in § 22, that the work of the senses is to perceive, that of the understanding to think, i. e., to judge. Finally, in the “Critique of Practical Reason,” fourth edition, p. 247; Rosenkranz's edition, p. 281, he says that the understanding is discursive; its ideas are thoughts, not perceptions. All this is in Kant's own words.
From this it follows that this perceptible world would exist for us even if we had no understanding at all; that it comes into our head in a quite inexplicable manner, which he constantly indicates by his strange expression the perception is given, without ever explaining this indefinite and metaphorical expression further.
Now all that has been quoted is contradicted in the most glaring manner by the whole of the rest of his doctrine of the understanding, of its categories, and of the possibility of experience as he explains it in the Transcendental Logic. Thus (Critique of Pure Reason, p. 79; V. 105), the understanding through its categories brings unity into the manifold of perception, and the pure conceptions of the understanding refer a priori to objects of perception. P. 94; V. 126, the “categories are the condition of experience, whether of perception, which is found in it, or of thought.” V. p. 127, the understanding is the originator of experience. V. p. 128, the categories determine the perception of objects. V. p. 130, all that we present to ourselves as connected in the object (which is yet certainly something perceptible and not an abstraction), has been so connected by an act of the understanding. V. p. 135, the understanding is explained anew as the faculty of combining a priori, and of bringing the multiplicity of given ideas under the unity of apperception; but according to all ordinary use of words, apperception is not the thinking of a conception, but is perception. V. p. 136, we find a first principle of the possibility of all perception in connection with the understanding. V. p. 143, it stands as the heading, that all sense perception is conditioned by the categories. At the same place the logical function of the judgment also brings the manifold of given perceptions under an apperception in general, and the manifold of a given perception stands necessarily under the categories. V. p. 144, unity comes into perception, by means of the categories, through the understanding. V. p. 145, the thinking of the understanding is very strangely explained as synthetically combining, connecting, and arranging the manifold of perception. V. p. 161, experience is only possible through the categories, and consists in the connection of sensations, which, however, are just perceptions. V. p. 159, the categories are a priori knowledge of the objects of perception in general. Further, here and at V. p. 163 and 165, a chief doctrine of Kant's is given, this: that the understanding first makes Nature possible, because it prescribes laws for it a priori, and Nature adapts itself to the system of the understanding, and so on. Nature, however, is certainly perceptible and not an abstraction; therefore, the understanding must be a faculty of perception. V. p. 168, it is said, the conceptions of the understanding are the principles of the possibility of experience, and the latter is the condition of phenomena in space and time in general; phenomena which, however, certainly exist in perception. Finally, p. 189-211; V. 232-265, the long proof is given (the incorrectness of which is shown in detail in my essay on the principle of sufficient reason, § 23) that the objective succession and also the coexistence of objects of experience are not sensuously apprehended, but are only brought into Nature by the understanding, and that Nature itself first becomes possible in this way. Yet it is certain that Nature, the course of events, and the coexistence of states, is purely perceptible, and no mere abstract thought.
I challenge every one who shares my respect towards Kant to reconcile these contradictions and to show that in his doctrine of the object of experience and the way it is determined by the activity of the understanding and its twelve functions, Kant thought something quite distinct and definite. I am convinced that the contradiction I have pointed out, which extends through the whole Transcendental Logic, is the real reason of the great obscurity of its language. Kant himself, in fact, was dimly conscious of the contradiction, inwardly combated it, but yet either would not or could not bring it to distinct consciousness, and therefore veiled it from himself and others, and avoided it by all kinds of subterfuges. This is perhaps also the reason why he made out of the faculties of knowledge such a strange complicated machine, with so many wheels, as the twelve categories, the transcendental synthesis of imagination, of the inner sense, of the transcendental unity of apperception, also the schematism of the pure conceptions of the understanding, &c., &c. And notwithstanding this great apparatus, not even an attempt is made to explain the perception of the external world, which is after all the principal fact in our knowledge; but this pressing claim is very meanly rejected, always through the same meaningless metaphorical expression: “The empirical perception is given us.” On p. 145 of the fifth edition, we learn further that the perception is given through the object; therefore the object must be something different from the perception.
If, now, we endeavour to investigate Kant's inmost meaning, not clearly expressed by himself, we find that in reality such an object, different from the perception, but which is by no means a conception, is for him the proper object for the understanding; indeed that it must be by means of the strange assumption of such an object, which cannot be presented in perception, that the perception first becomes experience. I believe that an old deeply-rooted prejudice in Kant, dead to all investigation, is the ultimate reason of the assumption of such an absolute object, which is an object in itself, i. e., without a subject. It is certainly not the perceived object, but through the conception it is added to the perception by thought, as something corresponding to it; and now the perception is experience, and has value and truth, which it thus only receives through the relation to a conception (in diametrical opposition to my exposition, according to which the conception only receives value and truth from the perception). It is then the proper function of the categories to add on in thought to the perception this directly non-perceptible object. “The object is given only through perception, and is afterwards thought in accordance with the category” (Critique of Pure Reason, first edition, p. 399). This is made specially clear by a passage on p. 125 of the fifth edition: “Now the question arises whether conceptions a priori do not also come first as conditions under which alone a thing can be, not perceived certainly, but yet thought as an object in general,” which he answers in the affirmative. Here the source of the error and the confusion in which it is involved shows itself distinctly. For the object as such exists always only for perception and in it; it may now be completed through the senses, or, when it is absent, through the imagination. What is thought, on the contrary, is always an universal non-perceptible conception, which certainly can be the conception of an object in general; but only indirectly by means of conceptions does thought relate itself to objects, which always are and remain perceptible. For our thinking is not able to impart reality to perceptions; this they have, so far as they are capable of it (empirical reality) of themselves; but it serves to bring together the common element and the results of perceptions, in order to preserve them, and to be able to use them more easily. But Kant ascribes the objects themselves to thought, in order to make experience and the objective world dependent upon understanding, yet without allowing understanding to be a faculty of perception. In this relation he certainly distinguishes perception from thought, but he makes particular things sometimes the object of perception and sometimes the object of thought. In reality, however, they are only the object of the former; our empirical perception is at once objective, just because it proceeds from the causal nexus. Things, not ideas different from them, are directly its object. Particular things as such are perceived in the understanding and through the senses; the one-sided impression upon the latter is at once completed by the imagination. But, on the contrary, as soon as we pass over to thought, we leave the particular things, and have to do with general conceptions, which cannot be presented in perception, although we afterwards apply the results of our thought to particular things. If we hold firmly to this, the inadmissibleness of the assumption becomes evident that the perception of things only obtains reality and becomes experience through the thought of these very things applying its twelve categories. Rather in perception itself the empirical reality, and consequently experience, is already given; but the perception itself can only come into existence by the application to sensation of the knowledge of the causal nexus, which is the one function of the understanding. Perception is accordingly in reality intellectual, which is just what Kant
