being. But many of the problems with which reflective thought is still
struggling have not been furthered in the least by information which
has been collected during the centuries which have elapsed since they
were attacked by the early Greek philosophers.

Thus, we are still discussing the distinction between "appearance" and
"reality," and many and varied are the opinions at which philosophers
arrive. But Thales, who heads the list of the Greek philosophers, had
quite enough material, given in his own experience, to enable him to
solve this problem as well as any modern philosopher, had he been able
to use the material. He who is familiar with the history of philosophy
will recognize that, although one may smile at Augustine's accounts of
the races of men, and of the spontaneous generation of small animals,
no one has a right to despise his profound reflections upon the nature
of time and the problems which arise out of its character as past,
present, and future.

The fact is that metaphysics does not lag behind because of our lack of
material to work with. The difficulties we have to face are nothing
else than the difficulties of reflective thought. Why can we not tell
clearly what we mean when we use the word "self," or speak of
"knowledge," or insist that we know an "external world"? Are we not
concerned with the most familiar of experiences? To be sure we
are--with experiences familiarly, but vaguely and unanalytically, known
and, hence, only half known. All these experiences the great men of
the past had as well as we; and if they had greater powers of
reflection, perhaps they saw more deeply into them than we do. At any
rate, we cannot afford to assume that they did not.

One thing, however, I must not omit to mention. Although one man