Chapter II: Appendix: Criticism of the Kantian Philosophy (2)

I have given it above as the chief merit of Kant that he distinguished the phenomenon from the thing in itself, explained the whole visible world as phenomenon, and therefore denied all validity to its laws beyond the phenomenon. It is certainly remarkable that he did not deduce this merely relative existence of the phenomenon from the simple undeniable truth which lay so near him, “_No object without a subject_,” in order thus at the very root to show that the object, because it always exists merely in relation to a subject, is dependent upon it, conditioned by it, and therefore conditioned as mere phenomenon, which does not exist in itself nor unconditioned. Berkeley, to whose merits Kant did not do justice, had already made this important principle the foundation-stone of his philosophy, and thereby established an immortal reputation. Yet he himself did not draw the proper conclusions from this principle, and so he was both misunderstood and insufficiently attended to. In my first edition I explained Kant’s avoidance of this Berkeleian principle as arising from an evident shrinking from decided idealism; while, on the other hand, I found idealism distinctly expressed in many passages of the “Critique of Pure Reason,” and accordingly I charged Kant with contradicting himself. And this charge was well founded, if, as was then my case, one only knew the “Critique of Pure Reason” in the second or any of the five subsequent editions printed from it. But when later I read Kant’s great work in the first edition, which is already so rare, I saw, to my great pleasure, all these contradictions disappear, and found that although Kant does not use the formula, “No object without a subject,” he yet explains, with just as much decision as Berkeley and I do, the outer world lying before us in space and time as the mere idea of the subject that knows it. Therefore, for example, he says there without reserve (p. 383): “If I take away the thinking subject, the whole material world must disappear, for it is nothing but a phenomenon in the sensibility of our subject, and a class of its ideas.” But the whole passage from p. 348-392, in which Kant expounded his pronounced idealism with peculiar beauty and clearness, was suppressed by him in the second edition, and instead of it a number of remarks controverting it were introduced. In this way then the text of the “Critique of Pure Reason,” as it has circulated from the year 1787 to the year 1838, was disfigured and spoilt, and it became a self-contradictory book, the sense of which could not therefore be thoroughly clear and comprehensible to any one. The particulars about this, and also my conjectures as to the reasons and the weaknesses which may have influenced Kant so to disfigure his immortal work, I have given in a letter to Professor Rosenkranz, and he has quoted the principal passage of it in his preface to the second volume of the edition of Kant’s collected works edited by him, to which I therefore refer. In consequence of my representations, Professor Rosenkranz was induced in the year 1838 to restore the “Critique of Pure Reason” to its original form, for in the second volume referred to he had it printed according to the _first_ edition of 1781, by which he has rendered an inestimable service to philosophy; indeed, he has perhaps saved from destruction the most important work of German literature; and this should always be remembered to his credit. But let no one imagine that he knows the “Critique of Pure Reason” and has a distinct conception of Kant’s teaching if he has only read the second or one of the later editions. That is altogether impossible, for he has only read a mutilated, spoilt, and to a certain extent ungenuine text. It is my duty to say this here decidedly and for every one’s warning.

Yet the way in which Kant introduces the _thing in itself_ stands in undeniable contradiction with the distinctly idealistic point of view so clearly expressed in the first edition of the “Critique of Pure Reason,” and without doubt this is the chief reason why, in the second edition, he suppressed the principal idealistic passage we have referred to, and directly declared himself opposed to the Berkeleian idealism, though by doing so he only introduced inconsistencies into his work, without being able to remedy its principal defect. This defect, as is known, is the introduction of the _thing in itself_ in the way chosen by him, the inadmissibleness of which was exposed at length by G. E. Schulze in “_Ænesidemus_,” and was soon recognised as the untenable point of his system. The matter may be made clear in a very few words. Kant based the assumption of the thing in itself, though concealed under various modes of expression, upon an inference from the law of causality—an inference that the empirical perception, or more accurately the _sensation_, in our organs of sense, from which it proceeds, must have an external cause. But according to his own account, which is correct, the law of causality is known to us _a priori_, consequently is a function of our intellect, and is thus of _subjective_ origin; further, sensation itself, to which we here apply the law of causality, is undeniably _subjective_; and finally, even space, in which, by means of this application, we place the cause of this sensation as object, is a form of our intellect given _a priori_, and is consequently _subjective_. Therefore the whole empirical perception remains always upon a _subjective_ foundation, as a mere process in us, and nothing entirely different from it and independent of it can be brought in as a _thing in itself_, or shown to be a necessary assumption. The empirical perception actually is and remains merely our idea: it is the world as idea. An inner nature of this we can only arrive at on the entirely different path followed by me, by means of calling in the aid of self-consciousness, which proclaims the will as the inner nature of our own phenomenon; but then the thing in itself will be one which is _toto genere_ different from the idea and its elements, as I have explained.

