ical
explanation of consciousness than the comparative consideration of its
development. We know that a new-born child has no consciousness, but
that it is slowly and gradually acquired and developed. We perceive
for ourselves how unconscious actions become conscious, and _vice
versa_. Innumerable actions which at first are troublesome and have
to be learnt with consciousness and reflection--as for instance
walking, swimming, singing, and so forth--become unconscious only by
repetition, practice, and the habit of using the organs. On the
contrary, unconscious actions become conscious as soon as we direct
our attention to them or our self-observation is attracted to them; as
for instance when we miss a step in going up stairs or touch a wrong
note on the piano; and beyond a doubt, conscious and unconscious
actions pass into each other without any distinct line of demarcation.
Finally, we see no less plainly by a comparative consideration of the
soul-life of animals, that their consciousness is slowly, gradually,
and serially developed, and that a long unbroken series of steps leads
from unconscious to conscious existence. From these comparative and
genetic experiences we may draw the conclusion that consciousness,
like sensation and volition, like all the other soul-activities, is a
function of the organism, a mechanical activity of the cells; and, as
such, is referable to chemical and physical processes. Hence, if we
were in a position to understand force as a necessary function of
matter, we could explain consciousness, as well as the soul in
general, as a necessary function of certain cells.

How little Du Bois-Reymond is acquainted with the facts of comparative
and genetic psychology, nothing shows more strikingly than the
following astounding proposition in the "Ignorabimus-speech:"--"Where
the material conditions for psychical activity, in the form of a
nervous system, are wanting, as in plants, the naturalist cannot
recognise a soul-life, and, on this point, he but seldom meets with
contradiction." Begging your pardon! Every naturalist who is familiar
with the comparative morphology and physiology of the lower animals
will here put in a decided contradiction, for he can no more refuse to
admit the undoubted sensation and voluntary motion of the one-celled
Infusoria than of the many-celled hydroid polyps. The body of the true
Infusoria (Ciliata, Acineta, &c.), and many other Protista, remain
throughout life one si