On the Will in Nature/Physical Astronomy

NO part of my doctrine could I have less hoped to see corroborated by empirical science than that, in which the fundamental truth, that Kant's thing–in–itself (Ding an sich) is the Will, is applied by me even to inorganic Nature, and in which I show the active principle in all fundamental forces of Nature to be absolutely identical with what is known to us within ourselves as the Will. It has therefore been particularly gratifying to me to have found that an eminent empiricist, yielding to the force of truth, had gone so far as to express this paradox in the exposition of his scientific doctrine. I allude to Sir John Herschel and to his Treatise on Astronomy, the first edition of which appeared in 1833, and a second enlarged one in 1849, under the title Outlines of Astronomy. Herschel, who, as an astronomer, was acquainted with gravity, not only in the one-sided and really coarse part which it acts on earth, but also in the nobler one performed by it in universal Space, where the celestial bodies play with each other, betray mutual inclination, exchange as it were amorous glances, yet never allow themselves to come into rude contact, and thus continue dancing their dignified minuet to the music of the spheres, while they keep at a respectful distance from one another, when he comes to the statement of the law of gravitation in the seventh chapter, 1 expresses himself as follows :

1 Herschel, Treatise on Astronomy, chap. 7, § 371 of the 1st edition, 1833.


"All bodies with which we are acquainted, when raised into the air and quietly abandoned, descend to the earth's surface in lines perpendicular to it. They are therefore urged thereto by a force or effort, the direct or indirect result of a consciousness and a will existing somewhere, though beyond our power to trace, which force we term gravity" 1

The writer who reviewed Herschel's book in the October number of the Edinburgh Review of 1833, anxious, as a true Englishman, before all things to prevent the Mosaic record 2 from being imperilled, takes great umbrage at this passage, rightly observing that it cannot refer to the will of God Almighty, who has called Matter and all its proper ties into being; he utterly refuses to recognise the validity of the proposition itself, and denies that it follows consistently from the preceding upon which Herschel wishes to found it. My opinion is, that it undoubtedly would logically follow from that (because the contents of a conception are determined by its origin), but that the antecedent itself is false. It asserts namely, that the origin of the conception of causality is experience, more especially such experience as we ourselves make in acting by means of our

1 Even Copernicus had said the same thing long before: "Equidem existimo Gravitatem non aliud esse quam appetentiam quandam naturalem, partibus inditam a divina providentia opificis universorum, ut in unitatem integritatemque suam se conferant, in formam Globi coeuntes. Quam affectionem credibile est etiam Soli, Lunae caeterisque errantium fulgoribus, inesse, ut ejus efficacia, in ea qua se repraesentant rotunditate permaneant; quae nihilominus multis modis suos efficiunt circuitus" [I believe that gravity is nothing but a natural craving instilled in all parts by the divine providence of the creator of all things so that they attain their unity and perfection by entering into the spherical form. This tendency seems to be inherent even in the sun, moon, and other planets, and by virtue of it they continue in that roundness in which they manifest themselves, despite the fact that they carry out their revolutions and rotations in many different ways.] ("Nicol. Copernici, De revolutionibus orbium coelestium, Lib. I, Cap. IX. Compare Exposition des Découvertes de M. le Chevalier Newton par M. Maclaurin; traduit de l'Anglois par M. Lavirotte, Paris, 1749, p. 45). Herschel evidently saw, that if we hesitate to explain gravity, as Descartes did, by an impulse from outside, we are absolutely driven to admit a will inherent in bodies. Non datur tertium [There is no third possibility]. [Add. to 3rd ed.]

