Strauss, the greatest theologian of our century, was showing it to be the
opposite. The clear-sighted author of _The Old Faith and the New_ had
already clearly perceived that the soul-activities of man, and therefore
also his consciousness, as functions of the central nervous system, all
spring from a common source, and, from a monistic point of view, come
under the same category. The "exact" Berlin physiologist shut this
knowledge out from his mind, and, with a short-sightedness almost
inconceivable, placed this special neurological question alongside of the
one great "world-riddle," the fundamental question of substance, the
general question of the connection between matter and energy.[16]

As I long ago pointed out, these two great questions are not two separate
"world-riddles." The neurological problem of consciousness is only a
special case of the all comprehending cosmological problem, the question
of substance. "If we understood the nature of matter and energy, we
should also understand how the substance underlying them can under
certain conditions feel, desire, and think." Consciousness, like feeling
and willing, among the higher animals is a mechanical work of the
ganglion-cells, and as such must be carried back to chemical and physical
events in the plasma of these. And by the employment of the genetic and
comparative method we reach the conviction that consciousness, and
consequently reason also, is not a brain-function exclusively peculiar to
man; it occurs also in many of the higher animals, not in Vertebrates
only, but even in Articulates. Only in degree, through a higher stage of
cultivation, does the consciousness of man differ from that of the more
perfect lower animals, and the same is true of all other activities of
the human soul.

By these and other results of comparative physiology our whole psychology
is placed on a new and firm monistic basis. The older mystical conception