body of facts presented in a science, to take careful note of the
assumptions upon which that science rests, to analyze the concepts of
which it makes use, to mark the methods which it employs, and to gain a
fair idea of its scope and of its relation to other sciences. Such a
reflection upon our scientific knowledge is philosophical reflection,
and it may result in a classification of the sciences, and in a general
view of human knowledge as a whole. Such a view may be illuminating in
the extreme; it can only be harmful when its significance is
misunderstood.

But, it may be argued, why may not the man of science do all this for
himself? Why should he leave it to the philosopher, who is presumably
less intimately acquainted with the sciences than he is?

To this I answer: The work should, of course, be done by the man who
will do it best. All our subdivision of labor should be dictated by
convenience. But I add, that experience has shown that the workers in
the special sciences have not as a rule been very successful when they
have tried to philosophize.

Science is an imperious mistress; she demands one's utmost efforts; and
when a man turns to philosophical reflection merely "by the way," and
in the scraps of time at his disposal after the day's work is done, his
philosophical work is apt to be rather superficial. Moreover, it does
not follow that, because a man is a good mathematician or chemist or
physicist, he is gifted with the power of reflective analysis. Then,
too, such men are apt to be imperfectly acquainted with what has been
done in the past; and those who are familiar with the history of
philosophy often have occasion to remark that what is laid before them,
in ignorance of the fact that it is neither new nor original, is a