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substance, on the contrary, means to conceive such an object (the simple) as cannot be
presented to the senses. Yet, in spite of this, the cosmological idea extends the connec-
tion of the conditioned with its condition (whether this is mathematical or dynamical)
so far that experience never can keep up with it. It is therefore with regard to this point
always an Idea, whose object never can be adequately given in any experience.
§ 51. In the first place, the use of a system of categories becomes here so obvious
and unmistakable that, even if there were not several other proofs of it, this alone would
sufficiently prove it indispensable in the system of pure reason. There are only four such
transcendent Ideas, as many as there are classes of categories; in each of which, however,
they refer only to the absolute completeness of the series of the conditions for a given
conditioned. In accordance with these cosmological Ideas, there are only four kinds of
dialectical assertions of pure reason, which, being dialectical, prove that to each of them,
on equally specious principles of pure reason, a contradictory assertion stands opposed.
As all the metaphysical art of the most subtle distinction cannot prevent this opposition, it
compels the philosopher to recur to the first sources of pure reason itself. This antinomy,
not arbitrarily invented but founded in the nature of human reason, and hence unavoidable
and never ceasing, contains the following four theses together with their antitheses:
1
Thesis
The world has, as to time and space, a beginning (limit).Antithesis
The world is, as to time and space, infinite.2
Thesis
Everything in the world consists of [elements that are] simple.Antithesis
There is nothing simple, but everything is composite.3
Thesis
There are in the world causes through freedom.Antithesis
There is no freedom, but all is nature.4
Thesis
In the series of the world-causes there is some necessary being.Antithesis
There is nothing necessary in the world, but in this series all is contingent.§ 52a.Here is the most singular phenomenon of human reason, no other instance
of which can be shown in any other use of reason. If we, as is commonly done, represent
to ourselves the appearances of the sensible world as things in themselves, if we assume
the principles of their combination as principles universally valid of things in themselves
and not merely of experience, as is usually, nay, without our Critiqueunavoidably, done,
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