ical language and in briefest outline, what he offers us in
place of the philosophy of Hume.

Kant did not try to refute, as did Reid, the doctrine, urged by
Descartes and by his successors, that all those things which the mind
directly perceives are to be regarded as complexes of ideas. On the
contrary, he accepted it, and he has made the words "phenomenon" and
"noumenon" household words in philosophy.

The world which seems to be spread out before us in space and time is,
he tells us, a world of things _as they are revealed to our senses and
our intelligence_; it is a world of manifestations, of phenomena. What
things-in-themselves are like we have no means of knowing; we know only
things as they appear to us. We may, to be sure, talk of a something
distinct from phenomena, a something not revealed to the senses, but
thought of, a _noumenon_; but we should not forget that this is a
negative conception; there is nothing in our experience that can give
it a filling, for our experience is only of phenomena. The reader will
find an unmistakable echo of this doctrine in Herbert Spencer's
doctrine of the "Unknowable" and its "manifestations."

Now, Berkeley had called all the things we immediately perceive
_ideas_. As we have seen, he distinguished between "ideas of sense"
and "ideas of memory and imagination." Hume preferred to give to these
two classes different names--he called the first _impressions_ and the
second _ideas_.

The associations of the word "impression" are not to be mistaken.
Locke had taught that between ideas in the memory and genuine
sensations there is the difference that the latter are due to the
"brisk acting" of objects without us. Objects impress us, and we have
sensations or impressions. To be sure, Hume, after employing the word
"impression," goes on to argue that we have no evidence that there are
external objects, which cause impressions. But he retains the word
"impression," nevertheless, and his use of it perceptibly colors his
thought.

In Kant's distinction between phenomena and noumena we have the lineal
descendant of the old distinction between the circle of our ideas and
the something outside of them that causes them and of which they are
supposed to give information. Hume said we have no reason to believe
such a thing exists, but are impelled by our nature to believe in it.
Kant is not so much concerned to prove the nonexistence of noumena,
things-in-themselves, as he is