Similar considerations apply to the brain that the physiologist thinks he is examining. There is an experience in him which has a remote causal connection with the brain that he thinks he is seeing. He can only know concerning that brain such elements of structure as will be reproduced in his visual sensation. Concerning properties that are not structural, he can know nothing whatever. He has no right to say that the contents of a brain are different from those of the mind that goes with it. If it is a living brain, he has evidence through testimony and analogy that there is a mind that goes with it. If it is a dead brain, evidence is lacking either way.
Source: Bertrand Russell : Mind and Matter (1950?)
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