[46] I can quote two observations in support of this. M. Brieux, to whom I was relating this part of my argument, stopped me, saying, "You have guessed right; I represent to myself thought issuing from brain in the form of an electric gleam." Dr. Simon also informed me, during the reading of my manuscript, that he saw "thought floating over the brain like an ignis fatuus."
CHAPTER IV
MODERN THEORIES
It may be thought that the objection taken above to parallelism and materialism is personal to myself, because I have put it forward as the consequence of my analysis of the respective shares of thought and matter in every act of cognition. This is not so. I am here in harmony with other philosophers who arrived at the same conclusions long before me, and it may be useful to quote them.
We will begin with the prince of idealists, Berkeley. "'Everything you know or conceive other than spirits,' says Philonous to Hylas, 'is but your ideas; so then when you say that all ideas are occasioned by impressions made in the brain, either you conceive this brain or you do not. If you conceive it, you are in that case talking of ideas imprinted in an idea which is the cause of this very idea, which is absurd. If you do not conceive it, you are talking unintelligibly, you are not forming a reasonable hypothesis.' 'How can it be reasonable,' he goes on to say, 'to think that the brain, which is a sensible thing, i.e. which can be apprehended by the senses—an idea consequently which only exists in the mind—is the cause of our other ideas?'"[47]
Thus, in the reasoning of Berkeley, the function of the brain cannot explain the production of ideas, because the brain itself is an idea, and an idea cannot be the cause of all our other ideas.
M. Bergson's argument is quite similar, although he takes a very different standpoint from that of idealism. He takes the word image in the vaguest conceivable sense. To explain the meaning of this word he simply says: "images which are perceived when I open my senses, and unperceived when I close them." He also remarks that the external objects are images, and that the brain and its molecular disturbances are likewise images. And he adds, "For this image which I call cerebral disturbance to generate the external images, it would have to contain them in one way or another, and the representation of the whole material universe would have to be implicated in that of this molecular movement. Now, it is enough to enunciate such a proposition to reveal its absurdity."[48]