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 intra-cerebral phenomena, whereas it ignores them.

Let me repeat that there is no such thing as intra-cerebral sensibility. The consciousness is absolutely insensitive with regard to the dispositions of the cerebral substance and its mode of work. It is not the nervous undulation which our consciousness perceives, but the exciting cause of this wave—that is, the external object. The consciousness does not feel that which is quite close to it, but is informed of that which passes much further off. Nothing that is produced inside the cranium interests it; it is solely occupied with objects of which the situation is extra-cranial. It does not penetrate into the brain, we might say, but spreads itself like a sheet over the periphery of the body, and thence springs into the midst of the external objects.

There is, therefore, I do not say a contradiction, but a very striking contrast between these two facts. The consciousness is conditioned, kept up, and nourished by the working of the cerebral substance, but knows nothing of what passes in the interior of that substance. This consciousness might itself be compared to a parasitical organism which plunges its tap roots into the nerve centres, and of which the organs of perception, borne on long stalks, emerge from the cranium and perceive everything outside