They are concepts of connection， and thereby of the objects themselves， whereas the former are only concepts of a mere comparison of concepts already given， hence of quite another nature and use. By my systematic division 24 they are saved from this confusion. But the value of my special table of the categories will be still more obvious， when we separate the table of the transcendental concepts of Reason from the concepts of the understanding.
The latter being of quite another nature and origin， they must have quite another form than the former. This so necessary separation has never yet been made in any system of metaphysics for， as a rule， these rational concepts all mixed up with the categories， like children of one family， which confusion was unavoidable in the absence of a definite system of categories. 第一章Third Part Of The Main Transcendental Problem. How Is Metaphysics In General Possible？
Sect. 40. Pure mathematics and pure science of nature had no occasion for such a deduction， as we have made of both， for their own safety and certainty.
For the former rests upon its own evidence； and the latter (though sprung from pure sources of the understanding) upon experience and its thorough confirmation. Physics cannot altogether refuse and dispense with the testimony of the latter； because with all its certainty， it can never， as philosophy， rival mathematics. Both sciences therefore stood in need of this inquiry， not for themselves， but for the sake of another science， metaphysics. Metaphysics has to do not only with concepts of nature， which always find their application in experience， but also with pure rational concepts， which never can be given in any possible experience. Consequently the objective reality of these concepts (viz.， that they are not mere chimeras)， and the truth or falsity of metaphysical assertions， cannot be discovered or confirmed by any experience. This part of metaphysics however is precisely what constitutes its essential end， to which the rest is only a means， and thus this science is in need of such a deduction for its， own sake.
The third question now proposed relates therefore as it were to the root and essential difference of metaphysics， i.e.， the occupation of Reason with itself， and the supposed knowledge of objects arising immediately from this incubation of its own concepts， without requiring， or indeed being able to reach that knowledge through， experience. 25 Without solving this problem reason never is justified. The empirical use to which reason limits the pure understanding， does not fully satisfy the proper destination of the latter. Every single experience is only a part of the whole sphere of its domain， but the absolute totality of all possible experience is itself not experience. Yet it is a necessary [concrete] problem for reason， the mere representation of which requires concepts quite different from the categories， whose use is only immanent， or refers to experience， so far as it can be given. Whereas the concepts of reason aim at the completeness， i.e.， the collective unity of all possible experience， and thereby transcend every given experience. Thus they become transcendent. As the understanding stands in need of categories for experience， reason contains in itself the source of ideas， by which I mean necessary concepts， whose object cannot be given in any experience. The latter are inherent in the nature of reason， as the former are in that of the understanding.
