serted that fire was the first principle, and states as the
fundamental maxim of his philosophy that "all is convertible into fire,
and fire into all." There was so much confusion in his doctrines as to
give him the name of "The Obscure." "The moral system of Heraclitus
was based on the physical. He held that heat developed morality,
moisture immorality. He accounted for the wickedness of the drunkard
by his having a moist soul, and inferred that a warm, dry soul was
noblest and best."

Anaxagoras taught the mechanical processes of the universe, and
advanced many theories of the origin of animal life and of material
objects. Anaxagoras was a man of wealth, who devoted all of his time
and means to philosophy. He recognized two principles, one material
and the other spiritual, but failed to connect the two, and in
determining causes he came into open conflict with the religion of the
times, and asserted that the "divine miracles" were nothing more than
natural {219} causes. He was condemned for his atheism and thrown into
prison, but, escaping, he was obliged to end his days in exile.

Another notable example of the early Greek philosophy is found in
Pythagoras, who asserted that number was the first principle. He and
his followers found that the "whole heaven was a harmony of number."
The Pythagoreans taught that all comes from one, but that the odd
number is finite, the even infinite; that ten was a perfect number.
They sought for a criterion of truth in the relation of numbers.
Nothing could exist or be formed without harmony, and this harmony
depended upon number, that is, upon the union of contrary elements.
The musical octave was their best example to illustrate their meaning.
The union of the atoms in modern chemistry illustrates in full the
principle of number after which they were striving. It emphasized the
importance of measurements in investigation. Much more might be said
about the elaborate system of the Pythagoreans; but the main principle
herein stated must suffice.

_The Weakness of Ionian Philosophy_.--Viewed from the modern standpoint
of scientific research, the early philosophers of Greece appear puerile
and insignificant. They directed their thoughts largely toward nature,
but instead of systematic observation and comparison they used the
speculative and hypothetical methods to ascertain truth. They had
turned from the credulity of ancient tradition to simple faith in the
mind to determ