Are There Limits to Cognition? 115realism constructs another, imperceptible reality that it
conceives as analogous to the first. Therefore, metaphys-
ical realism is necessarily dualistic.
Wherever metaphysical realism notices a relationship
between perceptible things (approaching something
through movement; something objective entering con-
sciousness, etc.) it posits a reality. Yet the relationship it
notices cannot be perceived; it can only be expressed
through thinking. This conceptual relationship is arbi-
trarily made into something akin to the perceptible. For
this line of thinking, then, the real world is composed of
perceptual objects that emerge and disappear in eternal
flux, and of imperceptible forces that produce the percep-
tual objects and endure.
Metaphysical realism is a contradictory mixture of na-
ive realism and idealism. Its hypothetical forces are im-
perceptible entities with perceptual qualities. Beyond that
region of the world for whose form of existence a means
of cognition is present in perception, it is determined to
acknowledge still another region, for which this means is
inadequate, and which can be ascertained only by think-
ing. Metaphysical realism, however, cannot, at the same
time, decide to recognize that the form of existence trans-
mitted by thinking—the concept or idea—is an equally
valid factor with perception. To avoid the contradiction of
imperceptible percepts, we must admit that the relation-
ships between percepts, as transmitted through thinking,
can have no other form of existence for us than that of
concepts. If we reject the invalid components of meta-
physical realism, the world presents itself as the sum of