nor contained in it, and by means of synthetical judgements a
priori, leave far behind us the limits of experience; for example,
in the proposition, "the world must have a beginning," and such
like. Thus metaphysics, according to the proper aim of the science,
consists merely of synthetical propositions a priori.



VI. The Universal Problem of Pure Reason.

It is extremely advantageous to be able to bring a number of
investigations under the formula of a single problem. For in this
manner, we not only facilitate our own labour, inasmuch as we define
it clearly to ourselves, but also render it more easy for others to
decide whether we have done justice to our undertaking. The proper
problem of pure reason, then, is contained in the question: "How are
synthetical judgements a priori possible?"

That metaphysical science has hitherto remained in so vacillating
a state of uncertainty and contradiction, is only to be attributed
to the fact that this great problem, and perhaps even the difference
between analytical and synthetical judgements, did not sooner
suggest itself to philosophers. Upon the solution of this problem,
or upon sufficient proof of the impossibility of synthetical knowledge
a priori, depends the existence or downfall of the science of
metaphysics. Among philosophers, David Hume came the nearest of all
to this problem; yet it never acquired in his mind sufficient
precision, nor did he regard the question in its universality. On
the contrary, he stopped short at the synthetical proposition of the
connection of an effect with its cause (principium causalitatis),