The great defect of the Kantian system in this point, which, as has been said, was soon pointed out, is an illustration of the truth of the beautiful Indian proverb: “No lotus without a stem.” The erroneous deduction of the thing in itself is here the stem; yet only the method of the deduction, not the recognition of a thing in itself belonging to the given phenomenon. But this last was Fichte’s misunderstanding of it, which could only happen because he was not concerned with truth, but with making a sensation for the furtherance of his individual ends. Accordingly he was bold and thoughtless enough to deny the thing in itself altogether, and to set up a system in which, not, as with Kant, the mere form of the idea, but also the matter, its whole content, was professedly deduced _a priori_ from the subject. In doing this, he counted with perfect correctness upon the want of judgment and the stupidity of the public, which accepted miserable sophisms, mere hocus-pocus and senseless babble, for proofs; so that he succeeded in turning its attention from Kant to himself, and gave the direction to German philosophy in which it was afterwards carried further by Schelling, and ultimately reached its goal in the mad sophistry of Hegel.

I now return to the great mistake of Kant, already touched on above, that he has not properly separated perceptible and abstract knowledge, whereby an inextricable confusion has arisen which we have now to consider more closely. If he had sharply separated ideas of perception from conceptions merely thought _in abstracto_, he would have held these two apart, and in every case would have known with which of the two he had to do. This, however, was unfortunately not the case, although this accusation has not yet been openly made, and may thus perhaps be unexpected. His “object of experience,” of which he is constantly speaking, the proper object of the categories, is not the idea of perception; neither is it the abstract conception, but it is different from both, and yet both at once, and is a perfect chimera. For, incredible as it may seem, he lacked either the wisdom or the honesty to come to an understanding with himself about this, and to explain distinctly to himself and others whether his “object of experience, _i.e._, the knowledge produced by the application of the categories,” is the idea of perception in space and time (my first class of ideas), or merely the abstract conception. Strange as it is, there always runs in his mind something between the two, and hence arises the unfortunate confusion which I must now bring to light. For this end I must go through the whole theory of elements in a general way.

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The “Transcendental Æsthetic” is a work of such extraordinary merit that it alone would have been sufficient to immortalise the name of Kant. Its proofs carry such perfect conviction, that I number its propositions among incontestable truths, and without doubt they are also among those that are richest in results, and are, therefore, to be regarded as the rarest thing in the world, a real and great discovery in metaphysics. The fact, strictly proved by him, that a part of our knowledge is known to us _a priori_, admits of no other explanation than that this constitutes the forms of our intellect; indeed, this is less an explanation than merely the distinct expression of the fact itself. For _a priori_ means nothing else than “not gained on the path of experience, thus not come into us from without.” But what is present in the intellect, and has not come from without, is just what belongs originally to the intellect itself, its own nature. Now if what is thus present in the intellect itself consists of the general mode or manner in which it must present all its objects to itself, this is just saying that what is thus present is the intellect’s forms of knowing, _i.e._, the mode, fixed once for all, in which it fulfils this its function. Accordingly, “knowledge _a priori_” and “the intellect’s own forms” are at bottom only two expressions for the same things thus to a certain extent synonyms.

