On p. 137 of the fifth edition, it is the faculty of knowledge generally. On p. 132; V. 171, it is the faculty of rules. On p. 158; V. 197, however, it is said: “It is not only the faculty of rules, but the source of principles (Grundsätze) according to which everything comes under rules;” and yet above it was opposed to the reason because the latter alone was the faculty of principles (Principien). On p. 160; V. 199, the understanding is the faculty of conceptions; but on p. 302; V. 359, it is the faculty of the unity of phenomena by means of rules.
Against such really confused and groundless language on the subject (even though it comes from Kant) I shall have no need to defend the explanation which I have given of these two faculties of knowledge – an explanation which is fixed, clearly defined, definite, simple, and in full agreement with the language of all nations and all ages. I have only quoted this language as a proof of my charge that Kant follows his symmetrical, logical system without sufficiently reflecting upon the subject he is thus handling.
Now, as I have said above, if Kant had seriously examined how far two such different faculties of knowledge, one of which is the specific difference of man, may be known, and what, in accordance with the language of all nations and all philosophers, reason and understanding are, he would never, without further authority than the intellectus theoreticus and practicus of the Schoolmen, which is used in an entirely different sense, have divided the reason into theoretical and practical, and made the latter the source of virtuous conduct. In the same way, before Kant separated so carefully conceptions of the understanding (by which he sometimes means his categories, sometimes all general conceptions) and conceptions of the reason (his so-called Ideas), and made them both the material of his philosophy, which for the most part deals only with the validity, application, and origin of all these conceptions; – first, I say, he ought to have really examined what in general a conception is. But this very necessary investigation has unfortunately been also neglected, and has contributed much to the irremediable confusion of intuitive and abstract knowledge which I shall soon refer to. The same want of adequate reflection with which he passed over the questions: what is perception? what is reflection? what is conception? what is reason? what is understanding? allowed him to pass over the following investigations, which were just as inevitably necessary: what is it that I call the object, which I distinguish from the idea? what is existence? what is object? what is subject? what is truth, illusion, error? But he follows his logical schema and his symmetry without reflecting or looking about him. The table of judgments ought to, and must, be the key to all wisdom.
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
