other forms than the human, and warns us
against the dogmatic assumption that the human conception of existence
should be absolutely adequate. But he seems to be quite sure that the
thing-in-itself works constantly, and consequently always gives us only
what our powers can master. This assumption was a consequence of Kant's
rationalistic tendency, but one for which no warrant can be given.
Evolutionism and systematism are opposing tendencies which can never
be absolutely harmonised one with the other. Evolution may at any time
break some form which the system-monger regards as finally established.
Darwin himself felt a great difference in looking at variation as an
evolutionist and as a systematist. When he was working at his evolution
theory, he was very glad to find variations; but they were a hindrance
to him when he worked as a systematist, in preparing his work on
Cirripedia. He says in a letter: "I had thought the same parts of the
same species more resemble (than they do anyhow in Cirripedia) objects
cast in the same mould. Systematic work would be easy were it not
for this confounded variation, which, however, is pleasant to me as a
speculatist, though odious to me as a systematist." ("Life and Letters",
Vol. II. page 37.) He could indeed be angry with variations even as
an evolutionist; but then only because he could not explain them, not
because he could not classify them. "If, as I must think, external
conditions produce little DIRECT effect, what the devil determines each
particular variation?" (Ibid. page 232.) What Darwin experienced in
his particular domain holds good of all knowledge. All knowledge is
systematic, in so far as it strives to put phenomena in quite definite
relations, one to another. But the systematisation can never be
complete. And here Darwin has contributed much to widen the world for
us. He has shown us forces and tendencies in nature which make absolute
systems impossible, at the same time that they give us new objects and
problems. There is still a place for what Lessing called "the unceasing
striving after truth," while "absolute truth" (in the sense of a closed
system) is unattainable so long as life and experience are going on.

There is here a special remark to be made. As we have seen above, recent
research has shown that natural selection or struggle for life is no
explanation of variations. Hugo de Vries distinguishes between partial
and embryonal variations, or between variati