ed the eyes of the world to the fact that the forms of
knowledge are also the property of the subject. I know things only as they
appear to me, as I represent them in virtue of the constitution of my
intellect; the world is my idea. The Kantian theory, however, is capable of
simplification, the various forms of cognition may be reduced to a single
one, to the category of causality or principle of sufficient reason--which
was preferred by Kant himself--as the general expression of the regular
connection of our representations. This principle, in correspondence with
the several classes of objects, or rather of representations--viz., pure
(merely formal) intuitions, empirical (complete) intuitions, acts of will,
abstract concepts--has four forms: it is the _principium rationis essendi,
rationis fiendi, rationis agendi, rationis cognoscendi_. The _ratio
essendi_ is the law which regulates the coexistence of the parts of space
and the succession of the divisions of time. The _ratio fiendi_ demands for
every change of state another from which it regularly follows as from its
cause, and a substance as its unchangeable substratum--matter. All changes
take place necessarily, all that is real is material; the law of causality
is valid for phenomena alone, not beyond them, and holds only for the
states of substances, not for substances themselves. In inorganic nature
causes work mechanically, in organic nature as stimuli (in which the
reaction is not equal to the action), and in animated nature as motives.
A motive is a conscious (but not therefore a free) cause; the law of
motivation is the _ratio agendi_. This serial order, "mechanical cause,
stimulus, and motive," denotes only distinctions in the mode of action, not
in the necessity of action. Man's actions follow as inevitably from his
character and the motives which influence him as a clock strikes the hours;
the freedom of the will is a chimera. Finally, the _ratio cognoscendi_
determines that a judgment must have a sufficient ground in order to be
true. Judgment or the connection of concepts is the chief activity of the
reason, which, as the faculty of abstract thought and the organ of science,
constitutes the difference between man and the brute, while the possession
of the understanding with its intuition of objects is common to both. In
opposition to the customary overestimation of this gift of mediate
representations, of language, and of reflection, Schopenhauer gives
prom