CHAPTER IV.

ON THE FIRST CLASS OF OBJECTS FOR THE SUBJECT, AND THAT FORM OF THE PRINCIPLE OF SUFFICIENT REASON WHICH PREDOMINATES IN IT.

§ 17. _General Account of this Class of Objects._

The first class of objects possible to our representative faculty, is that of _intuitive, complete, empirical_ representations. They are _intuitive_ as opposed to mere thoughts, _i.e._ abstract conceptions; they are _complete_, inasmuch as, according to Kant's distinction, they not only contain the formal, but also the material part of phenomena; and they are _empirical_, partly as proceeding, not from a mere connection of thoughts, but from an excitation of feeling in our sensitive organism, as their origin, to which they constantly refer for evidence as to their reality: partly also because they are linked together, according to the united laws of Space, Time and Causality, in that complex without beginning or end which forms our _Empirical Reality_. As, nevertheless, according to the result of Kant's teaching, this _Empirical Reality_ does not annul their _Transcendental Ideality_, we shall consider them here, where we have only to do with the formal elements of knowledge, merely as representations.

§ 18. _Outline of a Transcendental Analysis of Empirical Reality._

The forms of these representations are those of the inner and outer sense; namely, _Time_ and _Space_. But these are only _perceptible_ when _filled_. Their _perceptibility_ is _Matter_, to which I shall return further on, and again in § 21. _If Time were the only form_ of these representations, there could be no _coexistence_, therefore nothing _permanent_ and no _duration_. For _Time_ is only perceived when filled, and its course is only perceived by the _changes_ which take place in that which fills it. The _permanence_ of an object is therefore only recognized by contrast with the _changes_ going on in other objects _coexistent_ with it. But the representation of _coexistence_ is impossible in Time alone; it depends, for its completion, upon the representation of _Space_; because, in mere Time, all things _follow one another_, and in mere Space all things are _side by side_; it is accordingly only by the combination of Time and Space that the representation of coexistence arises.

_On the other hand, were Space the sole form_ of this class of representations, there would be no _change_; for change or alteration is _succession_ of states, and _succession_ is only possible in _Time_. We may therefore define Time as the possibility of opposite states in one and the same thing.

Thus we see, that although infinite divisibility and infinite extension are common to both Time and Space, these two forms of empirical representations differ fundamentally, inasmuch as what is essential to the _one_ is without any meaning at all for the _other_: juxtaposition having no meaning in Time, succession no meaning in Space. The empirical representations which belong to the orderly complex of reality, appear notwithstanding in both forms together; nay, the _intimate union_ of both is the condition of reality which, in a sense, grows out of them, as a product grows out of its factors. Now it is the Understanding which, by means of its own peculiar function, brings about this _union_ and connects these heterogeneous forms in such a manner, that _empirical reality_--albeit only for that Understanding--arises out of their mutual interpenetration, and arises as a collective representation, forming a complex, held together by the forms of the principle of sufficient reason, but whose limits are problematical. Each single representation belonging to this class is a part of this complex, each one taking its place in it according to laws known to us _à priori_; in it therefore countless objects _coexist_, because Substance, _i.e._ Matter, remains permanent in spite of the ceaseless flow of Time, and because its states change in spite of the rigid immobility of Space. In this complex, in short, the whole objective, real world exists for us. The reader who may be interested in this, will find the present rough sketch of the analysis of empirical reality further worked out in § 4 of the first volume of "Die Welt als Wille und Vorstellung,"[55] where a closer explanation is given of the way in which the Understanding effects this union and thus creates for itself the empirical world. He will also find a very important help in the table, "_Prædicabilia à priori_ of Time, Space, and Matter," which is added to the fourth chapter of the second volume of the same work, and which I recommend to his attention, as it especially shows how the contrasts of Time and Space are equally balanced in Matter, as their product, under the form of Causality.

[55] Vol. i. p. 12, and _seqq._ of the 1st edition; p. 9 of the 3rd edition.

We shall now proceed to give a detailed exposition of that function of the Understanding which is the basis of empirical reality; only we must first, by a few incidental explanations, remove the more immediate objections which the fundamental idealism of the view I have adopted might encounter.

§ 19. _Immediate Presence of Representations._

Now as, notwithstanding this union through the Understanding of the forms of the inner and outer sense in representing Matter and with it a permanent outer world, all _immediate_ knowledge is nevertheless acquired by the Subject through the _inner_ sense alone--the outer sense being again Object for the inner, which in its turn perceives the perceptions of the outer--and as therefore, with respect to the _immediate presence_ of representations in its consciousness, the Subject remains under the rule of _Time_ alone, as the form of the _inner sense_:[56] it follows, that only one representation can be present to it (the Subject) at the same time, although that one may be very complicated. When we speak of representations as _immediately present_, we mean, that they are not only known in the union of Time and Space effected by the Understanding--an intuitive faculty, as we shall soon see--through which the collective representation of empirical reality arises, but that they are known in mere Time alone, as representations of the inner sense, and just at the neutral point at which its two currents separate, called the _present_. The necessary condition mentioned in the preceding paragraph for the immediate presence of a representation of this class, is its causal action upon our senses and consequently upon our organism, which itself belongs to this class of objects, and is therefore subject to the causal law which predominates in it and which we are now about to examine. Now as therefore, on the one hand, according to the laws of the inner and outer world, the Subject cannot stop short at that one representation; but as, on the other hand, there is no coexistence in Time alone: that single representation must always vanish and be superseded by others, in virtue of a law which we cannot determine _à priori_, but which depends upon circumstances soon to be mentioned. It is moreover a well-known fact, that the imagination and dreams reproduce the immediate presence of representations; the investigation of that fact, however, belongs to empirical Psychology. Now as, notwithstanding the transitory, isolated nature of our representations with respect to their immediate presence in our consciousness, the Subject nevertheless retains the representation of an all-comprehensive complex of reality, as described above, by means of the function of the Understanding; representations have, on the strength of this antithesis, been viewed, as something quite different when considered as belonging to that complex than when considered with reference to their immediate presence in our consciousness. From the former point of view they were called _real things_; from the latter only, representations κατ' ἐξοχήν. This view of the matter, which is the ordinary one, is known under the name of _Realism_. On the appearance of modern philosophy, _Idealism_ opposed itself to this _Realism_ and has since been steadily gaining ground. Malebranche and Berkeley were its earliest representatives, and Kant enhanced it to the power of Transcendental Idealism, by which the co-existence of the Empirical Reality of things with their Transcendental Ideality becomes conceivable, and according to which Kant expresses himself as follows:[57] "_Transcendental Idealism_ teaches that all phenomena are representations only, not things by themselves." And again:[58] "Space itself is nothing but mere representation, and whatever is in it must therefore be contained in that representation. There is nothing whatever in Space, except so far as it is really represented in it." Finally he says:[59] "If we take away the thinking Subject, the whole material world must vanish; because it is nothing but a phenomenon in the sensibility of our own subject and a certain class of its representations." In India, Idealism is even a doctrine of popular religion, not only of Brahminism, but of Buddhism; in Europe alone is it a paradox, in consequence of the essentially and unavoidably realistic principle of Judaism. But Realism quite overlooks the fact, that the so-called existence of these real things is _absolutely nothing but their being represented_ (_ein Vorgestellt-werden_), or--if it be insisted, that only the immediate presence in the consciousness of the Subject can be called being represented κατ' ἐντελέχειαν--it is even only a possibility of being represented κατὰ δύναμιν. The realist forgets that the Object ceases to be Object apart from its reference to the Subject, and that if we take away that reference, or think it away, we at once do away with all objective existence. Leibnitz, while he clearly felt the Subject to be the necessary condition for the Object, was nevertheless unable to get rid of the thought that objects exist by themselves and independently of all reference whatsoever to the Subject, _i.e._ independently of being represented. He therefore assumed in the first place a world of objects exactly like the world of representations and running parallel with it, having no direct, but only an outward connection with it by means of a _harmonia præstabilita_;--obviously the most superfluous thing possible, for it never comes within perception, and the precisely similar world of representations which does come within perception, goes its own way regardless of it. When, however, he wanted to determine more closely the essence of these things existing objectively in themselves, he found himself obliged to declare the Objects in themselves to be Subjects (_monades_), and by doing so he furnished the most striking proof of the inability of our consciousness, in as far as it is merely cognitive, to find within the limits of the intellect--_i.e._ of the apparatus by means of which we represent the world--anything beyond Subject and Object; the representer and the represented. Therefore, if we abstract from the objectivity of an Object, or in other words, from its being represented (_Vorgestellt-werden_), if we annul it in its quality as an Object, yet still wish to retain something, we can meet with nothing but _the Subject_. Conversely, if we desire to abstract from the subjectivity of the Subject, yet to have something over, the contrary takes place, and this leads to Materialism.

[56] Compare Kant, "Krit. d. r. Vern." Elementarlehre. Abschnitt ii. Schlüsse a. d. Begr. _b_ and _c_. 1st edition, pp. 33 and 34; 5th edition, p. 49. (Transl. M. Müller, p. 29, _b_ and _c_.)

[57] Kant, "Krit. d. r. V." Kritik des Vierten Paralogismus der transcendentalen Psychologie, p. 369, 1st edition. (Engl. Transl. by M. Müller, p. 320.)

[58] _Ibid._ 1st edition, pp. 374-375. Note. (Engl. Transl. p. 325. Note.)

[59] Kant, "Krit. d. r. V." "Betrachtung über die Summe," &c., p. 383 of 1st edition. (Engl. Transl. p. 331.)

Spinoza, who never thoroughly sifted the matter, and never therefore acquired a clear notion of it, nevertheless quite understood the necessary correlation between Subject and Object as so essential, that they are inconceivable without it; consequently he defined it as an identity in the Substance (which alone exists) of that which knows, with that which has extension.

OBSERVATION.--With reference to the chief argument of this paragraph, I take the opportunity to remark that if, in the course of this treatise, for the sake of brevity and in order to be more easily understood, I at any time use the term _real objects_, I mean by it nothing but the intuitive representations that are united to form the complex of empirical reality, which reality in itself always remains ideal.

§ 20. _Principle of Sufficient Reason of Becoming._

In the Class of Objects for the Subject just described, the principle of sufficient reason figures as the _Law of Causality_, and, as such, I call it the _Principle of Sufficient Reason of Becoming, principium rationis sufficientis fiendi_. By it, all objects presenting themselves within the entire range of our representation are linked together, as far as the appearance and disappearance of their states is concerned, _i.e._ in the movement of the current of Time, to form the complex of empirical reality. The law of causality is as follows. When one or several real objects pass into any new state, some other state must have preceded this one, upon which the new state regularly follows, _i.e._ as often as that preceding one occurs. This sort of following we call _resulting_; the first of the states being named a _cause_, the second an _effect_. When a substance takes fire, for instance, this state of ignition must have been preceded by a state, 1^o, of affinity to oxygen; 2^o, of contact with oxygen; 3^o, of a given temperature. Now, as ignition must necessarily follow immediately upon this state, and as it has only just taken place, that state cannot always have been there, but must, on the contrary, have only just supervened. This supervening is called a _change_. It is on this account that the law of causality stands in exclusive relation to _changes_ and has to do with them alone. Every effect, at the time it takes place, is a _change_ and, precisely by not having occurred sooner, infallibly indicates some other _change_ by which it has been preceded. That other _change_ takes the name of _cause_, when referred to the following one--of _effect_, when referred to a third necessarily preceding _change_. This is the chain of causality. It is necessarily without a beginning. By it, each supervening state must have resulted from a preceding change: in the case just mentioned, for instance, from the substance being brought into contact with free heat, from which necessarily resulted the heightened temperature; this contact again depended upon a preceding change, for instance the sun's rays falling upon a burning-glass; this again upon the removal of a cloud from before the sun; this upon the wind; the wind upon the unequal density of the atmosphere; this upon other conditions, and so forth _in infinitum_. When a state contains all the requisite conditions for bringing about a new state excepting _one, this one_, when at last it arrives, is, in a sense, rightly called the cause κατ' ἐξοχήν, inasmuch as we here have the final--in this case the decisive--change especially in view; but if we leave out this consideration, no single condition of the causal state has any advantage over the rest with reference to the determination of the causal connection in general, merely because it happens to be the last. Thus the removal of the cloud in the above example, is in so far the cause of the igniting, as it took place later than the direction of the burning-glass towards the object; but this might have taken place after the removal of the cloud and the addition of oxygen might have occurred later still: in this respect therefore it is the accidental order of things that determines which is the cause. On closer inspection, however, we find that it is _the entire state_ which is the cause of the ensuing one, so that the chronological order in which its single conditions were brought about, is in all essential respects indifferent. With reference to a given case therefore, the last occurring condition of a state may be called the cause κατ' ἐξοχήν, because it completes the measure of the necessary conditions, and its appearance thus becomes the decisive change. For purposes of general consideration, however, it is only the _entire_ state which, by bringing about its successor, can be regarded as the cause. The single requisites which, added together, complete and constitute the cause may be called causal elements (_ursächliche Momente_) or even _conditions_, and into these accordingly the cause may be subdivided. On the other hand, it is quite wrong to call the objects themselves causes, instead of the states: some would, for instance, call the burning-glass in the above example the cause of the ignition; while others, again, would call the cloud the cause; others the sun or the oxygen, and so on arbitrarily and without order. But it is absurd to call an object the cause of another object; first of all, because objects not only contain form and quality, but _Matter_ also, which has neither beginning or end; secondly, because the law of causality refers exclusively to _changes_, _i.e._ to the entrance and exit of states in Time, wherein it regulates that special relation, in reference to which the earlier state is called _cause_, the later _effect_, and the necessary connection between both, the _resulting_ of the one from the other.

I here refer the thoughtful reader to the explanations I have given in my chief work.[60] For it is of the highest importance that our conception of the true and proper meaning of the law of causality and the sphere of its validity should be perfectly clear and definite: before all things, that we should recognize, that this law refers solely and exclusively to _changes_ of material states and to nothing else whatever; consequently, that it ought not to be brought in when _these_ are not in question. The law of causality is the regulator of the _changes_ undergone in Time by objects of our outer _experience_; but these objects are all material. Each change can only be brought about by another having preceded it, which is determined by a rule, and then the new change takes place as being necessarily induced by the preceding one. This necessity is the causal nexus.

[60] "Die Welt a. W. u. V." vol. ii. chap. 4, especially p. 42 and _seq._ of the 2nd edition; p. 46 _seq._ of the 3rd edition.

However simple therefore the law of causality is, we nevertheless find it expressed quite differently in all philosophical manuals, from the earliest down to the latest ages: namely, in a broader, more abstract, therefore less definite way. We are, for instance, informed, now, that it is that by which something else comes into being; now, that it is what produces another thing or gives it reality, &c. &c. Wolf says: _Causa est principium, a quo existentia, sive actualitas, entis alterius dependet_; whereas it is obvious that in causality we have only to do with changes in the form of uncreated, indestructible Matter, and that a springing into existence of what did not previously exist is an impossibility. Want of clearness of thought may, no doubt, in most cases have led to these views of the causal relation; but surely sometimes an _arrière-pensée_ lurks in the background--a theological intention coqueting with the Cosmological Proof, for whose sake it is ready to falsify even transcendental, _à priori_ truths, the mother's milk of human understanding. We find the clearest instance of this in Thomas Brown's book, "On the Relation of Cause and Effect," a work of 460 pages, which, in 1835, had already reached its fourth edition, and has probably since gone through several more, and which, in spite of its wearisome, pedantic, rambling prolixity, does not handle the subject badly. Now this Englishman rightly recognises, that it is invariably with _changes_ that the causal law has to do, and that every effect is accordingly a _change_. Yet, although it can hardly have escaped him, he is unwilling to admit that every cause is likewise a _change_, and that the whole process is therefore nothing but the uninterrupted nexus of _changes_ succeeding one another in Time. On the contrary, he persists in clumsily calling the cause an _object_ or _substance_, which precedes the change, and in tormenting himself throughout his tedious book with this entirely false expression, which spoils all his explanations, notwithstanding his own better knowledge and against his conscience, simply in order that his definition may on no account stand in the way of the Cosmological Proof, which others might hereafter state elsewhere.--But what can a truth be worth which needs devices such as these to prepare its way?

