Silent Years 191of the sensible."^11 To be sure, sensitive knowledge presupposes the use of
certain concepts of the understanding; but this use of the understanding
is merely logical, or perhaps better, merely formal. It is of secondary im¬
portance compared to the real use of the understanding by means of which
"the concepts themselves, whether of things, or relations, are given."^12
This new thesis of the radical discontinuity of sensibility and intellect
is closely connected with two other doctrines that make their first appear¬
ance in this work — namely, that of the subjectivity of space and time, and
that of the essentially rational nature of morality. Space and time are no
longer intellectual concepts. They are subjective forms of our sensibility.
Spatio-temporal objects, or phenomena, are precisely not things in them¬
selves. All of science deals with mere phenomena. Whereas he had tried to
explain space in his earliest writings as an effect of the internal principles
of physical monads and had differentiated between mathematical and phys¬
ical space, in 1770 Kant accepted only one kind of space. It was then only
a formal characteristic of the sensible world, which could therefore be a
criterion for distinguishing phenomena from noumena. One of the rules
important for keeping metaphysics pure from any admixture of the sensible
reads: "If of any concept of the understanding whatsoever there is predi¬
cated generally anything which belongs to the relations of space and time,
it must not be asserted objectively; it only denotes the condition, in the
absence of which a given concept would not be sensitively cognizable."^13
Spatiality and temporality are negative criteria that allow us to exclude con¬
cepts from pure metaphysics.
Kant still believed in 1770 that there were concepts independent of
space and time in the required sense and that a genuine metaphysics, freed
of anything that is merely sensible, was possible. In other words, he still
believed that he could make interesting and significant claims about "things
which in themselves cannot be the objects of the outer senses (such as man
possesses)."^14 He thought it was important that we can make claims about
immaterial things that are "altogether exempt from the universal condition
of externally, namely spatially, sensible things."^15 He argued for a dogmatic
end of the understanding that was different from its merely negative elenc-
tic purpose that would keep the sensitive distinct from the noumenal. This
dogmatic end was so important to him because "in accordance with it the
general principles of the pure understanding, such as are displayed in
ontology or in rational psychology, lead to some paradigm, which can only
be conceived by the pure understanding and which is a common measure
for all other things insofar as they are realities."^16 The pure principles of