Therefore from the doctrine of the Transcendental Æsthetic I knew of nothing to take away, only of something to add. Kant did not carry out his thought to the end, especially in this respect, that he did not reject Euclid’s whole method of demonstration, even after having said on p. 87; V. 120, that all geometrical knowledge has direct evidence from perception. It is most remarkable that one of Kant’s opponents, and indeed the acutest of them, G. E. Schulze (_Kritik der theoretischen Philosophie_, ii. 241), draws the conclusion that from his doctrine an entirely different treatment of geometry from that which is actually in use would arise; and thus he thought to bring an apagogical argument against Kant, but, in fact, without knowing it, he only began the war against the method of Euclid. Let me refer to § 15 of the first book of this work.

After the full exposition of the universal _forms_ of perception given in the Transcendental Æsthetic, one necessarily expects to receive some explanation as to its _content_, as to the way in which the _empirical_ perception comes into our consciousness, how the knowledge of this whole world, which is for us so real and so important, arises in us. But the whole teaching of Kant contains really nothing more about this than the oft-repeated meaningless expression: “The empirical element in perception is _given_ from without.” Consequently here also from the _pure forms of perception_ Kant arrives with one spring at _thinking_ at the _Transcendental Logic_. Just at the beginning of the Transcendental Logic (Critique of Pure Reason, p. 50; V. 74), where Kant cannot avoid touching upon the content of the empirical perception, he takes the first false step; he is guilty of the πρωτον ψευδος. “Our knowledge,” he says, “has two sources, receptivity of impressions and spontaneity of conceptions: the first is the capacity for receiving ideas, the second that of knowing an object through these ideas: through the first an _object_ is given us, through the second it is thought.” This is false; for according to it the _impression_, for which alone we have mere receptivity, which thus comes from without and alone is properly “given,” would be already an _idea_, and indeed an _object_. But it is nothing more than a mere _sensation_ in the organ of sense, and only by the application of the _understanding_ (_i.e._, of the law of causality) and the forms of perception, space and time, does our _intellect_ change this mere _sensation_ into an _idea_, which now exists as an object in space and time, and cannot be distinguished from the latter (the object) except in so far as we ask after the thing in itself, but apart from this is identical with it. I have explained this point fully in the essay on the principle of sufficient reason, § 21. With this, however, the work of the understanding and of the faculty of perception is completed, and no conceptions and no thinking are required in addition; therefore the brute also has these _ideas_. If conceptions are added, if thinking is added, to which spontaneity may certainly be attributed, then knowledge of _perception_ is entirely abandoned, and a completely different class of ideas comes into consciousness, non-perceptible abstract conceptions. This is the activity of the _reason_, which yet obtains the whole content of its thinking only from the previous perception, and the comparison of it with other perceptions and conceptions. But thus Kant brings thinking into the perception, and lays the foundation for the inextricable confusion of intuitive and abstract knowledge which I am now engaged in condemning. He allows the perception, taken by itself, to be without understanding, purely sensuous, and thus quite passive, and only through thinking (category of the understanding) does he allow an _object_ to be apprehended: thus he brings _thought into the perception_. But then, again, the object of thinking is an individual real object; and in this way thinking loses its essential character of universality and abstraction, and instead of general conceptions receives individual things as its object: thus again he _brings perception into thinking_. From this springs the inextricable confusion referred to, and the consequences of this first false step extend over his whole theory of knowledge. Through the whole of his theory the utter confusion of the idea of perception with the abstract idea tends towards a something between the two which he expounds as the object of knowledge through the understanding and its categories, and calls this knowledge _experience_. It is hard to believe that Kant really figured to himself something fully determined and really distinct in this object of the understanding; I shall now prove this through the tremendous contradiction which runs through the whole Transcendental Logic, and is the real source of the obscurity in which it is involved.

In the “Critique of Pure Reason,” p. 67-69; V. 92-94; p. 89, 90; V. 122, 123; further, V. 135, 139, 153, he repeats and insists: the understanding is no faculty of perception, its knowledge is not intuitive but discursive; the understanding is the faculty of judging (p. 69; V. 94), and a judgment is indirect knowledge, an idea of an idea (p. 68; V. 93); the understanding is the faculty of thinking, and thinking is knowledge through conceptions (p. 69; V. 94); the categories of the understanding are by no means the conditions under which objects are given in perception (p. 89; V. 122), and perception in no way requires the functions of thinking (p. 91; V. 123); our understanding can only think, not perceive (V. pp. 135, 139). Further, in the “Prolegomena,” § 20, he says that perception, sensation, _perceptio_, belongs merely to the senses; judgment to the understanding alone; and 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 denies.

