ther to define
its _status a priori_--that I should exhibit the reason why the two
other suggestions have necessarily failed. For to my mind it is
perfectly obvious that this reason is to be found, and found only, in
the fact that they are both dualistic. The inherent, the fatal, and the
closely similar difficulties which attach to both the dualistic
theories, attach to them merely because they _are_ dualistic. The
'nonsense' of each of them is really identical, and arises only because
they both make the same irrational attempt to find more in the effect
than they have put into the cause. In other words, both the dualistic
theories suppose that the physical chains of causation is complete
within itself, and that the mental chain is also complete within itself:
yet they both proceed to the contradiction that one of these chains is
able to allow some of its causal influence to escape, as it were, in
order to constitute the other chain. It makes no difference, in point
of logic, whether such an escape is supposed to take place from the
physical chain (materialism) or from the mental chain (spiritualism): in
either case the fundamental principle of causality is alike
impugned--the principle, that is, of there being an equivalency between
cause and effect, such that you cannot get more out of your effect than
you have put into your cause. Both these dualistic theories, although
they take opposite views as to which of the two chains of causation is
the cause of the other, nevertheless agree in supposing that there _are_
two chains of causation, and that one of them _does_ act causally upon
the other: and it is in this matter of their common consent that they
both commit suicide. Every process in the physical sphere must be
supposed to have its equations satisfied within that sphere: else the
doctrine of the conservation of energy would be contravened, and thus
the causation contemplated could no longer be contemplated as physical.
Similarly, every process in the mental sphere must be supposed to have
its equations satisfied within that sphere: else the causation
contemplated could no longer be contemplated as mental: some of the
equations must be supposed not to have been satisfied within the mental
sphere, but to have been carried over into the physical sphere--thus to
have either created or destroyed certain quantities of energy within
that sphere, and thus, also, to have introduced elements of endless
confusion into the oth