If we were to admit external objects to be things by themselves, it would be simply impossible to understand how we can arrive at a knowledge of their reality outside us, considering that we always depend on representations which are inside us. It is surely impossible that we should feel outside us, and not inside us, and the whole of our self-consciousness cannot give us anything but our own determinations. Thus sceptical idealism forces us to take refuge in the only place that is left to us, namely, in the ideality of all phenomena: the very ideality which, though as yet unprepared for its consequences, we established in our own transcendental Æsthetic. If then we ask whether, consequently, dualism only must be admitted in psychology, we answer, certainly, but only in its empirical acceptation. In the connection of experience matter, as the substance of phenomena, is really given to the external sense in the same manner as the thinking I, likewise as the substance of phenomena, is given to the internal sense; and it is according to the rules which this category introduces into the empirical connection of our external as well as internal perceptions, that phenomena on both sides must be connected among themselves. If, on the contrary, as often happens, we were to extend the concept of dualism and take it in its transcendental acceptation, then neither it, nor on one side the pneumatism, or on the other side the materialism, which are opposed to dualism, would have the smallest foundation; we should have missed the determination of our concepts, and have mistaken the difference in our mode of representing objects, which, with regard to what they are in themselves, remain always unknown to us, for a difference of the things themselves. No doubt I, as represented by the internal sense in time, and objects in space outside me, are two specifically different phenomena, but they are not therefore conceived as different things. The transcendental object, which forms the foundation of external phenomena, and the other, which forms the foundation of our internal intuition, is therefore neither matter, nor a thinking being by itself, but simply an unknown cause of phenomena which supply to us the empirical concept of both.
If therefore, as evidently forced to do by this very criticism, we remain faithful to the old rule, never to push questions beyond where possible experience can supply us with an object, we shall never dream of going beyond the objects of our senses and asking what they may be by themselves, that is, without any reference to our senses. But if the psychologist likes to take phenomena for things by themselves, then, whether he admit into his system, as a materialist, matter only, or, as a spiritualist, thinking beings only (according to the form of our own internal sense), or, as a dualist, both, as things existing in themselves, he will always be driven by his mistake to invent theories as to how that which is not a thing by itself, but a phenomenon only, could exist by itself.
Consideration
on the Whole of Pure Psychology, as affected by these Paralogisms
If we compare the science of the soul, as the physiology of the internal sense, with the science of the body, as a physiology of the objects of external senses, we find, besides many things which in both must be known empirically, this important difference, that in the latter many things can be known a priori from the mere concept of an extended and impermeable being, while in the former nothing can be known a priori and synthetically from the concept of a thinking being. The cause is this. Though both are phenomena, yet the phenomena of the external sense have something permanent, which suggests a substratum of varying determinations, and consequently a synthetical concept, namely, that of space, and of a phenomenon in space; while time, the only form of our internal intuition, has nothing permanent, and makes us to know the change of determinations only, but not the determinable object. For in what we call soul there is a continuous flux, and nothing permanent, except it may be (if people will so have it) the simple I, so simple because this representation has no contents, consequently nothing manifold, so that it seems to represent, or more accurately to indicate, a simple object. This I or Ego would have to be an intuition, which, being presupposed in all thought (before all experience), might as an intuition a priori supply synthetical propositions, if it should be possible to get any knowledge by pure reason of the nature of a thinking being in general. But this I is neither an intuition nor a concept of any object, but the mere form of consciousness which can accompany both classes of representations, and impart to them the character of knowledge, provided something else be given in intuition which supplies matter for a representation of an object. Thus we see that the whole of rational psychology is impossible as transcending the powers of human reason, and nothing remains to us but to study our soul under the guidance of experience, and to keep ourselves within the limits of questions which do not go beyond the line where the material can be supplied by possible internal experience.
But although rational psychology is of no use in extending our knowledge, but as such is made up of paralogisms only, we cannot deny to it an important negative utility, if it does not pretend to be more than a critical investigation of our dialectical syllogisms, as framed by our common and natural reason.
What purpose can be served by psychology founded on pure principles of reason? Its chief purpose is meant to be to guard our thinking self against the danger of materialism. This purpose however is answered, as we have shown, by the concept which reason gives of our thinking self. For, so far from there being any fear lest, if matter be taken away, all thought, and even the existence of thinking beings might vanish, it has been on the contrary clearly shown that, if we take away the thinking subject, the whole material world would vanish, because it is nothing but a phenomenon in the sensibility of our own subject, and a certain class of its representations.
