But to assume anything of this kind is against the principle of Idealism, which proposes to deduce all other things from the Intelligence. Now certain determined representations—as, for instance, of a world, of a material world in space, existing without any work of our own—are to be deduced from the action of the Intelligence; but you cannot deduce anything determined from an undetermined; the form of all deductions, the category of ground and sequence, is not applicable here. Hence the action of the Intelligence, which is made the ground, must be a determined action, and since the action of the Intelligence itself is the highest ground of explanation, that action must be so determined by the Intelligence itself, and not by anything foreign to it. Hence the presupposition of Idealism will be this: the Intelligence acts, but by its very essence it can only act in a certain manner. If this necessary manner of its action is considered apart from the action, it may properly be called Laws of Action. Hence, there are necessary laws of the Intelligence.
This explains also, at the same time, the feeling of necessity which accompanies the determined representations; the Intelligence experiences in those cases, not an impression from without, but feels in its action the limits of its own Essence. In so far as Idealism makes this only reasonable and really explanatory presupposition of necessary laws of the Intelligence, it is called Critical or Transcendental Idealism. A transcendent Idealism would be a system which were to undertake a deduction of determined representations from the free and perfectly lawless action of the Intelligence: an altogether contradictory presupposition, since, as we have said above, the category of ground and sequence is not applicable in that case.
The laws of action of the Intelligence, as sure as they are to be founded in the one nature of the Intelligence, constitute in themselves a system; that is to say, the fact that the Intelligence acts in this particular manner under this particular condition is explainable, and explainable because under a condition it has always a determined mode of action, which again is explainable from one highest fundamental law. In the course of its action the Intelligence gives itself its own laws; and this legislation itself is done by virtue of a higher necessary action or Representation. For instance: the law of Causality is not a first original law, but only one of the many modes of combining the manifold, and to be deduced from the fundamental law of this combination; this law of combining the manifold is again, like the manifold itself, to be deduced from higher laws.
Hence, even Critical Idealism can proceed in a twofold manner. Either it deduces this system of necessary modes of action, and together with it the objective representations arising therefrom, really from the fundamental laws of the Intelligence, and thus causes gradually to arise under the very eyes of the reader or hearer the whole extent of our representations; or it gathers these laws—perhaps as they are already immediately applied to objects; hence, in a lower condition, and then they are called categories—gathers these laws somewhere, and now asserts, that the objects are determined and regulated by them.
I ask the critic who follows the last-mentioned method, and who does not deduce the assumed laws of the Intelligence from the Essence of the Intelligence, where he gets the material knowledge of these laws, the knowledge that they are just these very same laws; for instance, that of Substantiality or Causality? For I do not want to trouble him yet with the question, how he knows that they are mere immanent laws of the Intelligence. They are the laws which are immediately applied to objects, and he can only have obtained them by abstraction from these objects, i. e. from Experience. It is of no avail if he takes them, by a roundabout way, from logic, for logic is to him only the result of abstraction from the objects, and hence he would do indirectly, what directly might appear too clearly in its true nature. Hence he can prove by nothing that his postulated Laws of Thinking are really Laws of Thinking, are really nothing but immanent laws of the Intelligence. The Dogmatist asserts in opposition, that they are not, but that they are general qualities of Things, founded on the nature of Things, and there is no reason why we should place more faith in the unproved assertion of the one than in the unproved assertion of the other. This course of proceeding, indeed, furnishes no understanding that and why the Intelligence should act just in this particular manner. To produce such an understanding, it would be necessary to premise something which can only appertain to the Intelligence, and from those premises to deduce before our eyes the laws of Thinking.
By such a course of proceeding it is above all incomprehensible how the object itself is obtained; for although you may admit the unproved postulates of the critic, they explain nothing further than the qualities and relations of the Thing: (that it is, for instance, in space, manifested in time, with accidences which must be referred to a substance, &c.) But whence that which has these relations and qualities? whence then the substance which is clothed in these forms? This substance Dogmatism takes refuge in, and you have but increased the evil.
We know very well: the Thing arises only from an act done in accordance with these laws, and is, indeed, nothing else than all these relations gathered together by the power of imagination; and all these relations together are the Thing. The Object is the original Synthesis of all these conceptions. Form and Substance are not separates; the whole formness is the substance, and only in the analysis do we arrive at separate forms.
But this the critic, who follows the above method, can only assert, and it is even a secret whence he knows it, if he does know it. Until you cause the whole Thing to arise before the eyes of the thinker, you have not pursued Dogmatism into its last hiding places. But this is only possible by letting the Intelligence act in its whole, and not in its partial, lawfulness.
Hence, an Idealism of this character is unproven and unprovable. Against Dogmatism it has no other weapon than the assertion that it is in the right; and against the more perfected criticism no other weapon than impotent anger, and the assurance that you can go no further than itself goes.
Finally a system of this character puts forth only those laws, according to which the objects of external experience are determined. But these constitute by far the smallest portion of the laws of the Intelligence. Hence, on the field of Practical Reason and of Reflective Judgment, this half criticism, lacking the insight into the whole procedure of reason, gropes about as in total darkness.