2 Which he has more at heart than all the wisdom and truth in the world. [Add. to 3rd ed.]


own efforts upon bodies belonging to the outer world. It is only in countries like England, where the light of Kantian philosophy has not yet begun to dawn, that the Concept of causality can be thought of as originating in experience (professors of philosophy, who pooh-pooh Kant's doctrines and think me beneath their notice, being left out of the question); least of all can it be thought of by those who are acquainted with my proof of the a priority of that conception, which differs completely from Kant's proof and rests upon the fact, that knowledge of causality must necessarily precede all perception of the outer world itself as its condition; since perception is only brought about through the transition effected by the understanding from the sensation in the organ of sense to its cause, which cause now presents itself as an object in Space, itself like wise an a priori intuition. Now, as the perception of objects must be anterior to our conscious action upon them, the experience of that conscious action cannot be the origin of the conception of causality; for, before I can act upon things, they must first have acted upon me as motives. I have entered fully into all that has to do with this in my chief work, 1 and in the second edition of my treatise on the Principle of Sufficient Reason, § 21, 2 where the assumption adopted by Herschel finds special refutation; it is therefore useless to enter into it once more here. But it would be even quite possible to refute this assumption empirically, since it would necessarily follow from it, that a man who came into the world without arms or legs, could never attain any knowledge of causality or perception of the outer world. Now Nature has effectually disproved this by a case, of which I have reproduced the account from its original source in the above-mentioned chapter of my chief

1 See The World as Will and Representation. vol. ii. ch. 4, pp. 38-42 (3rd edition, pp. 41-46).

2 ibid., p. 74 (3rd edition, p. 79), p. 92 of the translation in the present volume.


work, p. 40. 1 In this assertion of Herschel's therefore, we have another instance of a right conclusion drawn from wrong premisses. Now this always happens when we have obtained immediate insight into a truth by a right aperçu [insight], but are at a loss to find out and clearly define our reasons for knowing it, owing to our inability to bring them to clear consciousness. For, in all original insight, conviction exists before proof: the proof being invariably excogitated afterwards.

The immediate manifestation of gravity is more evident in each part of liquid, than of solid, matter, owing to the perfect freedom of motion of the parts among each other. In order therefore to penetrate into this aperçu [insight], which is the true source of Herschel's assertion, let us look attentively at a torrent dashing headlong over rocks and ask ourselves whether so determined an impetus, so boisterous a vehemence, can arise without an exertion of strength, and whether an exertion of strength is conceivable without will. And so it is precisely in every case in which we become aware of anything moving spontaneously, of any primary, uncommunicated force: we are constrained to think its innermost essence as will. This much at any rate is certain, that Herschel, like all the empiricists in so many different branches of science whose evidence I have quoted above, had arrived here at the limit where nothing more is left behind the Physical but the Metaphysical; that this had brought him to a standstill, and that he, as well as the rest of them, was unable to find anything beyond that limit, but the will.

Herschel moreover, like most of these empiricists, is here still hampered by the opinion that will is inseparable from conciousness. As I have expatiated enough above upon this fallacy, and its correction through my doctrine, it is needless for me to enter into it here again.

1 3rd edition, p. 44,


The attempt has repeatedly been made, since the beginning of this century, to ascribe vitality to the inorganic world. Quite wrongly: for living and organic are convertible conceptions, and with death the organic ceases to be organic. But no limit in the whole of Nature is so sharply drawn as the line which separates the organic from the inorganic: that is to say, the line between the region in which Form is the essential and permanent, Matter the accidental and changing, and the region in which this relation is entirely reversed. This is no vacillating boundary like that perhaps between animals and plants, between solid and liquid, between gas and steam: to endeavour to destroy it therefore, is intentionally to bring confusion into our ideas. On the other hand, I am the first who has asserted that a will must be attributed to all that is lifeless and inorganic. For, with me, the will is not, as has hitherto been assumed, an accident of cognition and therefore of life; but life itself is manifestation of will. Knowledge, on the contrary, is really an accident of life, and life of Matter. But Matter itself is only the perceptibility of the phenomena of the will. Therefore we are compelled to recognise volition in every effort or tendency which proceeds from the nature of a material body, and properly speaking constitutes that nature, or manifests itself as phenomenon by means of that nature; and there can consequently be no Matter without manifestation of will. The lowest and on that account most universal manifestation of will is gravity, wherefore it has been called a primary and essential property of Matter.

The usual view of Nature assumes two fundamentally different principles of motion, therefore it supposes that the movement of a body may have two different origins: i.e., that it proceeds either from the inside, in which case it is attributed to the will; or from the outside, and then it is occasioned by causes. This principle is generally


