rence whether
the source of it be regarded as natural or super-natural, material or
mental: so that a man be fated to will only in certain ways--and this
with all the rigour which belongs to causation as physical--it is
scarcely worth while to dispute whether the predestination is of God or
of Nature. There can be no question, however, that in this matter the
possibility which I have supposed to be suggested by the spiritualist is
more far-fetched than that which obviously lies to the hand of the
materialist; and, moreover, that it too plainly wears the appearance of
a desperate device to save a hollow theory.

It remains to add that this great difficulty against the spiritualistic
theory has been revealed in all its force only during the present
generation. Since the days of fetishism, indeed, the difficulty has
always been an increasing one--growing with the growth of the perception
of uniformity on the one hand, and of mechanical as distinguished from
volitional agency on the other. But it was not until the correlation of
all the physical forces had been proved by actual experiment, and the
scientific doctrine of the conservation of energy became as a
consequence firmly established, that the difficulty in question assumed
the importance of a logical barrier to the theory of mental changes
acting as efficient causes of material changes.

FOOTNOTES:

[Footnote 3: In the opinion of some modern writers the indestructibility
of matter and the conservation of energy are alone sufficient to explain
all the facts of natural causation. 'For,' it is urged, 'if in any case
similar antecedents did not determine similar consequents, on one or
other of these occasions some _quantum_ of force, or of matter, or of
both, must have disappeared--or, which is the same thing, the law of
causation cannot have been constant.' In a future chapter I shall have
to recur to this view. Meanwhile I have only to observe that whether or
not the law of causation is nothing more than a re-statement of the fact
that matter and energy are indestructible, it is equally true that this
fact is at least a necessary _condition_ to the operation of that law.]

CHAPTER II.

MATERIALISM.

This is the theory which presents great fascination to the student of
physical science. By laborious investigation physiology has established
the fact beyond the reach of rational dispute, that there is a constant
relation of concomitancy between cerebral acti