And what have our own worthy, honest German professors of philosophy been doing in behalf of their dearly beloved Cosmological Proof, since Kant dealt it the death-blow in his Critique of Pure Reason?--they, who prize truth above everything. They were, indeed, at their wits' ends, for--as these worthies well know, though they do not say so--_causa prima_ is, just as well as _causa sui_, a _contradictio in adjecto_, albeit the former expression is more generally used than the latter. It is besides usually pronounced with a very serious, not to say solemn, air; nay, many people, especially English Reverends, turn up their eyes in a truly edifying way when they impressively and emphatically mention that _contradictio in adjecto_: 'the first cause.' They know that a first cause is just as inconceivable as the point at which Space ends or the moment when Time first began. For every cause is a _change_, which necessarily obliges us to ask for the preceding change that brought it about, and so on _in infinitum, in infinitum_! Even a first state of Matter, from which, as it has ceased to be, all following states could have proceeded, is inconceivable. For if this state had in itself been the cause of the following ones, they must likewise have existed from all eternity, and the actual state existing at the present moment could not have only just now come into being. If, on the other hand, that first state only began to be causal at some given period, something or other must have _changed_ it, for its inactivity to have ceased; but then something must have occurred, some change must have taken place; and this again obliges us to ask for its cause--_i.e._ a change which preceded it; and here we are once more on the causal ladder, up which we are whipped step by step, higher and higher, _in infinitum, in infinitum_! (These gentlemen will surely not have the face to talk to me of Matter itself arising out of nothing! If so, they will find corollaries at their service further on.) The causal law therefore is not so accommodating as to let itself be used like a hired cab, which we dismiss when we have reached our destination; rather does it resemble the broom brought to life by the apprentice-wizard in Göthe's poem,[61] which, when once set in motion, does not leave off running and fetching water until the old master-wizard himself stops it, which he alone has the power to do. These gentlemen, however, have no master-wizards among them. So what did they do, these noble, genuine lovers of truth, ever on the alert, of course, to proclaim the advent of real merit to the world as soon as it shows itself in their profession, who far from wishing to divert attention from the works of those who are really what _they_ only seem to be, by craftily ignoring and meanly keeping them dark, are naturally foremost to acknowledge their worth--aye, surely, as surely as folly loves wisdom above everything? What did they do, I say, to help their old friend, the sorely distressed Cosmological Proof, now at its last gasp? Oh, they hit upon a shrewd device. "Friend," they said, "you are in sorry plight since your fatal encounter with that stubborn old man in Königsberg, and indeed your brethren, the Ontological and Physico-theological Proofs are in no better condition. Never mind, you shall not be abandoned by us (that is what we are paid for, you know); only you must alter your dress and your name--there is no help for it--for if we call you by your right name, everyone will take to his heels. Now _incognito_, on the contrary, we can take you by the arm, and once more lead you into society; only, as we have just said, it must be _incognito_! That is sure to answer! First of all, your argument must henceforth be called _The Absolute_. This has a foreign, dignified, aristocratic ring; and no one knows better than we do all that can be done with Germans by assuming airs of importance. Of course all know what the real meaning is, and pique themselves upon that knowledge. But you yourself must come forward disguised, in the form of an enthymeme. Be sure and leave behind you all those prosyllogisms and premisses, by which you used to drag us wearily up the long climax, for everyone knows how utterly useless they are. Come forward with a bold face and a self-sufficient, supercilious air, like a man of few words, and at one bound you will reach the goal. Exclaim (and we will chime in), '_The Absolute_, confound it! _that_ must _exist_, or there would be nothing at all!' Here, strike the table with your fist. Whence does the Absolute come? 'What a silly question! Did not I tell you it was the Absolute?'--That will do, forsooth! That will do! Germans are accustomed to content themselves with words instead of thoughts. Do we not train them to it from their cradle? Only look at Hegelianism! What is it but empty, hollow, nauseous twaddle! Yet how brilliant a career was that of this philosophical time-server! A few mercenary individuals had only to strike up a laudation of this stuff, and they at once found an echo to their voices in the empty hollow of a thousand numskulls--an echo which still continues to resound, and to extend--and behold! an ordinary intellect, a common impostor soon became a sublime thinker. Take heart, therefore! Besides, our friend and patron, we will also second you in other ways, for how, indeed, are we to get a living without you? So that carping old faultfinder, Kant, has been criticizing Reason, and clipping her wings, has he? Well, then, we will invent a _new_ sort of Reason, such as has never been heard of--a Reason that does not think, but which has direct intuition--a Reason which sees Ideas (a high-flown word, made to mystify), sees them bodily; or which apprehends directly that which you and others seek to prove; or, again, a Reason which has forebodings of all this--this last for the benefit of those who do not care to make large concessions, but also are satisfied with very little. Let us thus pass off early inculcated, popular conceptions for direct revelations of this new kind of Reason, _i.e._ for inspirations from above. As for that old-fashioned Reason, which criticism has criticized away, let us degrade it, call it Understanding, and send it about its business. Well, and what is to become of real, true Understanding?--What in the world have we to do with real, true Understanding?--You smile incredulously; but we know our listeners, and the _harum_, _horum_ we see on the students' benches before us. Bacon of Verulam already in his time said: 'Young men learn to believe at Universities.' Of this they can learn as much as they wish from us; we have a good stock of articles of faith on hand. Should any misgivings assail you, remember that we are in Germany, where what would have been impossible in any other country, has been found possible: where a dull-witted, ignorant, pseudo-philosopher, whose ineffably hollow verbiage disorganizes peoples' brains completely and permanently, a scribbler of nonsense--I am speaking of our dearly beloved Hegel--has not only been actually proclaimed a profound thinker with impunity, and even without incurring ridicule, but is readily accepted as such: yes, indeed, for this fiction has found credence for the last thirty years, and is believed to this day!--Once therefore we have this Absolute with your help, we are quite safe, in spite of Kant and his Critique.--We may then philosophise in a lofty tone, making the Universe proceed from _the Absolute_ by means of the most heterogeneous deductions, one more tiresome than the other--this, by the way, being their only point of resemblance. We can call the world the Finite, and the Absolute the Infinite--thus giving an agreeable variety to our nonsense--and talk of nothing but God, explaining how, why, wherefore, by what voluntary or involuntary process he created or brought forth the world, showing whether he be within or without it, and so forth, as if Philosophy were Theology, and as if it sought for enlightenment concerning God, not concerning the Universe!"

[61] Göthe, "Der Zauberlehrling."

The Cosmological Proof, with which we here have to do, and to which the above apostrophe is addressed, consists thus, properly speaking, in the assertion, that the principle of the sufficient reason of _becoming_, or the law of causality, necessarily leads to a thought which destroys it and declares it to be null and void. For the _causa prima_ (_absolutum_) can only be reached by proceeding upwards from consequence to reason, through a series prolonged _ad libitum_; but it is impossible to stop short at the _causa prima_ without at once annulling the principle of sufficient reason.

Having thus briefly and clearly shown the nullity of the Cosmological Proof, as I had in my second chapter already shown the nullity of the Ontological Proof, the sympathizing reader may perhaps expect me to do the same with respect to the Physico-theological Proof, which is a great deal more plausible. As, however, this belongs by its nature to a different department of philosophy, it would be quite out of place here. I therefore refer him to Kant's Critique of Pure Reason, as well as to his Critique of the Faculty of Judgment, where he treats this subject _ex professo_; I likewise refer him, as a complement to Kant's purely negative procedure, to my own positive one in "The Will in Nature,"[62] a work which, though small in bulk, is rich and weighty in content. As for the indifferent reader, he is free to let this and indeed all my writings pass down unread to his descendants. It matters not to me; for I am here, not for one generation only, but for many.

[62] The translation of which follows the Fourfold Root in the present volume.

Now, as the law of causality is known to us _à priori_, and is therefore a transcendental law, applicable to every possible experience and consequently without exception, as will be shown in § 21; as moreover it decides, that upon a given, definite, relatively first state, a second equally definite one inevitably ensues by rule, _i.e._, always; the relation between cause and effect is a necessary one, so that the causal law authorizes us to form hypothetical judgments, and thereby shows itself to be a form of the principle of sufficient reason, upon which principle all judgments must be founded and, as will be shown further on, all _necessity_ is based.

This form of our principle I call the _principle of the sufficient reason of becoming_, because its application invariably pre-supposes a change, the entering upon a new state: consequently a becoming. One of its essential characteristics is this: that the cause always precedes the effect in Time (compare § 47), and this alone gives us the original criterion by which to distinguish which is cause and which effect, of two states linked together by the causal nexus. Conversely, in some cases, the causal nexus is known to us through former experience; but the rapidity with which the different states follow upon each other is so great, that the order in which this happens escapes our perception. We then conclude with complete certitude from causality to succession: thus, for instance, we infer that the igniting of gunpowder precedes its explosion.[63]

[63] Here I refer my readers to "Die Welt als Wills und Vorstellung," vol. ii. chap. 4, p. 41 of the 2nd edition, and p. 45 of the 3rd edition.

From this essential connection between causality and succession it follows, that the conception of reciprocity, strictly speaking, has no meaning; for it presumes the effect to be again the cause of its cause: that is, that what follows is at the same time what precedes. In a "Critique of Kantian Philosophy," which I have added to my chief work, and to which I refer my readers,[64] I have shown at length that this favourite conception is inadmissible. It may be remarked, that authors usually have recourse to it just when their insight is becoming less clear, and this accounts for the frequency of its use. Nay, it is precisely when a writer comes to the end of his conceptions, that the word '_reciprocity_' presents itself more readily than any other; it may, in fact, be looked upon as a kind of alarm-gun, denoting that the author has got out of his depth. It is also worthy of remark, that the word _Wechselwirkung_, literally reciprocal action--or, as we have preferred translating it, _reciprocity_--is only found in the German language, and that there is no precise equivalent for it in daily use in any other tongue.

[64] "Die Welt a. W. u. V." vol. i. pp. 517-521 of the 2nd edition, and pp. 544-549 of the 3rd edition.

From the law of causality spring two corollaries which, in virtue of this origin, are accredited as cognitions _à priori_, therefore as unquestionable and without exception. They are, _the law of inertia_ and that _of permanence of substance_. The first of these laws avers, that every state in which a body can possibly be--consequently that of repose as well as that of any kind of movement--must last for ever without change, diminution, or augmentation, unless some cause supervenes to alter or annul it. But the other law, by which the eternity of Matter is affirmed, results from the fact, that the law of causality is exclusively applicable to _states_ of bodies, such as repose, movement, form, and quality, since it presides over their temporal passing in or out of being; but that it is by no means applicable to the existence of _that which endures_ these states, and is called _Substance_, in order precisely to express its exemption from all arising and perishing. '_Substance is permanent_' means, that it can neither pass into, nor out of being: so that its quantity existing in the universe can neither be increased nor diminished. That we know this _à priori_, is proved by the consciousness of unassailable certainty with which, when we see a body disappear--whether it be by conjuring, by minute subdivision, by combustion, volatilisation, or indeed any process whatever--we all nevertheless firmly assume that its substance, _i.e._ its _matter_, must still exist somewhere or other in undiminished quantity, whatever may have become of its _form_; likewise, when we perceive a body suddenly in a place, where it was not before, that it must have been brought there or formed by some combination of invisible particles--for instance, by precipitation--but that it, _i.e._ its substance, cannot have then started into existence; for this implies a total impossibility and is utterly inconceivable. The certainty with which we assume this beforehand (_à priori_), proceeds from the fact, that our Understanding possesses absolutely no form under which to conceive the beginning and end of Matter. For, as before said, the law of causality--the only form in which we are able to conceive changes at all--is solely applicable to _states_ of bodies, and never under any circumstances to the existence of _that which undergoes_ all changes: _Matter_. This is why I place the principle of the permanence of Matter among the corollaries of the causal law. Moreover, we cannot have acquired _à posteriori_ the conviction that substance is permanent, partly because it cannot, in most instances, be empirically established; partly also, because every empirical knowledge obtained exclusively by means of induction, has only approximate, consequently precarious, never unconditioned, certainty. The firmness of our persuasion as to this principle is therefore of a different kind and nature from our security of conviction with regard to the accuracy of any _empirically_ discovered law of Nature, since it has an entirely different, perfectly unshakable, never vacillating firmness. The reason of this is, that the principle expresses a _transcendental_ knowledge, _i.e._ one which determines and fixes, _prior_ to all experience, what is in any way possible within the whole range of experience; but, precisely by this, it reduces the world of experience to a mere cerebral phenomenon. Even the most universal among the non-transcendental laws of Nature and the one least liable to exception--the law of gravitation--is of empirical origin, consequently without guarantee as to its absolute universality; wherefore it is still from time to time called in question, and doubts occasionally arise as to its validity beyond our solar system; and astronomers carefully call attention to any indications corroborative of its doubtfulness with which they may happen to meet, thereby showing that they regard it as merely empirical. The question may of course be raised, whether gravitation takes effect between bodies which are separated by an _absolute_ vacuum, or whether its action within a solar system may not be mediated by some sort of ether, and may not cease altogether between fixed stars; but these questions only admit of an empirical solution, and this proves that here we have not to do with a knowledge _à priori_. If, on the other hand, we admit with Kant and Laplace the hypothesis, as the most probable one, that each solar system has developed out of an original _nebula_ by a gradual process of condensation, we still cannot for a moment conceive the possibility of that original substance having sprung into being out of _nothing_: we are forced to assume the anterior existence of its particles somewhere or other, as well as their having been brought together somehow or other, precisely because of the transcendental nature of the principle of the permanence of Substance. In my Critique of Kantian Philosophy,[65] I have shown at length, that _Substance_ is but another word for _Matter_, the conception of substance not being realisable excepting in _Matter_, and therefore deriving its origin from _Matter_, and I have also specially pointed out how that conception was formed solely to serve a surreptitious purpose. Like many other equally certain truths, this eternity of Matter (called the permanence of substance) is forbidden fruit for professors of philosophy; so they slip past it with a bashful, sidelong glance.

[65] "Die Welt a. W. u. V." vol. i. p. 550 of 2nd, and 580 of 3rd edition.

