The World as Will and Representation

basis of politics it would be excellent, as the basis of ethics it is worthless. For he who seeks to establish a rule for the wills of all, as is demanded by that moral principle, necessarily stands in need of a rule himself; otherwise everything would be alike to him. But this rule can only be his own egoism, since it is only this that is affected by the conduct of others; and therefore it is only by means of this egoism, and with reference to it, that each one can have a will concerning the conduct of others, and that it is not a matter of indifference to him. Kant himself very naively intimates this (p. 123 of the “Critique of Practical Reason;” Rosenkranz’s edition, p. 192), where he thus prosecutes the search for maxims for the will: “If every one regarded the need of others with complete indifference, and thou also didst belong to such an order of things, wouldst thou consent thereto?” Quam temere in nosmet legem sancimus iniquam! would be the rule of the consent inquired after. So also in the “Fundamental Principles of the Metaphysic of Morals” (p. 56 of the third, and p. 50 of Rosenkranz’s, edition): “A will which resolved to assist no one in distress would contradict itself, for cases might arise

in which it required the love and sympathy of others,” &c. &c. This principle of ethics, which when light is thrown upon it is therefore nothing else than an indirect and disguised expression of the old, simple principle, “Quod tibi fieri non vis, alteri ne feceris,” is related first and directly to passivity, suffering, and then only by means of this to action. Therefore, as we have said, it would be thoroughly serviceable as a guide for the constitution of the State, which aims at the prevention of the suffering of wrong, and also desires to procure for all and each the greatest sum of well-being. But in ethics, where the object of investigation is action as action, and in its direct significance for the actor—not its consequences, suffering, or its relation to others—in this reference, I say, it is altogether inadmissible, because at bottom it really amounts to a principle of happiness, thus to egoism.

We cannot, therefore, share Kant’s satisfaction that his principle of ethics is not a material one, i.e., one which sets up an object as a motive, but merely formal, whereby it corresponds symmetrically to the formal laws with which the “Critique of Pure Reason” has made us familiar. Certainly it is, instead of a law, merely a formula for finding such a law. But, in the first place, we had this formula already more briefly and clearly in the “Quod tibi fieri non vis, alteri ne feceris;” and, secondly, the analysis of this formula shows that it is simply and solely the reference to one’s own happiness that gives it content, and therefore it can only be serviceable to a rational egoism, to which also every legal constitution owes its origin.

Another mistake which, because it offends the feelings of every one, has often been condemned, and was satirised by Schiller in an epigram, is the pedantic rule that for an act to be really good and meritorious it must be done simply and solely out of respect for the known law and the conception of duty, and in accordance with a maxim known to the reason in abstracto, and not from any inclination, not from benevolence felt towards others, not from tender-hearted compassion, sympathy, or emotion of the heart, which (according to the “Critique of Practical Reason,” p. 213; Rosenkranz’s edition, p. 257) to right-thinking persons are indeed very burdensome, as confusing their deliberate maxims. The act must be performed unwillingly and with self-compulsion. Remember that nevertheless the hope of reward is not allowed to enter, and estimate the great absurdity of the demand. But, what is saying more, this is directly opposed to the true spirit of virtue; not the act, but the willingness to do it, the love from which it proceeds, and without which it is a dead work, constitutes its merit. Therefore Christianity rightly teaches that all outward works are worthless if they do not proceed from that genuine disposition which consists in true goodwill and pure love, and that what makes blessed and saves is

not the works done (opera operata), but the faith, the genuine disposition, which is the gift of the Holy Ghost alone, and which the free, deliberative will, having only the law in view, does not produce. This demand of Kant’s, that all virtuous conduct shall proceed from pure, deliberate respect for the law and in accordance with its abstract maxims, coldly and without inclination, nay, opposed to all inclination, is just the same thing as if he asserted that every work of art must be accomplished by a well-considered application of æsthetical rules. The one is just as perverse as the other. The question, already handled by Plato and Seneca, whether virtue can be taught, is to be answered in the negative. We must finally make up our minds to see, what indeed was the source of the Christian doctrine of election by grace, that as regards its chief characteristic and its inner nature, virtue, like genius, is to a certain extent inborn; and that just as little as all the professors of æsthetics could impart to any one the power of producing works of genius, i.e., genuine works of art, so little could all the professors of ethics and preachers of virtue transform an ignoble into a virtuous and noble character, the impossibility of which is very much more

apparent than that of turning lead into gold. The search for a system of ethics and a first principle of the same, which would have practical influence and would actually transform and better the human race, is just like the search for the philosopher’s stone. Yet I have spoken at length at the end of the fourth book of the possibility of an entire change of mind or conversion of man (new birth), not by means of abstract (ethics) but of intuitive knowledge (the work of grace). The contents of that book relieve me generally of the necessity of dwelling longer upon this point.

That Kant by no means penetrated to the real significance of the ethical content of actions is shown finally by his doctrine of the highest good as the necessary combination of virtue and happiness, a combination indeed in which virtue would be that which merits happiness. He is here involved in the logical fallacy that the conception of merit, which is here the measure or test, already presupposes a theory of ethics as its own measure, and thus could not be deducible from it. It appeared in our fourth book that all genuine virtue, after it has attained to its highest grade, at last leads to a complete renunciation in which all willing finds an end. Happiness, on the other hand, is a satisfied wish; thus the two are essentially incapable of being combined. He who has been enlightened by my exposition requires no further explanation of the complete perverseness of this Kantian view of the highest good. And, independent of my positive exposition, I have no further negative exposition to give.

Kant’s love of architectonic symmetry meets us also in the “Critique of Practical Reason,” for he has given it the shape of the “Critique of Pure Reason,” and has again introduced the same titles and forms with manifest intention, which becomes specially apparent in the table of the categories of freedom.

The “Philosophy of Law” is one of Kant’s latest works, and is so poor that, although I entirely disagree with it, I think a polemic against it is superfluous, since of its own weakness it must die a natural death, just as if it were not the work of this great man, but the production of an ordinary mortal. Therefore, as regards the “Philosophy of Law,” I give up the negative mode of procedure and refer to the positive, that is, to the short outline of it given in the fourth book. Just one or two general remarks on Kant’s “Philosophy of Law” may be made here. The errors which I have condemned in considering the “Critique of Pure Reason,” as clinging to Kant throughout, appear in the “Philosophy of Law” in such excess that one often believes he is reading a satirical parody of the Kantian style, or at least that he is listening to a Kantian. Two principal errors, however, are these. He desires (and many have since then desired) to separate the Philosophy of Law sharply from ethics, and yet not to make the former dependent upon positive legislation, i.e., upon arbitrary sanction, but to let the conception of law exist for itself pure and a priori. But this is not possible; because conduct, apart from its

ethical significance, and apart from the physical relation to others, and thereby from external sanction, does not admit even of the possibility of any third view. Consequently, when he says, “Legal obligation is that which can be enforced,” this can is either to be understood physically, and then all law is positive and arbitrary, and again all arbitrariness that achieves its end is law; or the can is to be understood ethically, and we are again in the province of ethics. With Kant the conception of legal right hovers between heaven and earth, and has no ground on which to stand; with me it belongs to ethics. Secondly, his definition of the conception law is entirely negative, and thereby inadequate.(11) Legal right is that which is consistent with the compatibility of the respective freedom of individuals together, according to a general law. Freedom (here the empirical, i.e., physical, not the moral freedom of the will) signifies not being hindered or interfered with, and is thus a mere negation; compatibility, again, has exactly the same significance. Thus we remain with mere negations and obtain no positive conception, indeed do not learn at all, what is really being spoken about, unless we know it already from some other source. In the course of the exposition the most perverse views afterwards develop themselves,

such as that in the state of nature, i.e., outside the State, there is no right to property at all, which really means that all right or law is positive, and involves that natural law is based upon positive law, instead of which the case ought to be reversed. Further, the founding of legal acquisition on possession; the ethical obligation to establish the civil constitution; the ground of the right of punishment, &c., &c., all of which, as I have said, I do not regard as worth a special refutation. However, these Kantian errors have exercised a very injurious influence. They have confused and obscured truths long known and expressed, and have occasioned strange theories and much writing and controversy. This certainly cannot last, and we see already how truth and sound reason again make way for themselves. Of the latter, the “Naturrecht” of J. C. F. Meister specially bears evidence, and is thus a contrast to many a preposterous theory, though I do not regard it as on this account a pattern of perfection.

On the “Critique of Judgment” also, after what has been said, I must be very short. We cannot but be surprised that Kant, to whom art certainly was very foreign, and who to all appearance had little susceptibility for the beautiful, indeed probably never had the opportunity of seeing an important work of art, and who seems, finally, to have had no knowledge of Goethe, the only man of his century and nation who was fit to be placed by his side as his giant equal,—it is, I say, surprising how, notwithstanding all this, Kant was able to render a great and permanent service to the philosophical consideration of art and the beautiful. His merit lies in this, that much as men had reflected upon the beautiful and upon art, they had yet really always considered it only from the empirical point of view, and had investigated upon a basis of facts what quality distinguished the object of any kind which was called beautiful from other objects of the same kind. On this path they first arrived at quite special principles, and then at more general ones. They sought to separate true artistic beauty from false, and to discover marks of this genuineness, which could then serve again as rules. What gives pleasure as beautiful and what does not, what

therefore is to be imitated, what is to be striven against, what is to be avoided, what rules, at least negative rules, are to be established, in short, what are the means of exciting æsthetic satisfaction, i.e., what are the conditions of this residing in the object—this was almost exclusively the theme of all treatises upon art. This path was followed by Aristotle, and in the most recent times we find it chosen by Home, Burke, Winckelmann, Lessing, Herder, and many others. It is true that the universality of the æsthetical principles discovered finally led back to the subject, and it was observed that if the effect upon the subject were adequately known we would then also be able to determine a priori the causes of this which lie in the object, and thus alone this method of treatment could attain to the certainty of a science. This occasioned once and again psychological disquisitions. Specially however, Alexander Baumgarten produced with this intention a general æsthetic of all beauty, in which he started from the conception of the perfection of sensuous knowledge, that is, of knowledge of perception. With him also, however, the subjective part is done with as soon as this conception has been established, and he passes on to the objective part and to the practical, which is connected

with it. But here also the merit was reserved for Kant of investigating seriously and profoundly the feeling itself, in consequence of which we call the object occasioning it beautiful, in order to discover, wherever it was possible, the constituent elements and conditions of it in our nature. His investigation, therefore, took an entirely subjective direction. This path was clearly the right one, for in order to explain a phenomenon which is given in its effects, one must know accurately this effect itself, if one is to determine thoroughly the nature of the cause. Yet Kant’s merit in this regard does not really extend much further than this, that he has indicated the right path, and by a provisional attempt has given an example of how, more or less, it is to be followed. For what he gave cannot be regarded as objective truth and as a real gain. He gave the method for this investigation, he broke ground in the right direction, but otherwise he missed the mark.