taken for granted as a matter of course and only occasionally brought explicitly into prominence; nevertheless, in order to make the case quite certain, I will point out a few passages from the earliest to the latest authors in which it is specially stated. In Phaedrus, 1 Plato makes the distinction between that which moves spontaneously from inside (soul) and that which receives movement only from outside (body), τσ υφ εαυτσυ κινουμενον και το, ω εξωδεν το κινεισδαι. 2 Aristotle establishes the principle in precisely the same way: απαν το φερομενον η υφ εαυτου κινειται, υπ αλου (quidquid fertur a se movetur, aut ab alio). 3 He returns to the subject in the next Book, chap. 4 and 5, and connects it with some explanatory details which lead him into considerable perplexity, on account precisely of the fallacy of the antithesis. 4 In more recent times again J. J. Rousseau brings forward the same antithesis with great naiveté and candour in his famous Profession de foi du vicaire Savoyard: 5 "J'aperçois dans les corps deux sortes de mouvement, savoir: mouvement communiqué et mouvement spontané ou volontaire: dans le premier la cause motrice est étrangère au corps mû; et dans le second elle est en lui-même" [I observe in bodies two kinds of motion, namely, communicated or spontaneous or voluntary motion. In the first case the motive cause is foreign to the body moved; in the second it is inherent in the body itself]. But even in our time and in the stilted, puffed-up style which is peculiar to it, Burdach holds forth as follows 6 "The cause that determines a movement lies either inside or outside of that which

1 Plato, Phaedrus, p. 319 Biponti edition

2 "That which is moved by itself and that which is moved from outside." [Tr.] And we find the same distinction again in the 10th Book De Legibus, p. 85. [After him Cicero repeats it in the two last chapters of his Somnium Scipionis. Add. to 3rd ed.]

3 " All that is moved, is moved either by itself or by something else." [Tr.] Aristotle, Physics, vii. 2.

4 Maclaurin, too, in his Account of Newton's Discoveries, p. 102, lays down this principle as his starting-point. [Add. to 3rd ed.]

5 Émile, iv. p. 27. Biponti edition.

6 Burdach, Physiologie, vol. iv. p. 323.


moves. Matter is external existence; it has powers of motion, but it only brings them into play under certain spacial conditions and external oppositions: the soul alone is an ever active and internal thing, and only those bodies which have souls find within themselves inducement to move, and move of their own free will, independently of outer mechanical circumstances."

Now here however I must say, as [Peter] Abelard once did: si omnes patres sic, at ego non sic [Although the church fathers say so, I do not say so]: for, in opposition to this principle, however great may be its antiquity and universality, my doctrine maintains, that there are not two origins of movement differing fundamentally from one another; that movement does not proceed either from inside, when it is ascribed to the will, or from outside, when it is brought about by causes; but that both things are inseparable and take place simultaneously with every movement made by a body. For movement which is admitted to arise from the will, always presupposes a cause also: this cause, in beings that have knowledge, is a motive; but without it, even in these beings, movement is impossible. On the other hand, the movement of a body which is admitted to have been brought about by an outward cause, is nevertheless in itself a manifestation of the will of that body which has only been evoked by that cause. Accordingly there is only one, uniform, universal and exceptionless principle of all movement, whose inner condition is will and whose outer occasion is cause, which latter may also take the form of a stimulus or of a motive, according to the nature of the thing moved.

All that is known to us of things in a merely empirical or a posteriori way, is in itself will; whereas, so far as they can be determined a priori, things belong exclusively to representation, to mere phenomenon. Natural phenomena therefore become proportionately less easy to comprehend, the more distinctly the will manifests itself


in them, i.e. the higher they stand on the scale of beings; whereas, they become more and more comprehensible the smaller the amount of their empirical content, be cause they remain more and more within the sphere of mere representation, the forms of which, known to us a priori, are the principle of comprehensibility. Accordingly, it is only so long as we limit ourselves to this sphere that is to say, only when we have before us mere representation, mere form without empirical content, that our comprehension is complete and thorough: that is, in the a priori sciences, Arithmetic, Geometry, Phoronomy [geometric science of motion] and Logic. Here everything is in the highest degree comprehensible; our insight is quite clear and satisfactory: it leaves nothing to be desired, since we are even unable to conceive that anything could be otherwise than it is. This comes from our having here exclusively to do with the forms of our own intellect. Thus the more we are able to comprehend in a relation, the more it consists of mere phenomenon and the less it has to do with the thing–in–itself. Applied Mathematics, Mechanics, Hydraulics, &c. &c., deal with the lowest degrees of objectification of the will, in which the largest part still remains within the sphere of mere representation; nevertheless even here there is already an empirical element which stands in the way of entire comprehension, which makes the transparency less complete, and in which the inexplicable shows itself. For the same reason, only few departments of Physics and of Chemistry continue to admit of a mathematical treatment; whereas higher up in the scale of beings this has to be entirely done away with, precisely because of the preponderance of content over form in these phenomena. This content is will, the a posteriori, the thing–in–itself, the free, the causeless. Under the heading "Physiology of Plants," I have shown how in beings that live and have knowledge, motive and act of will, representation and volition, separate


