nt in all classification, whether of the
phenomena of Mind or of the grosser phenomena of Matter is uniformly and
always the same--the law of intellectual action.

Science then resolves itself into a determination of this Law of mental
activity, so that in an ultimate analysis, all science is metaphysical,
just as all science primarily is physical. Here, as elsewhere, Law can
be studied only in its objective manifestations. The Law of Thinking can
be educed only from expressed Thought, but the Law is not objective
thought, any more than the idea of the sculptor is marble, or the
conception of the painter is paint. The simplest expression of thought
is not the syllogism but the logical proposition. Now, it is plain that
if the proposition is the formulation--the material representative of
thought--if we study it as we study other natural symbols, we will find
in it the fundamental Law of Thinking, and ultimately the fundamental
Law of all Science: just as, if it were possible to reduce all
elementary substances to one, the chemist would be able to find in that
one a condensed expression of chemical science.

What then is a proposition? Simply stated, it is the assertion of
relation between two terms; or more abstractly, it is the reference of
an individual to its species--the assertion of a classification. We find
here the same duality which we noticed above. If we give prominence to
the individual notion, we consider the proposition in extension; if we
turn our attention to the specific notion we consider the proposition in
intention: in the one case referring to the individuals composing the
class, in the other to the attributes composing the class-type. The
first corresponds to induction, the second to deduction. When we study
individuals we study physics; when we study the attributes composing the
class-type, we study metaphysics. The Law of Thinking as educed from a
study of the proposition is the law of classification. The proposition,
considered affirmatively, asserts explicitly agreement between certain
attributes of two terms; that is, it asserts a classification. The aim
of science is to reach this proposition, to discover and assert the
principle of classification--in other words, to formulate metaphysically
what nature has presented physically. We must find, then, the first or
fundamental law of thinking in this _integration_ or classification.
This fundamental law may be subdivided into two species, accordin