In the “Critique of Æsthetical Judgment” the observation first of all forces itself upon us that Kant retains the method which is peculiar to his whole philosophy, and which I have considered at length above—I mean the method of starting from abstract knowledge in order to establish knowledge of perception, so that the former serves him, so to speak, as a camera obscura in which to receive and survey the latter. As in the “Critique of Pure Reason” the forms of judgment are supposed to unfold to him the knowledge of our whole world of perception, so in this “Critique of Æsthetical Judgment” he does not start from the beautiful itself, from the perceptible and immediately beautiful, but from the judgment of the beautiful, the so-called, and very badly so-called, judgment of taste. This is his problem. His attention is especially aroused by the circumstance that such a judgment is clearly the expression of something that takes place in the subject, but yet is just as universally valid as if it concerned a quality of the object. It is this that struck him, not the beautiful itself. He starts always merely from the assertions of others, from the judgment of the beautiful, not from the beautiful itself. It is therefore as if he knew it simply from hearsay, not directly. A blind man of high understanding could almost in the same way make up a theory of colours from very accurate reports which he had heard concerning them. And really we can only venture to regard Kant’s philosophemes concerning the beautiful as in almost the same position. Then we shall find that his theory is very ingenious indeed, that here and there telling and true observations are made; but his real solution of the problem is so very insufficient, remains so far below the dignity of the subject, that it can never occur to us to accept it as objective truth. Therefore I consider myself relieved from the necessity of refuting it; and here also I refer to the positive part of my work.

With regard to the form of his whole book, it is to be observed that it originated in the idea of finding in the teleological conception the key to the problem of the beautiful. This inspiration is deduced, which is always a matter of no difficulty, as we have learnt from Kant’s successors. Thus there now arises the strange combination of the knowledge of the beautiful with that of the teleology of natural bodies in one faculty of knowledge called judgment, and the treatment of these two heterogeneous subjects in one book. With these three powers of knowledge, reason, judgment, and understanding, a variety of symmetrical-architectonic amusements are afterwards undertaken, the general inclination to which shows itself in many ways in this book; for example, in the forcible adaptation of the whole of it to the pattern of the “Critique of Pure Reason,” and very specially in the antinomy of the æsthetical judgment, which is dragged in by the hair. One might also extract a charge of great inconsistency from the fact that after it has been incessantly repeated in the “Critique of Pure Reason” that the understanding is the faculty of judgment, and after the forms of its judgment have been made the foundation-stone of all philosophy, a quite special faculty of judgment now appears, which is completely different from the former. For the rest, what I call the faculty of judgment, the capacity for translating knowledge of perception into abstract knowledge, and again of applying the latter correctly to the former, is explained in the positive part of my work.

By far the best part of the “Critique of Æsthetical Judgment” is the theory of the sublime. It is incomparably more successful than that of the beautiful, and does not only give, as that does, the general method of investigation, but also a part of the right way to it—so much so that even though it does not give the real solution of the problem, it yet touches very closely upon it.

In the “Critique of the Teleological Judgment,” on account of the simplicity of the matter, we can recognise perhaps more than anywhere else Kant’s rare talent of turning a thought this way and that way, and expressing it in a multitude of different ways, until out of it there grows a book. The whole book is intended to say this alone: although organised bodies necessarily appear to us as if they were constructed in accordance with a conceived design of an end which preceded them, yet we are not justified in assuming that this is objectively the case. For our intellect, to which things are given from without and indirectly, which thus never knows their inner nature through which they arise and exist, but merely their outward side, cannot otherwise comprehend a certain quality peculiar to organised productions of nature than by analogy, for it compares it with the intentionally accomplished works of man, the nature of which is determined by a design and the conception of this design. This analogy is sufficient to enable us to comprehend the agreement of all the parts with the whole, and thus indeed to give us the clue to their investigation; but it must by no means on this account be made the actual ground of explanation of the origin and existence of

such bodies. For the necessity of so conceiving them is of subjective origin. Somewhat in this way I would epitomise Kant’s doctrine on this question. In its most important aspect he had expounded it already in the “Critique of Pure Reason,” p. 692-702; V., 720-730. But in the knowledge of this truth also we find David Hume to be Kant’s worthy forerunner. He also had keenly controverted that assumption in the second part of his “Dialogues concerning Natural Religion.” The difference between Hume’s criticism of that assumption and Kant’s is principally this, that Hume criticised it as an assumption based upon experience, while Kant, on the other hand, criticised it as an a priori assumption. Both are right, and their expositions supplement each other. Indeed what is really essential in the Kantian doctrine on this point we find already expressed in the commentary of Simplicius on Aristotle’s Physics: “ἡ δε πλανη γεγονεν αυτοις απο του ἡγεισθαι, παντα τα ἑνεκα του γινομενα κατα προαιρεσιν γενεσθαι και λογισμον, τα δε φυσει μη ὁυτως ὁραν γινομενα.” (_Error iis ortus est ex eo, quod credebant, omnia, quæ propter finem aliquem fierent, ex proposito et ratiocinio fieri, dum videbant, naturæ opera non ita fieri._) Schol. in Arist., ex edit. Berol., p. 354. Kant is perfectly right in the matter; and it was necessary that after

it had been shown that the conception of cause and effect is inapplicable to the whole of nature in general, in respect of its existence, it should also be shown that in respect of its qualities it is not to be thought of as the effect of a cause guided by motives (designs). If we consider the great plausibility of the physico-theological proof, which even Voltaire held to be irrefragable, it was clearly of the greatest importance to show that what is subjective in our comprehension, to which Kant had relegated space, time, and causality, extends also to our judgment of natural bodies; and accordingly the compulsion which we feel to think of them as having arisen as the result of premeditation, according to designs, thus in such a way that the idea of them preceded their existence, is just as much of subjective origin as the perception of space, which presents itself so objectively, and that therefore it must not be set up as objective truth. Kant’s exposition of the matter, apart from its tedious prolixity and repetitions, is excellent. He rightly asserts that we can never succeed in explaining the nature of organised bodies from merely mechanical causes, by which he understands the undesigned and regular effect of all the universal forces of nature. Yet I find here

another flaw. He denies the possibility of such an explanation merely with regard to the teleology and apparent adaptation of organised bodies. But we find that even where there is no organisation the grounds of explanation which apply to one province of nature cannot be transferred to another, but forsake us as soon as we enter a new province, and new fundamental laws appear instead of them, the explanation of which is by no means to be expected from the laws of the former province. Thus in the province of the mechanical, properly so called, the laws of gravitation, cohesion, rigidity, fluidity, and elasticity prevail, which in themselves (apart from my explanation of all natural forces as lower grades of the objectification of will) exist as manifestations of forces which cannot be further explained, but themselves constitute the principles of all further explanation, which merely consists in reduction to them. If we leave this province and come to the phenomena of chemistry, of electricity, magnetism, crystallisation, the former principles are absolutely of no use, indeed the former laws are no longer valid, the former forces are overcome by others, and the phenomena take place in direct contradiction to them, according to new laws, which, just like the former ones, are original and inexplicable, i.e., cannot be reduced to more general

ones. Thus, for example, no one will ever succeed in explaining even the dissolving of a salt in water in accordance with the laws proper to mechanics, much less the more complicated phenomena of chemistry. All this has already been explained at length in the second book of the present work. An exposition of this kind would, as it seems to me, have been of great use in the “Critique of the Teleological Judgment,” and would have thrown much light upon what is said there. Such an exposition would have been especially favourable to his excellent remark that a more profound knowledge of the real being, of which the things of nature are the manifestation, would recognise both in the mechanical (according to law) and the apparently intentional effects of nature one and the same ultimate principle, which might serve as the more general ground of explanation of them both. Such a principle I hope I have given by establishing the will as the real thing in itself; and in accordance with it generally in the second book and the supplements to it, but especially in my work “On the Will in Nature,” the insight into the inner nature of the apparent design and of the harmony and agreement of the whole of nature has perhaps become clearer and deeper.

Therefore I have nothing more to say about it here.

The reader whom this criticism of the Kantian philosophy interests should not neglect to read the supplement to it which is given in the second essay of the first volume of my “Parerga and Paralipomena,” under the title “Noch einige Erläuterungen zur Kantischen Philosophie” (Some Further Explanations of the Kantian Philosophy). For it must be borne in mind that my writings, few as they are, were not composed all at once, but successively, in the course of a long life, and with long intervals between them. Accordingly, it must not be expected that all I have said upon one subject should stand together in one place.

“ ‘Warum willst du dich von uns Allen Und unsrer Meinung entfernen?’ Ich schreibe nicht euch zu gefallen, Ihr sollt was lernen.” —GOETHE. First Half. The Doctrine Of The Idea Of Perception. (To § 1-7 of the First Volume.) Chapter I. The Standpoint of Idealism.