Besides in the passages quoted, the assumption of Kant here criticised will be found expressed with admirable clearness in the “Critique of Judgment,” § 36, just at the beginning; also in the “Metaphysical Principles of Natural Science,” in the note to the first explanation of “Phenomenology.” But with a _naïveté_ which Kant ventured upon least of all with reference to this doubtful point, it is to be found most distinctly laid down in the book of a Kantian, Kiesewetter’s “_Grundriss einer algemeinen Logik_,” third edition, part i., p. 434 of the exposition, and part ii., § 52 and 53 of the exposition; similarly in Tieftrunk’s “_Denklehre in rein Deutschem Gewande_” (1825). It there appears so clearly how those disciples who do not themselves think become a magnifying mirror of the errors of every thinker. Once having determined his doctrine of the categories, Kant was always cautious when expounding it, but his disciples on the contrary were quite bold, and thus exposed its falseness.

According to what has been said, the object of the categories is for Kant, not indeed the thing in itself, but yet most closely akin to it. It is the _object in itself_; it is an object that requires no subject; it is a particular thing, and yet not in space and time, because not perceptible; it is an object of thought, and yet not an abstract conception. Accordingly Kant really makes a triple division: (1.) the idea; (2.) the object of the idea; (3.) the thing in itself. The first belongs to the sensibility, which in its case, as in that of sensation, includes the pure forms of perception, space and time. The second belongs to the understanding, which thinks it through its twelve categories. The third lies beyond the possibility of all knowledge. (In support of this, _cf._ Critique of Pure Reason, first edition, p. 108 and 109.) The distinction of the idea from the object of the idea is however unfounded; this had already been proved by Berkeley, and it appears from my whole exposition in the first book, especially chap. i. of the supplements; nay, even from Kant’s own completely idealistic point of view in the first edition. But if we should not wish to count the object of the idea as belonging to the idea and identify it with the idea, it would be necessary to attribute it to the thing in itself: this ultimately depends on the sense which is attached to the word object. This, however, always remains certain, that, when we think clearly, nothing more can be found than idea and thing in itself. The illicit introduction of that hybrid, the object of the idea, is the source of Kant’s errors; yet when it is taken away, the doctrine of the categories as conceptions _a priori_ also falls to the ground; for they bring nothing to the perception, and are not supposed to hold good of the thing in itself, but by means of them we only think those “objects of the ideas,” and thereby change ideas into experience. For every empirical perception is already experience; but every perception which proceeds from sensation is empirical: this sensation is related by the understanding, by means of its sole function (knowledge _a priori_ of the law of causality), to its cause, which just on this account presents itself in space and time (forms of pure perception) as object of experience, material object, enduring in space through all time, yet as such always remains idea, as do space and time themselves. If we desire to go beyond this idea, then we arrive at the question as to the thing in itself, the answer to which is the theme of my whole work, as of all metaphysics in general. Kant’s error here explained is connected with his mistake, which we condemned before, that he gives no theory of the origin of empirical perception, but, without saying more, treats it as _given_, identifying it with the mere sensation, to which he only adds the forms of intuition or perception, space and time, comprehending both under the name sensibility. But from these materials no objective idea arises: this absolutely demands the relation of the idea to its cause, thus the application of the law of causality, and thus understanding; for without this the sensation still remains always subjective, and does not take the form of an object in space, even if space is given with it. But according to Kant, the understanding must not be assigned to perception; it is supposed merely to _think_, so as to remain within the transcendental logic. With this again is connected another mistake of Kant’s: that he left it to me to adduce the only valid proof of the _a priori_ nature of the law of causality which he rightly recognised, the proof from the possibility of objective empirical perception itself, and instead of it gives a palpably false one, as I have already shown in my essay on the principle of sufficient reason, § 23. From the above it is clear that Kant’s “object of the idea” (2) is made up of what he has stolen partly from the idea (1), and partly from the thing in itself (3). If, in reality, experience were only brought about by the understanding applying its twelve different functions in order to _think_ through as many conceptions _a priori_, the objects which were previously merely perceived, then every real thing would necessarily as such have a number of determinations, which, as given _a priori_, absolutely could not be thought away, just like space and time, but would belong quite essentially to the existence of the thing, and yet could not be deduced from the properties of space and time. But only one such determination is to be found—that of causality. Upon this rests materiality, for the essence of matter consists in action, and it is through and through causality (_cf._ Bk. II. ch. iv.) But it is materiality alone that distinguishes the real thing from the picture of the imagination, which is then only idea. For matter, as permanent, gives to the thing permanence through all time, in respect of its matter, while the forms change in conformity with causality. Everything else in the thing consists either of determinations of space or of time, or of its empirical properties, which are all referable to its activity, and are thus fuller determinations of causality. But causality enters already as a condition into the empirical perception, and this is accordingly a thing of the understanding, which makes even perception possible, and yet apart from the law of causality contributes nothing to experience and its possibility. What fills the old ontologies is, with the exception of what is given here, nothing more than relations of things to each other, or to our reflection, and a farrago of nonsense.

