Finally， all natural necessity in the sensible world is conditional， as it always presupposes the dependence of things upon others， and unconditional necessity must be sought only in the unity of a cause different from the world of sense. But as the causality of this cause， in its turn， were it merely nature， could never render the existence of the contingent (as its consequent) comprehensible， reason frees itself by means of the Theological Idea from fatalism， (both as a blind natural necessity in the coherence of nature itself， without a first principle， and as a blind causality of this principle itself)， and leads to the concept of a cause possessing freedom， or of a Supreme Intelligence. Thus the transcendental Ideas serve， if not to instruct us positively， at least to destroy the rash assertions of Materialism， of Naturalism， and of Fatalism， and thus to afford scope for the moral Ideas beyond the field of speculation. These considerations， I should think， explain in some measure the natural predisposition of which I spoke. The practical value， which a merely speculative science may have， lies without the bounds of this science， and can therefore be considered as a scholion merely， and like all scholia does not form part of the science itself. This application however surely lies within the bounds of philosophy， especially of philosophy drawn from the pure sources of reason， where its speculative use in metaphysics must necessarily be at unity with its practical use in morals. Hence the unavoidable dialectics of pure reason， considered in metaphysics， as a natural tendency， deserves to be explained not as an illusion merely， which is to be removed， but also， if possible， as a natural provision as regards its end， though this duty， a work of supererogation， cannot justly be assigned to metaphysics proper. The solutions of these questions which are treated in the chapter on the Regulative Use of the Ideas of Pure Reason 40 should be considered a second scholion which however has a greater affinity with the subject of metaphysics. For there certain rational principles are expounded which determine a priori the order of nature or rather of the understanding， which seeks nature's laws through experience. They seem to be constitutive and legislative with regard to experience， though they spring from pure reason， which cannot be considered， like the understanding， as a principle of possible experience. Now whether or not this harmony rests upon the fact， that just as nature does not inhere in appearances or in their source (the sensibility) itself， but only in so far as the latter is in relation to the understanding， as also a systematic unity in applying the understanding to bring about an entirety of all possible experience can only belong to the understanding when in relation to reason； and whether or not experience is in this way mediately subordinate to the legislation of reason： may be discussed by those who desire to trace the nature of reason even beyond its use in metaphysics， into the general principles of a history of nature；
I have represented this task as important， but not attempted its solution， in the book itself. 41 And thus I conclude the analytical solution of the main question which I had proposed： How is metaphysics in general possible？ by ascending from the data of its actual use in its consequences， to the grounds of its possibility. 第一章Solution Of The General Question Of The Prolegomena： "How Is Metaphysics Possible As A Science？"
Metaphysics， as a natural disposition of reason， is actual， but if considered by itself alone (as the analytical solution of the third principal question showed)， dialectical and illusory. If we think of taking principles from it， and in using them follow the natural， but on that account not less false， illusion， we can never produce science， but only a vain dialectical art， in which one school may outdo another， but none can ever acquire a just and lasting approbation. In order that as a science metaphysics may be entitled to claim not mere fallacious plausibility， but insight and conviction， a Critique of Reason must itself exhibit the whole stock of a priori concepts， their division according to their various sources (Sensibility， Understanding， and Reason)， together with a complete table of them， the analysis of all these concepts， with all their consequences， especially by means of the deduction of these concepts， the possibility of synthetical cognition a priori， the principles of its application and finally its bounds， all in a complete system. Critique， therefore， and critique alone， contains in itself the whole well- proved and well-tested plan， and even all the means required to accomplish metaphysics， as a science； by other ways and means it is impossible. The question here therefore is not so much how this performance is possible， as how to set it going， and induce men of clear heads to quit their hitherto perverted and fruitless cultivation for one that will not deceive， and how such a union for the common end may best be directed. This much is certain， that whoever has once tasted Critique will be ever after disgusted with all dogmatical twaddle which be formerly put up with， because his reason must have something， and could find nothing better for its support. Critique stands in the same relation to the common metaphysics of the schools， as chemistry does to alchemy， or as astronomy to the astrology of the fortune-teller.