In boundless space countless shining spheres, about each of which, and illuminated by its light, there revolve a dozen or so of smaller ones, hot at the core and covered with a hard, cold crust, upon whose surface there have been generated from a mouldy film beings which live and know—this is what presents itself to us in experience as the truth, the real, the world. Yet for a thinking being it is a precarious position to stand upon one of those numberless spheres moving freely in boundless space without knowing whence or whither, and to be only one of innumerable similar beings who throng and press and toil, ceaselessly and quickly arising and passing away in time, which has no beginning and no end; moreover, nothing permanent but matter alone and the recurrence of the same varied organised forms, by means of certain ways and channels which are there once for all. All that empirical science can teach is only the more exact nature and law of these events. But now at last modern philosophy especially through Berkeley and Kant, has called to mind that all this is first of all merely a phenomenon of the brain, and is affected with such great, so many, and such different subjective conditions that its supposed absolute reality vanishes away, and leaves room for an entirely different scheme of the world, which consists of what lies at the foundation of that phenomenon, i.e., what is related to it as the thing in itself is related to its mere manifestation.

“The world is my idea” is, like the axioms of Euclid, a proposition which every one must recognise as true as soon as he understands it; although it is not a proposition which every one understands as soon as he hears it. To have brought this proposition to clear consciousness, and in it the problem of the relation of the ideal and the real, i.e., of the world in the head to the world outside the head, together with the problem of moral freedom, is the distinctive feature of modern philosophy. For it was only after men had spent their labour for thousands of years upon a mere philosophy of the object that they discovered that among the many things that make the world so obscure and doubtful the first and chiefest is this, that however immeasurable and massive it may be, its existence yet hangs by a single thread; and this is the actual consciousness in which it exists. This condition, to which the existence of the world is irrevocably subject, marks it, in spite of all empirical reality, with the stamp of ideality, and therefore of mere phenomenal appearance. Thus on one side at least the world must be recognised as akin to dreams, and indeed to be classified along with them. For the same function of the

brain which, during sleep, conjures up before us a completely objective, perceptible, and even palpable world must have just as large a share in the presentation of the objective world of waking life. Both worlds, although different as regards their matter, are yet clearly moulded in the one form. This form is the intellect, the function of the brain. Descartes was probably the first who attained to the degree of reflection which this fundamental truth demands, and consequently he made it the starting-point of his philosophy, though provisionally only in the form of a sceptical doubt. When he took his cogito ergo sum as alone certain, and provisionally regarded the existence of the world as problematical, he really discovered the essential and only right starting-point of all philosophy, and at the same time its true foundation. This foundation is essentially and inevitably the subjective, the individual consciousness. For this alone is and remains immediate; everything else, whatever it may be, is mediated and conditioned through it, and is therefore dependent upon it. Therefore modern philosophy is rightly regarded as starting with Descartes, who was the father of it. Not long afterwards Berkeley followed the same path further, and attained to idealism proper, i.e., to the knowledge that the world which is extended in space, thus the objective, material world in

general, exists as such simply and solely in our idea, and that it is false, and indeed absurd, to attribute to it, as such, an existence apart from all idea and independent of the knowing subject, thus to assume matter as something absolute and possessed of real being in itself. But his correct and profound insight into this truth really constitutes Berkeley’s whole philosophy; in it he had exhausted himself.

Thus true philosophy must always be idealistic; indeed, it must be so in order to be merely honest. For nothing is more certain than that no man ever came out of himself in order to identify himself directly with things which are different from him; but everything of which he has certain, and therefore immediate, knowledge lies within his own consciousness. Beyond this consciousness, therefore, there can be no immediate certainty; but the first principles of a science must have such certainty. For the empirical standpoint of the other sciences it is quite right to assume the objective world as something absolutely given; but not so for the standpoint of philosophy, which has to go back to what is first and original. Only consciousness is immediately given; therefore the basis of philosophy is limited to facts of consciousness, i.e., it is essentially idealistic. Realism which commends itself to the crude understanding, by the appearance which it assumes of being matter-of-fact, really starts from an arbitrary assumption, and is therefore an empty castle in the air, for it ignores or denies the first of all facts, that all that we know lies within consciousness. For that the objective existence of things is conditioned through a subject whose ideas they are, and consequently that the objective world exists only as idea, is no hypothesis, and still less a dogma, or even a paradox set up for the sake of discussion; but it is the most certain and the simplest truth; and the knowledge of it is only made difficult by the fact that it is indeed so simple, and that it is not every one who has sufficient power of reflection to go back to the first elements of his consciousness of things. There can never be an absolute and independent objective existence; indeed such an existence is quite unintelligible. For the objective, as such, always and essentially has its existence in the consciousness of a subject, is thus the idea of this subject, and consequently is conditioned by it, and also by its forms, the forms of the idea, which depend upon the subject and not on the object.

That the objective world would exist even if there existed no conscious being certainly seems at the first blush to be unquestionable, because it can be thought in the abstract, without bringing to light the contradiction which it carries within it. But if we desire to realise this abstract thought, that is, to reduce it to ideas of perception, from which alone (like everything abstract) it can have content and truth, and if accordingly we try to imagine an objective world without a knowing subject, we become aware that what we then imagine is in truth the opposite of what we intended, is in fact nothing else than the process in the intellect of a knowing subject who perceives an objective world, is thus exactly what we desired to exclude. For this perceptible and real world is clearly a phenomenon of the brain; therefore there lies a contradiction in the assumption that as such it ought also to exist independently of all brains.

The principal objection to the inevitable and essential ideality of all objects, the objection which, distinctly or indistinctly, arises in every one, is certainly this: My own person also is an object for some one else, is thus his idea, and yet I know certainly that I would continue to exist even if he no longer perceived me. But all other objects also stand in the same relation to his intellect as I do; consequently they also would continue to exist without being perceived by him. The answer to this is: That other being as whose object I now regard my person is not absolutely the subject, but primarily is a knowing individual. Therefore, if he no longer existed, nay, even if there existed no other conscious being except myself, yet the subject, in whose idea alone all objects exist, would by no means be on that account abolished. For I myself indeed am this subject, as every conscious being is. Consequently, in the case assumed, my person would certainly continue to exist, but still as idea, in my own knowledge. For even by me myself it is always known only indirectly, never immediately; because all existence as idea is indirect. As object, i.e., as extended, occupying space and acting, I know my body only in the perception of my

brain. This takes place by means of the senses, upon data supplied by which the percipient understanding performs its function of passing from effect to cause, and thereby, in that the eye sees the body or the hands touch it, it constructs that extended figure which presents itself in space as my body. By no means, however, is there directly given me, either in some general feeling of bodily existence or in inner self-consciousness, any extension, form, or activity, which would then coincide with my nature itself, which accordingly, in order so to exist, would require no other being in whose knowledge it might exhibit itself. On the contrary, that general feeling of bodily existence, and also self-consciousness, exists directly only in relation to the will, that is, as agreeable or disagreeable, and as active in the acts of will, which for external perception exhibit themselves as actions of the body. From this it follows that the existence of my person or body as something extended and acting always presupposes a knowing being distinct from it; because it is essentially an existence in apprehension, in the idea, thus an existence for another. In fact, it is a phenomenon of brain, just as much whether the brain in which it exhibits itself is my own or belongs to another person. In

the first case one’s own person divides itself into the knowing and the known, into object and subject, which here as everywhere stand opposed to each other, inseparable and irreconcilable. If, then, my own person, in order to exist as such, always requires a knowing subject, this will at least as much hold good of the other objects for which it was the aim of the above objection to vindicate an existence independent of knowledge and its subject.

However, it is evident that the existence which is conditioned through a knowing subject is only the existence in space, and therefore that of an extended and active being. This alone is always something known, and consequently an existence for another. On the other hand, every being that exists in this way may yet have an existence for itself, for which it requires no subject. Yet this existence for itself cannot be extension and activity (together space-occupation), but is necessarily a being of another kind, that of a thing in itself, which, as such, can never be an object. This, then, would be the answer to the leading objection set forth above, which accordingly does not overthrow the fundamental truth that the objectively given world can only exist in the idea, thus only for a subject.

We have further to remark here that Kant also, so long at least as he remained consistent, can have thought no objects among his things in themselves. For this follows from the fact that he proves that space, and also time, are mere forms of our perception, which consequently do not belong to things in themselves. What is neither in space nor in time can be no object; thus the being of things in themselves cannot be objective, but of quite a different kind, a metaphysical being. Consequently that Kantian principle already involves this principle also, that the objective world exists only as idea.

In spite of all that one may say, nothing is so persistently and ever anew misunderstood as Idealism, because it is interpreted as meaning that one denies the empirical reality of the external world. Upon this rests the perpetual return to the appeal to common sense, which appears in many forms and guises; for example, as an “irresistible conviction” in the Scotch school, or as Jacobi’s faith in the reality of the external world. The external world by no means presents itself, as Jacobi declares, upon credit, and is accepted by us upon trust and faith. It presents itself as that which it is, and performs directly what it promises. It must be remembered that Jacobi, who set up such a credit or faith theory of the world, and had the fortune to impose it upon a few professors of philosophy, who for thirty years have philosophised upon the same lines lengthily and at their ease, is the same man who once denounced Lessing as a Spinozist, and afterwards denounced Schelling as an atheist, and who received from the latter the well-known and well-deserved castigation. In keeping with such zeal, when he reduced the external world to a mere matter of faith he only wished to open the door to faith in general, and to prepare belief for that which was afterwards really to be made a matter of belief; as if, in order to introduce a paper currency, one should seek to appeal to the fact that the value of the ringing coin also depends merely on the stamp which the State has set upon it. Jacobi, in his doctrine that the reality of the external world is assumed upon faith, is just exactly “the transcendental realist who plays the empirical idealist” censured by Kant in the “Critique of Pure Reason,” first edition, p. 369.

