246 Kant: A Biography
about God must be unsound. They cannot establish knowledge in any sense.
If they are taken as establishing knowledge, they inevitably lead us to con¬
tradict ourselves. Kant tries to show that rational psychology, philosoph¬
ical cosmology, and rational theology are doomed to failure, at least if
understood as purely theoretical enterprises. These are the chapters of the
Critique that earned him the name of' "Alleszermalmer" (all-crushing). In¬
deed, Kant appears to leave little of traditional metaphysics and ontology
standing. The end result of his critical labors may seem to resemble Hume's
skepticism.
Kant puts this result in a different way — and in a way that eventually
caused great problems for him. He argues — perhaps better, asserts — that
this result is equivalent to saying that we cannot know noumena, but only
phenomena, or that we cannot know things as they are in themselves but
only as they appear to us. Thus we can never know what holds the world
together in its innermost being, or what things are apart from our con¬
ceptual apparatus. We cannot even know who or what we ourselves ulti¬
mately are. We can have a negative conception of what a noumenon is, that
is, we can say what it cannot be. Thus it cannot have spatial or temporal char¬
acteristics. Since space and time are forms of intuition, that is, part of the
epistemic conditions necessary for knowledge of appearances, things in
themselves - that is, things apart from how we must perceive them — can¬
not have perceptual characteristics. But we cannot have a positive concept
of a noumenon. It is merely a limiting concept, a placeholder for a posi¬
tion that no human concept will ever reach.
In the Paralogisms of Pure Reason, Kant tries to show that the tradi¬
tional claims about the human soul — that it is substance, that it is simple,
that it is a unity, and that it is possibly related to things in space (the four
classes of the categories are again at work here) - are based on fallacious
reasoning (i.e., on a paralogism). Kant claims that there is a transcenden¬
tal ground that tempts us to draw conclusions that do not follow from any
evidence that could possibly be given to us. To be sure, whenever we think,
we experience ourselves as subjects. But whenever we do so experience
ourselves, we can be sure that we are only "appearing" to ourselves, and
that these experiences do not provide insight into who we "really" are, in¬
dependent of experience. Empirical psychology deals with this phenom¬
enon. We know just as little about who we "really" are as we know about
things in themselves. Kant readily acknowledges that there seems to be a
"second" self, that is, the self that "has" the appearance or is "doing" the
experiencing. In his language, this is the "I think," which is a part of every