distinct from the act by
which I think of it. To think that one thinks and nothing more, is not
to think.

The soul is the principle of life, it is said. Yes; and similarly the
category of force or energy has been conceived as the principle of
movement. But these are concepts, not phenomena, not external realities.
Does the principle of movement move? And only that which moves has
external reality. Does the principle of life live? Hume was right when
he said that he never encountered this idea of himself--that he only
observed himself desiring or performing or feeling something.[27] The
idea of some individual thing--of this inkstand in front of me, of that
horse standing at my gate, of these two and not of any other individuals
of the same class--is the fact, the phenomenon itself. The idea of
myself is myself.

All the efforts to substantiate consciousness, making it independent of
extension--remember that Descartes opposed thought to extension--are but
sophistical subtilties intended to establish the rationality of faith in
the immortality of the soul. It is sought to give the value of objective
reality to that which does not possess it--to that whose reality exists
only in thought. And the immortality that we crave is a phenomenal
immortality--it is the continuation of this present life.

The unity of consciousness is for scientific psychology--the only
rational psychology--simply a phenomenal unity. No one can say what a
substantial unity is. And, what is more, no one can say what a substance
is. For the notion of substance is a non-phenomenal category. It is a
noumenon and belongs properly to the unknowable--that is to say,
according to the sense in which it is understood. But in its
transcendental sense it is something really unknowable and strictly
irrational. It is precisely this concept of substance that an
unforewarned mind reduces to a use that is very far from that pragmatic
application to which William James referred.

And this application is not saved by understanding it in an idealistic
sense, according to the Berkeleyan principle that to be is to be
perceived (_esse est percipi_). To say that everything is idea or that
everything is spirit, is the same as saying that everything is matter or
that everything is energy, for if everything is idea or everything
spirit, and if, therefore, this diamond is idea or spirit, just as my
consciousness is, it is not plain why the diamond should not endure for
e