By the endless chain of causes and effects which directs all _changes_ but never extends beyond them, two existing things remain untouched, precisely because of the limited range of its action: on the one hand, _Matter_, as we have just shown; on the other hand, the primary _forces of Nature_. The first (matter) remains uninfluenced by the causal nexus, because it is _that which undergoes_ all changes, or _on which_ they take place; the second (the primary forces), because it is they alone _by which_ changes or effects become possible; for they alone give causality to causes. _i.e._ the faculty of operating, which the causes therefore hold as mere vassals a fief. Cause and effect are _changes_ connected together to necessary succession in Time; whereas the forces of Nature by means of which all causes operate, are exempt from all change; in this sense therefore they are outside Time, but precisely on that account they are always and everywhere in reserve, omnipresent and inexhaustible, ever ready to manifest themselves, as soon as an opportunity presents itself in the thread of causality. A _cause_, like its _effect_, is invariably something individual, a single change; whereas a force of Nature is something universal, unchangeable, present at all times and in all places. The attraction of a thread by amber, for instance, at the present moment, is an effect; its cause is the preceding friction and actual contact of the amber with the thread; and the _force of Nature_ which acts in, and presides over, the process, is Electricity. The explanation of this matter is to be found in my chief work,[66] and there I have shown in a long chain of causes and effects how the most heterogeneous natural forces successively come into play in them. By this explanation the difference between transitory phenomena and permanent forms of operation, becomes exceedingly clear; and as, moreover, a whole section (§ 26) is devoted to the question, it will be sufficient here to give a brief sketch of it. The _rule_, by which a force of Nature manifests itself in the chain of causes and effects--consequently the link which connects it with them--is the law of Nature. But the confusion between forces of Nature and causes is as frequent as it is detrimental to clearness of thought. It seems indeed as though no one had accurately defined the difference between these conceptions before me, however great may have been the urgency for such a distinction. Not only are forces of Nature turned into causes by such expressions as, 'Electricity, Gravity, &c., are the _cause_ of so-and-so,' but they are even often turned into effects by those who search for a cause for Electricity, Gravity, &c. &c., which is absurd. Diminishing the number of the forces of Nature, however, by reducing one to another, as for instance Magnetism is in our days reduced to Electricity, is a totally different thing. Every _true_, consequently really primary force of Nature--and every fundamental chemical property belongs to these forces--is essentially a _qualitas occulta_, _i.e._ it does not admit of physical, but only of metaphysical explanation: in other words, of an explanation which transcends the world of phenomena. No one has carried this confusion, or rather identification, of causes with forces of Nature further than Maine de Biran in his "Nouvelles considérations des rapports du physique au moral," for it is essential to his philosophy. It is besides remarkable, that when he speaks of causes, he rarely uses the word _cause_ alone, but almost always speaks of _cause ou force_, just as we have seen Spinoza above (§ 8) write _ratio sive causa_ no less than eight times in the same page. Both writers are evidently conscious that they are identifying two disparates, in order to be able to make use of the one or the other, according to circumstances; for this end they are obliged to keep the identification constantly before their readers' mind.--

[66] See "Die Welt a. W. u. V." vol. i. § 26, p. 153 of the 2nd, and p. 160 of the 3rd edition.

Now Causality, as the director of each and every change, presents itself in Nature under _three_ distinct forms: as _causes_ in the strictest acceptation of the word, as _stimuli_, and as _motives_. It is just upon this difference that the real, essential distinction between inorganic bodies, plants, and animals is based, and not upon external, anatomical, let alone chemical, distinctions.

A _cause_, in its narrowest sense, is that upon which changes in the _inorganic_ kingdom alone ensue: those changes, that is to say, which form the theme of Mechanics, Physics, and Chemistry. Newton's third fundamental law, "Action and reaction are equal to one another," applies exclusively to this cause, and enunciates, that the state which precedes (the cause) undergoes a change equivalent to that produced by it (the effect). In this form of causality alone, moreover, does the degree of the effect always exactly correspond to the degree of the cause, so as to enable us accurately to calculate the one by means of the other.

The second form of causality is the _stimulus_; it reigns over _organic_ life, as such, _i.e._ over plant life and the vegetative, that is, the unconscious, part of animal life. This second form is characterized by the absence of the distinctive signs of the first. In it accordingly action and reaction are not equal, nor does the intensity of the effect by any means correspond throughout all its degrees to the intensity of the cause; in fact, the opposite effect may even be produced by intensifying the cause.

The third form of causality is the _motive_. Under this form causality rules animal life proper: that is, the exterior, consciously performed actions of all animals. The medium for motives is _knowledge_: an intellect is accordingly needed for susceptibility to motives. The true characteristic of the animal is therefore the faculty of knowing, of representing (_Das Vorstellen_). Animals, as such, always move towards some aim and end, which therefore must have been _recognised_ by them: that is to say, it must have presented itself to them as something different from themselves, yet of which they are conscious. Therefore the proper definition of the animal would be: 'That which knows;' for no other definition quite hits the mark or can even perhaps stand the test of investigation. Movement induced by motives is necessarily wanting where there is no cognitive faculty, and movement by stimuli alone remains, _i.e._ plant life. Irritability and sensibility are therefore inseparable. Still motives evidently act in a different way from stimuli; for the action of the former may be very brief, nay, need only be momentary; since their efficacy, unlike that of stimuli, stands in no relation whatever to the duration of that action, to the proximity of the object, &c. &c. A motive needs but to be perceived therefore, to take effect; whereas stimuli always require outward, often even inward, contact and invariably a certain length of time.

This short sketch of the three forms of causality will suffice here. They are more fully described in my Prize-essay on Free Will.[67] One thing, however, still remains to be urged. The difference between cause, stimulus, and motive, is obviously only a consequence of the various degrees of _receptivity_ of beings; the greater their receptivity, the feebler may be the nature of the influence: a stone needs an impact, while man obeys a look. Nevertheless, both are moved by a sufficient cause, therefore with the same necessity. For '_motivation_'[68] is only causality passing through knowledge; the intellect is the medium of the motives, because it is the highest degree of receptivity. By this, however, the law of causality loses nothing whatever of its rigour and certainty; for motives are causes and operate with the same necessity which all causes bring with them. This necessity is easy to perceive in animals because of the greater simplicity of their intellect, which is limited to the perception of what is present. Man's intellect is double: for not only has he intuitive, but abstract, knowledge, which last is not limited to what is present. Man possesses Reason; he therefore has a power of elective decision with clear consciousness: that is, he is able to weigh against one another motives which exclude each other, as such; in other terms, he can let them try their strength on his will. The most powerful motive then decides him, and his actions ensue with just the same necessity as the rolling of a ball after it has been struck. Freedom of Will[69] means (not professorial twaddle but) "_that a given human being, in a given situation, can act in two different ways_." But the utter absurdity of this assertion is a truth as certain and as clearly proved, as any truth can be which passes the limits of pure mathematics. In my Essay on Free Will, to which the Norwegian Society awarded the prize, this truth is demonstrated more clearly, methodically, and thoroughly than has been done before by anyone else, and this moreover with special reference to those facts of our consciousness by which ignorant people imagine that absurdity to be confirmed. In all that is essential however, Hobbes, Spinoza, Priestley, Voltaire, and even Kant[70] already taught the same doctrine. Our professional philosophers, of course, do not let this interfere with their holding forth on Free Will, as if it were an understood thing which had never been questioned. But what do these gentlemen imagine the above-named great men to have come into the world for, by the grace of Nature? To enable them (the professors) to earn their livelihood by philosophy?--Since I had proved this truth in my prize-essay more clearly than had ever been done before, and since moreover a Royal Society had sanctioned that proof by placing my essay among its memoranda, it surely behoved these worthies, considering the views they held, to make a vigorous attack upon so pernicious a doctrine, so detestable a heresy, and thoroughly to refute it. Nay, this duty was all the more imperative as, in my other essay "On the Foundation of Morality,"[71] I had proved the utter groundlessness of Kant's practical Reason with its Categorical Imperative which, under the name of the Moral Law, is still used by these gentlemen as the corner-stone of their own shallow systems of morality. I have shown it to be a futile assumption so clearly and irrefutably, that no one with a spark of judgment can possibly believe any longer in this fiction.--"Well, and so they probably did."--Oh no! They take good care not to venture on such slippery ground! Their ability consists in holding their tongues; silence is all they have to oppose to intelligence, earnestness, and truth. In not one of the products of their useless scribblings that have appeared since 1841, has the slightest notice been taken of my Ethics--undoubtedly the most important work on Moral Philosophy that has been published for the last sixty years--nay, their terror of me and of my truth is so great, that none of the literary journals issued by Academies or Universities has so much as mentioned the book. _Zitto, zitto_, lest the public should perceive anything: in this consists the whole of their policy. The instinct of self-preservation may, no doubt, be at the bottom of these artful tactics. For would not a philosophy, whose sole aim was truth, and which had no other consideration in view, be likely to play the part of the iron pot among the earthen ones, were it to come in contact with the petty systems composed under the influence of a thousand personal considerations by people whose chief qualification is the propriety of their sentiments? Their wretched fear of my writings is the fear of truth. Nor can it be denied, that precisely this very doctrine of the complete necessity of all acts of the will stands in flagrant contradiction with all the hypotheses of their favourite old-woman's philosophy cut after the pattern of Judaism. Still, that severely tested truth, far from being disturbed by all this, as a sure datum and criterion, as a true δός μοι ποῦ στῶ, proves the futility of all that old-woman's philosophy and the urgent need of a fundamentally different, incomparably deeper view of the Universe and of Man;--no matter whether that view be compatible with the official duties of a professional philosopher or not.

[67] See "Die beiden Grundprobleme der Ethik," p. 30-34.

[68] The word "motivation," though it may appear objectionable to the English reader, seemed unavoidable here, as being Schopenhauer's own term, for which there is no adequate equivalent in general use in our language. [Translator's note.]

[69] Here used in the absolute sense of _liberum arbitrium indifferentiæ_. [Tr.]

[70] "Whatever conception one may form of freedom of the will, for metaphysical purposes, its phenomena, human actions, are nevertheless determined by universal laws of Nature, just as well as every other occurrence in Nature." "Ideen zu einer allgemeinen Geschichte." Anfang. I. Kant. "All the acts of a man, so far as they are phenomena, are determined from his empirical character and from the other concomitant causes, according to the order of Nature; and if we could investigate all the manifestations of his will to the very bottom, there would be not a single human action which we could not predict with certainty and recognize from its preceding conditions as necessary. There is no freedom therefore with reference to this empirical character, and yet it is only with reference to it that we can consider man, when we are merely observing, and, as is the case in anthropology, trying to investigate the motive causes of his actions physiologically."--"Kritik. d. r. Vern." p. 549 of the 1st edition, and p. 577 of the 5th edition. (Engl. Transl. by M. Müller, p. 474.)

"It may therefore be taken for granted, that if we could see far enough into a man's mode of thinking, as it manifests itself in his inner, as well as outer actions, for us to know every, even the faintest motive, and in like manner all the other causes which act upon these, it would be possible to calculate his conduct in future with the same certainty as an eclipse of the sun or moon."--"Kritik der praktischen Vernunft" ed. Rosenkranz, p. 230 and p. 177 of the 4th edition.

[71] Published in the same volume with the Prize-Essay on "Free Will." See "Die beiden Grundprobleme der Ethik."

§ 21. À priori _character of the conception of Causality_.

_Intellectual Character of Empirical Perception._

THE UNDERSTANDING.

In the professorial philosophy of our philosophy-professors we are still taught to this day, that perception of the outer world is a thing of the senses, and then there follows a long dissertation upon each of the five senses: whereas no mention whatever is made of the intellectual character of perception: that is to say, of the fact, that it is mainly the work of the Understanding, which, by means of its own peculiar form of Causality, together with the forms of pure sensibility, Time and Space, which are postulated by Causality, primarily creates and produces the objective, outer world out of the raw material of a few sensations. And yet in its principal features, I had stated this matter in the first edition of the present treatise[72] and soon after developed it more fully in my treatise "On Vision and Colours" (1816), of which Professor Rosas has shown his appreciation by allowing it to lead him into plagiarism.[73] But our professors of philosophy have not thought fit to take the slightest notice either of this, or indeed of any of the other great and important truths which it has been the aim and labour of my whole life to set forth, in order to secure them as a lasting possession to mankind. It does not suit their tastes, or fit into their notions; it leads to no Theology, nor is it even adapted to drill students for higher State purposes. In short, professional philosophers do not care to learn from me, nor do they even see how much they might learn from me: that is, all that their children and their children's children will learn from me. They prefer to sit down and spin a long metaphysical yarn, each out of his own thoughts, for the benefit of the public; and no doubt, if fingers are a sufficient qualification, they have it. How right was Macchiavelli when he said, as Hesiod[74] before him: "There are three sorts of heads: firstly, those which acquire knowledge of things and comprehend them by themselves; secondly, those which recognise the truth when it is shown them by others; and thirdly, those which can do neither the one nor the other."[75]--

[72] Anno 1813, pp. 53-55.

[73] For further details see my "Will in Nature," p. 19 of the 1st edition, and p. 14 of the 3rd. (P. 230 _et seqq._ of the translation of the "Will in Nature," which follows the "Fourfold Root" in the present volume.)

[74] Hesiod, ἔργα, 293.

[75] Macchiavelli, "Il principe," cap. 22.

One must indeed be forsaken by all the gods, to imagine that the outer, perceptible world, filling Space in its three dimensions and moving on in the inexorable flow of Time, governed at every step by the laws of Causality, which is without exception, and in all this merely obeying laws we can indicate before all experience of them--that such a world as this, we say, can have a real, objective existence outside us, without any agency of our own, and that it can then have found its way into our heads through bare sensation and thus have a second existence within us like the one outside. For what a miserably poor thing is mere sensation, after all! Even in the noblest of our organs it is nothing but a local, specific feeling, susceptible of some slight variation, still in itself always subjective and, as such therefore, incapable of containing anything objective, anything like perception. For sensation is and remains a process within the organism and is limited, as such, to the region within the skin; it cannot therefore contain anything which lies beyond that region, or, in other words, anything that is outside us. A sensation may be pleasant or unpleasant--which betokens a relation to the Will--but nothing objective can ever lie in any sensation. In the organs of the senses, sensation is heightened by the confluence of the nerve-extremities, and can easily be excited from without on account of their extensive distribution and the delicacy of the envelope which encloses them; it is besides specially susceptible to particular influences, such as light, sound, smell; notwithstanding which it is and remains mere sensation, like all others within our body, consequently something essentially subjective, of whose changes we only become immediately conscious in the form of the _inner_ sense, Time: that is, successively. It is only when the _Understanding_ begins to act--a function, not of single, delicate nerve-extremities, but of that mysterious, complicated structure weighing from five to ten pounds, called the brain--only when it begins to apply its sole form, _the causal law_, that a powerful transformation takes place, by which subjective sensation becomes objective perception. For, in virtue of its own peculiar form, therefore _à priori_, _i.e._ _before_ all experience (since there could have been none till then), the Understanding conceives the given corporeal sensation as an _effect_ (a word which the Understanding alone comprehends), which _effect_, as such, necessarily implies a _cause_. Simultaneously it summons to its assistance _Space_, the form of the _outer_ sense, lying likewise ready in the intellect (_i.e._ the brain), in order to remove that cause _beyond_ the organism; for it is by this that the external world first arises, Space alone rendering it possible, so that pure intuition _à priori_ has to supply the foundation for empirical perception. In this process, as I shall soon show more clearly, the Understanding avails itself of all the several data, even the minutest, which are presented to it by the given sensation, in order to construct the cause of it in Space in conformity with them. This intellectual operation (which is moreover explicitly denied both by Schelling[76] and by Fries[77]), does not however take place discursively or reflectively, _in abstracto_, by means of conceptions and words; it is, on the contrary, an intuitive and quite direct process. For by it alone, therefore exclusively _in_ the Understanding and _for_ the Understanding, does the real, objective, corporeal world, filling Space in its three dimensions, present itself and further proceed, according to the same law of causality, to change in Time, and to move in Space.--It is therefore the Understanding itself which has to create the objective world; for this world cannot walk into our brain from outside all ready cut and dried through the senses and the openings of their organs. In fact, the senses supply nothing but the raw materials which the Understanding at once proceeds to work up into the objective view of a corporeal world, subject to regular laws, by means of the simple forms we have indicated: Space, Time, and Causality. Accordingly our every-day _empirical perception_ is an _intellectual_ one and has a right to claim this predicate, which German pseudo-philosophers have given to a pretended intuition of dream-worlds, in which their beloved _Absolute_ is supposed to perform its evolutions. And now I will proceed to show how wide is the gulf which separates sensation from perception, by pointing out how raw is the material out of which the beautiful edifice is constructed.

[76] Schelling, "Philosophische Schriften" (1809), vol. i. pp. 237 and 238.

[77] Fries, "Kritik der Vernunft." vol. i. pp. 52-56 and p. 290 of the 1st edition.

