This is the question that rational philosophy of necessity must raise when it has arrived at its consciousness; in fact, it is that in which its consciousness consists. The result of the investigation with Kant is: we have no pure rational knowledge (no synthetic judgement a priori). For knowledge only vouchsafes the form of knowledge, while the material comes to us through experience, i.e., by means of the impressions of external objects upon our senses. Only both factors together provide knowledge. For example, the statement of pure reason: “everything that occurs has a cause,” is not yet knowledge; a specific occurrence and a specific something that is its cause are obligatory for it to become knowledge. All our knowledge, then, is experience-knowledge, and beyond possible experience, hence of transcendental [übersinnlichen] things that do not affect our senses (God, freedom), we can have no knowledge at all.
But there is more than this!
Even our actual knowledge, thus experience-knowledge, is untrue, for we only attain it through the medium of both of our sensory perspectives space and time, and these are merely our (subjective) inherent forms without truthful (objective) existence. It is not the existence of things that is subject to doubt, but the opposite: without this, we would have no sensory impressions and thus no notions [Vorstellungen] at all. Only its true quality (“the thing in itself”) is not perceived, because things (objectively) do not consist in space and time, while we can only observe them as in space and time. Our knowledge therefore receives only phenomena, not the things in themselves. And the objects of our knowledge (not, of course, the objects in themselves) comply with our method of knowledge, and not the other way around.
The sum is this: we have absolutely no knowledge of transcendental things, and our knowledge of sensory things is mistaken, it yields us only the phenomenon, not the thing in itself. That, then, would be a renunciation of all knowledge. But now comes help: all of this is only true of theoretical reason, that is, thought directed to perceiving objects that are extant outside of itself. By contrast, practical reason, that is, thought directed to the generation of objects (actions) that are not already in existence, thus where it manifests itself as ought, discovers these objects as goal without external impressions on the senses and therefore apart from the medium of space and time, purely from its own laws. To wit, there is a commandment of the good within us, which we do not derive from experience and which commands us to do the good without taking experience into consideration, i.e., without taking a consequence, a utility, a convenience to us, into account, but only for the sake of the good – a “categorical imperative.” This then is pure rational knowledge. From this unconditional commandment of the good follow, purely a priori, freedom, immortality, God: freedom, because without a commandment it would be preposterous; immortality or a world beyond this world, because reward and punishment do not follow upon fulfillment or violation of that which reason consistently must require; God, because without Him reward and punishment could not be realized. Practical reason, accordingly, is the area in which truly pure rational knowledge (synthetic judgement a priori) exists; through it alone, therefore, we gain knowledge of transcendental things, and only its knowledge is true and reliable, while theoretical knowledge, because it borrows from experience, is fictitious.
Its scientific motivation
The way of the Kantian system, as is known, is this: we construct all of our knowledge via certain forms and concepts which we do not draw from experience, but already must have within ourselves prior to our being capable of any knowledge, e.g., the relation of cause and effect. We would not consider actual causes and effects in terms of these relations, but as isolated phenomena, if this was not implanted in us prior to all observation. The epitome of these forms and laws of thought is reason.
The question is whether reason, without which we can have no experience, is also capable of vouchsafing us knowledge without experience (a priori). This does not have to do with such knowledge that contains nothing other than what reason is in itself, a mere expansion of that which lies in the essence of those forms (analytical knowledge), e.g., that the cause precedes the effect, which is precisely what the concept of cause expresses. Rather, it concerns the knowledge of objects outside of its own forms (synthetic knowledge), e.g., God, immortality: “are synthetic judgements possible a priori?”
Obviously this fictitious nature of all experience, which is the basis upon which Kant puts experience, is no mere doubt but a positive certain conception, and at once presents itself as the actual character of his system. That by which Kant is forced into this conception must be demonstrated, in order to bring the essence of the critical philosophy to clarity.
The basis upon which it is supported is the assumption that space and time, chiefly however, that time is merely a notion pertaining to our own sensorial nature, corresponding to nothing in the object. Kant of course deduced from this fictitiousness of the notion of time, that time has no subsisting and no inherent existence in things, nor is it a deduced concept. But such a reasoning regarding an individual element of knowledge cannot possible be the deepest mainspring of a system upon which a philosophical epoch is grounded. With the same reasoning, could have denied the truthfulness and objectivity of all logical forms (cause and effect – unconditional). Rather, it is grounded on a much deeper mainspring, which itself first determines this reasoning.
