e are unable to say
flatly whether they are plants or animals, that we are therefore
unable to fix accurately the frontiers between plant and animal life,
all these things make Herr Duehring logically anxious to fix a
decisively distinguishing line, which in the next breath he declares
cannot be thoroughly relied on. But there is no need for us to go to
the doubtful region; intermediate between plants and animals are
sensitive plants which at the least contact fold their leaves or close
their petals. Are insect eating plants utterly without sensation? Even
Herr Duehring cannot make such an assertion without indulging in
"unscientific half-poetry."

In the third place Herr Duehring is again giving free rein to his
imagination when he says that sensation is psychologically existent,
even when the nerve apparatus is exceedingly simple. This is found
regularly among reptiles yet Herr Duehring is the first to say that
they have no sensation because they have no nerves. Sensation is not
necessarily bound up with nerves but it is bound up with some
albuminous substance the true nature of which has not yet been
discovered.

In addition, the biological knowledge of Herr Duehring becomes
exceedingly evident in that he is not ashamed to fling at Darwin the
question do animals develop from plants? so that it is a question
whether he is more ignorant with regard to plants or animals.

Of life in general Herr Duehring can only tell us "The change in the
form of matter which fulfills itself by plastic constructive
arrangement remains a distinguishing characteristic of the individual
life-process."

That is all that we learn of life and with respect to the plastic
creative arrangement we sink knee deep in the nonsense of Duehring's
jargon. If we want to learn what life is we shall have to look at the
problem a little more closely on our own account.

That organic change in matter is the most universal and distinctive
evidence of life has been declared by physiological chemists and
chemical physiologists times without number during the last thirty
years and their utterances are translated by Herr Duehring into his
own clear and elegant language. But to define life as an organic
change of matter is simply to define life as life, for organic change
of matter, or change of matter with plastic creative arrangement is a
statement which must itself be explained by life, and the explanation
in its turn by the difference between organic