It is true that I do not know thus this thinking self any better according to its qualities, nor can I perceive its permanence, or even the independence of its existence from the problematical transcendental substratum of external phenomena, both being necessarily unknown to us. But as it is nevertheless possible that I may find reason, from other than purely speculative causes, to hope for an independent, and, during every possible change of my states, permanently abiding existence of my thinking nature, much is gained if, though I freely confess my own ignorance, I can nevertheless repel the dogmatical attacks of a speculative opponent, showing to him that he can never know more of the nature of the subject, in order to deny the possibility of my expectations, than I can know, in order to cling to them.
Three dialectical questions, which form the real object of all rational psychology, are founded on this transcendental illusion of our psychological concepts, and cannot be answered except by means of the considerations in which we have just been engaged, namely, (1) the question of the possibility of the association of the soul with an organic body, that is, of animality and the state of the soul in the life of man; (2) the question of the beginning of that association of the soul at the time and before the time of our birth; (3) the question of the end of that association of the soul at and after the time of death (immortality).
What I maintain is, that all the difficulties which we imagine to exist in these questions, and with which, as dogmatical objections, people wish to give themselves an air of deeper insight into the nature of things than the common understanding can ever claim, rest on a mere illusion, which leads us to hypostasise what exists in thought only, and to accept it in the same quality in which it is thought as a real object, outside the thinking subject, taking in fact extension, which is phenomenal only, for a quality of external things, existing without our sensibility also, and movement as their effect, taking place by itself also, and independently of our senses. For matter, the association of which with the soul causes so much misgiving, is nothing but a mere orm, or a certain mode of representing an unknown object by that intuition which we call the external sense. There may, therefore, well be something outside us to which the phenomenon which we call matter corresponds; though in its quality of phenomenon it cannot be outside us, but merely as a thought within us, although that thought represents it thro
ugh the external sense as existing outside us. Matter, therefore, does not signify a class of substances totally heterogeneous and different from the object of the internal sense (the soul), but only the different nature of the phenomenal appearance of objects (in themselves unknown to us), the representations of which we call external, as compared with those which we assign to the internal sense, although, like other thoughts, those external representations also belong to the thinking subject only. They possess however this illusion that, as they represent objects in space, they seem to separate themselves from the soul and to move outside it, although even the space, in which they are seen, is nothing but a representation of which no homogeneous original can ever be found outside the soul. The question therefore is no longer as to the possibility of an association of the soul with other known and foreign substances outside us, but only as to the connection of the representations of the internal sense with the modifications of our external sensibility, and how these can be connected with each other according to constant laws, and acquire cohesion in experience.
So long as we connect internal and external phenomena with each other as mere representations in our experience, there is nothing irrational, nor anything to make the association of both senses to appear strange. As soon however as we hypostatise the external phenomena, looking upon them no longer as representations, but as things existing by themselves and outside us, with the same quality in which they exist inside us, and referring to our own thinking subject their acts which they, as phenomena, show in their mutual relation, the effective causes outside us assume a character which will not harmonise with their effects within us, because that character refers to the external senses only, but the effects to the internal sense, both being entirely unhomogeneous, though united in the same subject. We then have no other external effects but changes of place, and no forces but tendencies, which have for their effects relations in space only. Within us, on the contrary, those effects are mere thoughts, without any relations of space, movement, shape, or local determination between them; and we entirely lose the thread of the causes in the effects which ought to show themselves in the internal sense. We ought to consider therefore that bodies are not objects by themselves which are present to us, but a mere appearance of we do not know what unknown object, and that movement likewise is not the effect of that unknown cause, but only the appearance of its influence on our senses. Both are not something outside us, but only representation within us, and consequently it is not the movement of matter which produces representations within us, but that motion itself (and matter also, which makes itself known through it) is representation only. Our whole self-created difficulty turns on this, how and why the representations of our sensibility are so connected with each other that those which we call external intuitions can, according to empirical laws, be represented as objects outside us; a question which is entirely free from the imagined difficulty of explaining the origin of our representations from totally heterogeneous efficient causes, existing outside us, the confusion arising from our mistaking the phenomenal appearance of an unknown cause for the very cause outside us. In judgments in which there is a misapprehension confirmed by long habit, it is impossible to bring its correction at once to that clearness which can be produced in other cases, where no inevitable illusion confuses our concept. Our attempt therefore at freeing reason from these sophistical theories can hardly claim as yet that perspicuity which would render it perfectly satisfactory. I hope however to arrive at greater lucidity in the following manner.
