a. The a priori fact of sensuous existence, the forms of sensuous existence, constitute the beginning of this transcendentalism. Kant calls the judgment of the same the transcendental æsthetic. Nowadays æsthetic signifies the knowledge of the beautiful. But here the doctrine of intuition or perception is taken from the point of view of its universality, i.e. from what in it pertains to the subject as such. Perception, says Kant, is the knowledge of an object given to us through the senses; sensuousness, however, is the capacity of being affected by conceptions as external. Now, according to Kant, in perception there are to be found all manner of contents, and in dealing with this he first of all distinguishes feeling as external, such as redness, colour, hardness, &c., and then as internal, such as justice, wrath, love, fear, pleasurable and religious feelings, &c. He says content such as this forms the one constituent and pertains to feeling; all this is subjective and merely subjective. In this sensuous element there is, however, a universal sensuous element likewise contained, which as such does not belong to feeling in so far as it is immediately determined; in such a content this ‘other’ consists in the categories of space and time, which of themselves are void and empty. The filling in is performed by the content, by colour, softness, hardness, &c., as regards space; while as regards time, the same content, so soon as it is something transient, or again some other content, and in particular inward feelings are what causes the determination. Space and time are consequently pure, i.e. abstract perceptions in which we place outside of us the content of individual sensations, either in time as succeeding one another, or in space as separate from one another. Here we thus meet with the division between subjectivity and objectivity, for if we isolate the ‘alongside of’ and ‘after’ we have space and time. It is the act of a priori sensuousness to project the content; the forms of intuition or perception constitute this pure perception.[333] Now everything indeed is termed perception, even thought and consciousness; God, who certainly pertains to thought alone, is said to be comprehended by perception or intuition, the so-called immediate consciousness.
Kant further remarks in this regard, (1) “Space is no empirical Notion which has been derived from outward experiences.” But the Notion is never really anything empiric: it is in barbarous forms like this that Kant, however, always expresses himself: “For in order that I may relate my sensations to something outside of me, I must presuppose space.” Of time Kant speaks in similar terms: “In order that something outside of me may be represented in separate space or time, the conception of space and time must come first, or it cannot be derived from experience, for experience first becomes possible through this antecedent conception.” That is to say, time and space which may appear as objective, since their particular filling in certainly belongs to subjective feeling, are not empirical; for consciousness has time and space first of all in itself. (2) “Space is a necessary conception which lies at the basis of all external perceptions. Space and time are conceptions a priori, because we cannot represent things without space and time. Time is a necessary basis for all phenomena.” As a priori, space and time are universal and necessary, that is to say we find this to be the case; but it does not follow that they must be previously present as conceptions. They are fundamental indeed, but they are likewise an external universal. Kant however places the matter somewhat in this fashion: there are things-in-themselves outside, but devoid of time and space; consciousness now comes, and it has time and space beforehand present in it as the possibility of experience, just as in order to eat it has mouth and teeth, &c., as conditions necessary for eating. The things which are eaten have not the mouth and teeth, and as eating is brought to bear on things, so space and time are also brought to bear on them; just as things are placed in the mouth and between the teeth, so is it with space and time. (3) “Space and time are not general Notions of the relations of things, but pure intuitive perceptions. For we can only represent to ourselves one space; there are not different component parts of space.” The same is the case with time. The abstract conception tree, for example, is in its actuality a number of individual and separate trees, but spaces are not such particulars, nor are they parts; for one immediate continuity remains, and hence a simple unity. Ordinary perception has always something individual before it; space or time are always however one only, and therefore a priori. It might however be replied to Kant: The nature of space and time undoubtedly involves their being an abstract universal; but there is in like manner only one blue. (4) “Each Notion or conception certainly comprises an infinite number of conceptions under itself, but not within itself; nevertheless this last is the case in space and time, and they are therefore intuitive perceptions and not Notions or conceptions.”[334] Space and time, then, are certainly not thought-determinations, if no thoughts are there present, but a Notion, so soon as we have a Notion of them.
