ed to be unfree, whether
it be bound by the causal sequence _a, b, c, d_, or by the causal
sequence _Aa, Bb, Cc, Dd_--I answer that this is a point which we have
to consider by-and-by. Meanwhile I am only endeavouring to make clear
the essential distinction between the philosophical theories of Monism
and Materialism. And the effect of this distinction is to show that, for
the purposes of clear analysis, we may wholly neglect either side of the
double reality. If we happen to be engaged on any physiological
inquiry, we may altogether neglect the processes of ideation with which
any process of cerebration may be concerned; while, if we happen to be
engaged upon any psychological inquiry, we may similarly neglect the
processes of cerebration with which any process of ideation may be
concerned. Seeing that each is equally an index of a common sequence, it
can make no difference which of them we take as our guide, although for
purposes of practical inquiry it is of course expedient to take the
cerebral index when we are dealing with the objective side of the
problem, and the mental index when dealing with the subjective. In the
following pages, therefore, I shall altogether neglect the cerebral
index. The inquiry on which we are engaged belongs to the region of
mind, and, therefore, after what has just been said, it will be apparent
that I am entitled to adopt the standpoint of a spiritualist, to the
extent of fastening attention only upon the mental side of the problem.
For although the theory of Monism teaches, as against Spiritualism, that
no one of the mental sequences could take place without a corresponding
physical sequence, the theory also teaches the converse proposition; and
therefore it makes no difference which of the two phenomenal sequences
is taken as our index of the ontological.

Now, it clearly makes a great difference whether the mental changes
concerned in volition are regarded as effects or as causes. According
to Materialism, the mental changes are the effects of cerebral changes,
which were themselves the effects of precedent cerebral changes.
According to Spiritualism, these mental changes are the causes, not only
of the cerebral changes, but also of one another. According to Monism,
the mental changes may be regarded as the causes of the cerebral, or
_vice versa_, seeing that in neither case are we stating a real
truth--the real truth being that it is only a cerebro-mental change
which can cause any