we know that it exists;
its problem is how to account for our knowledge. It asks what must the
nature of things be, seeing that they are known; and what is the nature
of thought, seeing that it knows facts?

There is no hope whatsoever for ethics, or religion, or philosophy--no
hope even for science--in a theory which would apply evolution all the
way up from inorganic matter to life, but which would postulate an
absolute break at consciousness. The connection between thought and
things is there to begin with, whether we can account for it or not; if
it were not, then natural science would be impossible. It would be
palpably irrational even to try to find out the nature of things by
thinking. The only science would be psychology, and even that would be
the science of "symbols of an unknown entity." What symbols of an
unknown can signify, or how an unknown can produce symbols of itself
across an impassable gulf--Mr. Spencer, Mr. Huxley, and Mr. Tyndall have
yet to inform us.

It is the more necessary to insist on this, because the division between
thought and matter, which is admitted by these writers, is often grasped
at by their opponents, as a means of warding off the results which they
draw from the theory of evolution. When science breaks its sword,
religion assails it, with the fragment. It is not at once evident that
if this chasm were shown to exist, knowledge would be a chimera; for
there would be no outer world at all, not even a phenomenal one, to
supply an object for it. We _must_ postulate the ultimate unity of all
beings with each other and with the mind that knows them, just because
we are intellectual and moral beings; and to destroy this unity is to
"kill reason itself, as it were, in the eye," as Milton said.

Now, evolution not only postulates unity, or the unbroken continuity of
all existence, but it also negates all differences, except those which
are expressions of that unity. It is not the mere assertion of a
substratum under qualities; but it implies that the substratum
penetrates into the qualities, and manifests itself in them. That which
develops--be it plant, child, or biological kingdom--is, at every stage
from lowest to highest, a concrete unity of all its differences; and in
the whole history of its process its actual content is always the same.
The environment of the plant evokes that content, but it adds nothing to
it. No addition of anything absolutely new, no external aggregation, no