The true idealism, on the contrary, is not the empirical but the transcendental. This leaves the empirical reality of the world untouched, but holds fast to the fact that every object, thus the empirically real in general, is conditioned in a twofold manner by the subject; in the first place materially or as object generally, because an objective existence is only conceivable as opposed to a subject, and as its idea; in the second place formally, because the mode of existence of an object, i.e., its being perceived (space, time, causality), proceeds from the subject, is pre-arranged in the subject. Therefore with the simple or Berkeleian idealism, which concerns the object in general, there stands in immediate connection the Kantian idealism, which concerns the specially given mode or manner of objective existence. This proves that the whole material world, with its bodies, which are extended in space and, by means of time, have causal relations to each other, and everything that depends upon this—that all this is not something which is there independently of our head, but essentially presupposes the functions of our brain by means of which and in which alone such an objective arrangement of things is possible. For time, space, and causality, upon which all those real and objective events rest, are themselves nothing more than functions

of the brain; so that thus the unchangeable order of things which affords the criterion and clue to their empirical reality itself proceeds only from the brain, and has its credentials from this alone. All this Kant has expounded fully and thoroughly; only he does not speak of the brain, but calls it “the faculty of knowledge.” Indeed he has attempted to prove that when that objective order in time, space, causality, matter, &c., upon which all the events of the real world ultimately rest, is properly considered, it cannot even be conceived as a self-existing order, i.e., an order of the thing in itself, or as something absolutely objective and unconditionally given, for if one tries to think this out it leads to contradictions. To accomplish this was the object of the antinomies, but in the appendix to my work I have proved the failure of the attempt. On the other hand, the Kantian doctrine, even without the antinomies, leads to the insight that things and the whole mode of their existence are inseparably bound up with our consciousness of them. Therefore whoever has distinctly grasped this soon attains to the conviction that the assumption that things also exist as such, apart from and independently of our consciousness, is really absurd. That we are so deeply involved in time,

space, causality, and the whole regular process of experience which rests upon them, that we (and indeed the brutes) are so perfectly at home, and know how to find our way from the first—this would not be possible if our intellect were one thing and things another, but can only be explained from the fact that both constitute one whole, the intellect itself creates that order, and exists only for things, while they, on the other hand, exist only for it.

But even apart from the deep insight, which only the Kantian philosophy gives, the inadmissibility of the assumption of absolute realism which is so obstinately clung to may be directly shown, or at least made capable of being felt, by the simple exhibition of its meaning in the light of such considerations as the following. According to realism, the world is supposed to exist, as we know it, independently of this knowledge. Let us once, then, remove all percipient beings from it, and leave only unorganised and vegetable nature. Rock, tree, and brook are there, and the blue heaven; sun, moon, and stars light this world, as before; yet certainly in vain, for there is no eye to see it. Let us now in addition place in it a percipient being. Now that world presents itself again in his brain, and repeats itself within it precisely as it was formerly without it. Thus to the first world a second has been added, which, although completely separated from it, resembles it to a nicety. And now the subjective world of this perception is precisely so constituted in subjective, known space as the objective world in objective, infinite space. But the subjective world has this advantage over the objective, the knowledge that that space, outside there, is infinite; indeed it can also

give beforehand most minutely and accurately the whole constitution or necessary properties of all relations which are possible, though not yet actual, in that space, and does not require to examine them. It can tell just as much with regard to the course of time, and also with regard to the relation of cause and effect which governs the changes in that external world. I think all this, when closely considered, turns out absurd enough, and hence leads to the conviction that that absolute objective world outside the head, independent of it and prior to all knowledge, which at first we imagined ourselves to conceive, is really no other than the second, the world which is known subjectively, the world of idea, as which alone we are actually able to conceive it. Thus of its own accord the assumption forces itself upon us, that the world, as we know it, exists also only for our knowledge, therefore in the idea alone, and not a second time outside of it.(12) In accordance, then, with this assumption, the thing in itself, i.e., that which exists independently of our knowledge and of every knowledge, is to be regarded as something completely different from the idea and all its attributes, thus from objectivity in general. What this is will be the subject of our

On the other hand, the controversy concerning the reality of the external world considered in § 5 of the first volume rests upon the assumption, which has just been criticised, of an objective and a subjective world both in space, and upon the impossibility which arises in connection with this presupposition of a transition from one to the other, a bridge between the two. Upon this controversy I have still to add the following remarks.

The subjective and the objective do not constitute a continuous whole. That of which we are immediately conscious is bounded by the skin, or rather by the extreme ends of the nerves which proceed from the cerebral system. Beyond this lies a world of which we have no knowledge except through pictures in our head. Now the question is, whether and how far there is a world independent of us which corresponds to these pictures. The relation between the two could only be brought about by means of the law of causality; for this law alone leads from what is given to something quite different from it. But this law itself has first of all to prove its validity. Now it must either be of objective or of subjective origin; but in either case it lies upon one or the other side, and therefore cannot supply the bridge between them. If, as Locke and Hume assume, it is a posteriori, thus drawn from experience, it is of objective origin, and belongs then itself to the external world which is in question. Therefore it cannot attest the reality of this world, for then, according to Locke’s method, causality would be proved from experience, and the reality of experience from causality. If, on the contrary, it is given a priori, as Kant

has more correctly taught us, then it is of subjective origin, and in that case it is clear that with it we remain always in the subjective sphere. For all that is actually given empirically in perception is the occurrence of a sensation in the organ of sense; and the assumption that this, even in general, must have a cause rests upon a law which is rooted in the form of our knowledge, i.e., in the functions of our brain. The origin of this law is therefore just as subjective as that of the sensation itself. The cause of the given sensation, which is assumed in consequence of this law, presents itself at once in perception as an object, which has space and time for the form of its manifestation. But these forms themselves again are entirely of subjective origin; for they are the mode or method of our faculty of perception. That transition from the sensation to its cause which, as I have repeatedly pointed out, lies at the foundation of all sense-perception is certainly sufficient to give us the empirical presence in space and time of an empirical object, and is therefore quite enough for the practical purposes of life; but it is by no means sufficient to afford us any conclusion as to the existence and real

nature, or rather as to the intelligible substratum, of the phenomena which in this way arise for us. Thus that on the occasion of certain sensations occurring in my organs of sense there arises in my head a perception of things which are extended in space, permanent in time, and causally efficient by no means justifies the assumption that they also exist in themselves, i.e., that such things with these properties belonging absolutely to themselves exist independently and outside of my head. This is the true outcome of the Kantian philosophy. It coincides with an earlier result of Locke’s, which is just as true, but far more easily understood. For although, as Locke’s doctrine permits, external things are absolutely assumed as the causes of sensations, yet there can be no resemblance between the sensation in which the effect consists and the objective nature of the cause which occasions it. For the sensation, as organic function, is primarily determined by the highly artificial and complicated nature of our organs of sense. It is therefore merely excited by the external cause, but is then perfected entirely in accordance with its own laws, and thus is completely subjective. Locke’s philosophy was the criticism of the functions of sense; Kant has given us the criticism of the functions of the brain. But to all

this we have yet to add the Berkeleian result, which has been revised by me, that every object, whatever its origin may be, is as object already conditioned by the subject, is in fact merely its idea. The aim of realism is indeed the object without subject; but it is impossible even to conceive such an object distinctly.

From this whole inquiry it follows with certainty and distinctness that it is absolutely impossible to attain to the comprehension of the inner nature of things upon the path of mere knowledge and perception. For knowledge always comes to things from without, and therefore must for ever remain outside them. This end would only be reached if we could find ourselves in the inside of things, so that their inner nature would be known to us directly. Now, how far this is actually the case is considered in my second book. But so long as we are concerned, as in this first book, with objective comprehension, that is, with knowledge, the world is, and remains for us, a mere idea, for here there is no possible path by which we can cross over to it.

But, besides this, a firm grasp of the point of view of idealism is a necessary counterpoise to that of materialism. The controversy concerning the real and the ideal may also be regarded as a controversy concerning the existence of matter. For it is the reality or ideality of this that is ultimately in question. Does matter, as such, exist only in our idea, or does it also exist independently of it? In the latter case it would be the thing in itself; and whoever assumes a self-existent matter must also, consistently, be a materialist, i.e., he must make matter the principle of explanation of all things. Whoever, on the contrary, denies its existence as a thing in itself is eo ipso an idealist. Among the moderns only Locke has definitely and without ambiguity asserted the reality of matter; and therefore his teaching led, in the hands of Condillac, to the sensualism and materialism of the French. Only Berkeley directly and without modifications denies matter. The complete antithesis is thus that of idealism and materialism, represented in its extremes by Berkeley and the French materialists (Hollbach). Fichte is not to be mentioned here: he deserves no place among true philosophers; among those elect of mankind who, with deep earnestness, seek not their own things but the truth, and therefore must

not be confused with those who, under this pretence, have only their personal advancement in view. Fichte is the father of the sham philosophy, of the disingenuous method which, through ambiguity in the use of words, incomprehensible language, and sophistry, seeks to deceive, and tries, moreover, to make a deep impression by assuming an air of importance—in a word, the philosophy which seeks to bamboozle and humbug those who desire to learn. After this method had been applied by Schelling, it reached its height, as every one knows, in Hegel, in whose hands it developed into pure charlatanism. But whoever even names this Fichte seriously along with Kant shows that he has not even a dim notion of what Kant is. On the other hand, materialism also has its warrant. It is just as true that the knower is a product of matter as that matter is merely the idea of the knower; but it is also just as one-sided. For materialism is the philosophy of the subject that forgets to take account of itself. And, accordingly, as against the assertion that I am a mere modification of matter, this must be insisted upon, that all matter exists merely in my idea; and it is no less right. A knowledge, as yet obscure, of these relations seems to have been

the origin of the saying of Plato, “ὑλη αληθινον ψευδος” (materia mendacium verax).