Every glimpse of the world shows change, act. But rational coherence is timeless – “general and necessary.” Should Kant wish to recognize this changing world, he would have to recognize a cause and a coherence of the same, which reason isn’t, and therefore cannot find either. That would be impossible for it, because it would contradict the basic conception of rational philosophy. If he should wish to deny the existence of changing things, then he would also find this to be impossible, in that he very well saw and declared that without the existence of these things it would be absolutely impossible to comprehend why we imagine this or that and not always the same thing, and that the thought forms are not yet knowledge unto themselves [für sich], but require an object and content for that.
There remained only one escape for him: maintain both: there is rational coherence, and things really exist, and only deny the rock of offense, the mutable character of the latter. He builds his system upon this foundation. Space and time are only fictitious because they are the forms of mutability. In Kant’s view, if we weren’t bound to these forms, “the same determinations which we now perceive as change, yield knowledge in which the perception of time and thereby that of change does not even arise,” and in that case we would recognize the true nature of things. But now, space and time are the medium for all knowledge of extant objects; this can, then, only yield phenomena. In this way he solves the difficulty that denies mutability, causality, act concurrently with time, indeed as reality itself being nothing other than “filling time,” so that only mere logical relations remain, everything shrinks to mere determinations of thought as in a mathematical point. This is the fundamental perception, and rationalistic philosophy by no means gains it from investigation, but rather unconsciously brings it into the investigation. Kant believes he can flee from the resultlessness of this result, to the area of practice. That is to say, thought as ethical requirement requires objects that are timeless, eternal, immutable. For it was the undoubted presumed notion of his time, that the ethos is a system of mere logically connected rules, and this notion cannot be refuted as mere logical coherence in physical things could, by any and every glance at the world. The ethos only could be accepted if it were based upon mere rational coherence. Here or nowhere could pure a priori be recognized, and the results thereby attain the certainly of logical laws. God, immortality, and freedom had to be demonstrated on these grounds in order to be elevated beyond any doubt.
The relation of Kant to Spinoza
Thus this entire system is driven from out of the basic assumption of rationalism: there is no change. Spinoza asserts the rational coherence of the actual world. Kant, by contrast – both the later Kant, and the Kant prompted to investigate by the effort of the Wolffian school – had the insight that the world of experience does not allow the problem to be solved, that we here find undeniable change, freedom, act. He therefore abandons this world as fictitious, and flees from it with his rule of reason into another, which he first fabricates by his thought, in which he is capable of completing the task because he first institutes it in terms of the task. He seeks an unconditional, a causa sui in Spinoza’s sense, i.e., such a one that is not the first like God, but which our thought contains as initial notion. For him, that is the notion of unconditionality itself with the character of universality and necessity that necessarily adheres to it. From this, likewise according to logical laws, all actions must flow; in this consists the ethos. It may produce nothing else, or else it would no longer be unconditional, as its concept testifies, the foundation of the conditioned. For this reason it postulates freedom of the will. That is to say, being determined by covetousness (thus by objects outside of thought) is denied, but likewise every motive outside of rational thought itself – love, exaltation as well as self-interest – is rejected as contrary to morality. Hence, reason requires actions categorically, unconditionally, only as consequences of itself. Good and evil are not characteristics that precede our thought, and condition it; rather, they first arise through the form of universality and necessity that underlie our thought. But the ought itself is after all a real power and contains in itself the notion of change, since an action is to be generated which does not yet exist. The world of phenomena had therefore to be surrendered. Thought manifests itself to us as ought, the imperative, as commandment and prohibition, only because we belong to the fictitious world of change. Apart from this, there would be no question of ought; rather, reason would itself faultlessly accomplish the actions that flow from it; considered more precisely: there would be no ought and no act, but rather reason would exist simultaneously with its consequences. Not only the condition of action but also the condition of the intelligible world would be deduced from that unconditional. As proposition [Satz] of universality (non-contradiction) it contains the agreement of the act corresponding to it and its consequences for happiness, thus a condition of allocation according to desert (“the highest good”) and a world disposer that makes this happen – God. The latter, as product of that unconditional, is therefore bound to the law thereof, and cannot exercise pardon and grace. The actual God is therefore also in this intelligible world the abstract thought of logical universality and necessity, a God without understanding and will, as with Spinoza.
