applied to the physical world. Even mathematics, therefore, lend
themselves to the philosophic inference drawn by Henri Bergson and
others, that all conceptual systems of the human mind have a merely
conditional truth, depending on the circumstances of their application.

2. Another fountain-head of Pragmatic philosophy has been Darwinism.
Indeed, the Pragmatic is the only philosophizing which has completely
assimilated Evolution. The insight into the real fluidity of natural
species ought long ago to have toned down the artificial rigidity of
logical classifications. To know reality man can no longer rest in a
'timeless' contemplation of a static system; he must expand his thoughts
so as to cope with a perpetually changing process. Since the world
changes, his 'truths' must change to fit it. He is faced with the
necessity of a continuous reconstruction of beliefs. This influence of
Darwin has inspired the logical theories of Professor Dewey and the
'Chicago School' of Pragmatists. Thought in their writings is
essentially the instrument of this readjustment. Its function is to
effect the necessary changes in beliefs as economically and usefully as
possible. It is an evolving process which keeps pace with the evolution
of reality and the changing situations of mortal life.

3. It is not, however, entirely the reaction of science upon philosophy
which has given birth to Pragmatism. Philosophy itself has been rent by
internal convulsions. These have been emphasized in the work of Dr.
F.C.S. Schiller, who has shown that already in the days of Plato the
distinction between 'truth' and 'error' was baffling philosophy, that
Plato's _Theaetetus_ has failed to establish it, and that the famous
dictum of Protagoras, 'Man is the measure of all things,' distinctly
foreshadows the 'Pragmatic,' or, as he calls it, the 'Humanist,'
solution of the difficulty.