Objective perception makes use, properly speaking, of only two senses; touch and sight. These alone supply the data upon which, as its basis, the Understanding constructs the objective world by the process just described. The three other senses remain on the whole subjective; for their sensations, while pointing to an external cause, still contain no data by which its relations _in Space_ can be determined. Now _Space_ is the form of all perception, _i.e._ of _that_ apprehension, in which alone _objects_ can, properly speaking, present themselves. Therefore those other three senses can no doubt serve to announce the presence of objects we already know in some other way; but no construction in Space, consequently no objective perception, can possibly be founded on their data. A rose cannot be constructed from its perfume, and a blind man may hear music all his life without having the slightest objective representation either of the musicians, or of the instruments, or of the vibrations of the air. On the other hand, the sense of hearing is of great value as a medium for language, and through this it is the sense of _Reason_. It is also valuable as a medium for music, which is the only way in which we comprehend numerical relations not only _in abstracto_, but directly, _in concreto_. A musical sound or tone, however, gives no clue to spacial relations, therefore it never helps to bring the nature of its cause nearer to us; we stop short at it, so that it is no datum for the Understanding in its construction of the objective world. The sensations of touch and sight alone are such data; therefore a blind man without either hands or feet, while able to construct Space for himself _à priori_ in all its regularity, would nevertheless acquire but a very vague representation of the objective world. Yet what is supplied by touch and sight is not by any means perception, but merely the raw material for it. For perception is so far from being contained in the sensations of touch and sight, that these sensations have not even the faintest resemblance to the qualities of the things which present themselves to us through them, as I shall presently show. Only what really belongs to sensation must first be clearly distinguished from what is added to it by the intellect in perception. In the beginning this is not easy, because we are so accustomed to pass from the sensation at once to its cause, that the cause presents itself to us without our noticing the sensation apart from it, by which, as it were, the premisses are supplied to this conclusion drawn by the Understanding.

Thus touch and sight have each their own special advantages, to begin with; therefore they assist each other mutually. Sight needs no contact, nor even proximity; its field is unbounded and extends to the stars. It is moreover sensitive to the most delicate degrees of light, shade, colour, and transparency; so that it supplies the Understanding with a quantity of nicely defined data, out of which, by dint of practice, it becomes able to construct the shape, size, distance, and nature of bodies, and represents them at once perceptibly. On the other hand, touch certainly depends upon contact; still its data are so varied and so trustworthy, that it is the most searching of all the senses. Even perception by sight may, in the last resort, be referred to touch; nay, sight may be looked upon as an imperfect touch extending to a great distance, which uses the rays of light as long feelers; and it is just because it is limited to those qualities which have light for their medium and is therefore one-sided, that it is so liable to deception; whereas touch supplies the data for cognising size, shape, hardness, softness, roughness, temperature, &c. &c., quite immediately. In this it is assisted, partly by the shape and mobility of our arms, hands, and fingers, from whose position in feeling objects the Understanding derives its data for constructing bodies in Space, partly by muscular power, which enables it to know the weight, solidity, toughness, or brittleness of bodies: all this with the least possible liability to error.

These data nevertheless do not by any means yet give perception, which is always the work of the Understanding. The sensation I have in pressing against a table with my hand, contains no representation of a firm cohesion of parts in that object, nor indeed anything at all like it. It is only when my Understanding passes from that sensation to its cause, that the intellect constructs for itself a body having the properties of solidity, impenetrability, and hardness. If in the dark, I put my hand upon a flat surface, or lay hold of a ball of about three inches in diameter, the same parts of my hand feel the pressure in both cases; it is only by the different position which my hand takes that, in the one or in the other case, my Understanding constructs the shape of the body whose contact is the cause of the sensation, for which it receives confirmation from the changes of position which I make. The sensations in the hand of a man born blind, on feeling an object of cubic shape, are quite uniform and the same on all sides and in every direction: the edges, it is true, press upon a smaller portion of his hand, still nothing at all like a cube is contained in these sensations. His Understanding, however, draws the immediate and intuitive conclusion from the resistance felt, that this resistance must have a cause, which then presents itself through that conclusion as a hard body; and through the movements of his arms in feeling the object, while the hand's sensation remains unaltered, he constructs the cubic shape in Space, which is known to him _à priori_. If the representation of a cause and of Space, together with their laws, had not already existed within him, the image of a cube could never have proceeded from those successive sensations in his hand. If a rope be drawn through his hand, he will construct, as the cause of the friction he feels and of its duration, a long cylindrical body, moving uniformly in the same direction in that particular position of his hand. But the representation of movement, _i.e._ of change of place in Space by means of Time, never could arise for him out of the mere sensation in his hand; for that sensation can neither contain, nor can it ever by itself alone produce any such thing. It is his intellect which must, on the contrary, contain within itself, before all experience, the intuitions of Space, Time, and together with them that of the possibility of movement; and it must also contain the representation of Causality, in order to pass from sensation--which alone is given by experience--to a cause of that sensation, and to construct that cause as a body having this or that shape, moving in this or that direction. For how great is the difference between a mere sensation in my hand and the representations of causality, materiality, and mobility in Space by means of Time! The sensation in my hand, even if its position and its points of contact are altered, is a thing far too uniform and far too poor in data, to enable me to construct out of it the representation of Space, with its three dimensions, and of the influences of bodies one upon another, together with the properties of expansion, impenetrability, cohesion, shape, hardness, softness, rest, and motion: the basis, in short, of the objective world. This is, on the contrary, only possible by the intellect containing within itself, anterior to all experience, Space, as the form of perception; Time, as the form of change; and the law of Causality, as the regulator of the passing in and out of changes. Now it is precisely the pre-existence before all experience of all these forms, which constitutes the Intellect. Physiologically, it is a function of the brain, which the brain no more learns by experience than the stomach to digest, or the liver to secrete bile. Besides, no other explanation can be given of the fact, that many who were born blind, acquire a sufficiently complete knowledge of the relations of Space, to enable them to replace their want of eyesight by it to a considerable degree, and to perform astonishing feats. A hundred years ago Saunderson, for instance, who was blind from his birth, lectured on Optics, Mathematics, and Astronomy at Cambridge.[78] This, too, is the only way to explain the exactly opposite case of Eva Lauk, who was born without arms or legs, yet acquired an accurate perception of the outer world by means of sight alone as rapidly as other children.[79] All this therefore proves that Time, Space, and Causality are not conveyed into us by touch or by sight, or indeed at all from outside, but that they have an internal, consequently not empirical, but intellectual origin. From this again follows, that the perception of the bodily world is an essentially intellectual process, a work of the Understanding, to which sensation merely gives the opportunity and the data for application in individual cases.

[78] Diderot, in his "Lettre sur les Aveugles," gives a detailed account of Saunderson.

[79] See "Die Welt a. W. u. V." vol. ii. chap. 4.

I shall now prove the same with regard to the sense of sight. Here the only immediate datum is the sensation experienced by the retina, which, though admitting of great variety, may still be reduced to the impression of light and dark with their intermediate gradations and to that of colours proper. This sensation is entirely subjective: that is to say, it only exists within the organism and under the skin. Without the Understanding, indeed, we should never even become conscious of these gradations, excepting as of peculiar, varied modifications of the feeling in our eye, which would bear no resemblance to the shape, situation, proximity, or distance of objects outside us. For _sensation_, in seeing, supplies nothing more than a varied affection of the retina, exactly like the spectacle of a painter's palette with divers splashes of colour. Nor would anything more remain over in our consciousness, were we suddenly deprived of all our Understanding--let us say by paralysis of the brain--at a moment when we were contemplating a rich and extensive landscape, while the sensation was left unchanged: for this was the raw material out of which our Understanding had just before been constructing that perception.

Now, that the Understanding should thus be able, from such limited material as light, shade and colour, to produce the visible world, inexhaustibly rich in all its different shapes, by means of the simple function of referring effects to causes assisted by the intuition of Space, depends before all things upon the assistance given by the sensation itself, which consists in this: first, that the retina, as a surface, admits of a juxtaposition of impressions; secondly, that light always acts in straight lines, and that its refraction in the eye itself is rectilinear; finally, that the retina possesses the faculty of immediately feeling from which direction the light comes that impinges upon it, and this can, perhaps, only be accounted for by the rays of light penetrating below the surface of the retina. But by this we gain, that the mere impression at once indicates the direction of its cause; that is, it points directly to the position of the object from which the light proceeds or is reflected. The passage to this object as a cause no doubt presupposes the knowledge of causal relations, as well as of the laws of Space; but this knowledge constitutes precisely the furniture of the _Intellect_, which, here also, has again to create perception out of mere sensation. Let us now examine its procedure in doing so more closely.

The first thing it does is to set right the impression of the object, which is produced on the retina upside down. That original inversion is, as we know, brought about in the following manner. As each point of the visible object sends forth its rays towards all sides in a rectilinear direction, the rays from its upper extremity cross those from its lower extremity in the narrow aperture of the pupil, by which the former impinge upon the bottom, the latter upon the top, those projected from the right side upon the left, and _vice versa_. The refracting apparatus of the eye, which consists of the _humor aqueus_, _lens_, _et corpus vitreum_, only serves to concentrate the rays of light proceeding from the object, so as to find room for them on the small space of the retina. Now, if seeing consisted in mere sensation, we should perceive the impression of the object turned upside down, because we receive it thus; but in that case we should perceive it as something within our eye, for we should stop short at the sensation. In reality, however, the Understanding steps in at once with its causal law, and as it has received from sensation the datum of the direction in which the ray impinged upon the retina, it pursues that direction retrogressively up to the cause on both lines; so that this time the crossing takes place in the opposite direction, and the cause presents itself upright as an external object in Space, _i.e._ in the position in which it originally sent forth its rays, not that in which they reached the retina (see fig. 1).--The purely intellectual nature of this process, to the exclusion of all other, more especially of physiological, explanations, may also be confirmed by the fact, that if we put our heads between our legs, or lie down on a hill head downwards, we nevertheless see objects in their right position, and not upside down; although the portion of the retina, which is usually met by the lower part of the object is then met by the upper: in fact, everything is topsy turvy excepting the Understanding.

The _second_ thing which the Understanding does in converting sensation into perception, is to make a single perception out of a double sensation; for each eye in fact receives its own separate impression from the object we are looking at; each even in a slightly different direction: nevertheless that object presents itself as a single one. This can only take place in the Understanding, and the process by which it is brought about is the following: Our eyes are never quite parallel, excepting when we look at a distant object, _i.e._ one which is more than 200 feet from us. At other times they are both directed towards the object we are viewing, whereby they converge, so as to make the lines proceeding from each eye to the exact point of the object on which it is fixed, form an _angle_, called the _optic angle_; the lines themselves are called _optic axes_. Now, when the object lies straight before us, these lines exactly impinge upon the centre of each retina, therefore in two points which correspond exactly to each other in each eye. The Understanding, whose only business it is to look for the _cause_ of all things, at once recognises the impression as coming from a _single_ outside point, although here the sensation is double, and attributes it to _one_ cause, which therefore presents itself as a single object. For all that is perceived by us, is perceived as a _cause_--that is to say, as the cause of an effect we have experienced, consequently _in the Understanding_. As, nevertheless, we take in not only a single point, but a considerable surface of the object with both eyes, and yet perceive it as a single object, it will be necessary to pursue this explanation still further. All those parts of the object which lie to one side of the vertex of the optic angle no longer send their rays straight into the centre, but to the side, of the retina in each eye; in both sides, however, to the same, let us say the left, side. The points therefore upon which these rays impinge, _correspond symmetrically to each other_, as well as the centres--in other words, they are _homonymous points_. The Understanding soon learns to know them, and accordingly extends the above-mentioned rule of its causal perception to them also; consequently it not only refers those rays which impinge upon the centre of each retina, but those also which impinge upon all the other symmetrically corresponding places in both retinas, to a single radiant point in the object viewed: that is, it sees all these points likewise as single, and the entire object also. Now, it should be well observed, that in this process it is not the outer side of one retina which corresponds to the outer side of the other, and the inner to the inner of each, but the right side of one retina which corresponds to the right side of the other, and so forth; so that this symmetrical correspondence must not be taken in a physiological, but in a geometrical sense. Numerous and very clear illustrations of this process, and of all the phenomena which are connected with it, are to be found in Robert Smith's "Optics," and partly also in Kästner's German translation (1755). I only give _one_ (fig. 2), which, properly speaking, represents a special case, mentioned further on, but which may also serve to illustrate the whole, if we leave the point R out of question. According to this illustration, we invariably direct both eyes equally towards the object, in order that the symmetrically corresponding places on both retinas may catch the rays projected from the same points. Now, when we move our eyes upwards and downwards, to the sides, and in all directions, the point in the object which first impinged upon the central point of each retina, strikes a different place every time, but in all cases one which, in each eye, corresponds to the place bearing the same name in the other eye. In examining (_perlustrare_) an object, we let our eyes glide backwards and forwards over it, in order to bring each point of it successively into contact with the centre of the retina, which sees most distinctly: we feel it all over with our eyes. It is therefore obvious that seeing singly with two eyes is in fact the same process as feeling a body with ten fingers, each of which receives a different impression, each moreover in a different direction: the totality of these impressions being nevertheless recognised by the Understanding as proceeding from _one_ object, whose shape and size it accordingly apprehends and constructs in Space. This is why it is possible for a blind man to become a sculptor, as was the case, for instance, with the famous Joseph Kleinhaus, who died in Tyrol, 1853, having been a sculptor from his fifth year.[80] For, no matter from what cause it may have derived its data, perception is invariably an operation of the Understanding.

[80] The Frankfort "Konversationsblatt," July 22, 1853, gives the following account of this sculptor:--"The blind sculptor, Joseph Kleinhaus, died at Nauders, in Tyrol, on the 10th inst. Having lost his eyesight through small-pox when he was five years old, he began to amuse himself with carving and modelling, as a pastime. Prugg gave him some instructions, and supplied him with models, and at the age of twelve he carved a Christ in life-size. During a short stay in Nissl's workshop at Fügen, his progress was so rapid, that, thanks to his good capacities and talents, his fame as the blind sculptor soon spread far and wide. His works are numerous and of various kinds. His Christs alone, of which there are about four hundred, bear special witness to his proficiency, particularly if his blindness is taken into consideration. He sculptured many other objects besides, and, but two months ago, he modelled a bust of the Emperor Franz Joseph of Austria which has been sent to Vienna."

But just as a single ball seems to me double, if I touch it with my fingers crossed--since my Understanding, at once reverting to the cause and constructing it according to the laws of Space, takes for granted that the fingers are in their normal position and of course cannot do otherwise than attribute two spherical surfaces, which come in contact with the outer sides of the first and middle fingers, to two different balls--just so also does an object seem double, if my eyes, instead of converging symmetrically and enclosing the optic angle at a single point of the object, each view it at a different inclination--in other words, if I squint. For the rays, which in this case emanate from one point of the object, no longer impinge upon those symmetrically corresponding points in both retinas with which my mind has grown familiar by long experience, but upon other, quite different ones which, in a symmetrical position of the eyes, could only be affected in this way by different bodies; I therefore now see _two_ objects, precisely because perception takes place by means of, and within, the Understanding.--The same thing happens without squinting when, for instance, I look fixedly at the furthest of two objects placed at unequal distances before me, and complete the optic angle at it; for then the rays emanating from the nearer object do not impinge upon symmetrically corresponding places in both retinas, wherefore my Understanding attributes them to two objects, _i.e._ I see the nearer object double (see fig. 2, page 70). If, on the contrary, I complete the optic angle at the nearer object, by looking steadily at it, the further object appears double. It is easy to test this by holding a pencil two feet from the eyes, and looking alternately at it and at some other more distant object behind it.

