Friday, July 31, 2015

A provisional reply to David Parker

Yesterday, David sent me his reply to my ’Notes on the relevance of neurophysiology to self-knowledge’. In reply, I wrote to him: ‘I am at present absorbed in Kant and Aristotle, but I should like to reply to your comments before I go to Prague for my 'Three days' in September. You write 'that what we know about the brain now is sufficient to offer, in principle, a physiological account of consciousness.' I shall contend that what we know about the brain now is sufficient for us to realize that what we experience thanks to our brains cannot be performed by our brains; there must be a non-corporeal entity that transforms what goes on in the brain into the world in which we live.

In his reply, David asked: ‘Why do you say that consciousness has to be non-corporeal?’

I answered: ‘My reply will be all about it. The best I can do at the moment is to refer to the 4th Notes on my blog:

Aristotle may help; he notes that topos (place/space) has three dimensions, length, breadth  and depth, by which all body is defined. This might suggest that topos is a body, and so he says: ‘But the place cannot be body; for if it were, there would be two bodies in the same place’ (Physics, 209a6-7, tr. Hardie and Gaye). ’Two bodies cannot be at one and the same place’ (213b20)

Everything that neurophysiology has so far detected and can ever detect in the brain by the technology corresponds to Aristotle’s notion of body: where is neuron A, there cannot be neuron B, where is a vesicle A containing neurotransmitter ‘a’, there cannot be a vesicle B containing the same (or different) kind of neurotransmitter. Concerning action potentials, let me take recourse to Wikipedia: “The action potential generated at the axon hillock propagates as a wave along the axon … The currents flowing in due to an action potential spread out in both directions along the axon. However, only the unfired part of the axon can respond with an action potential; the part that has just fired is unresponsive until the action potential is safely out of range and cannot re-stimulate that part.”

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When I look out of the window, I can see trees with their branches, a church and a few houses discernible behind the trees, Cam Peak in the distance, the blue sky-scape with the white clouds – all this is in space, all this is real. In so far as I see it, it all is composed in my brain on the basis of the neural structures inside the brain. Since what I can see in space around me – in my head – is real, in three dimensions, it cannot be corporeal, for in my brain there is no space for such corporeal structures. Does it make sense?’

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