Contradiction in Kant’s demand on reason
This explains that Kant completely grasped and followed the canon of Spinoza. The construction of his intelligible ordering is arranged entirely in accordance with it, even though for the things of observation he surrenders it. For this reason, a double world runs through the Kantian system: that of the phenomenon, i.e., the real coherence of act and event, and that of the essence, i.e., logical coherence, while Spinoza solely recognized the latter, and believed he had resolved the former by [referring to the] lack of taking the latter into account. For Spinoza, the world, as we observe it, is merely the unconditional in terms of its concept, with its necessary consequences. Kant recognizes these observations as something entirely different, and therefore also fictitious; but the ethical actions, the intelligible ordering, i.e., the true existence of things, for him as well is only the substance which underlies all thought (universality and necessity) and its affections. Spinoza denies freedom (the choice to do this or that) in the real world. Kant assumes this, and names it freedom of caprice; only he likewise denies it in the real world, where everything is necessity: reason contains the actions appropriate to it, the last judgement [das Weltgericht], etc., without choice. This unavoidable being-determined by reason Kant calls freedom of the will in contrast to freedom of arbitrariness. With Spinoza nothing can occur in the real world which is not necessary and thus just. The distinction between good and evil drops away. With Kant such can occur, and it is only in the kingdom that we ourselves have to construct or that lies beyond our experience, that this infallibility lies. It therefore does not need to justify the evil that experience demonstrates; in the realm of phenomena it can praise and reject, and is empowered to establish tasks which are not already fulfilled, and for which we are given the choice, as appears to us, to design a real ethics. – So, it appears that both of these apparently scarcely related systems, which above all construct the shrillest contradictions in ethics, nevertheless in turn are based on one and the same basic demand.
Usurpation for practical reason
Kant is generally accused of a string of inconsequentialities, but they have their deep origin in the task that he gives to all philosophy and which he must of necessity give to it, holding fast, as he did, to rational philosophy and nevertheless not blinded by it. For this task is in itself contradictory. From pure reason it requires synthetic knowledge, i.e., knowledge in which predicates are not derived from a concept, that are already given with that concept, but rather others that are not contained in it. “That are not contained in it” – what is that, other than: those which, according to reason, by their existence, are not inseparably bound to it, thus through a cause outside of reason. If Kant thereby only wanted rational coherence and knowledge from reason, he would have required no synthetic judgement, he would simply have had to deny the possibility of such. Or, there is no synthesis. There are effects, predicates, which are not contained in their causes, but could be produced or omitted by them. In that case, however, there is, in truth, act and change, even if the form of time and space would be the prejudice of the senses; in that case, it is not possible to consider the relation of things as in truth immutable, to recognize them through the capability of the necessary (reason), because it is free, not a priori, because it is directed not in terms of the laws of thought but according to causes, which precipitate change.
One might attempt to consider this dilemma itself as a product of our prejudice, the truth being that the immutable yet is a connection of new, and thus an object of synthetic, knowledge; that would be inconceivable to us. By that, one would have jumped beyond all ground of human thought and imagination, where no further examination can follow; but this vocation would by no means be in Kant’s spirit. For the form of sensory observation acquires it; by no means the logical law of contradiction. But now it has been shown that without reference to time and space, simply in terms of thought, synthetic knowledge and change are inseparable concepts, while on the other hand, synthetic knowledge and mere rational coherence (thus finding from reason) are contradictory.
Basis of the deception
Therefore, it is quite natural that this greatest of all investigators, who by virtue of the strict account he everywhere renders, undoubtedly lays claim to the rank of the most thoroughgoing and venerable of all rational philosophers, by his investigations was led to this place: reason vouchsafes no synthetic knowledge in the theoretical sphere. But when it nevertheless commits the contradiction in the practical sphere, it deceives itself only through the following confusion: our sense of ought, of impulse [Drang], of longing in us really precedes all sensory impressions, and insofar is a priori and certainly also has a synthetic force, it impels to certain actions, requires conditions, and points with certainty to a relation with God, the future, and blessedness. Only this impulse is not reason, it is a real power and in terms of its innermost essence continues to have an effect as act and change, by no means in logical manner, by no means according to the nature of reason. It is also, even though free of visible influences and elevated above them, still not an initiating cause but rather effected by a higher cause preceding it and distinguished from it. Precisely the character in it by which it is what it is and by which it alone can have the synthetic power to generate something from itself, to wit, the real, the force – it is precisely that character that Kant denies to it and declares it to be a delusion. What he allows to remain to it as truthful, the emptied thought of the a priori – this the synthetic power does not have. He thus employs the real impulse (which he has denied) to attribute its force to thought, which in terms of its nature it cannot have.
