to its object. But
such a dualism tends almost irresistibly to relapse into materialistic
monism, because of the fundamental place of physical conceptions in the
system of the sciences. Finally, in another and a more radical phase of
agnosticism, we find an attempt to make full provision for the
legitimate problems of epistemology. The only datum, the only existent
accessible to knowledge, is said to be the sensation, or state of
consciousness. In the words of Huxley:

"What, after all, do we know of this terrible 'matter' except
as a name for the unknown and hypothetical cause of states of
our own consciousness? And what do we know of that 'spirit'
over whose threatened extinction by matter a great lamentation
is arising, . . . except that it is also a name for an unknown
and hypothetical cause, or condition, of states of
consciousness?"[255:19]

The physical world is now to be regarded as a construction which does
not assimilate to itself the content of sensations, but enables one to
anticipate them. The sensation signifies a contact to which science can
provide a key for practical guidance.

[Sidenote: Experimentalism.]

Sect. 118. This last phase of naturalism is an attempt to state a pure
and consistent experimentalism, a workable theory of the routine of
sensations. But it commonly falls into the error of the vicious circle.
The hypothetical cause of sensations is said to be matter. From this
point of view the sensation is a complex, comprising elaborate physical
and physiological processes. But these processes themselves, on the
other hand, are said to be analyzable into sensations. Now two such
methods of analysis cannot be equally ultimate. If all of reality is
finally reducible to sensations, then the term sensation must be used
in a new sense to connote a self-subsistent being, and can no longer
refer merely to a function of certain physiological processes. The issue
of this would be some form of idealism or of the experience-philosophy
that is now coming so rapidly to the front.[256:20] But while it is true
that idealism has sometimes been intended, and that a radically new
philosophy of experience has sometimes been closely approached, those,
nevertheless, who have developed experimentalism from the naturalistic
stand-point have in reality achieved only a thinly disguised
materialism. For _the very ground of their agnosticism is
materialistic_.[256:21] Knowledge of re