The language in which the doctrine of the categories is expressed affords an evidence of its baselessness. What a difference in this respect between the Transcendental Æsthetic and the Transcendental Analytic! In the former, what clearness, definiteness, certainty, firm conviction which is freely expressed and infallibly communicates itself! All is full of light, no dark lurking-places are left: Kant knows what he wants and knows that he is right. In the latter, on the other hand, all is obscure, confused, indefinite, wavering, uncertain, the language anxious, full of excuses and appeals to what is coming, or indeed of suppression. Moreover, the whole second and third sections of the Deduction of the Pure Conceptions of the Understanding are completely changed in the second edition, because they did not satisfy Kant himself, and they have become quite different from the first edition, though not clearer. We actually see Kant in conflict with the truth in order to carry out his hypothesis which he has once fixed upon. In the Transcendental Æsthetic all his propositions are really proved from undeniable facts of consciousness, in the Transcendental Analytic, on the contrary, we find, if we consider it closely, mere assertions that thus it is and must be. Here, then, as everywhere, the language bears the stamp of the thought from which it has proceeded, for style is the physiognomy of the mind. We have still to remark, that whenever Kant wishes to give an example for the purpose of fuller explanation, he almost always takes for this end the category of causality, and then what he has said turns out correct; for the law of causality is indeed the real form of the understanding, but it is also its only form, and the remaining eleven categories are merely blind windows. The deduction of the categories is simpler and less involved in the first edition than in the second. He labours to explain how, according to the perception given by sensibility, the understanding produces experience by means of thinking the categories. In doing so, the words recognition, reproduction, association, apprehension, transcendental unity of apperception, are repeated to weariness, and yet no distinctness is attained. It is well worth noticing, however, that in this explanation he does not once touch upon what must nevertheless first occur to every one—the relation of the sensation to its external cause. If he did not intend this relation to hold good, he ought to have expressly denied it; but neither does he do this. Thus in this way he evades the point, and all the Kantians have in like manner evaded it. The secret motive of this is, that he reserves the causal nexus, under the name “ground of the phenomenon,” for his false deduction of the thing in itself; and also that perception would become intellectual through the relation to the cause, which he dare not admit. Besides this, he seems to have been afraid that if the causal nexus were allowed to hold good between sensation and object, the latter would at once become the thing in itself, and introduce the empiricism of Locke. But this difficulty is removed by reflection, which shows us that the law of causality is of subjective origin, as well as the sensation itself; and besides this, our own body also, inasmuch as it appears in space, already belongs to ideas. But Kant was hindered from confessing this by his fear of the Berkeleian idealism.