All objections may be divided into dogmatical, critical, and sceptical. The dogmatical attacks the proposition, the critical the proof of a proposition. The former presupposes an insight into the peculiar nature of the object in order to be able to assert the contrary of what the proposition asserts. It is therefore itself dogmatical, and pretends to know the peculiar nature of the object in question better than the opponent. The critical objection, as it says nothing about the worth or worthlessness of the proposition, and attacks the proof only, need not know the object itself better, or claim a better knowledge of it. All it wants to show is, that a proposition is not well grounded, not that it is false. The sceptical objection, lastly, places assertion and denial side by side, as of equal value, taking one or the other now as dogma, and now as denial; and being thus in appearance dogmatical on both sides, it renders every judgment on the object impossible. Both the dogmatical and sceptical objections must pretend to so much knowledge of their object as is necessary in order to assert or deny anything about it. The critical objection, on the contrary, wishes only to show that something purely futile and fanciful has been used in support of a proposition, and thus upsets a theory by depriving it of its pretended foundation, without wishing to establish itself anything else about the nature of the object.
According to the ordinary concepts of our reason with regard to the association between our thinking subject and the things outside us, we are dogmatical, and look upon them as real objects, existing independently of ourselves, in accordance with a certain transcendental dualism which does not reckon external phenomena as representations belonging to the subject, but places them, as they are given us in sensuous intuition, as objects outside us and entirely separated from the thinking subject. This mere assumption is the foundation of all theories on the association between soul and body. It is never asked whether this objective reality of phenomena is absolutely true, but it is taken for granted, and the only question seems to be, how it is to be explained and understood. The three systems which are commonly suggested, and which in fact are alone possible, are those, 1st, of physical influence, 2nd, of pre-established harmony, and 3rd, of supernatural assistance.
The second and third explanations of the association between soul and matter arise from objections to the first, which is that of the ordinary understanding, the objection being, that what appears as matter cannot by its immediate influence be the cause of representations, these being a totally heterogeneous class of effects. Those who start this objection cannot understand by the objects of the external senses matter, conceived as phenomenon only, and therefore itself a mere representation produced by whatever external objects. For in that case they would really say that the representations of external objects (phenomena) cannot be the external causes of the representations in our mind, which would be a meaningless objection, because nobody would think of taking for an external cause what he knows to be a mere representation. According to our principles the object of their theory can only be, that that which is the true (transcendental) object of our external senses cannot be the cause of those representations (phenomena) which we mean by the name of matter. As no one has any right to say that he knows anything of the transcendental cause of the representations of our external senses, their assertion is entirely groundless. And if the pretended reformers of the doctrine of physical influence represent, according to the ordinary views of transcendental dualism, matter, as such, as a thing by itself (not simply as a mere phenomenal appearance of an unknown thing), and then proceed in their objections to show that such an external object, which shows no causality but that of movements, can never be the efficient cause of representations, but that a third being must intervene in order to produce, if not reciprocal action, at least correspondence and harmony between the two, they would really begin their refutation. by admitting in their dualism the of a physical influence, and thus refute by their objection, not so much the physical influence as their own dualistic premisses. For all the difficulties with regard to a possible connection between a thinking nature and matter arise, without exception, from that too readily admitted dualistic representation, namely, that matter, as such, is not phenomenal, that is, a mere representation of the mind to which an unknown object corresponds, but the object itself, such as it exists outside us, and independent of all sensibility.
It is impossible, therefore, to start a dogmatical objection against the commonly received theory of a physical influence. For if the opp
onent were to say that matter and its movements are purely phenomenal and therefore mere representations, the only difficulty remaining to him would be that the unknown object of our senses could not be the cause of our representations, and this he has no right to say, because no one is able to determine what an unknown object may or may not be able to effect; and, according to our former arguments, he must necessarily admit this transcendental idealism, unless he wishes to hypostasise mere representations and place them outside himself as real things.
What is quite possible, however, is to raise a well-founded critical objection to the commonly received opinion of a physical influence. For the pretended association between two kinds of substances, the one thinking, the other extended, rests on a coarse dualism, and changes the latter, though they are nothing but representations of the thinking subject, into things existing by themselves. Thus the misunderstood physical influence may be entirely upset by showing that the proof which was to establish it, was surreptitiously obtained, and therefore, valueless.
Critique of Pure Reason Page 33