Realism necessarily leads, as we have said, to materialism. For if empirical perception gives us things in themselves, as they exist independently of our knowledge, experience also gives us the order of things in themselves, i.e., the true and sole order of the world. But this path leads to the assumption that there is only one thing in itself, matter; of which all other things are modifications; for the course of nature is here the absolute and only order of the world. To escape from these consequences, while realism remained in undisputed acceptance, spiritualism was set up, that is, the assumption of a second substance outside of and along with matter, an immaterial substance. This dualism and spiritualism, equally unsupported by experience and destitute of proof and comprehensibility, was denied by Spinoza, and was proved to be false by Kant, who dared to do so because at the same time he established idealism in its rights. For with realism materialism, as the counterpoise of which spiritualism had been devised, falls to the ground of its own accord, because then matter and the course of nature become mere phenomena, which are conditioned by the intellect, as they have their existence only in its idea. Accordingly spiritualism is the delusive and false safeguard against materialism, while the real and true safeguard is idealism, which, by making the objective world dependent upon us, gives the needed counterpoise to the position of dependence upon the objective world, in which we are placed by the course of nature. The world from which I part at death is, in another aspect, only my idea. The centre of gravity of existence falls back into the subject. What is proved is not, as in spiritualism, that the knower is independent of matter, but that all matter is dependent on him. Certainly this is not so easy to comprehend or so convenient to handle as spiritualism, with its two substances; but χαλεπα τα καλα.

In opposition to the subjective starting-point, “the world is my idea,” there certainly stands provisionally with equal justification the objective starting-point, “the world is matter,” or “matter alone is absolute” (since it alone is not subject to becoming and passing away), or “all that exists is matter.” This is the starting-point of Democritus, Leucippus, and Epicurus. But, more closely considered, the departure from the subject retains a real advantage; it has the start by one perfectly justified step. For consciousness alone is the immediate: but we pass over this if we go at once to matter and make it our starting-point. On the other hand, it would certainly be possible to construct the world from matter and its properties if these were correctly, completely, and exhaustively known to us (which is far from being the case as yet). For all that has come to be has become actual through causes, which could operate and come together only by virtue of the fundamental forces of matter. But these must be perfectly capable of demonstration at least objectively, even if subjectively we never attain to a knowledge of them. But such an explanation and construction of the world would not only have at its foundation the assumption of an existence in itself of matter (while in truth it is conditioned by the

subject), but it would also be obliged to allow all the original qualities in this matter to pass current and remain absolutely inexplicable, thus as qualitates occultæ. (Cf. § 26, 27 of the first volume.) For matter is only the vehicle of these forces, just as the law of causality is only the arranger of their manifestations. Therefore such an explanation of the world would always remain merely relative and conditioned, properly the work of a physical science, which at every step longed for a metaphysic. On the other hand, there is also something inadequate about the subjective starting-point and first principle, “the world is my idea,” partly because it is one-sided, since the world is far more than that (the thing in itself, will), and indeed its existence as idea is to a certain extent only accidental to it; but partly also because it merely expresses the fact that the object is conditioned by the subject, without at the same time saying that the subject, as such, is also conditioned by the object. For the assertion, “the subject would still remain a knowing being if it had no object, i.e., if it had absolutely no idea,” is just as false as the assertion of the crude understanding, “the world, the object, would still exist, even if there were no

subject.” A consciousness without an object is no consciousness. A thinking subject has conceptions for its object; a subject of sense perception has objects with the qualities corresponding to its organisation. If we rob the subject of all special characteristics and forms of its knowledge, all the properties of the object vanish also, and nothing remains but matter without form and quality, which can just as little occur in experience as a subject without the forms of its knowledge, but which remains opposed to the naked subject as such, as its reflex, which can only disappear along with it. Although materialism pretends to postulate nothing more than this matter—for instance, atoms—yet it unconsciously adds to it not only the subject, but also space, time, and causality, which depend upon special properties of the subject.

The world as idea, the objective world, has thus, as it were, two poles; the simple knowing subject without the forms of its knowledge, and crude matter without form and quality. Both are completely unknowable; the subject because it is that which knows, matter because without form and quality it cannot be perceived. Yet both are fundamental conditions of all empirical perception. Thus the knowing subject, merely as such, which is a presupposition of all experience, stands opposed as its pure counterpart to the crude, formless, and utterly dead (i.e., will-less) matter, which is given in no experience, but which all experience presupposes. This subject is not in time, for time is only the more definite form of all its ideas. The matter which stands over against it is, like it, eternal and imperishable, endures through all time, but is, properly speaking, not extended, for extension gives form, thus it has no spatial properties. Everything else is involved in a constant process of coming into being and passing away, while these two represent the unmoved poles of the world as idea. The permanence of matter may therefore be regarded as the reflex of the timelessness of the pure subject, which is simply assumed as the condition of all objects. Both belong to phenomena, not to the thing in itself, but they are the framework of the phenomenon. Both are arrived at only by abstraction, and are not given immediately, pure and for themselves.

The fundamental error of all systems is the failure to understand this truth. Intelligence and matter are correlates, i.e., the one exists only for the other, both stand and fall together, the one is only the reflex of the other. Indeed they are really one and the same thing regarded from two opposite points of view; and this one thing, I am here anticipating, is the manifestation of the will, or the thing in itself. Consequently both are secondary, and therefore the origin of the world is not to be sought in either of the two. But because of their failure to understand this, all systems (with the exception perhaps of that of Spinoza) sought the origin of all things in one of these two. Some of them, on the one hand, suppose an intelligence, νους, as the absolutely First and δημιουργος, and accordingly in this allow an idea of things and of the world to precede their actual existence; consequently they distinguish the real world from the world of idea; which is false. Therefore matter now appears as that through which the two are distinguished, as the thing in itself. Hence arises the difficulty of procuring this matter, the ὑλη, so that when added to the mere idea of the world it may impart reality to it. That original

intelligence must now either find it ready to hand, in which case it is just as much an absolute First as that intelligence itself, and we have then two absolute Firsts, the δημιουργος and the ὑλη; or the absolute intelligence must create this matter out of nothing, an assumption which our understanding refuses to make, for it is only capable of comprehending changes in matter, and not that matter itself should come into being or pass away. This rests ultimately upon the fact that matter is essential, the correlate of the understanding. On the other hand, the systems opposed to these, which make the other of the two correlates, that is, matter, the absolute First, suppose a matter which would exist without being perceived; and it has been made sufficiently clear by all that has been said above that this is a direct contradiction, for by the existence of matter we always mean simply its being perceived. But here they encounter the difficulty of bringing to this matter, which alone is their absolute First, the intelligence which is finally to experience it. I have shown this weak side of materialism in § 7 of the first volume. For me, on the contrary, matter and intelligence are inseparable correlates, which exist only for each other, and therefore merely relatively. Matter is

the idea of the intelligence; the intelligence is that in whose idea alone matter exists. The two together constitute the world as idea, which is just Kant’s phenomenon, and consequently something secondary. What is primary is that which manifests itself, the thing in itself, which we shall afterwards discover is the will. This is in itself neither the perceiver nor the perceived, but is entirely different from the mode of its manifestation.

As a forcible conclusion of this important and difficult discussion I shall now personify these two abstractions, and present them in a dialogue after the fashion of Prabodha Tschandro Daya. It may also be compared with a similar dialogue between matter and form in the “Duodecim Principia Philosophiæ” of Raymund Lully, c. 1 and 2. The Subject. I am, and besides me there is nothing. For the world is my idea. Matter. Presumptuous delusion! I, I am, and besides me there is nothing, for the world is my fleeting form. Thou art a mere result of a part of this form and altogether accidental. The Subject. What insane arrogance! Neither thou nor thy form would exist without me; ye are conditioned by me. Whosoever thinks me away, and believes he can still think ye there, is involved in gross delusion, for your existence apart from my idea is a direct contradiction, a meaningless form of words. Ye are simply means ye are perceived by me. My idea is the sphere of your existence; therefore I am its first condition. Matter.

Fortunately the audacity of your assertion will soon be put to silence in reality and not by mere words. Yet a few moments and thou actually art no more. With all thy boasting thou hast sunk into nothing, vanished like a shadow, and shared the fate of all my transitory forms. But I, I remain, unscathed and undiminished, from age to age, through infinite time, and behold unshaken the play of my changing form. The Subject. This infinite time through which thou boastest that thou livest, like the infinite space which thou fillest, exists only in my idea. Indeed it is merely the form of my idea which I bear complete in myself, and in which thou exhibitest thyself, which receives thee, and through which thou first of all existest. But the annihilation with which thou threatenest me touches me not; were it so, then wouldst thou also be annihilated. It merely affects the individual, which for a short time is my vehicle, and which, like everything else, is my idea. Matter.

And if I concede this, and go so far as to regard thy existence, which is yet inseparably linked to that of these fleeting individuals, as something absolute, it yet remains dependent upon mine. For thou art subject only so far as thou hast an object; and this object I am. I am its kernel and content, that which is permanent in it, that which holds it together, and without which it would be as disconnected, as wavering, and unsubstantial as the dreams and fancies of thy individuals, which have yet borrowed from me even the illusive content they possess. The Subject. Thou dost well to refrain from contesting my existence on the ground that it is linked to individuals; for, as inseparably as I am joined to them, thou art joined to thy sister, Form, and hast never appeared without her. No eye hath yet seen either thee or me naked and isolated; for we are both mere abstractions. It is in reality one being that perceives itself and is perceived by itself, but whose real being cannot consist either in perceiving or in being perceived, since these are divided between us two. Both.

We are, then, inseparably joined together as necessary parts of one whole, which includes us both and exists through us. Only a misunderstanding can oppose us two hostilely to each other, and hence draw the false conclusion that the one contests the existence of the other, with which its own existence stands or falls. This whole, which comprehends both, is the world as idea, or the world of phenomena. When this is taken away there remains only what is purely metaphysical, the thing in itself, which in the second book we shall recognise as the will. Chapter II. The Doctrine of Perception or Knowledge Of The Understanding.