“The combination of the manifold of perception” is repeatedly given as the essential operation of the understanding, by means of its twelve categories. Yet this is never adequately explained, nor is it shown what this manifold of perception is before it is combined by the understanding. But time and space, the latter in all its three dimensions, are _continua_, _i.e._, all their parts are originally not separate but combined. Thus, then, everything that exhibits itself in them (is given) appears originally as a _continuum_, _i.e._, its parts appear already combined and require no adventitious combination of a manifold. If, however, some one should seek to interpret that combining of the manifold of perception by saying that I refer the different sense-impressions of one object to this one only—thus, for example, perceiving a bell, I recognise that what affects my eye as yellow, my hand as smooth and hard, my ear as sounding, is yet only one and the same body,—then I reply that this is rather a consequence of the knowledge _a priori_ of the causal nexus (this actual and only function of the understanding), by virtue of which all those different effects upon my different organs of sense yet lead me only to one common cause of them, the nature of the body standing before me, so that my understanding, in spite of the difference and multiplicity of the effects, still apprehends the unity of the cause as a single object, which just on that account exhibits itself in perception. In the beautiful recapitulation of his doctrine which Kant gives at p. 719-726 or V. 747-754 of the “Critique of Pure Reason,” he explains the categories, perhaps more distinctly than anywhere else, as “the mere rule of the synthesis of that which empirical apprehension has given _a posteriori_.” It seems as if here he had something in his mind, such as that, in the construction of the triangle, the angles give the rule for the composition of the lines; at least by this image one can best explain to oneself what he says of the function of the categories. The preface to the “Metaphysical First Principles of Natural Science” contains a long note which likewise gives an explanation of the categories, and says that they “differ in no respect from the formal acts of the understanding in judging,” except that in the latter subject and predicate can always change places; then the judgment in general is defined in the same passage as “an act through which given ideas first become knowledge of an object.” According to this, the brutes, since they do not judge, must also have no knowledge of objects. In general, according to Kant, there are only conceptions of objects, no perceptions. I, on the contrary, say: Objects exist primarily only for perception, and conceptions are always abstractions from this perception. Therefore abstract thinking must be conducted exactly according to the world present in perception, for it is only their relation to this that gives content to conceptions; and we must assume for the conceptions no other _a priori_ determined form than the faculty of reflection in general, the nature of which is the construction of conceptions, _i.e._, of abstract non-perceptible ideas, which constitutes the sole function of the _reason_, as I have shown in the first book. I therefore require that we should reject eleven of the categories, and only retain that of causality, and yet that we should see clearly that its activity is indeed the condition of empirical perception, which accordingly is not merely sensuous but intellectual, and that the object so perceived, the object of experience, is one with the idea, from which there remains nothing to distinguish except the thing in itself.