and detach themselves more and more distinctly one from the other, the higher we ascend in the scale of beings. Now, in inorganic Nature also, the cause separates itself from the effect in just the same proportion, and the purely empirical which is precisely phenomenon of the will detaches itself more and more prominently; but, just with this, comprehensibility diminishes. This point merits fuller investigation, and I request my readers to give their whole and undivided attention to what I am about to say, as it is calculated to place the leading thought of my doctrine in the strongest possible light, both as to comprehensibility and cogency. But this is all I can do; for it is beyond my power to induce my contemporaries to prefer thoughts to verbiage; I can only console myself for not being the man of the age.

On the lowest step of the scale of Nature, cause and effect are quite homogeneous and quite equivalent. Here therefore we have perfect comprehension of the causal connection: for instance, the cause of the movement of one ball propelled by impact, is the movement of another, which loses just as much movement as the first one receives. Here causality is in the highest degree intelligible. What, notwithstanding, still remains mysterious, is restricted to the possibility of the passage of movement of a thing incorporeal from one body to another. The receptivity of bodies in this mode is so slight, that the effect to be produced has to pass over completely from its cause. The same holds good of all purely mechanical influences; and if they are not all just as instantaneously understood, it is either because they are hidden from us by accessory circumstances, or because we are confused by the complicated connection of many causes and effects. In itself, mechanical causality is everywhere equally, that is, in the highest degree, comprehensible; because cause and effect do not differ here as to quality, and because where


they differ as to quantity, as in the lever, mere Space and Time relations suffice to make the thing clear. But as soon as weights come also into play, a second mysterious element supervenes, gravity: and, where elastic bodies are concerned, elasticity also. Things change as soon as we begin to ascend in the scale of phenomena. Heat, considered as cause, and expansion, liquefaction, volatilization or crystallization, as effects, are not homogeneous; therefore their causal connection is not intelligible. The comprehensibility of causality has diminished: what a lower degree of heat caused to liquefy, a higher degree makes evaporate: that which crystallizes with less heat, melts when the heat is augmented. Warmth softens wax and hardens clay; light whitens wax and blackens chloride of silver. And, to go still further, when two salts are seen to decompose each other mutually and to form two new ones, elective affinity presents itself to us as an impenetrable mystery, and the properties of the two new bodies are not a combination of the properties of their separate elements. Nevertheless we are still able to follow the process and to indicate the elements out of which the new bodies are formed; we can even separate what has been united and restore the original quantities. Thus noticeable heterogeneousness and incommensurability between cause and effect have here made their appearance: causality has become more mysterious. And this becomes still more apparent when we compare the effects of electricity or of the Voltaic pile with their causes, i.e. with the friction of glass, or the piling and oxidation of the plates. Here all similarity between cause and effect at once vanishes; causality becomes shrouded in a thick veil, which men like Davy, Faraday and Ampère have strenuously endeavoured to lift. The only thing now discernible through that veil, are the laws ruling its mode of action, which may be brought into a schema such as +E and —E, communication


distribution, shock, ignition, analysis, charging, isolation, discharging, electric current, &c. &c., to this schema we are able to reduce and even to direct the effect; but of the process itself we know nothing: that remains an x. Here therefore cause and effect are completely heterogeneous, their connection is unintelligible, and we see bodies show great susceptibity to causal influences, the nature of which remains a secret for us. Moreover in proportion as we mount higher in the scale, the effect seems to contain more, the cause less. When we reach organic Nature therefore, in which the phenomenon of life presents itself, this is the case in a far higher degree still. If, as is done in China, we fill a pit with decaying wood, cover it with leaves from the same tree as the wood, and pour a solution of sulphur repeatedly over it, an abundant crop of edible mushrooms will spring up. A world of rapidly moving infusoria will arise from a little hay well watered. What a difference lies here between effect and cause! How much more does the former seem to contain than the latter! When we compare the seed, sometimes centuries, nay even thousands of years old, with the tree, or the soil with the specifically and strikingly different juices of innumerable plants, some healthy, some poisonous, some again nutritious, which spring from the same earth, upon which the same sun shines and the same rain falls, all resemblance ceases, and with it all comprehensibility for us. For here causality already appears in increased potency: that is, as stimulus and as susceptibility for stimulus. The schema of cause and effect alone has remained; we know that this is cause, that effect; but we know nothing whatever of the nature and disposition of causality. Between cause and effect there is not only no qualitative resemblance, but no quantitative relation: the relatively greater importance of the effect as compared with its cause increases more and more; the effect of the


