There seems to me to be false reasoning in the argument from analogy
which William James uses in his lectures on "Human Immortality." The
brain, he admits, is the organ of the mind, but may only sustain the
relation to it, he says, which the wire sustains to the electric current
which it transmits, or which the pipe sustains to the water which it
conveys.
Now the source and origin of the electric current is outside the wire
that transmits it, and it could sustain no other than a transient
relation to any outside material through which it passed. But if we
know anything, we know that the human mind or spirit is a vital part of
the human body; its source is in the brain and nervous system; hence, it
and the organ through which it is manifested are essentially one.
The analogy of the brain to the battery or dynamo in which the current
originates is the only logical or permissible one.