After repeated study of the “Critique of Pure Reason” at different periods of my life, a conviction has forced itself upon me with regard to the origin of the Transcendental Logic, which I now impart as very helpful to an understanding of it. Kant’s only discovery, which is based upon objective comprehension and the highest human thought, is the _apperçu_ that time and space are known by us _a priori_. Gratified by this happy hit, he wished to pursue the same vein further, and his love of architectonic symmetry afforded him the clue. As he had found that a pure intuition or perception _a priori_ underlay the empirical _perception_ as its condition, he thought that in the same way certain _pure conceptions_ as presuppositions in our faculty of knowledge must lie at the foundation of the empirically obtained _conceptions_, and that real empirical thought must be only possible through a pure thought _a priori_, which, however, would have no objects in itself, but would be obliged to take them from perception. So that as the _Transcendental Æsthetic_ establishes an _a priori_ basis of mathematics, there must, he supposed, also be a similar basis for logic; and thus, then for the sake of symmetry, the former received a pendant in a _Transcendental Logic_. From this point onwards Kant was no more free, no more in the position of purely, investigating and observing what is present in consciousness; but he was guided by an assumption and pursued a purpose—the purpose of finding what he assumed, in order to add to the Transcendental Æsthetic so happily discovered a Transcendental Logic analogous to it, and thus symmetrically corresponding to it, as a second storey. Now for this purpose he hit upon the table of judgments, out of which he constructed, as well as he could, the table of categories, the doctrine of twelve pure _a priori_ conceptions, which are supposed to be the conditions of our _thinking_ those very _things_ the _perception_ of which is conditioned by the two _a priori_ forms of sensibility: thus a _pure understanding_ now corresponded symmetrically to a _pure sensibility_. Then another consideration occurred to him, which offered a means of increasing the plausibility of the thing, by the assumption of the _schematism_ of the pure conceptions of the understanding. But just through this the way in which his procedure had, unconsciously indeed, originated betrayed itself most distinctly. For because he aimed at finding something _a priori_ analogous to every empirical function of the faculty of knowledge, he remarked that between our empirical perception and our empirical thinking, conducted in abstract non-perceptible conceptions, a connection very frequently, though not always, takes place, because every now and then we try to go back from abstract thinking to perception; but try to do so merely in order really to convince ourselves that our abstract thought has not strayed far from the safe ground of perception, and perhaps become exaggeration, or, it may be, mere empty talk; much in the same way as, when we are walking in the dark, we stretch out our hand every now and then to the guiding wall. We go back, then, to the perception only tentatively and for the moment, by calling up in imagination a perception corresponding to the conceptions which are occupying us at the time—a perception which can yet never be quite adequate to the conception, but is merely a temporary _representative_ of it. I have already adduced what is needful on this point in my essay on the principle of sufficient reason, § 28. Kant calls a fleeting phantasy of this kind a schema, in opposition to the perfected picture of the imagination. He says it is like a monogram of the imagination, and asserts that just as such a schema stands midway between our abstract thinking of empirically obtained conceptions, and our clear perception which comes to us through the senses, so there are _a priori schemata of the pure conceptions of the understanding_ between the faculty of perception _a priori_ of pure sensibility and the faculty of thinking _a priori_ of the pure understanding (thus the categories). These schemata, as monograms of the pure imagination _a priori_, he describes one by one, and assigns to each of them its corresponding category, in the wonderful “Chapter on the Schematism of the Pure Conceptions of the Understanding,” which is noted as exceedingly obscure, because no man has ever been able to make anything out of it. Its obscurity, however, vanishes if it is considered from the point of view here indicated, but there also comes out more clearly in it than anywhere else the intentional nature of Kant’s procedure, and of the determination formed beforehand of finding what would correspond to the analogy, and could assist the architectonic symmetry; indeed this is here the case to such a degree as to be almost comical. For when he assumes schemata of the pure (empty) _a priori_ conceptions of the understanding (categories) analogous to the empirical schemata (or representatives through the fancy of our actual conceptions), he overlooks the fact that the end of such schemata is here entirely wanting, For the end of the schemata in the case of empirical (real) thinking is entirely connected with the _material content_ of such conceptions. For since these conceptions are drawn from empirical perception, we assist and guide ourselves when engaged in abstract thinking by now and then casting a momentary glance back at the perception out of which the conceptions are framed, in order to assure ourselves that our thought has still real content. This, however, necessarily presupposes that the conceptions which occupy us are sprung from perception, and it is merely a glance back at their material content, indeed a mere aid to our weakness. But in the case of _a priori_ conceptions which as yet have no content at all, clearly this is necessarily omitted. For these conceptions are not sprung from perception, but come to it from within, in order to receive a content first from it. Thus they have as yet nothing on which they could look back. I speak fully upon this point, because it is just this that throws light upon the secret origin of the Kantian philosophising, which accordingly consists in this, that Kant, after the happy discovery of the two forms of intuition or perception _a priori_, exerted himself, under the guidance of the analogy, to prove that for every determination of our empirical knowledge there is an _a priori_ analogue, and this finally extended, in the schemata, even to a mere psychological fact. Here the apparent depth and the difficulty of the exposition just serve to conceal from the reader that its content remains a wholly undemonstrable and merely arbitrary assumption. But he who has penetrated at last to the meaning of such an exposition is then easily induced to mistake this understanding so painfully attained for a conviction of the truth of the matter. If, on the contrary, Kant had kept himself here as unprejudiced and purely observant as in the discovery of _a priori_ intuition or perception, he must have found that what is added to the pure intuition or perception of space and time, if an empirical perception arises from it, is on the one hand the sensation, and on the other hand the knowledge of causality, which changes the mere sensation into objective empirical perception, but just on this account is not first derived and learned from sensation, but exists _a priori_, and is indeed the form and function of the pure understanding. It is also, however, its sole form and function, yet one so rich in results that all our empirical knowledge rests upon it. If, as has often been said, the refutation of an error is only complete when the way it originated has been psychologically demonstrated, I believe I have achieved this, with regard to Kant’s doctrine of the categories and their schemata, in what I have said above.

