Let us briefly consider the ground upon which Kant bases his view of the
ideality of space and time. Kant asks:
“What then are time and space? Are they real existences? Or are
they merely relations or determinations of things, such however
as would equally belong to these things in themselves, though
they should never become objects of intuition; or _are they
such as belong only to the form of intuition, and consequently
to the subjective constitution of the mind_, without which
these predicates of time and space could not be attached to any
object?”[43] (Kr. d. r. V. § 2; “Meiklejohn,” p. 23.)
We should say, to state our opinion briefly, that space and time are not
“real existences,” i. e. they are not concrete objects, but they are real
nevertheless; they are not material things; not thingish realities, yet
they are objective properties of things. They are the forms of things
and processes, and belong to the things whether they become objects of
cognition or not. In this sense, they actually belong to the things in
themselves, viz. to the objective things.
Kant argues that space and time are not conceptions derived from outward
experience; they have not been abstracted from sense-impressions. They
are necessary representations _a priori_, they are not discursive ideas
or generalisations, for there is but one space and one time, space being
represented as infinite and time as eternal.
From these arguments Kant draws the conclusions that space and time do
not represent qualities of an object but that they are the form of all
sensory phenomena, space being the form of the external, time of the
internal sense. In other words, space and time belong to the subjective
condition of the sensibility and not to the objective world.
We answer that our conceptions of space and time are after all derived
from experience. Space and time are abstractions. There is no time in
itself. There is no space in itself. Space and time are not directly
derived from outward experience, nor are they derived from the
sense-elements of experience. Inner experience, i. e. reflection to the
exclusion of sense-impression, the experimenting with pure forms, will
lead to the construction of the concepts of space as well as of time.
Space and time, magnitudes and numbers having been constructed in the
mind of a thinking subject are applied to practical experience. When
counting three trees we do not abstract the number “three” from the three
trees, but we apply to them the system of numbers in our possession.
Says Kant:
“We never can imagine or make a representation to ourselves
of the non-existence of space, though we may easily enough
think that no objects are found in it. It must therefore be
considered as the condition of the possibility of phenomena and
by no means as a determination dependent upon them and is a
representation _a priori_, which necessarily supplies the basis
for external phenomena.”
Space being the generalised concept of extended form, and time that of
motion without reference to any contents, it is naturally impossible to
think the non-existence of space and time. Thinking is an act, it is a
process; and any act, any process, any event, is a reality which implies
or presupposes the existence of the forms of reality. We can think of
matter without reference to form, i. e. we can have the abstract idea
of matter; but we cannot think that there is any matter void of form.
This does by no means prove that form has nothing to do with matter. On
the contrary, it proves that form and matter are inseparable. The form
of existence need not therefore be called “the basis” of existence, it
is simply one universal feature of existence. And the form of existence
being bound up with existence itself, it is necessary that any thinking
existence in so far as it is real, in so far as it is at the same time
an object and part of the objective world should also be in possession
of the conditions to evolve the idea of form out of itself through inner
experience.
This inner experience of experimenting with pure forms is also a kind of
experience. It is not a purely subjective process; it is a subjective
process to the thinking subject, which to other subjects, however, would
appear as an objective process. The laws of pure form as stated in the
sciences of purely formal thought, are not merely subjective; they
possess objective validity. It is true and from our standpoint a matter
of course that the laws of form are _a priori_, which means, they hold
good for any pure form.
Modern positivism, such as we defend it, is monistic. We consider the
entire world as one great whole and do not forget that all noumenal
representations of certain features of the world, of matter, mind, form,
even of things and our own souls included, are mere abstractions. Reality
itself remains undivided and indivisible. Abstract concepts are mental
symbols invented to represent certain features of reality. But although
we can in our mind separate these features and distinguish them from
other features, in the world of reality they cannot be cut out or thought
of as things in themselves. Granting the oneness of reality which dawns
upon us instinctively before consciousness is fully matured, we are
inevitably led to the conception that there is but one form of reality,
which implies that there is but one space and one time.