<pa1> The Paralogisms of Pure Reason

[B399] A logical paralogism consists in the formal invalidity of a rational inference, whatever its content. By contrast, a transcendental paralogism has a transcendental ground for drawing a formally invalid conclusion. So a fallacy of this sort will be grounded in the nature of human reason, and will lead to an illusion which is compelling, but not inescapable.

<pa2> Now we come to a concept which was not included in the earlier general list of transcendental concepts. Yet it must be included in their number, but without altering the table in any way, or admitting it to be defective. This is the concept (or judgment, if you prefer) ‘I think’. You will easily see that it is the vehicle of all concepts in general, and hence also of the transcendental concepts. So it is always conceived along with them, and is therefore just as transcendental as they are.

<pa3> However, it does not belong to a section on its own, since its only function is to present every thought as belonging to consciousness. [B400] Nevertheless, however pure it is of the empirical (the impression of the senses), it also has the function of distinguishing two kinds of object arising from the nature of our faculty of representation: I, as thinking, am an object of inner sense, and I am called ‘soul’; and whatever is an object of outer sense is called ‘body’.

<pa4> Hence the expression ‘I’ (as a thinking being) already identifies the object of that branch of psychology which can be called the rational doctrine of the soul — provided that I do not seek to know any more about the soul than can be deduced from this concept ‘I’ in so far as it accompanies all thought, and independently of all experience (which defines me more closely and as a concrete individual).

<pa5> The rational doctrine of the soul is actually an undertaking of this kind. For it would no longer be a rational, but an empirical doctrine of the soul, if the slightest empirical element of my thought — any particular perception of my inner state — contaminated the cognitive criteria of this science. So we already have before us a candidate for a genuine science, built up on the single proposition: ‘I think.’ Here it is fully appropriate, and in accordance with the nature of a transcendental philosophy, that we should investigate whether or not at has any basis.

<pa6> One should not be deflected by the objection that this very proposition, which expresses the perception of itself, involves my having an inner experience, and hence that the rational [B401] doctrine of the soul which is to be built on it will never be pure, but partly grounded on an empirical principle. For this inner perception is nothing beyond the mere apperception ‘I think’, which even makes all transcendental concepts possible, since what is said in them is ‘I think substance’, ‘I think cause’, etc.

<pa7> For inner experience in general and its possibility (or perception in general and its relation to other perception, provided that no particular distinction between them, or determination, is empirically given) cannot be considered as empirical knowledge. Rather, it must be considered as knowledge of the empirical in general, and it belongs to the investigation of the possibility of any experience, which certainly is transcendental. But rational psychology would immediately degenerate into an empirical psychology if the slightest object of perception (if only pleasure or displeasure, for example) were added to the general representation of self-consciousness.

<pa8> [B402] Here we simply have to follow the leading-thread of the categories, except that here the first to be given is a thing, namely I, as thinking being. So we shall not alter the internal order of the categories as presented in their earlier table. Instead, we shall follow their sequence in reverse order, starting with the category of substance, through which a thing is represented in itself. So the following is the structure of the topics covered by the rational doctrine of the soul, from which everything else it may contain must be derived:

<pa11> [B403] All the concepts of the pure doctrine of the soul derive from these elements, merely by combining them, and without any need whatever to appeal to any other principle. This substance, simply as the object of inner sense, yields the concept of immateriality; as simple substance, that of incorruptibility; its identity as an intellectual substance yields personality; all these three elements together yield spirituality; the relation to objects in space yields interaction with bodies; and hence it represents thinking substance as the principle of life in matter, i.e. as soul (anima), and as the ground of animality; and animality limited to spirituality yields immortality.

<pa12> Now related to these concepts, there are four Paralogisms of a transcendental doctrine of the soul, which is wrongly held to be a science of pure reason about the nature of our thinking being. The only foundation [B404] we can lay for this science is the representation ‘I’, which is simple, and in itself wholly devoid of content. One cannot even say that it is a concept, but merely a consciousness which accompanies all concepts. Through this I, or he, or it (the thing) which thinks, nothing more is represented than a transcendental subject of the thoughts, = x. It is known only through the thoughts which are its predicates, and we can never have the least concept of it in separation from them. This is why we constantly go round in a circle, in that we must always already use the representation of it in order to make any judgment about it. We cannot get round this embarrassment, because consciousness in itself is not so much a representation which marks out a particular object, but it is rather a form of representation in general, in so far as representation is to be called knowledge. For this representation is the only thing of which I can say that I think anything through it.