stimulus too does not augment in proportion with the enhancement of that stimulus; in fact just the contrary often takes place. Finally, when we come to the sphere of beings which have knowledge, there is no longer any sort of resemblance or relation between the action performed and the object which, as representation, evokes it. Animals, however, as they are restricted to perceptible representations, still need the presence of the object acting as a motive, which action is then immediate and infallible (if we leave training, i.e. habit enforced by fear, out of the question). For animals are unable to carry about with them conceptions that might render them independent of present impressions, enable them to reflect, and qualify them for deliberate action. Man can do this. Therefore when at last we come to rational beings, the motive is even no longer a present, perceptible, actually existing, real thing, but a mere concept having its present existence only in the brain of the person who acts, but which is extracted from many multifarious perceptions, from the experience of former years, or has been handed down in words. Here the separation between cause and effect is so wide, the effect has grown so much stronger as compared with the cause, that the vulgar mind no longer perceives the existence of a cause at all, and the acts of the will appear to it to be unconditioned, causeless: that is to say, free. This is just why, when we reflect upon them from outside, the movements of our own body present themselves as if they took place without cause, or to speak more properly, by a miracle. Experience and reflection alone teach us that these movements, like all others, are only possible as the effects of causes, here called motives, and that, on this ascending scale, it is only as to material reality that the cause has failed to keep pace with the effect; whereas it has kept pace with it as to dynamical reality, energy. At this degree of the scale therefore the highest in Nature


causality has become less intelligible to us than ever. Nothing but the bare schema, taken in a quite general sense, now remains, and the ripest reflection is needed to recognise its applicability and the necessity that schema brings with it everywhere.

In the Grotto of Posilippo, darkness continues to augment as we advance towards the interior; but when once we have passed the middle, day-light again appears at the other end and shows us the way; so also in this case: just at the point where the outwardly directed light of the understanding with its form of causality, gradually yielding to increasing darkness, had been reduced to a feeble, flickering glimmer, behold! we are met by a totally different light proceeding from quite another quarter, from our own inner self, through the chance circumstance, that we, the judges, happen here to be the very objects that are to be judged. The growing difficulty of the comprehension of the causal nexus, at first so clear, had now become so great for perception and for the understanding the agent in it that, in animal actions, the very existence of that nexus seemed almost doubtful and those actions appeared to be a sort of miracle. But, just at this point, the observer receives from his own inner self the direct information that the agent in them is the will that very will, which he knows better and more intimately than any thing that external perception can ever supply. This knowledge alone must be the philosopher's key to an insight into the heart of all those processes in unconscious Nature, concerning which causal explanation although, here, to be sure, more satisfactory than in the processes last considered, and the clearer, the farther those processes were removed from these nevertheless had still left an unknown x, and could never quite illumine the inside of the process, even in a body propelled by impact or attracted by gravity. This x had continued expanding till


finally, on the highest degrees of the scale, it had wholly repelled causal explanation. But then, just when the power of causal explanation had been reduced to a minimum, that x revealed itself as the will reminding us of Mephistopheles when, yielding to Faust's learned exorcisms, he steps forth out of the huge grown poodle whose kernel he was [Faust I, line 1323]. In consequence of the considerations I have here set forth at length, we can surely hardly avoid recognising the identity of this x, even on the lowest degrees of the scale, where it was but faintly perceptible; then higher up, where it extended its obscurity more and more; and finally on the highest degrees, where it cast a shadow upon all things till, at the very top, it reveals itself to our consciousness in our own phenomenal being, as the will. The two primarily different sources of our knowledge, that is to say the inward and the outward source, have to be connected together at this point by reflection. It is quite exclusively out of this connection that our comprehension of Nature, and of our own selves arises; but then the inner side of Nature is disclosed to our intellect, which by itself alone can never reach further than to the mere outside; and the mystery which philosophy has so long tried to solve, lies open before us. For then indeed we clearly see what the Real and the Ideal (the thing–in– itself and the phenomenon) properly are; and this settles the principal question which has engaged the attention of philosophers since Descartes: that is to say, the question as to the relation between these two, whose complete diversity Kant had shown most thoroughly and with unexampled depth, yet whose absolute identity was immediately afterwards proclaimed by humbugs on the credit of intellectual intuition. But if we decline to avail ourselves of this insight, which is really the one strait gate to truth, we can never acquire comprehension of the intrinsic essence of Nature, to which absolutely no other road leads;