With all transcendental ideality the objective world retains empirical reality; the object is indeed not the thing in itself, but as an empirical object it is real. It is true that space is only in my head; but empirically my head is in space. The law of causality can certainly never enable us to get quit of idealism by building a bridge between things in themselves and our knowledge of them, and thus certifying the absolute reality of the world, which exhibits itself in consequence of its application; but this by no means does away with the causal relation of objects to each other, thus it does not abolish the causal relation which unquestionably exists between the body of each knowing person and all other material objects. But the law of causality binds together only phenomena, and does not lead beyond them. With that law we are and remain in the world of objects, i.e., the world of phenomena, or more properly the world of ideas. Yet the whole of such a world of experience is primarily conditioned by the knowledge of a subject in general as its necessary presupposition, and then by the special forms of our perception and apprehension, thus necessarily belongs to the merely phenomenal, and has no claim to pass for the world of things in themselves. Indeed the subject itself (so far as it is merely the knowing subject) belongs to the merely phenomenal, of which it constitutes the complementary half.

Without application of the law of causality, however, perception of an objective world could never be arrived at; for this perception is, as I have often explained, essentially matter of the intellect, and not merely of the senses. The senses afford us mere sensation, which is far from being perception. The part played by sensations of the senses in perception was distinguished by Locke under the name secondary qualities, which he rightly refused to ascribe to things in themselves. But Kant, carrying Locke’s method further, distinguished also, and refused to ascribe to things in themselves what belongs to the working up of this material (the sensations) by the brain. The result was, that in this was included all that Locke had left to things in themselves as primary qualities—extension, form, solidity, &c.—so that with Kant the thing in itself was reduced to a completely unknown quantity = x. With Locke accordingly the thing in itself is certainly without colour, sound, smell, taste, neither warm nor cold, neither soft nor hard, neither smooth nor rough; yet it has still extension and form, it is impenetrable, at rest or in motion, and has mass and number. With Kant, on the other hand, it has laid aside all these latter qualities also, because they are only possible by means of time, space, and

causality, and these spring from an intellect (brain), just as colours, tones, smells, &c., originate in the nerves of the organs of sense. The thing in itself has with Kant become spaceless, unextended, and incorporeal. Thus what the mere senses bring to the perception, in which the objective world exists, stands to what is supplied by the functions of the brain (space, time, causality) as the mass of the nerves of sense stand to the mass of the brain, after subtracting that part of the latter which is further applied to thinking proper, i.e., to abstract ideas, and is therefore not possessed by the brutes. For as the nerves of the organs of sense impart to the phenomenal objects colour, sound, taste, smell, temperature, &c., so the brain imparts to them extension, form, impenetrability, the power of movement, &c., in short all that can only be presented in perception by means of time, space, and causality. How small is the share of the senses in perception, compared with that of the intellect, is also shown by a comparison of the nerve apparatus for receiving impressions with that for working them up. The mass of the nerves of sensation of the whole of the organs of sense is very small compared with that of the brain, even in the case of

the brutes, whose brain, since they do not, properly speaking, i.e., in the abstract, think, is merely used for effecting perception, and yet when this is complete, thus in the case of mammals, has a very considerable mass, even after the cerebellum, whose function is the systematic guidance of movements, has been taken away.

That excellent book by Thomas Reid, the “Inquiry into the Human Mind” (first edition, 1764; 6th edition, 1810), as a negative proof of the Kantian truths, affords us a very thorough conviction of the inadequacy of the senses to produce the objective perception of things, and also of the non-empirical origin of the perception of space and time. Reid refutes Locke’s doctrine that perception is a product of the senses, by a thorough and acute demonstration that the collective sensations of the senses do not bear the least resemblance to the world as known in perception, and especially that the five primary qualities of Locke (extension, form, solidity, movement, and number) absolutely could not be afforded us by any sensation of the senses. Accordingly he gives up the question as to the mode of origination and the source of perception as completely insoluble; and although altogether unacquainted with Kant, he gives us, as it were, according to the regula falsi, a thorough proof of the intellectual nature of perception (really first explained by me as a consequence of the Kantian doctrine), and also of the a priori source, discovered by Kant, of its constituent elements, space, time, and causality, from which those primary qualities of Locke first proceed, but by means of which they are easily constructed. Thomas Reid’s book

is very instructive and well worth reading—ten times more so than all the philosophy together that has been written since Kant. Another indirect proof of the same doctrine, though in the way of error, is afforded by the French sensational philosophers, who, since Condillac trod in the footsteps of Locke, have laboured to show once for all that the whole of our perception and thinking can be referred to mere sensations (penser c’est sentir), which, after Locke’s example, they call idées simples, and through the mere coming together and comparison of which the whole objective world is supposed to build itself up in our heads. These gentlemen certainly have des idées bien simples. It is amusing to see how, lacking alike the profundity of the German and the honesty of the English philosopher, they turn the poor material of sensation this way and that way, and try to increase its importance, in order to construct out of it the deeply significant phenomena of the world of perception and thought. But the man constructed by them would necessarily be an Anencephalus, a Tête de crapaud, with only organs of sense and without a brain. To take only a couple of the better attempts of this sort out of a multitude of others, I may mention as examples Condorcet at the beginning

of his book, “Des Progrès de l’Esprit Humain,” and Tourtual on Sight, in the second volume of the _“__Scriptures Ophthalmologici Minores,__”__ edidit Justus Radius_ (1828).

The feeling of the insufficiency of a purely sensationalistic explanation of perception is in like manner shown in the assertion which was made shortly before the appearance of the Kantian philosophy, that we not only have ideas of things called forth by sensation, but apprehend the things themselves directly, although they lie outside us—which is certainly inconceivable. And this was not meant in some idealistic sense, but was said from the point of view of common realism. This assertion is well and pointedly put by the celebrated Euler in his “Letters to a German Princess,” vol. ii. p. 68. He says: “I therefore believe that the sensations (of the senses) contain something more than philosophers imagine. They are not merely empty perceptions of certain impressions made in the brain. They do not give the soul mere ideas of things, but actually place before it objects which exist outside it, although we cannot conceive how this really happens.” This opinion is explained by the following facts. Although, as I have fully proved, perception is brought about by application of the law of causality, of which we are conscious a priori, yet in sight the act of the understanding, by means of which we pass from the effect to the cause, by no means appears distinctly in consciousness; and therefore the sensation

does not separate itself clearly from the idea which is constructed out of it, as the raw material, by the understanding. Still less can a distinction between object and idea, which in general does not exist, appear in consciousness; but we feel the things themselves quite directly, and indeed as lying outside us, although it is certain that what is immediate can only be the sensation, and this is confined to the sphere of the body enclosed by our skin. This can be explained from the fact that outside us is exclusively a spatial determination. But space itself is a form of our faculty of perception, i.e., a function of our brain. Therefore that externality to us to which we refer objects, on the occasion of sensations of sight, is itself really within our heads; for that is its whole sphere of activity. Much as in the theatre we see the mountains, the woods, and the sea, but yet everything is inside the house. From this it becomes intelligible that we perceive things in the relation of externality, and yet in every respect immediately, but have not within us an idea of the things which lie outside us, different from these things. For things are in space, and consequently also external to us only in so far as we perceive

them. Therefore those things which to this extent we perceive directly, and not mere images of them, are themselves only our ideas, and as such exist only in our heads. Therefore we do not, as Euler says, directly perceive the things themselves which are external to us, but rather the things which are perceived by us as external to us are only our ideas, and consequently are apprehended by us immediately. The whole observation given above in Euler’s words, and which is quite correct, affords a fresh proof of Kant’s Transcendental Æsthetic, and of my theory of perception which is founded upon it, as also of idealism in general. The directness and unconsciousness referred to above, with which in perception we make the transition from the sensation to its cause, may be illustrated by an analogous procedure in the use of abstract ideas or thinking. When we read or hear we receive mere words, but we pass from these so immediately to the conceptions denoted by them, that it is as if we received the conceptions directly; for we are absolutely unconscious of the transition from the words to the conceptions. Therefore it sometimes happens that we do not know in what language it was that we read something yesterday which we now remember. Yet that such a transition always

takes place becomes apparent if it is once omitted, that is, if in a fit of abstraction we read without thinking, and then become aware that we certainly have taken in all the words but no conceptions. Only when we pass from abstract conceptions to pictures of the imagination do we become conscious of the transposition we have made.

Further, it is really only in perception in the narrowest sense, that is, in sight, that in empirical apprehension the transition from the sensation to its cause takes place quite unconsciously. In every other kind of sense perception, on the contrary, the transition takes place with more or less distinct consciousness; therefore, in the case of apprehension through the four coarser senses, its reality is capable of being established as an immediate fact. Thus in the dark we feel a thing for a long time on all sides until from the different effects upon our hands we are able to construct its definite form as their cause. Further, if something feels smooth we sometimes reflect whether we may not have fat or oil upon our hands; and again, if something feels cold we ask ourselves whether it may not be that we have very warm hands. When we hear a sound we sometimes doubt whether it was really an affection of our sense of hearing from without or merely an inner affection of it; then whether it sounded near and weak or far off and strong, then from what direction it came, and finally whether it was the voice of a man or of a brute, or the sound of an instrument; thus we investigate the cause of each effect

we experience. In the case of smell and taste uncertainty as to the objective nature of the cause of the effect felt is of the commonest occurrence, so distinctly are the two separated here. The fact that in sight the transition from the effect to the cause occurs quite unconsciously, and hence the illusion arises that this kind of perception is perfectly direct, and consists simply in the sensation alone without any operation of the understanding—this has its explanation partly in the great perfection of the organ of vision, and partly in the exclusively rectilineal action of light. On account of the latter circumstance the impression itself leads directly to the place of the cause, and since the eye is capable of perceiving with the greatest exactness and at a glance all the fine distinctions of light and shade, colour and outline, and also the data in accordance with which the understanding estimates distance, it thus happens that in the case of impressions of this sense the operation of the understanding takes place with such rapidity and certainty that we are just as little conscious of it as of spelling when we read. Hence arises the delusion that the sensation itself presents us directly with the objects. Yet it is just in sight that the operation of the understanding, consisting

in the knowledge of the cause from the effect, is most significant. By means of it what is felt doubly, with two eyes, is perceived as single; by means of it the impression which strikes the retina upside down, in consequence of the crossing of the rays in the pupils, is put right by following back the cause of this in the same direction, or as we express ourselves, we see things upright although their image in the eye is reversed; and finally by means of the operation of the understanding magnitude and distance are estimated by us in direct perception from five different data, which are very clearly and beautifully described by Dr. Thomas Reid. I expounded all this, and also the proofs which irrefutably establish the intellectual nature of perception, as long ago as 1816, in my essay “On Sight and Colour” (second edition, 1854; third edition, 1870), and with important additions fifteen years later in the revised Latin version of it which is given under the title, “Theoria Colorum Physiologica Eademque Primaria,” in the third volume of the “Scriptores Ophthalmologici Minores,” published by Justus Radius in 1830; yet most fully and thoroughly in the second (and third) edition of my essay “On the Principle of Sufficient Reason,” § 21. Therefore on this important subject I refer to

these works, so as not to extend unduly the present exposition.

