "theory of consciousness" and doing so by studying the electro chemical functioning of the brain.
If the ( human ) brain seems to produce "exalted states" of a nature that appears to be universal ( the zig zaggy patterns of much Cave Art, produced 35,000 years ago, seem very similar to exactly the same patterns reported by subjects under laboratory conditions under the influence of psychotropic drugs and in exalted states...)
What this guy seems to me to be saying is that if these patterns of the human mind exist within the brain itself they represent a materiality of sorts, the materality of the functioning human brain, a materiality of consciousness.
If you accept this there is no reason why - if they are structural and universalm -they should not and potentiality might become an object of study every bit as valid as the material, exterior world that supposedly exists "outside" the Cartesian mind.