From the transcendental point of view it is likewise maintained that this conception of space and time contains synthetic propositions a priori, connected with the consciousness of its necessity. Examples of these synthetic propositions are sought in statements such as that of space having three dimensions, or in the definition of a straight line, that it is the shortest distance between two points, and likewise in the statement that 5 + 7 = 12.[335] All these propositions are however very analytic. Kant nevertheless in the first place holds that such propositions do not take their rise from experience, or, as we might better express it, are not an individual contingent perception; this is very true, the perception is universal and necessary. In the second place he states that we acquire them from pure sensuous perception, and not through the understanding or Notion. But Kant does not grasp the two together, and yet this comprehension of them is involved in such propositions being immediately certain even in ordinary perception. When Kant then expresses himself (Kritik der reinen Vernunft, p. 49) to the effect that we have many sensations which constitute “the real matter,” with which we externally and inwardly “occupy our minds,” and that the mind has in itself in space and time “formal conditions of the mode in which we place them” (those manifold feelings) “in our mind,” the question of how mind arrives at having just these special forms now forces itself upon us. But what the nature of time and space is, it does not occur to the Kantian philosophy to inquire. To it what space and time are in themselves does not signify ‘What is their Notion,’ but ‘Are they external things or something in the mind?’
b. The second faculty, the understanding, is something very different from sensuousness; the latter is Receptivity, while Kant calls thought in general Spontaneity—an expression which belongs to the philosophy of Leibnitz. The understanding is active thought, I myself; it “is the faculty of thinking the object of sensuous perception.” Yet it has thoughts merely without real content: “Thoughts without content are void and empty, sensuous perceptions without Notions are blind.” The understanding thus obtains from the sensuous its matter, both empirical and a priori, time and space; and it thinks this matter, but its thoughts are very different from this matter. Or it is a faculty of a particular kind, and it is only when both occur, when the sensuous faculty has supplied material and the understanding has united to this its thoughts, that knowledge results.[336] The thoughts of the understanding as such are thus limited thoughts, thoughts of the finite only.
Now logic, as transcendental logic, likewise sets forth the conceptions which the understanding has a priori in itself and “whereby it thinks objects completely a priori.” Thoughts have a form which signifies their being the synthetic function which brings the manifold into a unity. I am this unity, the transcendental apperception, the pure apperception of self-consciousness. I = I; I must ‘accompany’ all our conceptions.[337] This is a barbarous exposition of the matter. As self-consciousness I am the completely void, general I, completely indeterminate and abstract; apperception is determination generally, the activity whereby I transplant an empirical content into my simple consciousness, while perception rather signifies feeling or conceiving. In order that a content may enter this One, it must be infected by its simplicity; it is thus that the content first becomes my content. The comprehending medium is ‘I’; whatever I have to do with must allow itself to be forced into these forms of unity. This is a great fact, an important item of knowledge; what thought produces is unity; thus it produces itself, for it is the One. Yet the fact that I am the one and, as thinking, the simplifier, is not by Kant satisfactorily set forth. The unity may likewise be called relation; for in so far as a manifold is presupposed, and as this on the one side remains a manifold while on the other side it is set forth as one, so far may it be said to be related.