But the finest thing of all is, that this experiment may quite well be reversed: so that, with two real objects straight before and close to us, and with our eyes wide open, we nevertheless see but _one_. This is the most striking proof that perception is a work of the Understanding and by no means contained in sensation. Let two cardboard tubes, about 8 inches long and 1-1/2 inches in diameter, be fastened parallel to one another, like those of a binocular telescope, and fix a shilling at the end of each tube. On applying our eyes to the opposite extremity and looking through the tubes, we shall see only _one_ shilling surrounded by _one_ tube. For in this case the eyes being forced into a completely parallel position, the rays emanating from the coins impinge exactly upon the centres of the two retinas and those points which immediately surround them, therefore upon places which correspond symmetrically to each other; consequently the Understanding, taking for granted the usual convergent position of the optic axes when objects are near, admits but one object as the cause of the reflected rays. In other words, we see but one object; so direct is the act of causal apprehension in the Understanding.

We have not space enough here to refute one by one the physiological explanations of single vision which have been attempted; but their fallacy is shown by the following considerations:--

1^o. If seeing single were dependent upon an organic connection, the corresponding points in both retinas, on which this phenomenon is shown to depend, would correspond _organically_, whereas they do so in a merely _geometrical_ sense, as has already been said. For, organically speaking, the two inner and two outer corners of the eyes are those which correspond, and so it is with the other parts also; whereas for the purpose of single vision, it is the right side of the right retina which corresponds to the right side of the left retina, and so on, as the phenomena just described irrefutably show. It is also precisely on account of the intellectual character of the process, that only the most intelligent animals, such as the higher mammalia and birds of prey--more especially owls--have their eyes placed so as to enable them to direct both optic axes to the same point.

2^o. The hypothesis of a confluence or partial intersection of the optic nerves before entering the brain, originated by Newton,[81] is false, simply because it would then be impossible to see double by squinting. Vesalius and Cæsalpinus besides have already brought forward anatomical instances in which subjects saw single, although neither fusion nor even contact of the optic nerves had taken place. A final argument against the hypothesis of a mixed impression is supplied by the fact, that on closing our right eye firmly and looking at the sun with our left, the bright image which persists for a time is always in the left, never in the right, eye: and _vice versa_.

[81] Newton, "Optics." Query 15.

The _third_ process by which the Understanding converts sensation into perception, consists in constructing bodies out of the simple surfaces hitherto obtained--that is, in adding the third dimension. This it does by estimating the expansion of bodies in this third dimension in Space--which is known to the Understanding _à priori_--through Causality, according to the degree in which the eye is affected by the objects, and to the gradations of light and shade. In fact, although objects fill Space in all three dimensions, they can only produce an impression upon the eye with two; for the nature of that organ is such, that our sensation, in seeing, is merely planimetrical, not stereometrical. All that is stereometrical in our perception is added by the Understanding, which has for its sole data the direction whence the eye receives its impression, the limits of that impression, and the various gradations of light and dark: these data directly indicate their causes, and enable us to distinguish whether what we have before us is a disk or a ball. This mental process, like the preceding ones, takes place so immediately and with such rapidity, that we are conscious of nothing but the result. It is this which makes perspective drawing so difficult a problem, that it can only be solved by mathematics and has to be learnt; although all it has to do, is to represent the sensation of seeing as it presents itself to our Understanding as a datum for the third process: that is, visual sensation in its merely planimetrical extension, to the _two_ dimensions of which extension, together with the said data in them, the Understanding forthwith adds the _third_, in contemplating a drawing as well as in contemplating reality. Perspective drawing is, in fact, a sort of writing which can be read as easily as printed type, but which few are able to write; precisely because our intellect, in perceiving, only apprehends effects with a view to constructing their causes, immediately losing sight of the former as soon as it has discovered the latter. For instance, we instantly recognise a chair, whatever position it may be in; while drawing a chair in any position belongs to the art which abstracts from this third process of the Understanding, in order to present the data alone for the spectator himself to complete. In its narrowest acceptation, as we have already seen, this is the art of drawing in perspective; in a more comprehensive sense, it is the whole art of painting. A painting presents us with outlines drawn according to the rules of perspective; lighter and darker places proportioned to the effect of light and shade; finally patches of colouring, which are determined as to quality and intensity by the teaching of experience. This the spectator reads and interprets by referring similar effects to their accustomed causes. The painter's art consists in consciously retaining the data of visual sensation in the artist's memory, as they are _before_ this third intellectual process; while we, who are not artists, cast them aside without retaining them in our memory, as soon as we have made use of them for the purpose described above. We shall become still better acquainted with this third intellectual process by now passing on to a fourth, which, from its intimate connection with the third, serves to elucidate it.

This _fourth_ operation of the Understanding consists in acquiring knowledge of the distance of objects from us: it is this precisely which constitutes that third dimension of which we have been speaking. Visual sensation, as we have said, gives us the _direction_ in which objects lie, but not their _distance_ from us: that is, not their _position_. It is for the _Understanding_ therefore to find out this distance; or, in other words, the distance must be inferred from purely _causal_ determinations. Now the most important of these is the _visual angle_, which objects subtend; yet even this is quite ambiguous and unable to decide anything by itself. It is like a word of double meaning: the sense, in which it is to be understood, can only be gathered from its connection with the rest. An object subtending the same visual angle may in fact be small and near, or large and far off; and it is only when we have previously ascertained its size, that the visual angle enables us to recognise its distance: and conversely, its size, when its distance is known to us. Linear perspective is based upon the fact that the visual angle diminishes as the distance increases, and its principles may here be easily deduced. As our sight ranges equally in all directions, we see everything in reality as from the interior of a hollow sphere, of which our eye occupies the centre. Now in the first place, an infinite number of intersecting circles pass through the centre of this sphere in all directions, and the angles measured by the divisions of these circles are the possible angles of vision. In the second place, the sphere itself modifies its size according to the length of radius we give to it; therefore we may also imagine it as consisting of an infinity of concentric, transparent spheres. As all radii diverge, these concentric spheres augment in size in proportion to their distance from us, and the degrees of their sectional circles increase correspondingly: therefore the true size of the objects which occupy them likewise increases. Thus objects are larger or smaller according to the size of the spheres of which they occupy similar portions--say 10°--while their visual angle remains unchanged in both cases, leaving it therefore undecided, whether the 10° occupied by a given object belong to a sphere of 2 miles, or of 10 feet diameter. Conversely, if the size of the object has been ascertained, the number of degrees occupied by it will diminish in proportion to the distance and the size of the sphere to which we refer it, and all its outlines will contract in similar proportion. From this ensues the fundamental law of all perspective; for, as objects and the intervals between them must necessarily diminish in constant proportion to their distance from us, all their outlines thereby contracting, the result will be, that with increasing distance, what is above us will descend, what is below us will ascend, and all that lies at our sides will come nearer together. This progressive convergence, this linear perspective, no doubt enables us to estimate distances, so far as we have before us an uninterrupted succession of visibly connected objects; but we are not able to do this by means of the visual angle alone, for here the help of another datum is required by the Understanding, to act, in a sense, as commentary to the visual angle, by indicating more precisely the share we are to attribute to distance in that angle. Now there are four principal data of this kind, which I am about to specify. Thanks to these data, even where there is no linear perspective to guide us, if a man standing at a distance of 200 feet appears to me subtending a visual angle twenty-four times smaller than if he were only 2 feet off, I can nevertheless in most cases estimate his size correctly. All this proves once more that perception is not only a thing of the senses, but of the intellect also.--I will here add the following special and interesting fact in corroboration of what I have said about the basis of linear perspective as well as about the intellectual nature of all perception. When I have looked steadily at a coloured object with sharply defined outlines--say a red cross--long enough for the physiological image to form in my eye as a green cross, the further the surface on to which I project it, the larger it will appear to me: and _vice versa_. For the image itself occupies an unvarying portion of my retina, _i.e._ the portion originally affected by the red cross; therefore when referred outwards, or, in other words, recognised as the effect of an external object, it forms an unchanging visual angle, say of 2°. Now if, in this case, where all commentary to the visual angle is wanting, I remove it to a distant surface, with which I necessarily identify it as belonging to its effect, the cross will occupy 2° of a distant and therefore larger sphere, and is consequently large. If, on the other hand, I project the image on to a nearer object, it will occupy 2° of a smaller sphere, and is therefore small. The resulting perception is in both cases completely objective, quite like that of an external object; and as it proceeds from an entirely subjective reason (from the image having been excited in quite a different way), it thus confirms the intellectual character of all objective perception.--This phenomenon (which I distinctly remember to have been the first to notice, in 1815) forms the theme of an essay by Séguin, published in the "_Comptes rendus_" of the 2nd August, 1858, where it is served up as a new discovery, all sorts of absurd and distorted explanations of it being given. _Messieurs les illustres confrères_ let pass no opportunity for heaping experiment upon experiment, the more complicated the better. _Expérience!_ is their watchword; yet how rarely do we meet with any sound, genuine reflection upon the phenomena observed! _Expérience! expérience!_ followed by twaddle.

To return to the subsidiary data which act as commentaries to a given visual angle, we find foremost among them the _mutationes oculi internæ_, by means of which the eye adapts its refractory apparatus to various distances by increasing and diminishing the refraction. In what these modifications consist, has not yet been clearly ascertained. They have been sought in the increased convexity, now of the _cornea_, now of the crystalline _lens_; but the latest theory seems to me the most probable one, according to which the lens is moved backwards for distant vision and forwards for near vision, lateral pressure, in the latter case, giving it increased protuberance; so that the process would exactly resemble the mechanism of an opera-glass. Kepler, however, had, in the main, already expressed this theory, which may be found explained in A. Hueck's pamphlet, "Die Bewegung der Krystallinse," 1841. If we are not clearly conscious of these inner modifications of the eye, we have at any rate a certain feeling of them, and of this we immediately avail ourselves to estimate distances. As however these modifications are not available for the purposes of clear sight beyond the range of from about 7 inches to 16 feet, the Understanding is only able to apply this datum within those limits.

Beyond them, however, the second datum becomes available: that is to say, the _optic angle_, formed by the two optic axes, which we had occasion to explain when speaking of single vision. It is obvious that this optic angle becomes smaller, the further the object is removed: and _vice versa_. This different direction of the eyes, with respect to each other, does not take place without producing a slight sensation, of which we are nevertheless only in so far conscious as the Understanding makes use of it, as a datum, in estimating distances intuitively. By this datum we are not only enabled to cognize the distance, but the precise position of the object viewed, by means of the parallax of the eyes, which consists in each eye seeing the object in a slightly different direction; so that if we close one eye, the object seems to move. Thus it is not easy to snuff a candle with one eye shut, because this datum is then wanting. But as the direction of the eyes becomes parallel as soon as the distance of the object reaches or exceeds 200 feet, and as the optic angle consequently then ceases to exist, this datum only holds good within the said distance.

Beyond it, the Understanding has recourse to _atmospheric perspective_, which indicates a greater distance by means of the increasing dimness of all colours, of the appearance of physical blue in front of all dark objects (according to Göthe's perfectly correct and true theory of colours), and also of the growing indistinctness of all outlines. In Italy, where the atmosphere is very transparent, this datum loses its power and is apt to mislead: Tivoli, for instance, seems to be very near when seen from Frascati. On the other hand, all objects appear larger in a mist, which is an abnormal exaggeration of the datum; because our Understanding assumes them to be further from us.

Finally, there remains the estimation of distance by means of the size (known to us intuitively) of intervening objects, such as fields, woods, rivers, &c. &c. This mode of estimation is only applicable where there is uninterrupted succession: in other words, it can only be applied to terrestrial, not to celestial objects. Moreover, we have in general more practice in using it horizontally than vertically: a ball on the top of a tower 200 feet high appears much smaller to us than when lying on the ground 200 feet from us; because, in the latter case, we estimate the distance more accurately. When we see human beings in such a way, that what lies between them and ourselves is in a great measure hidden from our sight, they always appear strikingly small.

The fact that our Understanding assumes everything it perceives in a horizontal direction to be farther off, therefore larger, than what is seen in a vertical direction, must partly be attributed to this last mode of estimating distances, inasmuch as it only holds good when applied horizontally and to terrestrial objects; but partly also to our estimation of distances by atmospheric perspective, which is subject to similar conditions. This is why the moon seems so much larger on the horizon than at its zenith, although its visual angle accurately measured--that is, the image projected by it on to the eye--is not at all larger in one case than in the other; and this also accounts for the flattened appearance of the vault of the sky: that is to say, for its appearing to have greater horizontal than vertical extension. Both phenomena therefore are purely intellectual or cerebral, not optical. If it be objected, that even when at its zenith, the moon occasionally has a hazy appearance without seeming to be larger, we answer, that neither does it in that case appear red; for its haziness proceeds from a greater density of vapours, and is therefore of a different kind from that which proceeds from atmospheric perspective. To this may be added what I have already said: that we only apply this mode of estimating distances in a horizontal, not in a perpendicular, direction; besides, in this case, other correctives come into play. It is related of Saussure that, when on the Mont Blanc, he saw so enormous a moon rise, that, not recognising what it was, he fainted with terror.

The properties of the telescope and magnifying glass, on the other hand, depend upon a separate estimate according to the visual angle alone: _i.e._, that of size by distance, and of distance by size; because here the four other supplementary means of estimating distances are excluded. The telescope in reality magnifies objects, while it only seems to bring them nearer; because their size being known to us empirically, we here account for its apparent increase by a diminution of their distance from us. A house seen through a telescope, for instance, seems to be ten times nearer, not ten times larger, than seen with the naked eye. The magnifying glass, on the contrary, does not really magnify, but merely enables us to bring the object nearer to our eyes than would otherwise be possible; so that it only appears as large as it would at that distance even without the magnifying glass. In fact, we are prevented from seeing objects distinctly at less than from eight to ten inches' distance from our eyes, by the insufficient convexity of the ocular lens and cornea; but if we increase the refraction by substituting the convexity of the magnifying glass for that of the lens and cornea, we then obtain a clear image of objects even when they are as near as half an inch from our eyes. Objects thus seen in close proximity to us and in the size corresponding to that proximity, are transferred by our Understanding to the distance at which we naturally see distinctly, _i.e._ to about eight or ten inches from our eyes, and we then estimate their magnitude according to this distance and to the given visual angle.

I have entered thus fully into detail concerning all the different processes by which seeing is accomplished, in order to show clearly and irrefragably that the predominant factor in them is _the Understanding_, which, by conceiving each change as an _effect_ and referring that effect to its _cause_, produces the cerebral phenomenon of the objective world on the basis of the _à priori_ fundamental intuitions of Space and Time, for which it receives merely a few data from the senses. And moreover the Understanding effects this exclusively by means of its own peculiar form, the law of Causality; therefore quite directly and intuitively, without any assistance whatever from reflection--that is, from abstract knowledge by means of conceptions and of language, which are the materials of _secondary_ knowledge, _i.e._ of _thought_, therefore of _Reason_.

That this knowledge through the Understanding is independent of Reason's assistance, is shown even by the fact, that when, at any time, the Understanding attributes a given effect to a wrong cause, actually perceiving that cause, whereby _illusion_ arises, our Reason, however clearly it may recognise _in abstracto_ the true state of the matter, is nevertheless unable to assist the Understanding, and the illusion persists undisturbed in spite of that better knowledge. The above-mentioned phenomena of seeing and feeling double, which result from an abnormal position of the organs of touch and sight, are instances of such illusions; likewise the apparently increased size of the rising moon; the image which forms in the focus of a concave mirror and exactly resembles a solid body floating in space; the painted relievo which we take for real; the apparent motion of a shore or bridge on which we are standing, if a ship happens to pass along or beneath it; the seeming proximity of very lofty mountains, owing to the absence of atmospheric perspective, which is the result of the purity of the air round their summits. In these and in a multitude of similar cases, our Understanding takes for granted the existence of the usual cause with which it is conversant and forthwith perceives it, though our Reason has arrived at the truth by a different road; for, the knowledge of the Understanding being anterior to that of the Reason, the intellect remains inaccessible to the teaching of the Reason, and thus the _illusion_--that is, the deception of the Understanding--remains immovable; albeit _error_--that is, the deception of the Reason--is obviated.--That which is correctly known by the Understanding is _reality_: that which is correctly known by the Reason is _truth_, or in other terms, a judgment having a sufficient reason; _illusion_ (that which is wrongly perceived) we oppose to _reality_: _error_ (that which is wrongly thought) to _truth_.

