its content,
according to our thought, that which compels the world to a progressive
realization as it were of the absolute Idea, which absolute idea has
existed somewhere, unattached from the world and before the world; and
that thought can recognize a content which is already a thought content
herein, from the beginning, appears self-evident. It is also evident
that what is here to be proved is already hidden in the hypothesis. But
that does not hinder Hegel, by any means, from drawing the further
conclusion from his proof of the identity of thought and existence that
his philosophy, because correct for his thought, is, therefore, the only
correct one, and that the identity of thought and existence must show
itself in this, that mankind should forthwith translate his philosophy
from theory to practice and the whole world shift itself to a Hegelian
base. This is an illusion which he shares alike with all philosophers.

In addition there is still another class of philosophers, those who
dispute the possibility of a perception of the universe or at least of
an exhaustive perception. To them belong, among the moderns, Hume and
Kant, and they have played a very distinguished role in the evolution of
philosophy. This point of view has been now refuted by Hegel, as far as
possible, from the idealistic standpoint. The materialistic additions
made by Feuerbach are more ingenious than deep. The most destructive
refutation of this as of all other fixed philosophic ideas is actual
result, namely experiment and industry. If we can prove the correctness
of our idea of an actual occurrence by experiencing it ourselves and
producing it from its constituent elements, and using it for our own
purposes into the bargain, the Kantian phrase "Ding an Sich" (thing in
itself) ceases to have any meaning. The chemical substances which go to
form the bodies of plants and animals remained just such "Dinge an Sich"
until organic chemistry undertook to show them one after the other,
whereupon the thing in itself became a thing for us, as the coloring
matter in the roots of madder, alizarin, which we no longer allow to
grow in the roots of the madder in the field, but make much more cheaply
and simply from coal tar. The Copernican system was for three hundred
years a hypothesis, with a hundred, a thousand, or ten thousand chances
in its favor, but still a hypothesis. But when Leverrier by means of the
data of this system not only discovered the exis