effort of the reason to reach a "first
principle" which should explain the universe. This early attempt was
purely speculative. It sought to interpret all phenomena by
_hypotheses_, that is, by suppositions, more or less plausible,
suggested by physical analogies or by _a priori_ rational conceptions.

Now there are two distinct aspects under which nature presents itself to
the observant mind. The first and most obvious is the _simple phenomena_
as perceived by the senses. The second is the _relations_ of
_phenomena_, cognized by the reason alone. Let phenomena, which are
indeed the first objects of perception, continue to be the chief and
almost exclusive object of thought, and philosophy is on the highway of
pure physics. On the other hand, instead of stopping at phenomena, let
their relations become the sole object of thought, and philosophy is now
on the road of purely mathematical or metaphysical abstraction. Thus two
schools of philosophy are developed, the one SENSATIONAL, the other
IDEALIST. Now these, it will be found, are the leading and
characteristic tendencies of the two grand divisions of the pre-Socratic
schools; the Ionian is _sensational_, the Italian is _idealist_.

These two schools have again been the subject of a further subdivision
based upon diverse habits of thought. The Ionian school sought to
explain the universe by _physical analogies._ Of these there are two
clear and obvious divisions--analogies suggested by living organisms,
and analogies suggested by mechanical arrangements. One class of
philosophers in the Ionian school laid hold on the first analogy. They
regarded the world as a living being, spontaneously evolving itself--a
vital organism whose successive developments and transformations
constitute all visible phenomena. A second class laid hold on the
analogy suggested by mechanical arrangements. For them the universe was
a grand superstructure, built up from elemental particles, arranged and
united by some ab-extra power or force, or else aggregated by some
inherent mutual affinity. Thus we have two sects of the Ionian school;
the first, _Dynamical_ or vital; the second, _Mechanical_.[400]

[Footnote 400: Ritter's "Ancient Philosophy," vol. i. pp. 191, 192.]

The Italian school sought to explain the universe by rational
conceptions and _a priori_ ideas. Now to those who seek, by simple
reflection, to investigate the relations of the external world this
marked distinction will prese