Now as ‘I’ is the universal transcendental unity of self-consciousness which binds together the empirical matter of conception generally, there are various modes in this relationship, and here we have the transcendental nature of the categories or universal thought-determinations. But Kant (Kritik der reinen Vernunft, pp. 70, 77) approaches these modes of simplicity by accepting them as they are classified in ordinary logic. For he says that in common logic particular kinds of judgment are brought forward; and since judgment is a special kind of relationship of the manifold, the various functions of thought which ‘I’ has in it are shown therein. But the following kinds of judgment have been noticed, viz. Universal, Particular and Singular; Affirmative, Negative, Infinite; Categorical, Hypothetical, Disjunctive; Assertoric, Problematic and Apodictic judgments. These particular modes of relationship now brought forward are the pure forms of the understanding. There are thus, according to Kant (Kritik der reinen Vernunft, pp. 75, 76, 78-82), twelve fundamental categories, which fall into four classes; and it is noteworthy, and deserves to be recognized, that each species of judgment again constitutes a triad. (1) The first kind of categories are those of Quantity, viz. Unity, Plurality and Totality. Plurality is negation of the one, the assertion of difference; and the third, the bringing of the other two into one, plurality circumscribed, the indeterminate plurality comprehended as one, is the Totality. (2) In the second series are the categories of Quality: Reality, Negation, Limitation. Limitation is as real or positive as negation. (3) The third series comprises the categories of relation, of connection; and first of all, indeed, the relation of Substantiality, Substance and Accident: then the relation of Causality, the relation of Cause and Effect, and finally Reciprocity. (4) The categories of Modality, of the relation of the objective to our thought, come fourth, viz. Possibility, Existence (actuality) and Necessity. Possibility should come second; in abstract thought, however, the empty conception comes first. It betrays a great instinct for the Notion when Kant says that the first category is positive, the second the negative of the first, the third the synthesis of the two. The triplicity, this ancient form of the Pythagoreans, Neo-Platonists and of the Christian religion, although it here reappears as a quite external schema only, conceals within itself the absolute form, the Notion. But since Kant says that a conception can determine itself in me as accidental, as cause, effect, unity, plurality, &c., we thereby have the whole of the metaphysics of the understanding. Kant does not follow up further the derivation of these categories, and he finds them imperfect, but he says that the others are derived from them. Kant thus accepts the categories in an empiric way, without thinking of developing of necessity these differences from unity. Just as little did Kant attempt to deduce time and space, for he accepted them likewise from experience—a quite unphilosophic and unjustifiable procedure.
Thinking understanding is thus indeed the source of the individual categories, but because on their own account they are void and empty, they only have significance through their union with the given, manifold material of perception, feeling, &c. Such connection of sensuous material with categories now constitutes the facts of experience, i.e. the matter of sensation after it is brought under the categories; and this is knowledge generally.[338] The matter of perception which pertains to the feelings or sensuous perception is not left in the determination of individuality and immediacy, but I am active in relation to it, inasmuch as I bring it into connection through the categories and elevate it into universal species, natural laws, &c. The question of whether a completed sensuousness or the Notion is the higher may accordingly be easily decided. For the laws of the heavens are not immediately perceived, but merely the change in position on the part of the stars. It is only when this object of immediate perception is laid hold of and brought under universal thought-determinations that experience arises therefrom, which has a claim to validity for all time. The category which brings the unity of thought into the content of feeling is thus the objective element in experience, which receives thereby universality and necessity, while that which is perceived is rather the subjective and contingent. Our finding both these elements in experience demonstrates indeed that a correct analysis has been made. Kant (Kritik der reinen Vernunft, pp. 119, 120) however connects with this the statement that experience grasps phenomena only, and that by means of the knowledge which we obtain through, experience we do not know things as they are in themselves, but only as they are in the form of laws of perception and sensuousness. For the first component part of experience, sensation, is doubtless subjective, since it is connected with our organs. The matter of perception is only what it is in my sensation. I know of this sensation only and not of the thing. But, in the second place, the objective, which ought to constitute the opposite to this subjective side, is itself subjective likewise: it does not indeed pertain to my feeling, but it remains shut up in the region of my self-consciousness; the categories are only determinations of our thinking understanding. Neither the one nor the other is consequently anything in itself, nor are both together, knowledge, anything in itself, for it only knows phenomena—a strange contradiction.
The transition of the category to the empiric is made in the following way: “Pure conceptions of the understanding are quite of a different nature from empiric, indeed from any sensuous perceptions;” we have thus “to show how pure conceptions of the understanding can be applied to phenomena.” This is dealt with by the transcendental faculty of judgment. For Kant says that in the mind, in self-consciousness, there are pure conceptions of the understanding and pure sensuous perceptions; now it is the schematism of the pure understanding, the transcendental faculty of the imagination, which determines the pure sensuous perception in conformity with the category and thus constitutes the transition to experience.[339] The connection of these two is again one of the most attractive sides of the Kantian philosophy, whereby pure sensuousness and pure understanding, which were formerly expressed as absolute opposites, are now united. There is thus here present a perceptive understanding or an understanding perception; but Kant does not see this, he does not bring these thoughts together: he does not grasp the fact that he has here brought both sides of knowledge into one, and has thereby expressed their implicitude. Knowledge itself is in fact the unity and truth of both moments; but with Kant the thinking understanding and sensuousness are both something particular, and they are only united in an external, superficial way, just as a piece of wood and a leg might be bound together by a cord. Thus, for example, the conception of substance in the schema becomes permanent in time,[340] i.e. the pure conception of the understanding, the pure category, is brought into unity with the form of pure sensuous perception.