The purely formal part of empirical perception--that is, Space, Time, and the law of Causality--is contained _à priori_ in the intellect; but this is not the case with the application of this formal part to empirical data, which has to be acquired by the Understanding through practice and experience. Therefore new-born infants, though they no doubt receive impressions of light and of colour, still do not apprehend or indeed, strictly speaking, see objects. The first weeks of their existence are rather passed in a kind of stupor, from which they awaken by degrees when their Understanding begins to apply its function to the data supplied by the senses, especially those of touch and of sight, whereby they gradually gain consciousness of the objective world. This newly-arising consciousness may be clearly recognised by the look of growing intelligence in their eyes and a degree of intention in their movements, especially in the smile with which they show for the first time recognition of those who take care of them. They may even be observed to make experiments for a time with their sight and touch, in order to complete their apprehension of objects by different lights, in different directions and at different distances: thus pursuing a silent, but serious course of study, till they have succeeded in mastering all the intellectual operations in seeing which have been described. The fact of this schooling can be ascertained still more clearly through those who, being born blind, have been operated upon late in life, since they are able to give an account of their impressions. Cheselden's blind man[82] was not an isolated instance, and we find in all similar cases the fact corroborated, that those who obtain their sight late in life, no doubt, see light, outlines, and colours, as soon as the operation is over, but that they have no objective perception of objects until their Understanding has learnt to apply its causal law to data and to changes which are new to it. On first beholding his room and the various objects in it, Cheselden's blind man did not distinguish one thing from another; he simply received the general impression of a totality all in one piece, which he took for a smooth, variegated surface. It never occurred to him to recognise a number of detached objects, lying one behind the other at different distances. With blind people of this sort, it is by the sense of touch, to which objects are already known, that they have to be introduced to the sense of sight. In the beginning, the patient has no appreciation whatever of distances and tries to lay hold of everything. One, when he first saw his own house from outside, could not conceive how so small a thing could contain so many rooms. Another was highly delighted to find, some weeks after the operation, that the engravings hanging on the walls of his room represented a variety of objects. The "Morgenblatt" of October 23rd, 1817, contains an account of a youth who was born blind, and obtained his sight at the age of seventeen. He had to learn intelligent perception, for at first sight he did not even recognise objects previously known to him through the sense of touch. Every object had to be introduced to the sense of sight by means of the sense of touch. As for the distances of the objects he saw, he had no appreciation whatever of them, and tried to lay hold indiscriminately of everything, far or near.--Franz expresses himself as follows:[83]--

"A definite idea of distance, as well as of form and size, is only obtained by sight and touch, and by reflecting on the impressions made on both senses; but for this purpose we must take into account the muscular motion and voluntary locomotion of the individual.--Caspar Hauser, in a detailed account of his own experience in this respect, states, that upon his first liberation from confinement, whenever he looked through the window upon external objects, such as the street, garden, &c., it appeared to him as if there were a shutter quite close to his eye, and covered with confused colours of all kinds, in which he could recognise or distinguish nothing singly. He says farther, that he did not convince himself till after some time during his walks out of doors, that what had at first appeared to him as a shutter of various colours, as well as many other objects, were in reality very different things; and that at length the shutter disappeared, and he saw and recognised all things in their just proportions. Persons born blind who obtain their sight by an operation in later years only, sometimes imagine that all objects touch their eyes, and lie so near to them that they are afraid of stumbling against them; sometimes they leap towards the moon, supposing that they can lay hold of it; at other times they run after the clouds moving along the sky, in order to catch them, or commit other such extravagancies. Since ideas are gained by reflection upon sensation, it is further necessary in all cases, in order that an accurate idea of objects may be formed from the sense of sight, that the powers of the mind should be unimpaired, and undisturbed in their exercise. A proof of this is afforded in the instance related by Haslam,[84] of a boy who had no defect of sight, but was weak in understanding, and who in his seventh year was unable to estimate the distances of objects, especially as to height; he would extend his hand frequently towards a nail on the ceiling, or towards the moon, to catch it. It is therefore the judgment which corrects and makes clear this idea, or perception of visible objects."

[82] See the original report in vol. 35 of the "Philosophical Transactions" as to this case.

[83] Franz, "The Eye, a treatise on preserving this organ in a healthy state and improving the sight." London, Churchill, 1839, pp. 34-36.

[84] Haslam's "Observations on Madness and Melancholy," 2nd ed. p. 192.

The intellectual nature of perception as I have shown it, is corroborated physiologically by Flourens[85] as follows:

"Il faut faire une grand distinction entre les sens et l'intelligence. L'ablation d'un tubercule détermine la perte de la _sensation_, du _sens_ de la vue; la rétine devient insensible, l'iris devient immobile. L'ablation d'un lobe cérébral laisse la _sensation_, le _sens_, la _sensibilité_ de la rétine, la _mobilité_ de l'iris; elle ne détruit que la _perception_ seule. Dans un cas, c'est un fait _sensorial_; et, dans l'autre, un fait _cérébral_; dans un cas, c'est la perte du _sens_; dans l'autre, c'est la perte de la _perception_. La distinction des perceptions et des sensations est encore un grand résultat; et it est démontré aux yeux. Il y a deux moyens de faire perdre la vision par l'encéphale: 1° par les tubercules, c'est la perte du sens, de la sensation; 2° par les lobes, c'est la perte de la perception, de l'intelligence. La sensibilité n'est donc pas l'intelligence; penser n'est donc pas sentir; et voilà toute une philosophie renversée. L'idée n'est donc pas la sensation; et voilà encore une autre preuve du vice radical de cette philosophie." And again, p. 77, under the heading: Séparation de la Sensibilité et de la Perception:--"Il y a une de mes expériences qui sépare nettement la _sensibilité_ de la _perception_. Quand on enlève le _cerveau proprement dit_ (_lobes_ ou _hémisphères cérébraux_) à un animal, l'animal perd la vue. Mais, par rapport a l'œil, rien n'est changé: les objets continuent à se peindre sur la rétine; l'_iris_ reste contractile, le _nerf optique_ sensible, parfaitement sensible. Et cependant l'animal ne voit plus; il n'y a plus _vision_, quoique tout ce qui est _sensation_ subsiste; il n'y a plus _vision_, parce qu'il n'y a plus _perception_. Le _percevoir_, et non le _sentir_, est donc le premier élément de l'_intelligence_. La _perception_ est partie de l'_intelligence_, car elle se perd avec l'_intelligence_, et par l'ablation du même organe, les _lobes_ ou _hémisphères cérébraux_; et la _sensibilité_ n'en est point partie, puisqu'elle subsiste après la perte de l'_intelligence_ et l'ablation des _lobes_ ou _hémisphères_."

[85] Flourens, "De la vie et de l'Intelligence," 2nd edition, Paris, Garnier Frères, 1852, p. 49.

The following famous verse of the ancient philosopher Epicharmus, proves that the ancients in general recognized the intellectual nature of perception: Νοῦς ὁρῇ καὶ νοῦς ἀκούει· τἆλλα κωφὰ καὶ τυφλά. (_Mens videt, mens audit; cætera surda et cœca._)[86] Plutarch in quoting this verse, adds:[87] ὡς τοῦ περὶ τὰ ὄμματα καὶ ὦτα πάθους, ἂν μὴ παρῇ τὸ φρονοῦν, αἴσθησιν οὐ ποιοῦντος (_quia affectio oculorum et aurium nullum affert sensum, intelligentia absente_). Shortly before too he says: Στράτωνος τοῦ φυσικοῦ λόγος ἐστίν, ἀποδεικνύων ὡς οὐδ' αἰσθάνεσθαι τοπαράπαν ἄνευ τοῦ νοεῖν ὑπάρχει. (_Stratonis physici exstat ratiocinatio, qua "sine intelligentia sentiri omnino nihil posse" demonstrat._)[88] Again shortly after he says: ὅθεν ἀνάγκη, πᾶσιν, οἷς τὸ αἰσθάνεσθαι, καὶ τὸ νοεῖν ὑπάρχειν, εἰ τῷ νοεῖν αἰσθάνεσθαι πεφύκαμεν (_quare necesse est, omnia, quæ sentiunt, etiam intelligere, siquidem intelligendo demum sentiamus_).[89] A second verse of Epicharmus might be connected with this, which is quoted by Diogenes Laertes (iii. 16):

Εὔμαιε, τὸ σοφόν ἐστιν οὐ καθ' ἓν μόνον, ἀλλ' ὅσα περ ζῇ, πάντα καὶ γνώμαν ἔχει.

[86] "It is the mind that sees and hears; all besides is deaf and blind." (Tr. Ad.)

[87] Plutarch, "De solert. animal." c. 3. "For the affection of our eyes and ears does not produce any perception, unless it be accompanied by thought." (Tr. Ad.)

[88] "Straton, the physicist, has proved that 'without thinking it is quite impossible to perceive.'" (Tr. Ad.)

[89] "Therefore it is necessary that all who perceive should also think, since we are so constituted as to perceive by means of thinking." (Tr. Ad.)

(_Eumaee, sapientia non uni tantum competit, sed quæcunque vivunt etiam intellectum habent._) Porphyry likewise endeavours to show at length that all animals have understanding.[90]

[90] Porph. "De abstinentia," iii. 21.

Now, that it should be so, follows necessarily from the intellectual character of perception. All animals, even down to the very lowest, must have Understanding--that is, knowledge of the causal law, although they have it in very different degrees of delicacy and of clearness; at any rate they must have as much of it as is required for perception by their senses; for sensation without Understanding would be not only a useless, but a cruel gift of Nature. No one, who has himself any intelligence, can doubt the existence of it in the higher animals. But at times it even becomes undeniably evident that their knowledge of causality is actually _à priori_, and that it does not arise from the habit of seeing one thing follow upon another. A very young puppy will not, for instance, jump off a table, because he foresees what would be the consequence. Not long ago I had some large curtains put up at my bed-room window, which reached down to the floor, and were drawn aside from the centre by means of a string. The first morning they were opened I was surprised to see my dog, a very intelligent poodle, standing quite perplexed, and looking upwards and sidewards for the cause of the phenomenon: that is, he was seeking for the change which he knew _à priori_ must have taken place. Next day the same thing happened again.--But even the lowest animals have perception--consequently Understanding--down to the aquatic polypus, which has no distinct organs of sensation, yet wanders from leaf to leaf on its waterplant, while clinging to it with its feelers, in search of more light.

Nor is there, indeed, any difference, beyond that of degree, between this lowest Understanding and that of man, which we however distinctly separate from his Reason. The intermediate gradations are occupied by the various series of animals, among which the highest, such as the monkey, the elephant, the dog, astonish us often by their intelligence. But in every case the business of the Understanding is invariably to apprehend directly causal relations: first, as we have seen, those between our own body and other bodies, whence proceeds objective perception; then those between these objectively perceived bodies among themselves, and here, as has been shown in § 20, the causal relation manifests itself in three forms--as cause, as stimulus, and as motive. All movement in the world takes place according to these three forms of the causal relation, and through them alone does the intellect comprehend it. Now, if, of these three, _causes_, in the narrowest sense of the word, happen to be the object of investigation for the Understanding, it will produce Astronomy, Mechanics, Physics, Chemistry, and will invent machines for good and for evil; but in all cases a direct, intuitive apprehension of the causal connection will in the last resort lie at the bottom of all its discoveries. For the sole form and function of the Understanding is this apprehension, and not by any means the complicated machinery of Kant's twelve Categories, the nullity of which I have proved.--(All comprehension is a direct, consequently intuitive, apprehension of the causal connection; although this has to be reduced at once to abstract conceptions in order to be fixed. To calculate therefore, is not to understand, and, in itself, calculation conveys no comprehension of things. Calculation deals exclusively with abstract conceptions of magnitudes, whose mutual relations it determines. By it we never attain the slightest comprehension of a physical process, for this requires _intuitive_ comprehension of space-relations, by means of which causes take effect. Calculations have merely practical, not theoretical, value. It may even be said that _where calculation begins, comprehension ceases_; for a brain occupied with numbers is, as long as it calculates, entirely estranged from the causal connection in physical processes, being engrossed in purely abstract, numerical conceptions. The result, however, only shows us _how much_, never _what_. "_L'expérience et le calcul_," those watchwords of French physicists, are not therefore by any means adequate [for thorough insight].)--If, again, _stimuli_ are the guides of the Understanding, it will produce Physiology of Plants and Animals, Therapeutics, and Toxicology. Finally, if it devotes itself to the study of _motives_, the Understanding will use them, on the one hand, theoretically, to guide it in producing works on Morality, Jurisprudence, History, Politics, and even Dramatic and Epic Poetry; on the other hand, practically, either merely to train animals, or for the higher purpose of making human beings dance to its music, when once it has succeeded in discovering which particular wire has to be pulled in order to move each puppet at its pleasure. Now, with reference to the function which effects this, it is quite immaterial whether the intellect turns gravitation ingeniously to account, and makes it serve its purpose by stepping in just at the right time, or whether it brings the collective or the individual propensities of men into play for its own ends. In its practical application we call the Understanding _shrewdness_ or, when used to outwit others, _cunning_; when its aims are very insignificant, it is called _slyness_ and, if combined with injury to others, _craftiness_. In its purely theoretical application, we call it simply _Understanding_, the higher degrees of which are named _acumen_, _sagacity_, _discernment_, _penetration_, while its lower degrees are termed _dulness_, _stupidity_, _silliness_, &c. &c. These widely differing degrees of sharpness are innate, and cannot be acquired; although, as I have already shown, even in the earliest stages of the application of the Understanding, _i.e._ in empirical perception, practice and knowledge of the material to which it is applied, are needed. Every simpleton has Reason--give him the premisses, and he will draw the conclusion; whereas _primary_, consequently intuitive, knowledge is supplied by the Understanding: herein lies the difference. The pith of every great discovery, of every plan having universal historical importance, is accordingly the product of a happy moment in which, by a favourable coincidence of outer and inner circumstances, some complicated causal series, some hidden causes of phenomena which had been seen thousands of times before, or some obscure, untrodden paths, suddenly reveal themselves to the intellect.--

By the preceding explanations of the processes in seeing and feeling, I have incontestably shown that empirical perception is essentially the work of _the Understanding_, for which the material only is supplied by the senses in sensation--and a poor material it is, on the whole; so that _the Understanding_ is, in fact, the artist, while the senses are but the under-workmen who hand it the materials. But the process consists throughout in referring from given effects to their causes, which by this process are enabled to present themselves as objects in Space. The very fact that we presuppose Causality in this process, proves precisely that this law must have been supplied by the Understanding itself; for it could never have found its way into the intellect from outside. It is indeed the first condition of all empirical perception; but this again is the form in which all external experience presents itself to us; how then can this law of Causality be derived from experience, when it is itself essentially presupposed by experience?--It was just because of the utter impossibility of this, and because Locke's philosophy had put an end to all _à priority_, that Hume denied the whole reality of the conception of Causality. He had besides already mentioned two false hypotheses in the seventh section of his "Inquiry concerning the Human Understanding," which recently have again been advanced: the one, that the effect of the will upon the members of our body; the other, that the resistance opposed to our pressure by outward objects, is the origin and prototype of the conception of Causality. Hume refutes both in his own way and according to his own order of ideas. I argue as follows. There is no causal connection whatever between acts of the will and actions of the body; on the contrary, both are immediately one and the same thing, only perceived in a double aspect--that is, on the one hand, in our self-consciousness, or inner sense, as acts of the will; on the other, simultaneously in exterior, spacial brain-perception, as actions of the body.[91] The second hypothesis is false, first because, as I have already shown at length, a mere sensation of touch does not yet give any objective perception whatever, let alone the conception of Causality, which never can arise from the feeling of an impeded muscular effort: besides impediments of this kind often occur without any external cause; secondly, because our pressing against an external object necessarily has a motive, and this already presupposes apprehension of that object, which again presupposes knowledge of Causality.--But the only means of radically proving the conception of Causality to be independent of all experience was by showing, as I have done, that the whole possibility of experience is conditioned by the conception of Causality. In § 23 I intend to show that Kant's proof, propounded with a similar intent, is false.