Three inconsistencies in his practical philosophy stemming from this
From this stem the inconsistencies of his practical reason, among which these three can be distinguished: that a real moral law follows from pure reason; that from this moral law not only actions but also conditions can be commanded; and finally, that not merely practical but also theoretical knowledge can be derived from it.
It is precisely the world of act which, in the case of what is to be known, transcends thought; it is precisely this which Kant also needs in the knowledge of what is to be produced. Like every idea, every commandment must also have an object, and this – the action, the human relation – pertains to the world which he regards as mere appearance, and which bears its character through and through. He cannot escape the fact that the essence of practical reason itself does not appear to us otherwise, for it is affected by this world, as an ought, as a free production of something new. The rational law of universality and necessity can be as little a practical commandment as the categories, or the unity of apperception, knowledge. If Kant, according to this law of reason, assumes the content, “act in such a way that thereafter all rational creatures can exist,” then he has thus drawn upon the entire world of appearance, and that which he denied in theoretical philosophy, he recognizes as true. Because living things, that they may exist or be annihilated, are things of which pure thought knows nothing. That a wound yields death, that withdrawal of food causes hunger, which one does not have from eternity, in short, continued existence and destruction are change, already in terms of thought. The highest truth and the summit of the system, the last judgment, presupposes that action has been taken, and arbitrarily taken, that it has been altered, and thus contains analytically that which is absolutely denied. How can practical reason, since it must draw upon experience, extend beyond the limits of possible experience, and how can truth arise? But if it does not draw on experience, the law of universality and necessity requires nothing other than that something does not cancel itself, and this something is again nothing other than the form of conceptual unity itself, as it is also subject to theoretical reason. That thought be thought, is the only content that the imperative can have.
If reason is the cause of the practical commandments and therefore determines their content, they can, as shown above, require only the actions of the individual. In Kant, however, their object is also the existence of general conditions, for example, the state directly and in its entirety, punishment as retributive justice. Kant confesses that this contradicts the original essence of reason, but it is capable of “expanding itself a priori by such postulates.” The real impulse of the ought in us is capable of such an expansion, such a pursuit of a world outside us; reason is not.
Through such expansion, Kant finally also succeeds in deriving theoretical results from practical thinking. Namely, God, immortality, the last judgment, from which practical reason does not grant the insight that we are effectuating them, or that they should exist, but that they really exist, where, therefore, practical reason, contrary to its own concepts, is directed not to the production of objects but to the knowledge of existing ones. In this, Kant is supported by his denial of time and change; for with this the difference between theoretical and practical cognition is really abolished; future and present, will and being become the same. The act, the choice, which, already in terms of words separates the practical from the theoretical, is precisely what is abandoned as untrue. Now here as well, the inner contradiction of the system should be most striking. While reason requires conditions of a certain sort, Kant recognizes its requirement (the future, dependent upon choice) as true, but not its fulfillment, for example, that a state would really exist. In invoking conditions of another sort, he recognizes not only the requirement, but also the fulfillment as being inevitable, e.g., God, immortality, the last judgment. He should have said: Reason demands the state, criminal justice, God, the last judgment, and its requirement, its ought-to-exist is true, and it is because reason commands it, which can have no other standard of truth; but whether they really exist is a question with which practical reason has nothing to do. Or he had to say: that which practical reason demands, also exists necessarily. But then not only God and immortality, but also the universal reasonableness of our actions; and this obviously contradicts the facts.
So stands Kant with regard to rational dogmatism, both for the consistent one of Spinoza’s and for the vague arbitrary one of the Wolffian school. The latter deduce the existing world of change from their unchanging laws of thought. Kant shows that this to be contradictory, but then he himself makes this contradiction, by deducing from the premisses a moral world, which also includes action and change.
