tuitions (Transcendental Aesthetic).%--The first part of the
Critique of Reason, the Transcendental Aesthetic, lays down the position
that _space and time_ are not independent existences, not real beings, and
not properties or relations which would belong to things in themselves
though they were not intuited, but _forms of our intuition_, which have
their basis in the subjective constitution of our, the human, mind. If we
separate from sensuous intuition all that the understanding thinks in it
through its concepts, and all that belongs to sensation, these two forms of
intuition remain, which may be termed pure intuitions, since they can be
considered apart from all sensation. As subjective _conditions_ (lying in
the nature of the subject) through which alone a thing can become an object
of intuition for us, they precede all empirical intuitions or are
_a priori_.

Space and time are neither substantial receptacles which contain all
that is real nor orders inhering in things in themselves, but forms of
intuition. Now all our representations are either pure or empirical in
their origin, and either intuitive or conceptual in character. Kant
advances four proofs for the position that space and time are not empirical
and not concepts, but pure intuitions: (1) Time is not an empirical
concept which has been abstracted from experience. For the coexistence or
succession of phenomena, _i.e._, their existence at the same time or at
different times (from which, as many believe, the representation of time
is abstracted), itself presupposes time--a coexistence or succession is
possible only in time. It is no less false that space is abstracted from
the empirical space relations of external phenomena, their existence
outside and beside one another, or in different places, for it is
impossible to represent relative situation except in space. Therefore
experience does not make space and time possible; but space and time first
of all make experience possible, the one outer, the other inner experience.
They are postulates of perception, not abstractions from it. (2) Time is a
necessary representation _a priori_. We can easily think all phenomena away
from it, but we cannot remove time itself in view of phenomena in general;
we can think time without phenomena, but not phenomena without time. The
same is true of space in reference to external objects. Both are conditions
of the possibility of phenomena. (3) Time is not a discursive or gener