Such is the simplest idea that can be given of the Kantian theory of categories, or, if it is preferred to employ the term often used and much discussed, such is the theory of the Kantian idealism, This theory, I will say frankly, hardly harmonises with the ideas I have set forth up to this point. To begin with, let us scrutinise the relation which can exist between the subject and the object. We have seen that the existence of the subject is hardly admissible, for it could only be an object in disguise. Cognition is composed in reality of an object and an act of consciousness. Now, how can we know if this act of consciousness, by adding itself to the object, modifies it and causes it to appear other than it is?
This appears to me an insoluble question, and probably, even, a factitious one. The idea that an object can be modified in its nature or in its aspect comes to us through the perception of bodies. We see that, by attacking a metal with acids, this metal is modified, and that by heating a body its colour and form become changed; or that by electrifying a thread it acquires new properties; or that when we place glasses before our eyes we change the visible aspect of objects; or that, if we have inflammation of the eyelids, light is painful, and so on. All these familiar experiments represent to us the varied changes that a body perceived can undergo; but it must be carefully remarked that in cases of this kind the alteration in the body is produced by the action of a second body, that the effect is due to an intercourse between two objects. On the contrary, when we take the Kantian hypothesis, that the consciousness modifies that which it perceives, we are attributing to the consciousness an action which has been observed in the case of the objects, and are thus transporting into one domain that which belongs to a different one; and we are falling into the very common error which consists in losing sight of the proper nature of the consciousness and making out of it an object.
If we set aside this incorrect assimilation, there no longer remains any reason for refusing to admit that we perceive things as they are, and that the consciousness, by adding itself to objects, does not modify them.
Phenomena and appearances do not, then, strictly speaking, exist. Till proof to the contrary, we shall admit that everything we perceive is real, that we perceive things always as they are, or, in other words, that we always perceive noumena.[26]
After having examined the relations of the consciousness with its objects, let us see what concerns the perception, by the consciousness, of the relations existing between these objects themselves. The question is to ascertain whether the a priorists are right in admitting that the establishment of these relations is the work of the consciousness. The rôle of synthetic power that is thus attributed to consciousness is difficult to conceive unless we alter the definition of consciousness to fit the case. In accordance with the definition we have given and the idea we have of it, the consciousness makes us acquainted with what a thing is, but it adds nothing to it. It is not a power which begets objects, nor is it a power which begets relations.
Let us carefully note the consequence at which we should arrive, if, while admitting, on the one hand, that our consciousness lights up and reveals the objects without creating them, we were, on the other hand, to admit that it makes up for this passivity by creating relations between objects. We dare not go so far as to say that this creation of relations is arbitrary and corresponds in no way to reality; or that, when we judge two neighbouring or similar objects, the relations of contiguity and resemblance are pure inventions of our consciousness, and that these objects are really neither contiguous nor similar.
It must therefore be supposed that the relation is already, in some manner, attracted into the objects; it must be admitted that our intelligence does not apply its categories haphazard or from the caprice of the moment; and it must be admitted that it is led to apply them because it has perceived in the objects themselves a sign and a reason which are an invitation to this application, and its justification. On this hypothesis, therefore, contiguity and resemblance must exist in the things themselves, and must be perceived; for without this we should run the risk of finding similar that which is different, and contiguous that which has no relation of time or space. Whence it results, evidently, that our consciousness cannot create the connection completely, and then we are greatly tempted to conclude that it only possesses the faculty of perceiving it when it exists in the objects.[27]
According to this conception, the rôle of the consciousness in the perception of a connection is that of a witness, as in the perception of objects. The consciousness does not create, but it verifies. Resemblance is a physical property of objects, like colour; and contiguity is a physical property of objects, like form. The connections between the objects form part of the group object and not of the group consciousness, and they are just as independent of consciousness as are the objects themselves.
Against this conclusion we must anticipate several objections. One of them will probably consist in accentuating the difference existing between the object and the connection from the dynamical point of view. That the object may be passively contemplated by the consciousness can be understood, it will be said; but the relation is not only an object of perception—it is, further, a principle of action, a power of suggestion, and an agent of change.