On the other hand, an observation which trenches on the province of æsthetics may find its place here. It follows from the proved intellectual nature of perception that the sight of beautiful objects—for example, of a beautiful view—is also a phenomenon of the brain. Its purity and completeness, therefore, depends not merely on the object, but also upon the quality of the brain, its form and size, the fineness of its texture, and the stimulation of its activity by the strength of the pulse of the arteries which supply it. Accordingly the same view appears in different heads, even when the eyes are equally acute, as different as, for example, the first and last impressions of a copper plate that has been much used. This is the explanation of the difference of capacity for enjoying natural beauty, and consequently also for reproducing it, i.e., for occasioning a similar phenomenon of the brain by means of an entirely different kind of cause, the arrangement of colours on a canvas.

The apparent immediacy of perception, depending on its entire intellectuality, by virtue of which, as Euler says, we apprehend the thing itself, and as external to us, finds an analogy in the way in which we feel the parts of our own bodies, especially when they suffer pain, which when we do feel them is generally the case. Just as we imagine that we perceive things where they are, while the perception really takes place in the brain, we believe that we feel the pain of a limb in the limb itself, while in reality it also is felt in the brain, to which it is conducted by the nerve of the affected part. Therefore, only the affections of those parts whose nerves go to the brain are felt, and not those of the parts whose nerves belong to the sympathetic system, unless it be that an unusually strong affection of these parts penetrates by some roundabout way to the brain, where yet for the most part it only makes itself known as a dull sense of discomfort, and always without definite determination of its locality. Hence, also, it is that we do not feel injuries to a limb whose nerve-trunk has been severed or ligatured. And hence, finally, the man who has lost a limb still sometimes feels pain in it, because the nerves which go to the brain are still there. Thus, in the two phenomena here compared, what goes on in the brain is apprehended as outside of it; in the case of perception, by means of the understanding, which extends its feelers into the outer world; in the case of the feeling of our limbs, by means of the nerves.

Chapter III. On The Senses. It is not the object of my writings to repeat what has been said by others, and therefore I only make here some special remarks of my own on the subject of the senses.

The senses are merely the channels through which the brain receives from without (in the form of sensations) the materials which it works up into ideas of perception. Those sensations which principally serve for the objective comprehension of the external world must in themselves be neither agreeable nor disagreeable. This really means that they must leave the will entirely unaffected. Otherwise the sensation itself would attract our attention, and we would remain at the effect instead of passing to the cause, which is what is aimed at here. For it would bring with it that marked superiority, as regards our consideration, which the will always has over the mere idea, to which we only turn when the will is silent. Therefore colours and sounds are in themselves, and so long as their impression does not pass the normal degree, neither painful nor pleasurable sensations, but appear with the indifference that fits them to be the material of pure objective perception. This is as far the case as was possible in a body which is in itself through and through will; and just in this respect it is worthy of admiration. Physiologically it rests upon the fact that in the organs of the nobler senses, thus in sight and hearing, the nerves which have to receive the specific outward impression are

quite insusceptible to any sensation of pain, and know no other sensation than that which is specifically peculiar to them, and which serves the purpose of mere apprehension. Thus the retina, as also the optic nerve, is insensible to every injury; and this is also the case with the nerve of hearing. In both organs pain is only felt in their other parts, the surroundings of the nerve of sense which is peculiar to them, never in this nerve itself. In the case of the eye such pain is felt principally in the conjunctiva; in the case of the ear, in the meatus auditorius. Even with the brain this is the case, for if it is cut into directly, thus from above, it has no feeling. Thus only on account of this indifference with regard to the will which is peculiar to them are the sensations of the eye capable of supplying the understanding with such multifarious and finely distinguished data, out of which it constructs in our head the marvellous objective world, by the application of the law of causality upon the foundation of the pure perceptions of space and time. Just that freedom from affecting the will which is characteristic of sensations of colour enables them, when their energy is heightened by transparency, as in the glow of

an evening sky, in painted glass, and the like, to raise us very easily into the state of pure objective will-less perception, which, as I have shown in my third book, is one of the chief constituent elements of the æsthetic impression. Just this indifference with regard to the will fits sounds to supply the material for denoting the infinite multiplicity of the conceptions of the reason.

Outer sense, that is, receptivity for external impressions as pure data for the understanding, is divided into five senses, and these accommodate themselves to the four elements, i.e., the four states of aggregation, together with that of imponderability. Thus the sense for what is firm (earth) is touch; for what is fluid (water), taste; for what is in the form of vapour, i.e., volatile (vapour, exhalation), smell; for what is permanently elastic (air), hearing; for what is imponderable (fire, light), sight. The second imponderable, heat, is not properly an object of the senses, but of general feeling, and therefore always affects the will directly, as agreeable or disagreeable. From this classification there also follows the relative dignity of the senses. Sight has the highest rank, because its sphere is the widest and its susceptibility the finest. This rests upon the fact that what affects it is an imponderable, that is, something which is scarcely corporeal, but is quasi spiritual. Hearing has the second place, corresponding to air. However, touch is a more thorough and well-informed sense. For while each of the other senses gives us only an entirely one-sided relation to the object, as its sound, or its relation to light, touch, which is closely bound up with general feeling and muscular power, supplies the understanding with the data at once for the form, magnitude, hardness, softness, texture, firmness, temperature, and weight of bodies, and all this with the least possibility of illusion and deception, to which all the other senses are far more subject. The two lowest senses, smell and taste, are no longer free from a direct affection of the will, that is, they are always agreeably or disagreeably affected, and are therefore more subjective than objective.

Sensations of hearing are exclusively in time, and therefore the whole nature of music consists in degrees of time, upon which depends both the quality or pitch of tones, by means of vibrations, and also their quantity or duration, by means of time. The sensations of sight, on the other hand, are primarily and principally in space; but secondarily, by reason of their duration, they are also in time. Sight is the sense of the understanding which perceives; hearing is the sense of the reason which thinks and apprehends. Words are only imperfectly represented by visible signs; and therefore I doubt whether a deaf and dumb man, who can read, but has no idea of the sound of the words, works as quickly in thinking with the mere visible signs of conceptions as we do with the real, i.e., the audible words. If he cannot read, it is well known that he is almost like an irrational animal, while the man born blind is from the first a thoroughly rational being.

Sight is an active, hearing a passive sense. Therefore sounds affect our mind in a disturbing and hostile manner, and indeed they do so the more in proportion as the mind is active and developed; they distract all thoughts and instantly destroy the power of thinking. On the other hand, there is no analogous disturbance through the eye, no direct effect of what is seen, as such, upon the activity of thought (for naturally we are not speaking here of the influence which the objects looked at have upon the will); but the most varied multitude of things before our eyes admits of entirely unhindered and quiet thought. Therefore the thinking mind lives at peace with the eye, but is always at war with the ear. This opposition of the two senses is also confirmed by the fact that if deaf and dumb persons are cured by galvanism they become deadly pale with terror at the first sounds they hear (Gilbert’s “Annalen der Physik,” vol. x. p. 382), while blind persons, on the contrary, who have been operated upon, behold with ecstasy the first light, and unwillingly allow the bandages to be put over their eyes again. All that has been said, however, can be explained from the fact that hearing takes place by means of a mechanical vibration of

the nerve of hearing which is at once transmitted to the brain, while seeing, on the other hand, is a real action of the retina which is merely stimulated and called forth by light and its modifications; as I have shown at length in my physiological theory of colours. But this whole opposition stands in direct conflict with that coloured-ether, drum-beating theory which is now everywhere unblushingly served up, and which seeks to degrade the eye’s sensation of light to a mechanical vibration, such as primarily that of hearing actually is, while nothing can be more different than the still, gentle effect of light and the alarm-drum of hearing. If we add to this the remarkable circumstance that although we hear with two ears, the sensibility of which is often very different, yet we never hear a sound double, as we often see things double with our two eyes, we are led to the conjecture that the sensation of hearing does not arise in the labyrinth or in the cochlea, but deep in the brain where the two nerves of hearing meet, and thus the impression becomes simple. But this is where the pons Varolii encloses the medulla oblongata, thus at the absolutely lethal spot, by the injury of which every animal is instantly killed, and from which the nerve

of hearing has only a short course to the labyrinth, the seat of acoustic vibration. Now it is just because its source is here, in this dangerous place, in which also all movement of the limbs originates, that we start at a sudden noise; which does not occur in the least degree when we suddenly see a light; for example, a flash of lightning. The optic nerve, on the contrary, proceeds from its thalami much further forward (though perhaps its source lies behind them), and throughout its course is covered by the anterior lobes of the brain, although always separated from them till, having extended quite out of the brain, it is spread out in the retina, upon which, on stimulation by light, the sensation first arises, and where it is really localised. This is shown in my essay upon sight and colour. This origin of the auditory nerve explains, then, the great disturbance which the power of thinking suffers from sound, on account of which thinking men, and in general all people of much intellect, are without exception absolutely incapable of enduring any noise. For it disturbs the constant stream of their thoughts, interrupts and paralyses their thinking, just because the vibration of the auditory nerve extends so deep into the brain, the whole mass of which feels the

oscillations set up through this nerve, and vibrates along with them, and because the brains of such persons are more easily moved than those of ordinary men. On the same readiness to be set in motion, and capacity for transmission, which characterises their brains depends the fact that in the case of persons like these every thought calls forth so readily all those analogous or related to it whereby the similarities, analogies, and relations of things in general come so quickly and easily into their minds; that the same occasion which millions of ordinary minds have experienced before brings them to the thought, to the discovery, that other people are subsequently surprised they did not reach themselves, for they certainly can think afterwards, but they cannot think before. Thus the sun shone on all statues, but only the statue of Memnon gave forth a sound. For this reason Kant, Gœthe, and Jean Paul were highly sensitive to every noise, as their biographers bear witness.(13) Gœthe in his last years bought a house which had fallen into disrepair close to his own, simply in order that he might not have to endure the noise that would be made in repairing it. Thus it was in vain that in his youth he followed the drum in order to harden himself against noise.

