Are There Limits to Cognition? 111the eye. “Nothing exists that cannot be perceived” is ac-
tually the first axiom of the naive human being, and its
converse is seen as equally valid: “Everything that can be
perceived exists.” The best proof of this assertion is the
naive human belief in immortality and in spirits. The na-
ive realist imagines the soul as fine, sense-perceptible
matter, which under certain circumstances, can even be-
come visible to ordinary human beings (i.e., the naive be-
lief in ghosts).
Compared to their “real world,” naive realists see ev-
erything else, such as the world of ideas, as unreal, as
“merely conceptual.” What we add to objects through
thinking are mere thoughts about things. Thought adds
nothing real to a percept.
But naive persons hold sense perception to be the sole
evidence of reality, not only for the existence ofthings,
but also for events. In this view, one thing can only affect
another if a sense-perceptible force proceeds from the one
and touches the other. In ancient physics, it was believed
that very fine matter streams out from objects and pene-
trates our souls through our sense organs.^3 Actually see-
ing such matter was said to be impossible only because of
the crudeness of our senses in comparison to the fineness
of the matter. In principle, this kind of matter was accord-
ed reality on the same grounds by which reality is accord-
ed to the objects of the sense-world— namely, because of
its mode of existence, which was thought of as analogous
to that of sense-perceptible reality.
- For instance, Plato’sTimaeus.