[91] Compare "Die Welt a. W. u. V." 3rd edition, vol. ii. p. 41. [The 3rd edition of "Die Welt a. W. u. V." contains at this place a supplement which is wanting in the 2nd edition, vol. ii. p. 38.--Note by the Editor of the 3rd edition.]

This is also the proper place for drawing attention to the fact, that Kant either did not clearly recognise in empirical perception the mediation of the causal law--which law is known to us before all experience--or that he intentionally evaded mentioning it, because it did not suit his purpose. In the "Critique of Pure Reason," for instance, the relation between causality and perception is not treated in the "Doctrine of Elements," but in the chapter on the "Paralogisms of Pure Reason," where one would hardly expect to find it; moreover it appears in his "Critique of the Fourth Paralogism of Transcendental Psychology," and only in the first edition.[92] The very fact that this place should have been assigned to it, shows that in considering this relation, he always had the transition from the phenomenon to the thing in itself exclusively in view, but not the genesis of perception itself. Here accordingly he says that the existence of a real external object is not given directly in perception, but can be added to it in thought and thus inferred. In Kant's eyes, however, he who does this is a Transcendental Realist, and consequently on a wrong road. For by his "outward object" Kant here means the thing in itself. The Transcendental Idealist, on the contrary, stops short at the perception of something empirically real--that is, of something existing outside us in Space--without needing the inference of a cause to give it reality. For _perception_, according to Kant, is quite directly accomplished without any assistance from the causal nexus, and consequently from the Understanding: he simply identifies perception with sensation. This we find confirmed in the passage which begins, "With reference to the reality of external objects, I need as little trust to inference," &c. &c.[93] and again in the sentence commencing with "Now we may well admit," &c. &c.[94] It is quite clear from these passages that perception of external things in Space, according to Kant, precedes all application of the causal law, therefore that the causal law does not belong to perception as an element and condition of it: for him, mere sensation is identical with perception. Only in as far as we ask what may, in a _transcendental_ sense, exist _outside of us_: that is, when we ask for the thing in itself, is Causality mentioned as connected with perception. Moreover Kant admits the existence, nay, the mere possibility, of causality only in reflection: that is, in abstract, distinct knowledge by means of conceptions; therefore he has no suspicion that its application is _anterior to all reflection_, which is nevertheless evidently the case, especially in empirical, sensuous perception which, as I have proved irrefragably in the preceding analysis, could never take place otherwise. Kant is therefore obliged to leave the genesis of empirical perception unexplained. With him it is a mere matter of the senses, given as it were in a miraculous way: that is, it coincides with sensation. I should very much like my reflective readers to refer to the passages I have indicated in Kant's work, in order to convince themselves of the far greater accuracy of my view of the whole process and connection. Kant's extremely erroneous view has held its ground till now in philosophical literature, simply because no one ventured to attack it; therefore I have found it necessary to clear the way in order to throw light upon the mechanism of our knowledge.

[92] Kant, "Krit. d. r. V." 1st edition, p. 367 _sqq._ (English translation by M. Müller, p. 318 _sqq._)

[93] Kant, "Krit. d. r. Vern." 1st edition, p. 371. (English translation, by M. Müller, p. 322.)

[94] Kant, "Krit. d. r. Vern." 1st edition, p. 372. (English translation, p. 323.)

Kant's fundamental idealistic position loses nothing whatever, nay, it even gains by this rectification of mine, in as far as, with me, the necessity of the causal law is absorbed and extinguished in empirical perception as its product and cannot therefore be invoked in behalf of an entirely transcendent question as to the thing in itself. On referring to my theory above concerning empirical perception, we find that its first datum, sensation, is absolutely subjective, being a process within the organism, because it takes place beneath the skin. Locke has completely and exhaustively proved, that the feelings of our senses, even admitting them to be roused by external causes, cannot have any resemblance whatever to the qualities of those causes. Sugar, for instance, bears no resemblance at all to sweetness, nor a rose to redness. But that they should need an external cause at all, is based upon a law whose origin lies demonstrably within us, in our brain; therefore this necessity is not less subjective than the sensations themselves. Nay, even _Time_--that primary condition of every possible _change_, therefore also of the change which first permits the application of the causal law--and not less _Space_--which alone renders the externalisation of causes possible, after which they present themselves to us as objects--even Time and Space, we say, are subjective forms of the intellect, as Kant has conclusively proved. Accordingly we find all the elements of empirical perception lying within us, and nothing contained in them which can give us reliable indications as to anything differing absolutely from ourselves, anything in itself.--But this is not all. What we think under the conception _matter_, is the residue which remains over after bodies have been divested of their shape and of all their specific qualities: a residue, which precisely on that account must be identical in all bodies. Now these shapes and qualities which have been abstracted by us, are nothing but the peculiar, specially defined _way in which these bodies act_, which constitutes precisely their difference. If therefore we leave these shapes and qualities out of consideration, there remains nothing but _mere activity in general_, pure action as such, Causality itself, objectively thought--that is, the reflection of our own Understanding, the externalised image of its sole function; and Matter is throughout pure Causality, its essence is Action in general.[95] This is why pure Matter cannot be perceived, but can only be thought: it is a something we add to every reality, as its basis, in thinking it. For pure Causality, mere action, without any defined mode of action, cannot become perceptible, therefore it cannot come within any experience.--Thus Matter is only the objective correlate to pure Understanding; for it is Causality in general, and nothing else: just as the Understanding itself is direct knowledge of cause and effect, and nothing else. Now this again is precisely why the law of causality is not applicable to Matter itself: that is to say, Matter has neither beginning nor end, but is and remains permanent. For as, on the one hand, Causality is the indispensable condition of all alternation in the accidents (forms and qualities) of Matter, _i.e._ of all passage in and out of being; but as, on the other hand, Matter is pure Causality itself, as such, objectively viewed: it is unable to exercise its own power upon itself, just as the eye can see everything but itself. "Substance" and Matter being moreover identical, we may call _Substance_, _action_ viewed _in abstracto_: _Accidents_, particular modes of action, action _in concreto_.--Now these are the results to which true, _i.e._ transcendental, Idealism leads. In my chief work I have shown that the thing in itself--_i.e._ whatever, on the whole, exists independently of our representation--cannot be got at by way of representation, but that, to reach it, we must follow quite a different path, leading through the inside of things, which lets us into the citadel, as it were, by treachery.--

[95] Compare "Die Welt a. W. u. V." 2nd edition; vol. i. sect. 4, p. 9; and vol. ii. pp. 48, 49 (3rd edition, vol. i. p. 10; vol. ii. p. 52). English translation, vol. i. pp. 9-10; vol. ii. p. 218.

But it would be downright chicanery, nothing else, to try and compare, let alone identify, such an honest, deep, thorough analysis of empirical perception as the one I have just given, which proves all the elements of perception to be subjective, with Fichte's algebraic equations of the _Ego_ and the _Non-Ego_; with his sophistical pseudo-demonstrations, which in order to be able to deceive his readers had to be clothed in the obscure, not to say absurd, language adopted by him; with his explanations of the way in which the _Ego_ spins the _Non-Ego_ out of itself; in short, with all the buffoonery of scientific emptiness.[96] Besides, I protest altogether against any community with this Fichte, as Kant publicly and emphatically did in a notice _ad hoc_ in the "Jenaer Litteratur Zeitung."[97] Hegelians and similar ignoramuses may continue to hold forth to their heart's content upon Kant-Fichteian philosophy: there exists a Kantian philosophy and a Fichteian hocus-pocus,--this is the true state of the case, and will remain so, in spite of those who delight in extolling what is bad and in decrying what is good, and of these Germany possesses a larger number than any other country.

[96] _Wissenschaftsleere_ (literally, _emptiness of science_), a pun of Schopenhauer's on the title of Fichte's _Wissenschaftslehre_ (_doctrine of science_), which cannot be rendered in English. (Tr.'s Note.)

[97] Kant, "Erklärung über Fichte's Wissenschaftslehre." See the "Intelligenzblatt" of the Jena Literary Gazette (1799), No. 109.

§ 22. _Of the Immediate Object._

Thus it is from the sensations of our body that we receive the data for the very first application of the causal law, and it is precisely by that application that the perception of this class of objects arises. They therefore have their essence and existence solely in virtue of the intellectual function thus coming into play, and of its exercise.

Now, as far as it is the starting-point, _i.e._ the mediator, for our perception of all other objects, I have called the bodily organism, in the first edition of the present work, the _Immediate Object_; this, however, must not be taken in a strictly literal sense. For although our bodily sensations are all apprehended directly, still this immediate apprehension does not yet make our body itself perceptible to us as an object; on the contrary, up to this point all remains subjective, that is to say, sensation. From this sensation certainly proceeds the perception of all other objects as the causes of such sensations, and these causes then present themselves to us as objects; but it is not so with the body itself, which only supplies sensations to consciousness. It is only _indirectly_ that we know even this body objectively, _i.e._ as an object, by its presenting itself, like all other objects, as the recognised cause of a subjectively given effect--and precisely on this account _objectively_--in our Understanding, or brain (which is the same). Now this can only take place when its own senses are acted upon by its parts: for instance, when the body is seen by the eye, or felt by the hand, &c., upon which data the brain (or understanding) forthwith constructs it as to shape and quality in space.--The immediate presence in our consciousness of representations belonging to this class, depends therefore upon the position assigned to them in the causal chain--by which all things are _connected_--relatively to the body (for the time being) of the Subject--by which (the Subject) all things are _known_.

§ 23. _Arguments against Kant's Proof of the_ à priority _of the conception of Causality_.

One of the chief objects of the "Critique of Pure Reason" is to show the universal validity, for all experience, of the causal law, its _à priority_, and, as a necessary consequence of this, its restriction to possible experience. Nevertheless, I cannot assent to the proof there given of the _à priority_ of the principle, which is substantially this:--"The _synthesis_ of the manifold by the imagination, which is necessary for all empirical knowledge, gives succession, but not yet determinate succession: that is, it leaves undetermined which of two states perceived was the first, not only in my imagination, but in the object itself. But definite order in this succession--through which alone what we perceive becomes experience, or, in other words, authorizes us to form objectively valid judgments--is first brought into it by the purely intellectual conception of cause and effect. Thus the principle of causal relation is the condition which renders experience possible, and, as such, it is given us _à priori_."[98]

[98] Kant, "Krit. d. r. Vern." 1st edition, p. 201; 5th edition, p. 246. (English translation by M. Müller, p. 176.) This is, however, not a literal quotation. (Tr.'s note.)

According to this, the order in which changes succeed each other in real objects becomes known to us as objective only by their causality. This assertion Kant repeats and explains in the "Critique of Pure Reason," especially in his "Second Analogy of Experience,"[99] and again at the conclusion of his "Third Analogy," and I request every one who desires to understand what I am now about to say, to read these passages. In them he affirms everywhere that _the objectivity of the succession of representations_--which he defines as their correspondence with the succession of real objects--is only known through the rule by which they follow upon one another: that is, through the law of causality; that my mere apprehension consequently leaves the objective relation between phenomena following one another quite undetermined: since I merely apprehend the succession of my own representations, but the succession in my apprehension does not authorize me to form any judgment whatever as to the succession in the object, unless that judgment be based upon causality; and since, besides, I might invert the order in which these perceptions follow each other in my apprehension, there being nothing which determines them as objective. To illustrate this assertion, Kant brings forward the instance of a house, whose parts we may consider in any order we like, from top to bottom, or from bottom to top; the determination of succession being in this case purely subjective and not founded upon an object, because it depends upon our pleasure. In opposition to this instance, he brings forward the perception of a ship sailing down a river, which we see successively lower and lower down the stream, which perception of the successively varying positions of the ship cannot be changed by the looker-on. In this latter case, therefore, he derives the subjective following in his own apprehension from the objective following in the phenomenon, and on this account he calls it an _event_. Now I maintain, on the contrary, that _there is no difference at all between these two cases, that both are events_, and that our knowledge of both is objective: that is to say, it is knowledge of changes in real objects recognized as such by the Subject. _Both are changes of relative position in two bodies._ In the first case, one of these bodies is a part of the observer's own organism, the eye, and the other is the house, with respect to the different parts of which the eye successively alters its position. In the second, it is the ship which alters its position towards the stream; therefore the change occurs between two bodies. Both are events, the only difference being that, in the first, the change has its starting-point in the observer's own body, from whose sensations undoubtedly all his perceptions originally proceed, but which is nevertheless an object among objects, and in consequence obeys the laws of the objective, material world. For the observer, as a purely cognising individual, any movement of his body is simply an empirically perceived fact. It would be just as possible in the second as in the first instance, to invert the order of succession in the change, were it as easy for the observer to move the ship up the stream as to alter the direction of his own eyes. For Kant infers the successive perception of different parts of the house to be neither objective nor an event, because it depends upon his own will. But the movement of his eyes in the direction from roof to basement is one event, and in the direction from basement to roof another event, just as much as the sailing of the ship. There is no difference whatever here, nor is there any difference either, as to their being or not being events, between my passing a troop of soldiers and their passing me. If we fix our eyes on a ship sailing close by the shore on which we are standing, it soon seems as if it were the ship that stood still and the shore that moved. Now, in this instance we are mistaken, it is true, as to the cause of the relative change of position, since we attribute it to a wrong cause; the real succession in the relative positions of our body towards the ship is nevertheless quite rightly and objectively recognised by us. Even Kant himself would not have believed that there was any difference, had he borne in mind that his own body was an object among objects, and that the succession in his empirical perceptions depended upon the succession of the impressions received from other objects by his body, and was therefore an objective succession: that is to say, one which takes place among objects _directly_ (if not indirectly) and independently of the will of the Subject, and which may therefore be quite well recognised without any causal connection between the objects acting successively on his body.

[99] _Ibid._ p. 189 of the 1st edition; more fully, p. 232 of the 5th edition. (English translation by M. Müller, p. 166.)