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After Kant had thus introduced such great errors into the first simple outlines of a theory of the faculty of perception, he adopted a variety of very complicated assumptions. To these belongs first of all the synthetic unity of apperception: a very strange thing, very strangely explained. “The _I think_ must be able to accompany all my ideas.” Must—be able: this is a problematic-apodictic enunciation; in plain English, a proposition which takes with one hand what it gives with the other. And what is the meaning of this carefully balanced proposition? That all knowledge of ideas is thinking? That is not the case: and it would be dreadful; there would then be nothing but abstract conceptions, or at any rate a pure perception free from reflection and will, such as that of the beautiful, the deepest comprehension of the true nature of things, _i.e._, of their Platonic Ideas. And besides, the brutes would then either think also, or else they would not even have ideas. Or is the proposition perhaps intended to mean: no object without a subject? That would be very badly expressed by it, and would come too late. If we collect Kant’s utterances on the subject, we shall find that what he understands by the synthetic unity of apperception is, as it were, the extensionless centre of the sphere of all our ideas, whose radii converge to it. It is what I call the subject of knowing, the correlative of all ideas, and it is also that which I have fully described and explained in the 22d chapter of the Supplements, as the focus in which the rays of the activity of the brain converge. Therefore, to avoid repetition, I now refer to that chapter.

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That I reject the whole doctrine of the categories, and reckon it among the groundless assumptions with which Kant burdened the theory of knowledge, results from the criticism given above; and also from the proof of the contradictions in the Transcendental Logic, which had their ground in the confusion of perception and abstract knowledge; also further from the proof of the want of a distinct and definite conception of the nature of the understanding and of the reason, instead of which we found in Kant’s writings only incoherent, inconsistent, insufficient, and incorrect utterances with regard to these two faculties of the mind. Finally, it results from the explanations which I myself have given of these faculties of the mind in the first book and its Supplements, and more fully in the essay on the principle of sufficient reason, § 21, 26, and 34,—explanations which are very definite and distinct, which clearly follow from the consideration of the nature of our knowledge, and which completely agree with the conceptions of those two faculties of knowledge that appear in the language and writings of all ages and all nations, but were not brought to distinctness. Their defence against the very different exposition of Kant has, for the most part, been given already along with the exposure of the errors of that exposition. Since, however, the table of judgments, which Kant makes the foundation of his theory of thinking, and indeed of his whole philosophy, has, in itself, as a whole, its correctness, it is still incumbent upon me to show how these universal forms of all judgment arise in our faculty of knowledge, and to reconcile them with my exposition of it. In this discussion I shall always attach to the concepts understanding and reason the sense given them in my explanation, which I therefore assume the reader is familiar with.

An essential difference between Kant’s method and that which I follow lies in this, that he starts from indirect, reflected knowledge, while I start from direct or intuitive knowledge. He may be compared to a man who measures the height of a tower by its shadow, while I am like him who applies the measuring-rule directly to the tower itself. Therefore, for him philosophy is a science _of_ conceptions, but for me it is a science _in_ conceptions, drawn from knowledge of perception, the one source of all evidence, and comprehended and made permanent in general conceptions. He passes over this whole world of perception which surrounds us, so multifarious and rich in significance, and confines himself to the forms of abstract thinking; and, although he never expressly says so, this procedure is founded on the assumption that reflection is the ectype of all perception, that, therefore, all that is essential in perception must be expressed in reflection, and expressed in very contracted forms and outlines, which are thus easily surveyed. According to this, what is essential and conformable to law in abstract knowledge would, as it were, place in our hands all the threads by which the varied puppet-show of the world of perception is set in motion before our eyes. If Kant had only distinctly expressed this first principle of his method, and then followed it consistently, he would at least have been obliged to separate clearly the intuitive from the abstract, and we would not have had to contend with inextricable contradictions and confusions. But from the way in which he solves his problem we see that that fundamental principle of his method was only very indistinctly present to his mind, and thus we have still to arrive at it by conjecture even after a thorough study of his philosophy.