it is worth while to delay upon
it.

Professor Hoeffding holds that mental phenomena and physical phenomena
must be regarded as parallel (see Chapter IX), and that we must not
conceive of ideas and material things as interacting. He writes:[1]--

"If it is contrary to the doctrine of the persistence of physical
energy to suppose a transition from the one province to the other, and
if, nevertheless, the two provinces exist in our experience as
distinct, then the two sets of phenomena must be unfolded
simultaneously, each according to its laws, so that for every
phenomenon in the world of consciousness there is a corresponding
phenomenon in the world of matter, and conversely (so far as there is
reason to suppose that conscious life is correlated with material
phenomena). The parallels already drawn point directly to such a
relation; it would be an amazing accident, if, while the characteristic
marks repeated themselves in this way, there were not at the foundation
an inner connection. Both the _parallelism_ and the _proportionality_
between the activity of consciousness and cerebral activity point to an
_identity_ at bottom. The difference which remains in spite of the
points of agreement compels us to suppose that one and the same
principle has found its expression in a double form. We have no right
to take mind and body for two beings or substances in reciprocal
interaction. We are, on the contrary, impelled to conceive the
material interaction between the elements composing the brain and
nervous system _as an outer form of the inner ideal unity of
consciousness_. What we in our inner experience become conscious of as
thought, feeling, and resolution, is thus represented in the material
world by certain material processes of the brain, which as such are
subject to the law of the persistence of energy, although this law
cannot be applied to the relation between cerebral and conscious
processes. It is as though the same thing were said in two languages."

Some monists are in the habit of speaking of the one Being to which
they refer phenomena of all sorts as the "Absolute." The word is a
vague one, and means very different things in different philosophies.
It has been somewhat broadly defined as "the ultimate principle of
explanation of the universe." He who turns to one principle of
explanation will conceive the Absolute in one way, and he who turns to
another will, naturally, understand something else by t