Kant says, Time cannot be perceived; therefore no succession of representations can be empirically perceived as objective: _i.e._ can be distinguished as changes in phenomena from the changes of mere subjective representations. The causal law, being a rule according to which states follow one another, is the only means by which the objectivity of a change can be known. Now, the result of his assertion would be, that no succession in Time could be perceived by us as objective, excepting that of cause and effect, and that every other succession of phenomena we perceive, would only be determined so, and not otherwise, by our own will. In contradiction to all this I must adduce the fact, that it is quite possible for phenomena to _follow upon_ one another without _following from_ one another. Nor is the law of causality by any means prejudiced by this; for it remains certain that each change is the effect of another change, this being firmly established _à priori_; only each change not only follows upon the single one which is its cause, but upon all the other changes which occur simultaneously with that cause, and with which that cause stands in no causal connection whatever. It is not perceived by me exactly in the regular order of causal succession, but in quite a different order, which is, however, no less objective on that account, and which differs widely from any subjective succession depending on my caprice, such as, for instance, the pictures of my imagination. The succession, in Time, of events which stand in no causal connection with each other is precisely what we call _contingency_.[100] Just as I am leaving my house, a tile happens to fall from the roof which strikes me; now, there is no causal connection whatever between my going out and the falling of the tile; yet the order of their succession--that is, that my going out preceded the falling of the tile--is objectively determined in my apprehension, not subjectively by my will, by which that order would otherwise have most likely been inverted. The order in which tones follow each other in a musical composition is likewise objectively determined, not subjectively by me, the listener; yet who would think of asserting that musical tones follow one another according to the law of cause and effect? Even the succession of day and night is undoubtedly known to us as an objective one, but we as certainly do not look upon them as causes and effects of one another; and as to their common cause, the whole world was in error till Copernicus came; yet the correct knowledge of their succession was not in the least disturbed by that error. Hume's hypothesis, by the way, also finds its refutation through this; since the following of day and night upon each other--the most ancient of all successions and the one least liable to exception--has never yet misled anyone into taking them for cause and effect of each other.

[100] In German _Zufall_, a word derived from the _Zusammenfallen_ (falling together), _Zusammentreffen_ (meeting together), or coinciding of what is unconnected, just as τὸ συμβεβηκός from συμβαίνειν. (Compare Aristotle, "Anal. post.," i. 4.)

Elsewhere Kant asserts, that a representation only shows reality (which, I conclude, means that it is distinguished from a mere mental image) by our recognising its necessary connection with other representations subject to rule (the causal law) and its place in a determined order of the time-relations of our representations. But of how few representations are we able to know the place assigned to them by the law of causality in the chain of causes and effects! Yet we are never embarrassed to distinguish objective from subjective representations: real, from imaginary objects. When asleep, we are unable to make this distinction, for our brain is then isolated from the peripherical nervous system, and thereby from external influences. In our dreams therefore, we take imaginary for real things, and it is only when we awaken: that is, when our nervous sensibility, and through this the outer world, once more comes within our consciousness, that we become aware of our mistake; still, even in our dreams, so long as they last, the causal law holds good, only an impossible material is often substituted for the usual one. We might almost think that Kant was influenced by Leibnitz in writing the passage we have quoted, however much he differs from him in all the rest of his philosophy; especially if we consider that Leibnitz expresses precisely similar views, when, for instance, he says: "La vérité des choses sensibles ne consiste que dans la liaison des phénomènes, qui doit avoir sa raison, et c'est ce qui les distingue des songes. ---- Le vrai Critérion, en matière des objets des sens, est la liaison des phénomènes, qui garantit les vérités de fait, à l'egard des choses sensibles hors de nous."[101]

[101] Leibnitz, "Nouveaux Essais sur l'Entendement," lib. iv. ch. ii. sect. 14.

It is clear that in proving the _à priority_ and the necessity of the causal law by the fact that the objective succession of changes is known to us only by means of that law, and that, in so far, causality is a condition for all experience, Kant fell into a very singular error, and one which is indeed so palpable, that the only way we can account for it is, by supposing him to have become so absorbed in the _à priori_ part of our knowledge, that he lost sight of what would have been evident to anyone else. The only correct demonstration of the _à priority_ of the causal law is given by me in § 21 of the present work. That _à priority_ finds its confirmation every moment in the infallible security with which we expect experience to tally with the causal law: that is to say, in the apodeictic certainty we ascribe to it, a certainty which differs from every other founded on induction--the certainty, for instance, of empirically known laws of Nature--in that we can conceive no exception to the causal law anywhere within the world of experience. We can, for instance, _conceive_ that in an exceptional case the law of gravitation might cease to act, but not that this could happen without a cause.

Kant and Hume have fallen into opposite errors in their proofs. Hume asserts that all _consequence_ is mere _sequence_; whereas Kant affirms that all _sequence_ must necessarily be _consequence_. Pure Understanding, it is true, can only conceive _consequence_ (causal result), and is no more able to conceive mere _sequence_ than to conceive the difference between right and left, which, like sequence, is only to be grasped by means of pure Sensibility. Empirical knowledge of the following of events in Time is, indeed, just as possible as empirical knowledge of juxtaposition of things in Space (this Kant denies elsewhere), but _the way in which_ things follow _upon_ one another in general in Time can no more be explained, than the way in which one thing follows _from_ another (as the effect of a cause): the former knowledge is given and conditioned by pure Sensibility; the latter, by pure Understanding. But in asserting that knowledge of the objective succession of phenomena can only be attained by means of the causal law, Kant commits the same error with which he reproaches Leibnitz:[102] that of "intellectualising the forms of Sensibility."--My view of succession is the following one. We derive our knowledge of the bare _possibility_ of succession from the form of Time, which belongs to pure Sensibility. The succession of real objects, whose form is precisely Time, we know empirically, consequently as _actual_. But it is through the Understanding alone, by means of Causality, that we gain knowledge of the _necessity_ of a succession of two states: that is, of a change; and even the fact that we are able to conceive the necessity of a succession at all, proves already that the causal law is not known to us empirically, but given us _à priori_. The Principle of Sufficient Reason is the general expression for the fundamental form of the necessary connection between all our objects, _i.e._ representations, which lies in the innermost depths of our cognitive faculty: it is the form common to all representations, and the only source of the conception of _necessity_, which contains absolutely nothing else in it and no other import, than that of the following of the consequence, when its reason has been established. Now, the reason why this principle determines the order of succession in Time in the class of representations we are now investigating, in which it figures as the law of causality, is, that Time is the form of these representations, therefore the necessary connection appears here as the rule of succession. In other forms of the principle of sufficient reason, the necessary connection it always demands will appear under quite different forms from that of Time, therefore not as succession; still it always retains the character of a necessary connection, by which the identity of the principle under all its forms, or rather the unity of the root of all the laws of which that principle is the common expression, reveals itself.

[102] Kant, "Kritik d. r. Vern." 1st edition, p. 275; 5th edition, p. 331. (English translation by M. Müller, p. 236.)

If Kant's assertion were correct, which I dispute, our only way of knowing the reality of succession would be through its necessity; but this would presuppose an Understanding that embraced all the series of causes and effects at once, consequently an omniscient Understanding. Kant has burdened the Understanding with an impossibility, merely in order to have less need of Sensibility.

How can we reconcile Kant's assertion that our only means of knowing the objective reality of succession is by the necessity with which effect follows cause, with his other assertion[103] that succession in Time is our only empirical criterion for determining which of two states is cause, and which effect. Who does not see the most obvious circle here?

[103] Kant, "Krit. d. r. Vern." vol. i. p. 203 of the 1st edition; p. 249 of the 5th edition. (English translation by M. Müller, p. 178.)

If we knew objectiveness of succession through Causality, we should never be able to think it otherwise than as Causality, and then it would be nothing else than Causality. For, if it were anything else, it would have other distinctive signs by which to be recognised; now this is just what Kant denies. Accordingly, if Kant were right, we could not say: "This state is the effect of that one, wherefore it follows it;" for following and being an effect, would be one and the same thing, and this proposition a tautology. Besides, if we do away with all distinction between following _upon_ and following _from_, we once more yield the point to Hume, who declared all consequence to be mere sequence and therefore denied that distinction likewise.

Kant's proof would, consequently, be reduced to this: that, empirically, we only know _actuality_ of succession; but as besides we recognise _necessity_ of succession in certain series of occurrences, and even know before all experience that every possible occurrence must have a fixed place in some one of these series, the reality and the _à priority_ of the causal law follow as a matter of course, the only correct proof of the latter being the one I have given in § 21 of this work.

Parallel with the Kantian theory: that the causal nexus alone renders objective succession and our knowledge of it possible, there runs another: that coexistence and our knowledge of it are only possible through reciprocity. In the "Critique of Pure Reason" they are presented under the title: "Third Analogy of Experience." Here Kant goes so far as to say that "the co-existence of phenomena, which exercise no reciprocal action on one another, but are separated by a perfectly empty space, could never become an object of possible perception"[104] (which, by the way, would be a proof _à priori_ that there is no empty space between the fixed stars), and that "the light which _plays between_ our eyes and celestial bodies"--an expression conveying surreptitiously the thought, that this starlight not only acts upon our eyes, but is acted upon by them also--"produces an intercommunity between us and them, and proves the co-existence of the latter." Now, even empirically, this last assertion is false; since the sight of a fixed star by no means proves its coexistence simultaneously with its spectator, but, at most, its existence some years, nay even some centuries before. Besides, this second Kantian theory stands and falls with the first, only it is far more easily detected; and the nullity of the whole conception of reciprocity has been shown in § 20.

[104] Kant, "Krit. d. r. Vern." pp. 212 and 213 of the 1st edition. (English translation, pp. 185 and 186.)

The arguments I have brought forward against Kant's proof may be compared with two previous attacks made on it by Feder,[105] and by G. E. Schulze.[106]

[105] Feder, "Ueber Raum und Causalität." sect. 29.

[106] G. E. Schulze, "Kritik der theoretischen Philosophie," vol. ii. p. 422 _sqq._

Not without considerable hesitation did I thus venture (in 1813) to attack a theory which had been universally received as a demonstrated truth, is repeated even now in the latest publications,[107] and forms a chief point in the doctrine of one for whose profound wisdom I have the greatest reverence and admiration; one to whom, indeed, I owe so much, that his spirit might truly say to me, in the words of Homer:

Ἀχλὺν δ' αὖ τοι ἀπ' ὀφθαλμῶν ἕλον, ἣ πρὶν ἐπῆεν.[108]

[107] For instance, in Fries' "Kritik der Vernunft," vol. ii. p. 85.

[108] I lifted from thine eyes the darkness which covered them before. (Tr.'s Ad.)

§ 24. _Of the Misapplication of the Law of Causality._

From the foregoing exposition it follows, that the application of the causal law to anything but _changes_ in the material, empirically given world, is an abuse of it. For instance, it is a misapplication to make use of it with reference to physical forces, without which no changes could take place; or to Matter, _on_ which they take place; or to the world, to which we must in that case attribute an absolutely objective existence independently of our intellect; indeed in many other cases besides. I refer the reader to what I have said on this subject in my chief work.[109] Such misapplications always arise, partly, through our taking the conception of cause, like many other metaphysical and ethical conceptions, in far _too wide_ a sense; partly, through our forgetting that the causal law is certainly a presupposition which we bring with us into the world, by which the perception of things outside us becomes possible; but that, just on that account, we are not authorized in extending beyond the range and independently of our cognitive faculty a principle, which has its origin in the equipment of that faculty, nor in assuming it to hold good as the everlasting order of the universe and of all that exists.

[109] "Die Welt a. W. u. V." 2nd edition, vol. ii. ch. iv. p. 42 _et seqq._; 3rd edition, vol. ii. p. 46 _et seqq._

§ 25. _The Time in which a Change takes place._

As the Principle of Sufficient Reason of Becoming is exclusively applicable to _changes_, we must not omit to mention here, that the ancient philosophers had already raised the question as to the time in which a change takes place, there being no possibility of it taking place during the existence of the preceding state nor after the new one has supervened. Yet, if we assign a special time to it between both states, a body would, during this time, be neither in the first nor in the second state: a dying man, for instance, would be neither alive nor dead; a body neither at rest nor in movement: which would be absurd. The scruples and sophistic subtleties which this question has evoked, may be found collected together in Sextus Empiricus "Adv. Mathem." lib. ix. 267-271, and "Hypat." iii. c. 14; the subject is likewise dealt with by Gellius, l. vi. c. 13--Plato[110] had disposed somewhat cavalierly of this knotty point, by maintaining that changes take place _suddenly_ and occupy _no time at all_; they occur, he says, in the ἐξαίφνης (_in repentino_), which he calls an ἄτοπος φύσις, ἐν χρόνῳ οὐδὲν οὖσα; a strange, timeless existence (which nevertheless comes within Time).

[110] Plato, "Parmenides," p. 138, ed. Bip.

It was accordingly reserved for the perspicacity of Aristotle to clear up this difficult point, which he has done profoundly and exhaustively in the sixth Book of Physics, chap. i.-viii. His proof that no change takes place suddenly (in Plato's ἐξαίφνης), but that each occurs only gradually and therefore occupies a certain time, is based entirely upon the pure, _à priori_ intuition of Time and of Space; but it is also very subtle. The pith of this very lengthy demonstration may, however, be reduced to the following propositions. When we say of objects that they limit each other, we mean, that both have their extreme ends in common; therefore only two extended things can be conterminous, never two indivisible ones, for then they would be _one_--_i.e._ only lines, but not mere points, can be conterminous. He then transfers this from Space to Time. As there always remains a line between two points, so there always remains a time between two _nows_; this is the time in which a change takes place--_i.e._ when _one_ state is in the first, and _another_ in the second, _now_. This time, like every other, is divisible to infinity; consequently, whatever is changing passes through an infinite number of degrees within that time, through which the second state gradually grows out of that _first_ one.--The process may perhaps be made more intelligible by the following explanation. Between two consecutive states the difference of which is perceptible to our senses, there are always several intermediate states, the difference between which is not perceptible to us; because, in order to be sensuously perceptible, the newly arising state must have reached a certain degree of intensity or of magnitude: it is therefore preceded by degrees of lesser intensity or extension, in passing through which it gradually arises. Taken collectively, these are comprised under the name of _change_, and the time occupied by them is called _the time of change_. Now, if we apply this to a body being propelled, the first effect is a certain vibration of its inner parts, which, after communicating the impulse to other parts, breaks out into external motion.--Aristotle infers quite rightly from the infinite divisibility of Time, that everything which fills it, therefore every change, _i.e._ every passage from one state to another, must likewise be susceptible of endless subdivision, so that all that arises, does so in fact by the concourse of an infinite multitude of parts; accordingly its genesis is always gradual, never sudden. From these principles and the consequent gradual arising of each movement, he draws the weighty inference in the last chapter of this Book, that nothing indivisible, no mere _point_ can move. And with this conclusion Kant's definition of Matter, as "that which moves in Space," completely harmonizes.

This law of the continuity and gradual taking place of all changes which Aristotle was thus the first to lay down and prove, we find stated three times by Kant: in his "Dissertatio de mundi sensibilis et intelligibilis forma," § 14, in the "Critique of Pure Reason,"[111] and finally in his "Metaphysical First Principles of Natural Science."[112] In all three places his exposition is brief, but also less thorough than that of Aristotle; still, in the main, both entirely agree. We can therefore hardly doubt that, directly or indirectly, Kant must have derived these ideas from Aristotle, though he does not mention him. Aristotle's proposition--οὐκ ἔστι ἀλλήλων ἐχόμενα τὰ νῦν ("the moments of the present are not continuous")--we here find expressed as follows: "between two moments there is always a time," to which may be objected that "even between two centuries there is none; because in Time as in Space, there must always be a pure limit."--Thus Kant, instead of mentioning Aristotle, endeavours in the first and earliest of his three statements to identify the theory he is advancing with Leibnitz' _lex continuitatis_. If they really were the same, Leibnitz must have derived his from Aristotle. Now Leibnitz[113] first stated this _Loi de la continuité_ in a letter to Bayle.[114] There, however, he calls it _Principe de l'ordre général_, and gives under this name a very general, vague, chiefly geometrical argumentation, having no direct bearing on the time of change, which he does not even mention.

[111] Kant, "Krit. d. r. Vern." 1st edition, p. 207; 5th edition, p. 253. (English translation by M. Müller, p. 182.)

[112] Kant, "Metaphysische Anfangsgründe der Naturwissenschaft." End of the "Allgemeine Anmerkung zur Mechanik."

[113] According to his own assertion, p. 189 of the "Opera philos." ed. Erdmann.

[114] _Ibid._ p. 104.