to whether he is right or is wrong? May we expect that the day will
come when he will be justified or condemned as is the astronomer on the
day predicted for an eclipse? Neither the philosophy of Locke, nor
that of Descartes, nor that of Kant, can be vindicated as can a
prediction touching an eclipse of the sun. To judge these men, we must
learn to think with them, to survey the road by which they travel; and
this we cannot do until we have learned the art.

Whether we like to admit it or not, we must admit, if we are
fair-minded and intelligent, that philosophy cannot speak with the same
authority as science, where science has been able to verify its
results. There are, of course, scientific hypotheses and speculations
which should be regarded as being quite as uncertain as anything
brought forward by the philosophers. But, admitting this, the fact
remains that there is a difference between the two fields as a whole,
and that the philosopher should learn not to speak with an assumption
of authority. No final philosophy has been attained, so palpably firm
in its foundation, and so admittedly trustworthy in its construction,
that we are justified in saying: Now we need never go back to the past
unless to gratify the historic interest. It is a weakness of young
men, and of older men of partisan temper, to feel very sure of matters
which, in the nature of things, must remain uncertain.

Since these things are so, and since men possess the power of
reflection in very varying degree, it is not surprising that we find it
worth while to turn back and study the thoughts of those who have had a
genius for reflection, even though they lived at a time when modern
science was awaiting its birth. Some things cannot be known until
other things are known; often there must be a vast collection of
individual facts before the generalizations of science can come into