<pa13> But right from the start, it must seem strange that the precondition of my thinking in general (which is therefore merely a quality of my subject) should at the same time be valid for everything which thinks. It must also seem strange that we can presume to use what seems to be an empirical proposition as the foundation for a necessary and universal judgment — namely that everything which thinks is constituted in the same way as the expression of self-consciousness asserts of me. [B405] But the reason for this lies in the fact that we must necessarily attribute to things apriori all the properties which constitute the preconditions under which alone we can think them. Now I can have no representation at all of thinking being through any outer experience, but only through self-consciousness. So such objects are nothing more than the carrying across of this my consciousness to other things, since this is the only way they can be represented as thinking beings. However, in this case the proposition ‘I think’ is taken as merely problematic — not in the sense that it might contain the perception of something existent (the Cartesian cogito ergo sum), but because of its mere possibility. The purpose is to see what properties might flow from as simple a proposition as this to its subject (whether or not such a subject exists).

<pa14> If our pure rational knowledge of thinking being in general were grounded in anything more than the cogito — if we also had recourse to observations about the play of our thoughts, and the natural laws of the thinking self to be drawn from them — then this would give rise to an empirical psychology, which would be a sort of natural science of inner sense. It might perhaps explain the appearances of inner sense, but it could never serve to reveal any properties which do not belong to any possible experience (e.g. those of the simple), [B406] nor could it provide a necessary demonstration of what belongs to the nature of thinking being in general. Consequently, it would not be a rational psychology.

<pa15> Now the proposition ‘I think’ (taken problematically) contains the form of every judgment of the understanding in general, and accompanies all the categories as their vehicle. So it is clear that the conclusions from it can contain only a transcendental use of the understanding. This use excludes any admixture of experience, and (as I have shown above), already at the very start we can form no optimistic concept of its progress. So I shall follow it through all the topics of the pure doctrine of the soul with a critical eye. However, for the sake of brevity, I shall proceed to examine them in an uninterrupted sequence.

<pa16> First of all, the following general observation may make us more acutely aware of this kind of reasoning. I do not know any object merely through thinking it, but I can know any object only through determining a given intuition by reference to the unity of consciousness, in which all thinking consists. Thus I do not know myself by being conscious of myself as thinking, but only when I am conscious to myself of the intuition of my self as determined in relation to the function of thought. So all modes of self-consciousness in thought [B407] (taken in itself) are not yet concepts-of-understanding of objects (categories), but are mere functions, which do not provide thought with any object at all for it to know, and hence do not provide my self as an object either. The object is not the consciousness of that which determines, but only the consciousness of the determinable self, that is, of my inner intuition (in so far as its multiplicity can be unified in accordance with the universal precondition of the unity of apperception in thought).

<pa17> 1. Now in all judgments, I am always the determining subject of the relation which the judgment consists in. But it is a deductively necessary, and indeed an analytic proposition that the I which I think must always be taken as the subject of thought, and not as something which can be considered merely as a predicate attached to the thought. However, this does not mean that I, as object, am for myself a self-subsistent being, or substance. This claim goes too far, since it requires data which are not met with at all in thought, and perhaps more than I will ever meet with (in thought) quite generally (in so far as I consider that which thinks merely as such).

<pa18> 2. It is already contained in the concept of thought (and hence it is an analytic proposition) that the I of apperception (and therefore in every thought) is singular, and cannot be broken up into a multiplicity of subjects. Consequently it denotes a logically simple subject. However, this [B408] does not mean that the thinking I is a simple substance, since that would be a synthetic proposition. The concept of substance always relates to intuitions; and since in my case these can only be sensory, it therefore lies completely outside the scope of the understanding and its thinking. And it is essentially only the understanding which is referred to here, when it is said that the I in thought is simple. In cases other than that of the self, it requires much paraphernalia to discern substance from what is given in intuition, let alone to discern whether it too could be simple (as with the parts of matter). So it would be miraculous if, in this case, which involves the poorest representation of all, substance were given to me so directly, as if through some sort of revelation.

<pa19> 3. The proposition of the identity of my self in all multiplicities of which I am conscious also lies in the concepts themselves, and is therefore an analytic proposition. However, this identity of the subject which I can be conscious of in all its representations has nothing to do with the intuition of the subject, through which it is given as an object. So the proposition cannot denote the identity of the person, meaning consciousness of the identity of one’s own substance as a thinking being through all its changing states. To prove this would require various [B409] synthetic judgments based on the given intuition; and it cannot be achieved merely by analysis of the analytic proposition ‘I think’.

<pa20> 4. I distinguish my own existence, as that of a thinking being, from other things external to me (which include my body). This is also an analytic proposition, since other things are those which I think as distinct from me. However, this gives me no means of knowing whether this consciousness of my self is possible at all without things external to me, through which representations are given to me; and hence whether I could exist simply as a thinking being (without being a human).

