satisfactorily. For example, he speaks of space and time, cause and
effect, substance and qualities, matter and mind, reality and
unreality. He certainly is in a position to add to our knowledge of
the things covered by these terms. But we should never overlook the
fact that the new knowledge which he gives us is a knowledge of the
same kind as that which we had before. He measures for us spaces and
times; he does not tell us what space and time are. He points out the
causes of a multitude of occurrences; he does not tell us what we mean
whenever we use the word "cause." He informs us what we should accept
as real and what we should repudiate as unreal; he does not try to show
us what it is to be real and what it is to be unreal.

In other words, the man of science _extends_ our knowledge and makes it
more accurate; he does not _analyze_ certain fundamental conceptions,
which we all use, but of which we can usually give a very poor account.

On the other hand, it is the task of _reflective thought_, not in the
first instance, to extend the limits of our knowledge of the world of
matter and of minds, but rather _to make us more clearly conscious of
what that knowledge really is_. Philosophical reflection takes up and
tries to analyze complex thoughts that men use daily without caring to
analyze them, indeed, without even realizing that they may be subjected
to analysis.

It is to be expected that it should impress many of those who are
introduced to it for the first time as rather a fantastic creation of
problems that do not present themselves naturally to the healthy mind.
There is no thoughtful man who does not reflect sometimes and about
some things; but there are few who feel impelled to go over the whole
edifice of their knowledge and examine it with a critical eye from its