In as far as we have to deal with our own determinations only and as we do not reach the implicit, the true objective, the Kantian philosophy called itself Idealism. But in this connection Kant (Kritik der reinen Vernunft, pp. 200, 201) brings forward a refutation of empirical or material idealism, thus: “I am conscious of my existence as determined in time. But all time-determination presupposes something permanent in perception. This permanence cannot be” a sensuous perception “in me.” For all the determining grounds of my existence which are met with in me are conceptions, and as such themselves require a constant element different from them, and in relation to which the change taking place in them—consequently “my existence in time,” in which they change, “may be determined.” Or I am conscious of my existence as of an empirical consciousness which is only capable of being determined in relation to something which is outside of me; i.e. I am conscious of something external to me. Conversely it may be said: I am conscious of external things as determined in time and as changing; these hence presuppose something constant which is not in them but outside of them. And this is ‘I,’ the transcendental ground of their universality and necessity, of their implicitude, the unity of self-consciousness. On another occasion Kant regards it thus (Kritik der reinen Vernunft, p. 101): These moments confuse themselves, because the constant element is itself a category. Idealism, when we regard it as signifying that nothing exists outside of my individual self-consciousness as individual, as also the refutation of this, the assertion that things exist outside of my self-consciousness as individual, are the one as bad as the other. The former is the idealism of Berkeley, in which self-consciousness as individual is alone in question, or the world of self-consciousness appears as a number of limited, sensuous, individual conceptions, which are as completely devoid of truth as though they were called things. The truth or untruth does not rest in their being things or conceptions, but in their limitation and contingency, whether as conceptions or things. The refutation of this idealism is nothing more than calling attention to the fact that this empirical consciousness does not exist in itself—just as those empiric things do not exist in themselves. But the knowing subject does not with Kant really arrive at reason, for it remains still the individual self-consciousness as such, which is opposed to the universal. As a matter of fact there is described in what we have seen only the empirical finite self-consciousness which requires a material from outside, or which is limited. We do not ask whether these facts of knowledge are in and for themselves true or untrue; the whole of knowledge remains within subjectivity, and on the other side there is the thing-in-itself as an external. This subjectivity is however concrete in itself; even the determinate categories of the thinking understanding are concrete, and much more is experience so—the synthesis of the sensation and the category.[341]
c. The third faculty Kant finds in reason, to which he advances from the understanding after the same psychological method; that is to say, he hunts through the soul’s sack to see what faculties are still to be found there; and thus by merest chance he lights on Reason. It would make no difference if there had been no Reason there, just as with physicists it is a matter of perfect indifference whether, for instance, there is such a thing as magnetism or not. “All our knowledge begins from the senses, thence proceeds to the understanding, and finishes up with reason; nothing higher than this is to be found in us, for it signifies the working up of the material of perception, and the reducing of it to the highest unity of thought.” Reason is therefore, according to Kant, the power of obtaining knowledge from principles, that is, the power of knowing the particular in the universal by means of Notions; the understanding, on the contrary, reaches its particular by means of perception. But the categories are themselves particular. The principle of reason, according to Kant, is really the universal, inasmuch as it finds the unconditioned involved in the conditioned knowledge of the understanding. Understanding is hence for him thought in finite relations; reason, on the contrary, is thought which makes the unconditioned its object. Since Kant’s time it has become customary in the language of philosophy to distinguish understanding and reason, while by earlier philosophers this distinction was not drawn. The product of reason is, according to Kant, the Idea—a Platonic expression—and he understands by it the unconditioned, the infinite.[342] It is a great step forward to say that reason brings forth Ideas; with Kant, however, the Idea is merely the abstract universal, the indeterminate.