<pa21> So nothing at all to do with my knowledge of my self as an object has been achieved through the analysis of the consciousness of my self in thought in general. The logical exposition of thought in general is wrongly taken as a metaphysical determination of the object.

<pa22> A bigger, indeed the only stumbling-block for my whole critique would be if it were possible to prove apriori that all thinking beings are simple substances in themselves. It would follow from this same ground of proof that, as such, they necessarily have personality, and are conscious of their existence separate from all matter. For in this way we would have made just one step beyond the world of the senses, and would have set foot in the territory of noumena. Then no-one could deny us [B410] the authority to expand further into this territory, to cultivate it, and, depending on each person’s good fortune, to take possession of it.

<pa23> For the proposition ‘Every thinking being is, as such, a simple substance’ is a synthetic apriori proposition, for two reasons. First, it goes beyond the concept on which it is based, and adds to thought in general the way in which it exists. Second, it adds to that concept a predicate (that of simplicity) which cannot be given in any experience at all. But if this were allowed, synthetic apriori propositions would not be feasible and admissible merely in relation to objects of possible experience, and indeed as principles of the possibility of this experience itself (which is what I have asserted), but would also be able to reach out to things in general and in themselves. This consequence would put an end to this whole critique, and would tell us to leave everything as it was in antiquity. However, this danger is not so great here, when one gets closer to the heart of things.

<pa24> In the methodology of rational psychology, there is an overarching paralogism, which can be set out in the following syllogism:

The major premise refers to a being which can be thought universally and in every respect, and so this includes how it might be given in intuition. But the minor premise refers to it only in so far as it considers itself, as subject, relative to thought and the unity of consciousness, and not also in connection with the intuition through which it is given to thought as object. So the conclusion is arrived at through the sophism of figure of speech, and hence fallaciously.*

<pa26> [B412] It will become absolutely clear that this reduction of the famous argument to a paralogism is perfectly correct, if you refer back to the General Remark on the Systematic Representation of the Principles, and to the section on Noumena. There I proved that the concept of a thing which can exist independently as a subject, and not just as a predicate, includes no objective reality at all. In other words, you could not know whether, in general, any object could correspond to it, since you would have no insight into the possibility of such a mode of existing. Consequently, it provides no knowledge at all.

<pa27> So if it is to be called a substance, and denote an object which can be given (i.e. if it is to be an item of knowledge), it must be grounded in a persisting intuition. Such an intuition is the indispensable precondition of the objective reality of a concept, since it is that through which alone the object is given. Now in [B413] inner intuition we have nothing at all which persists, since the I is only the consciousness of my thought. So as long as we confine ourselves merely to thought, we also lack the necessary precondition for applying the concept of substance (i.e. the concept of a self-subsistent subject) to itself as a thinking being. The simplicity of the substance, which is involved in this concept, is also completely lost along with its objective reality. It turns into nothing more than a logical and qualitative unity of self-consciousness in thought in general, and the subject could equally well be composite or not.

<pa28> Refutation of Mendelssohn’s proof of the permanence of the soul

The usual argument for proving that the soul cannot cease to be (assuming that it is a simple being), is that it cannot dissolve into parts. The perceptive philosopher Mendelssohn soon noticed that this was insufficient to guarantee its necessary continuation, since one could still suppose that its existence might cease through vanishing. In his Phaedo, he tried to save it from this sort of perishability, which would be genuine annihilation. He set out to prove that a simple being could in no way cease to be. His argument was that, since a simple being had no parts, and hence no multiplicity in it either, it could not possibly become less by losing part of its existence bit by bit. Consequently, it could not change into nothing [B414] gradually. So if it ceased to be, there would be no time at all between an instant at which it was, and another instant at which it was not — which is impossible.

<pa29> However, he failed to take the following into account. Let us accept that the nature of the soul is simple, in that it does not contain a multiplicity of parts external to each other, and hence an extensive magnitude. Nevertheless, it cannot be denied an intensive magnitude, any more than anything else which exists. In other words, it must have a degree of reality in respect of all its faculties — indeed, in respect of everything in general which constitutes its existence. But its reality can decrease through infinitely many smaller and smaller degrees. So this thing has only been assumed to be a substance, since its permanence has not yet been established independently. Although it could not change into nothing through the dissolution of its parts, it could through the gradual weakening of its powers — and hence through elanguescence, if I might be permitted to use this expression. For even consciousness itself has some degree or other at any given time, and it can always become less than it was before.*

<pa32> Consequently, the power of being conscious of oneself [B415] can also become less, and likewise all other powers.

