all things are made, and that he maintained that "all things are full
of gods." We find that Anaximander, the next in the list, assumed as
the source out of which all things proceed and that to which they all
return "the infinite and indeterminate"; and that Anaximenes, who was
perhaps his pupil, took as his principle the all-embracing air.

This trio constitutes the Ionian school of philosophy, the earliest of
the Greek schools; and one who reads for the first time the few vague
statements which seem to constitute the sum of their contributions to
human knowledge is impelled to wonder that so much has been made of the
men.

This wonder disappears, however, when one realizes that the appearance
of these thinkers was really a momentous thing. For these men turned
their faces away from the poetical and mythologic way of accounting for
things, which had obtained up to their time, and set their faces toward
Science. Aristotle shows us how Thales may have been led to the
formulation of his main thesis by an observation of the phenomena of
nature. Anaximander saw in the world in which he lived the result of a
process of evolution. Anaximenes explains the coming into being of
fire, wind, clouds, water, and earth, as due to a condensation and
expansion of the universal principle, air. The boldness of their
speculations we may explain as due to a courage born of ignorance, but
the explanations they offer are scientific in spirit, at least.

Moreover, these men do not stand alone. They are the advance guard of
an army whose latest representatives are the men who are enlightening
the world at the present day. The evolution of science--taking that
word in the broad sense to mean organized and systematized
knowledge--must be traced in the works of the Greek philosophers from