material phenomena by intellectual causes was the peculiar merit of
Anaxagoras, and places him in a very high rank among the thinkers of the
world. Moreover, he recognized the reason as the only faculty by which
we become cognizant of truth, the senses being too weak to discover the
real component particles of things. Like all the great inquirers, he was
impressed with the limited degree of positive knowledge compared with
what there is to be learned. "Nothing," says he, "can be known; nothing
is certain; sense is limited, intellect is weak, life is short,"--the
complaint, not of a sceptic, but of a man overwhelmed with the sense of
his incapacity to solve the problems which arose before his active mind.
Anaxagoras thought that this spirit ([Greek: nous]) gave to all those
material atoms which in the beginning of the world lay in disorder the
impulse by which they took the forms of individual things, and that this
impulse was given in a circular direction. Hence that the sun, moon, and
stars, and even the air, are constantly moving in a circle.

In the mean time another sect of philosophers had arisen, who, like the
Ionians, sought to explain Nature, but by a different method.
Anaximander, born 610 B.C., was one of the original mathematicians of
Greece, yet, like Pythagoras and Thales, speculated on the beginning of
things. His principle was that _The Infinite_ is the origin of all
things. He used the word _[Greek: archae] (beginning)_ to denote the
material out of which all things were formed, as the Everlasting, the
Divine. The idea of elevating an abstraction into a great first cause
was certainly a long stride in philosophic generalization to be taken at
that age of the world, following as it did so immediately upon such
partial and childish ideas as that any single one of the familiar
"elements" could be the primal cause of all things. It seems almost like
the speculations of our own time, when philosophers seek to find the
first cause in impersonal Force, or infinite Energy. Yet it is not