<pa33> So the permanence of the soul, considered merely as an object of inner sense, remains unproved, and even unprovable. Nevertheless, its permanence in life is self-evident, since the thinking being considered as a human is at the same time an object of outer sense. However, this is nothing like enough for the rational psychologist, who undertakes to prove the permanence of the soul even beyond life, on the basis of concepts alone.*

<pa40> [B416] Suppose we now take our above propositions in their synthetic interconnection, as they must also be taken in rational psychology as a system, since they are valid for all thinking beings. Suppose also that we start out from the category of relation, with the proposition that ‘All thinking [B417] beings are, as such, substances,’ and work backwards through the sequence of categories until the circle is closed. If we do this, then we finally come up against their existence. But in the system of rational psychology, these beings are not only conscious of themselves independently of external things, but they can also determine themselves (in respect of [B418] the permanence which necessarily belongs to the character of substance). But from this it follows that idealism is unavoidable in this rationalist system — at least of the problematic variety. And if the existence of external things is not required at all for us to determine our own existence in time, then that existence is also only arbitrarily assumed, without its ever being possible to provide a proof of it.

<pa41> Suppose, on the other hand, we follow the analytic procedure. Here, the basis from which we start is the ‘I think’, as a proposition which already includes an existence as given, and hence also modality. Then suppose we analyse it in order to know what it contains — that is, whether and how this I in space or time determines its existence through these alone. Then the propositions of the rational doctrine of the soul would start out, not from the concept of a thinking being in general, but from something actual. And from the way this is thought, after everything empirical in it has been separated off, [B419] it will be concluded what belongs to a thinking being in general — as the following table shows.

Now in the second proposition here, it is not determined whether I could exist and be thought only as subject, and not also as the predicate of a different subject. So the concept of a subject is here taken in a merely logical sense, and it remains undetermined whether or not it should be understood as including substance.

<pa42> But in the third proposition, the absolute unity of apperception is important in itself. It is the simple I in representation, to which is related all combination or separation, in which thought consists. And it is important even if I have not yet established anything about the characteristics or subsistence of the subject. Apperception is something real, and its simplicity is already grounded in its possibility. Now in space, there is nothing real which is simple, since points (which are the only simple things in space) are merely limits, and not themselves anything which can serve to make up space as a part. So it follows from this [B420] that it is impossible to explain my nature as nothing more than a thinking subject on the basis of materialism.

<pa43> But in the first proposition, my existence is considered as given. For it does not say that every thinking being exists (which would also imply absolute necessity, and hence go too far), but only ‘I exist thinking.’ Consequently, it is an empirical proposition, and includes the determinability of my existence merely in relation to my representations in time. But for this, again I first need something which persists, but which is not given to me at all in inner intuition in so far as I think of myself. Therefore through this simple self-consciousness it is quite impossible to determine the way in which I exist — namely whether as substance or accident. So, just as materialism is no use as a way of explaining my existence, spiritualism is just as unsatisfactory as an explanation. The conclusion is that, one way or the other, we cannot know anything about the nature of our soul which relates to the possibility of its separate existence in general.

<pa44> And again, we know the unity of consciousness only because we cannot avoid using it for experience to be possible. So how should we be able to use it to go beyond experience (our existence in life)? — let alone extend our knowledge to include the nature of all thinking beings in general, [B421] through the proposition ‘I think’, which, although it is empirical, is undetermined in relation to any kind of intuition.

<pa45> So there is no rational psychology as a body of knowledge, which would add anything to our self-knowledge. It exists only as a corrective, which sets uncrossable limits to speculative reason in this territory. On the one hand, it prevents us from throwing ourselves into the lap of soulless materialism; and on the other hand it prevents us from losing ourselves in superstitious spiritualism, which is without foundation for us in this life. Rather, it reminds us that the refusal of our reason to give any satisfactory answer to our impertinent questions about what lies beyond this life should be treated as its hint that we should turn our self-knowledge away from fruitless speculation about the transcendent towards its fruitful, practical use. Although this use is always directed only towards objects of experience, its principles derive from a higher source, and it determines our behaviour just as if our destiny reached infinitely beyond experience, and hence beyond this life.

<pa46> All this goes to show that rational psychology arose from a misunderstanding. The unity of consciousness, which is the source of the categories, is here mistaken for an intuition of the subject as object, and the category [B422] of substance is applied to it. But it is only a unity in thought, and through it alone no object is given. So the category of substance, which always presupposes a given intuition, cannot be applied to it, and hence this subject cannot be known at all. Thus the subject of the categories cannot obtain a concept of itself as an object of the categories by virtue of the fact that it thinks them. For in order to think them, it must ground them in its pure self-consciousness — which is precisely what needs to be explained. Similarly, the subject, in which the representation of time has its original ground, cannot use it to determine its own existence in time. And if it is impossible for the subject to determine its own existence in time, it is equally impossible for one’s self to be determined through the categories as a thinking being in general.*