are termed _Analogies of Experience_, those of modality _Postulates
of Empirical Thought in General_. The first runs, "All intuitions are
extensive quantities"; the second, "In all phenomena sensation, and the
real which corresponds to it in the object, has an intensive quantity,
i.e., a degree." The principle of the "Analogies" is, "All phenomena, as
far as their existence is concerned, are subject _a priori_ to rules,
determining their mutual relation in time" (in the second edition this is
stated as follows: "Experience is possible only through the representation
of a necessary connection of perceptions"). As there are three modes of
time, there result three "Analogies," the principles of permanence, of
succession (production), and of coexistence. These are: (1) "In all changes
of phenomena the substance is permanent, and its quantum is neither
increased nor diminished in nature." (2) "All changes take place according
to the law of connection between cause and effect"; or, "Everything that
happens (begins to be) presupposes something on which it follows according
to a rule." (3) "All substances, in so far as they are coexistent, stand in
complete community, that is, reciprocity, one to another." And, finally,
the three "Postulates": "That which agrees with the formal conditions of
experience (in intuition and in concepts) is possible," "That which is
connected with the material conditions of experience (sensation) is actual"
(perception is the only criterion of actuality). "That which, in its
connection with the actual, is determined by universal conditions of
experience, is (exists as) necessary."

As the categories of substance and causality are specially preferred to the
others by Kant and the Kantians, and are even proclaimed by some as the
only fundamental concepts, so also the principles of relation have an
established reputation for special importance. The leading ideas in the
proofs of the "Analogies of Experience"--for in spite of their underivative
character the principles require, and are capable of, proof--may next be
noted.

The time determinations of phenomena, the knowledge of their duration,
their succession, and their coexistence, form an indispensable part of our
experience, not only of scientific experience, but of everyday experience
as well. How is the objective time-determination of things and events
possible? If the matter in hand is the determination of the particulars of
a fight with a bloo