these questions should be
separated, and referred to particular heads; and, above all, that they
should be thoroughly discussed in an exact and settled terminology. To
arrange and classify all the objects of knowledge, to discuss them
systematically and, as far as possible, exhaustively, was evidently the
ambition, perhaps also the special function, of Aristotle. He would
survey the entire field of human knowledge; he would study nature as
well as humanity, matter as well as mind, language as well as thought;
he would define the proper limits of each department of study, and
present a regular statement of the facts and principles of each science.
And, in fact, he was the first who really separated the different
sciences and erected them into distinct systems, each resting upon its
own proper principles. He distributed philosophy into three
branches:--(i.) _Theoretic_; (ii.) _Efficient_; (iii.) _Practical_. The
Theoretic he divided into--1. _Physics_; _2. Mathematics_; 3.
_Theology_, or the Prime Philosophy--the science known in modern times
as Metaphysics. The Efficient embraces what we now term the arts,--1.
_Logic; 2. Rhetoric_; 3. _Poetics_. The Practical comprises--_1.
Ethics_; 2. _Politics_. On all these subjects he wrote separate
treatises. Thus, whilst Plato is the genius of abstraction, Aristotle is
eminently the genius of classification.

Such being the mental characteristics of the two men--their type of mind
so opposite--we are prepared to expect that, in pursuing his inquiries,
Aristotle would develop a different _Organon_ from that of Plato, and
that the teachings of Aristotle will give a new direction to philosophic
thought.

ARISTOTELIAN ORGANON.

Plato made use of psychological and logical analysis in order to draw
from the depth of consciousness certain fundamental ideas which are
inherent in the mind--born with it, and not derived from sense or
experience. These ideas he designates "the intelligible species" (ta
nooumena gene) as opposed to "the visible species"--the objects of
sense. Such ideas or principles being found, he uses them as
"starting-points" from which he may pass beyond the sensible world and
ascend to "the absolute," that is, to God.[674] Having thus, by
immediate abstraction, attained to universal and necessary ideas, he
descends to the outer world, and attempts by these ideas to construct an
intellectual theory of the universe.[675]

Aristotle will reverse this process. He will