s three categories, the third of which in each case arises
from the combination of the second and first,[1] but, nevertheless, is an
original (not a derivative) concept, since this combination requires a
special _actus_ of the understanding. Universality or totality is plurality
regarded as unity, limitation is reality combined with negation, community
is the reciprocal causality of substances, and necessity is the actuality
given by possibility itself. Kant omits, as unnecessary here, the useful,
easy, and not unpleasant task of noting the great number of derivative
concepts _a priori_ (predicables) which spring from the combination of
these twelve original concepts (predicaments = categories) with one
another, or with the modes of pure sensibility,--the concepts force,
action, passion, would belong as subsumptions under causality, presence
and resistance under community, origin, extinction, and change under
modality,--since his object is not a system, but only the principles of
one. His liking or even love for this division according to quantity,
quality, relation, and modality, which he always has ready as though it
were a universal key for philosophical problems, reveals a very strong
architectonic impulse, against which even his ever active skeptical
tendency is not able to keep up the battle.

[Footnote 1: Concerning this "neat observation," Kant remarked that it
might "perhaps have important consequences in regard to the scientific form
of all knowledge of reason." This prophecy was fulfilled, although in a
different sense from that which floated before his mind. Fichte and Hegel
composed their "thought-symphonies" in the three-four time given by Kant.]

In view of the derivation of the forms of thought from the forms of
judgment Kant does not stop to give a detailed proof that the categories
are concepts, and that they are pure. Their discursive (not intuitive)
character is evident from the fact that their reference to the object is
mediate only (and not, as in the case of intuition, immediate), and their
_a priori_ origin, from the necessity which they carry with them, and which
would be impossible if their origin were empirical. Here Kant starts from
Hume's criticism of the idea of cause. The Scottish skeptic had said that
the necessary bond between cause and effect can neither be perceived nor
logically demonstrated; that, therefore, the relation of causality is an
idea which we--with what right?--add to perce