Miletus is
generally accounted the founder and father of all philosophy. He was
born about 624 B.C. and died about 550 B.C. These dates are
approximate, and it should be understood that the same thing is true
of nearly all the dates of the early philosophers. Different scholars
vary, sometimes as much as ten years, in the dates they give. We shall
not enter into these questions at all, because they are of no
importance. And throughout these lectures it should be understood that
the dates given are approximate.

Thales, at any rate, was a contemporary of Solon and Croesus. He was
famous in antiquity for his mathematical and astronomical learning,
and also for his practical sagacity and wisdom. He is included in {21}
all the accounts of the Seven Sages. The story of the Seven Sages is
unhistorical, but the fact that the lists of their names differ
considerably as given by different writers, whereas the name of Thales
appears in all, shows with what veneration he was anciently regarded.
An eclipse of the sun occurred in 585 B.C., and Thales is alleged to
have predicted it, which was a feat for the astronomy of those times.
And he must have been a great engineer, for he caused a diversion of
the river Halys, when Croesus and his army were unable to cross it.
Nothing else is known of his life, though there were many apocryphal
stories.

No writings by Thales were extant even in the time of Aristotle, and
it is believed that he wrote nothing. His philosophy, if we can call
it by that name, consisted, so far as we know, of two propositions.
Firstly, that the principle of all things is water, that all comes
from water, and to water all returns. And secondly, that the earth is
a flat disc which floats upon water. The first, which is the chief
proposition, means that water is the one primal kind of existence and
that everything else in the universe is merely a modification of
water. Two questions will naturally occur to us. Why did Thales choose
water as the first principle? And by what process does water, in his
opinion, come to be changed into other things; how was the universe
formed out of water? We cannot answer either of these questions with
certainty. Aristotle says that Thales "probably derived his opinion
from observing that the nutriment of all things is moist, and that
even actual heat is generated therefrom, and that animal life is
sustained by water, ... and from the fact that the seeds of all things
possess {22}