It is not a matter of custom. On the other hand, the truly stoical indifference to noise of ordinary minds is astonishing. No noise disturbs them in their thinking, reading, writing, or other occupations, while the finer mind is rendered quite incapable by it. But just that which makes them so insensible to noise of every kind makes them also insensible to the beautiful in plastic art, and to deep thought or fine expression in literary art; in short, to all that does not touch their personal interests. The following remark of Lichtenberg’s applies to the paralysing effect which noise has upon highly intellectual persons: “It is always a good sign when an artist can be hindered by trifles from exercising his art. F—— used to stick his fingers into sulphur if he wished to play the piano.... Such things do not interfere with the average mind;... it acts like a coarse sieve” (Vermischte Schriften, vol. i. p. 398). I have long really held the opinion that the amount of noise which any one can bear undisturbed stands in inverse proportion to his mental capacity, and therefore may be regarded as a pretty fair measure of it. Therefore, if I hear the dogs barking for hours together in the court of a house without being stopped, I know what to

think of the intellectual capacity of the inhabitants. The man who habitually slams the door of a room, instead of shutting it with his hand, or allows this to go on in his house, is not only ill-bred, but is also a coarse and dull-minded fellow. That in English “sensible” also means gifted with understanding is based upon accurate and fine observation. We shall only become quite civilised when the ears are no longer unprotected, and when it shall no longer be the right of everybody to sever the consciousness of each thinking being, in its course of a thousand steps, with whistling, howling, bellowing, hammering, whip-cracking, barking, &c. &c. The Sybarites banished all noisy trades without the town; the honourable sect of the Shakers in North America permit no unnecessary noise in their villages, and the Moravians have a similar rule. Something more is said upon this subject in the thirtieth chapter of the second volume of the “Parerga.”

The effect of music upon the mind, so penetrating, so direct, so unfailing, may be explained from the passive nature of hearing which has been discussed; also the after effect which sometimes follows it, and which consists in a specially elevated frame of mind. The vibrations of the tones following in rationally combined numerical relations set the fibre of the brain itself in similar vibration. On the other hand, the active nature of sight, opposed as it is to the passive nature of hearing, makes it intelligible why there can be nothing analogous to music for the eye, and the piano of colours was an absurd mistake. Further, it is just on account of the active nature of the sense of sight that it is remarkably acute in the case of beasts that hunt, i.e., beasts of prey, while conversely the passive sense of hearing is specially acute in those beasts that are hunted, that flee, and are timid, so that it may give them timely warning of the pursuer that is rushing or creeping upon them.

Just as we have recognised in sight the sense of the understanding, and in hearing the sense of the reason, so we might call smell the sense of the memory, because it recalls to us more directly than any other the specific impression of an event or a scene even from the most distant past. Chapter IV. On Knowledge A Priori. From the fact that we are able spontaneously to assign and determine the laws of relations in space without having recourse to experience, Plato concludes (Meno, p. 353, Bip.) that all learning is mere recollection. Kant, on the other hand, concludes that space is subjectively conditioned, and merely a form of the faculty of knowledge. How far, in this regard, does Kant stand above Plato!

Cogito, ergo sum, is an analytical judgment. Indeed Parmenides held it to be an identical judgment: “το γαρ αυτο νοειν εστι τε και ειναι” (nam intelligere et esse idem est, Clem. Alex. Strom., vi. 2, § 23). As such, however, or indeed even as an analytical judgment, it cannot contain any special wisdom; nor yet if, to go still deeper, we seek to deduce it as a conclusion from the major premise, non-entis nulla sunt prædicata. But with this proposition what Descartes really wished to express was the great truth that immediate certainty belongs only to self-consciousness, to what is subjective. To what is objective, on the other hand, thus to everything else, only indirect certainty belongs; for it is arrived at through self-consciousness; and being thus merely at second hand, it is to be regarded as problematical. Upon this depends the value of this celebrated proposition. As its opposite we may set up, in the sense of the Kantian philosophy, cogito, ergo est, that is, exactly as I think certain relations in things (the mathematical), they must always occur in all possible experience;—this was an important, profound, and a late apperçu, which appeared in the form of the problem as to the possibility of synthetic judgments a priori, and has actually opened up the way to a deeper knowledge. This problem is the watchword of the Kantian philosophy, as the former proposition is that of the Cartesian, and shows εξ οἱων εισ οἱα.

Kant very fitly places his investigations concerning time and space at the head of all the rest. For to the speculative mind these questions present themselves before all others: what is time?—what is this that consists of mere movement, without anything that moves it?—and what is space? this omnipresent nothing, out of which nothing that exists can escape without ceasing to be anything at all? That time and space depend on the subject, are the mode in which the process of objective apperception is brought about in the brain, has already a sufficient proof in the absolute impossibility of thinking away time and space, while we can very easily think away everything that is presented in them. The hand can leave go of everything except itself. However, I wish here to illustrate by a few examples and deductions the more exact proofs of this truth which are given by Kant, not for the purpose of refuting stupid objections, but for the use of those who may have to expound Kant’s doctrine in future.

“A right-angled equilateral triangle” contains no logical contradiction; for the predicates do not by any means cancel the subject, nor are they inconsistent with each other. It is only when their object is constructed in pure perception that the impossibility of their union in it appears. Now if on this account we were to regard this as a contradiction, then so would every physical impossibility, only discovered to be such after the lapse of centuries, be a contradiction; for example, the composition of a metal from its elements, or a mammal with more or fewer than seven cervical vertebra,(14) or horns and upper incisors in the same animal. But only logical impossibility is a contradiction, not physical, and just as little mathematical. Equilateral and rectangled do not contradict each other (they coexist in the square), nor does either of them contradict a triangle. Therefore the incompatibility of the above conceptions can never be known by mere thinking, but is only discovered by perception—merely mental perception, however, which requires no experience, no real object. We should also refer here to the proposition of Giordano Bruno, which is also found in Aristotle: “An infinitely large body is necessarily immovable”—a proposition which cannot rest either upon experience or upon the principle of contradiction, since it speaks of things which cannot occur in any

experience, and the conceptions “infinitely large” and “movable” do not contradict each other; but it is only pure perception that informs us that motion demands a space outside the body, while its infinite size leaves no space over. Suppose, now, it should be objected to the first mathematical example that it is only a question of how complete a conception of a triangle the person judging has: if the conception is quite complete it will also contain the impossibility of a triangle being rectangular and also equilateral. The answer to this is: assume that his conception is not so complete, yet without recourse to experience he can, by the mere construction of the triangle in his imagination, extend his conception of it and convince himself for ever of the impossibility of this combination of these conceptions. This process, however, is a synthetic judgment a priori, that is, a judgment through which, independently of all experience, and yet with validity for all experience, we form and perfect our conceptions. For, in general, whether a given judgment is analytical or synthetical can only be determined in the particular case according as the conception of the subject in the mind of the person judging is more or less complete. The conception “cat” contains in the mind of a Cuvier a hundred times more

than in that of his servant; therefore the same judgments about it will be synthetical for the latter, and only analytical for the former. But if we take the conceptions objectively, and now wish to decide whether a given judgment is analytical or synthetical, we must change the predicate into its contradictory opposite, and apply this to the subject without a copula. If this gives a contradictio in adjecto, then the judgment was analytical; otherwise it was synthetical.

That Arithmetic rests on the pure intuition or perception of time is not so evident as that Geometry is based upon that of space.(15) It can be proved, however, in the following manner. All counting consists in the repeated affirmation of unity. Only for the purpose of always knowing how often we have already affirmed unity do we mark it each time with another word: these are the numerals. Now repetition is only possible through succession. But succession, that is, being after one another, depends directly upon the intuition or perception of time. It is a conception which can only be understood by means of this; and thus counting also is only possible by means of time. This dependence of all counting upon time is also betrayed by the fact that in all languages multiplication is expressed by “time,” thus by a time-concept: sexies, ἑξακις, six fois, sex mal. But simple counting is already a multiplication by one, and for this reason in Pestalozzi’s educational establishment the children are always made to multiply thus: “Two times two is four times one.” Aristotle already recognised the close relationship of number and time, and expounded it in the fourteenth chapter of the fourth book of the “Physics.” Time is for him “the number of motion” (“ὁ χρονος αριθμος εστι κινησεως”). He very profoundly suggests the question whether time could be if the soul were not, and answers it in the negative. If arithmetic had not this pure intuition or perception of time at its foundation, it would be no science a priori, and therefore its propositions would not have infallible certainty.