Impetus to further development: transcendental philosophy, result of Fichte’s and Kant’s standpoints
It lay within the essence of Kant’s criticism to become the impulse of a completely new development. The contradiction of pure thought and of the real world produced his system, and his activity, therefore, must be directed sharply to separate these opposites. Thereby, rational philosophy was not merely brought to the consciousness of its enterprise, but also inwardly, while with the separation, reason makes itself an object of its reflection. The earlier [philosophers] contemplated the world, into which they tacitly brought thought. Kant contemplates thought itself. In technical terms: transcendental philosophy arises, the philosophy which observes its own consciousness even as it takes up its objects, activity, the means of which it makes use. This measured separation of the faculty of knowledge from its objects, however, necessarily provokes a new philosophical question, namely, how is not merely the perception of the truth possible, but perceptibility at all? How do the two divorced worlds, reason and the objects outside of reason, unite into one, even if erroneous, idea? This question is deeply rooted in the essence of abstract philosophy and the subjective principle. The man who breaks away from the world must wonder: how can this world still excite ideas in me? The investigations of Descartes, Spinoza, and Leibniz on the connection between the body and the soul are already echoes of it. Now, however, the entire fate of philosophy has been laid upon it, and for the present it is crowding out everything else which is ultimately to be dealt with, which Kant himself pronounced to be the actual tasks, those regarding God, immortality, freedom. The development of philosophy is now continuing on this thread, and it is as if humanity will have attained its goal if it could explain how it came to imagine something.
The explanation which first presents itself, which Kant therefore, as the starting point, avails himself of, is that: things make sensory impressions upon us, we lend to this the form of reason, both together is imagination [Vorstellung]. However, a close inspection shows the inadequacy of this explanation, and this led to the system of Fichte. The impression on the senses, namely, is quite without reason, is purely physical; it cannot, therefore, become something intelligible, no matter the elevation; otherwise, one would be able to construct thinking just as well through physical ingredients. A thing is not a thought and can never become one, and the thought form can only be affected by a thought, not by a body and a physical effect. Thus, the connection between the two would be impossible. Kant did not here, in theoretical reason, have the truth of imagination, as in his practical deductions, but yet usurps the existence thereof. –
But why is it that he cannot establish a connection between reason and things, since, as experience shows, such really exists? The reason for this, as Fichte demonstrates, is that he contemplates reason as a still form, and consequently as a thing. A thing and another thing that is set over against it, will always remain apart. It was therefore necessary to regard reason as acting, not as the determinations of thought and laws, but as the activity of thought. This was the precondition for explaining this connection. In what manner it was to be explained, however, was in turn motivated for Fichte by the stage of the Kantian system. The previous philosophy generally had the conviction that only reason is true. Kant shared this conviction, but at the same time expressed what lies in it, namely, that things are untrue. Nevertheless he asserted their truth, but only as a veiled one. But this cannot mean anything other than: if things had been properly recognized, it would have to be understood that they too are nothing but reason, but that they are not reason alone. Kant thus unconsciously asserted it, and Fichte had only to explain it. But in doing so he completed his explanation of imagination [Vorstellens]. In other words, reason is both the forms of thought and the things, but it is both only by producing them in their activity. If, for example, the relation of cause and effect, which is of reason and not of experience, is analyzed, then there is already in it this, that something, one thing, produces the other thing. Hence, pure reason contains objects, and the Kantian distinction cannot be preserved at all; rather, the inevitable spillover from the form of reason to the object outside of it proves that they are not separate things, indeed they are not things at all, but only products of an undivided activity. Thus one can no longer ask how, by means of matter and the faculty of knowledge, imagination [Vorstellen] and cognition [Erkennen] are possible? For it is not matter, nor faculty of knowledge, but merely imagination and cognition.
This step was thus inevitable to rationalism, since it insisted that there was no truth outside of reason, and yet had to make comprehensible the possibility of an imagination [Vorstellung].
 Kritik der reinen Vernunft, pp. 274, 275.
 Ibid., p. 146.
 Ibid., p. 54.
 For Kant, even our a priori function is contaminated by the mixture of a false perception of time. That is to say, even the a priori judgement, in that it applies the categories to an object (if not to a specific, then to any conceivable object) which comes to our observation from the sensory world, contain a time relation, e.g., “that which occurs has a cause” is constructed upon the unity of time, denying thereby that anything can begin anew, can stick out from the unity of time. For this reason our judgements a priori are by no means valid for the objective relation, but only for our experience. They are the foundational principles according to which alone we can have an experience, but they are not the laws of the objective world. Accordingly, Kant even establishes contradictions (“antinomies”) in reason itself, in connection with its supreme conclusions or ideas, which have their origin in the fact that they everywhere are based on the perception of time.
 Kritik der reinen Vernunft, p. 102.
 Ibid., p. 36.
 This transition from Kant to Fichte is manifested most vividly in the essays by the latter in his and Niethammer’s Philosophischen Journal [Philosophical Journal].