for then indeed we fall into an irremovable error. Then, as I have already said, we maintain the view, that motion has two radically different primary principles with a solid partition-wall between them: i.e. movement by means of causes, and movement by means of the will. The first of these must then remain for ever incomprehensible as to its innermost essence, because, after all its explanations, there is still left that unknown x which contains the more, the higher the object under consideration stands in the scale of beings; while the second, movement by the will, presents itself as entirely disconnected from the principle of causality; as without reason; as freedom in individual actions: in other words, as completely opposed to Nature and utterly unexplainable. On the other hand, if the above-mentioned union of our external and internal knowledge has once been accomplished at the point where both meet, we then recognise two identities in spite of all accidental differences. That is to say, we recognise the identity of causality with itself on every degree of the scale of beings, and the identity of the x, which at first was unknown (i.e. of physical forces and vital phenomena), with the will which is within us. We recognise, I say, firstly the essential identity of causality under the various forms it is forced to assume on the different degrees of the scale, as it may manifest itself, now as a mechanical, chemical, or physical cause, now as a stimulus, and again as a perceptible or an abstract motive: we know it to be one and the same, not only when a propelling body loses as much movement as it imparts by impact, but also when in the combats of thought against thought, the victorious one, as the more powerful motive, sets Man in motion, a motion which follows with no less necessity than that of the ball which is struck. Where we ourselves are the things set in motion, where therefore the kernel of the process is well and intimately known to us,


instead of allowing ourselves to be dazzled and confused by this light and thereby losing sight of the causal connection as it lies before us everywhere else in the whole of Nature; instead of shutting out this insight for ever, we now apply the new knowledge we have acquired from within as a key to the knowledge of things outside us, and then we recognise the second identity, that of our will with the hitherto mysterious x that remains over after all causal explanation as an insoluble residue. Consequently we then say: even in cases in which the effect is brought about by the most palpable cause, the mysterious x in the process, the real innermost core of it, the true agent, the in-itself of all phenomena which, after all, is only given us as representation and according to the forms and laws of representation is essentially one and the same with what is known to us immediately and intimately as the will in the actions of our own body, which body is likewise given us as intuition and representation. This is (say what you will) the basis of true philosophy, and if the present age does not see this, many following ages will. Tempo è galantuomo! (se nessun' altro) [Time is a man of honor! (even if no one else is)]. Thus, just as, on the one hand, the essence of causality, which appears most clearly only on the lowest degree of the objectification of the will, is recognised by us again at every ascending step, even at the highest; so also, on the other hand, is the essence of the will recognised by us at every descending step in that ladder, even at the lowest, although this knowledge is only immediately acquired at the very highest. The old error asserts, that where there is will, there is no causality; and that where there is causality, there is no will. But we say: everywhere where there is causality, there is will ; and no will acts without causality. The punctum controversiae [point of controversy] therefore, is, whether will and causality can and must subsist together in one and the same process at the same time.


What makes the knowledge, that this is indeed the case, so difficult, is the circumstance, that we know causality and will in two fundamentally different ways: causality entirely from outside, quite indirectly, quite through the under standing; will entirely from inside, quite directly; and that accordingly the clearer the knowledge of the one in each given instance, the less clear is the knowledge of the other. Therefore we recognise the essence of the will least readily, where causality is most intelligible; and, where the will is most unmistakably evident, causality becomes so obscured, that the vulgar mind could venture to deny its existence altogether. Now, as Kant has taught us, causality is nothing but the form of the understanding itself, knowable a priori: that is, the essence of representation, as such, which is one side of the world; the other side is will: which is the thing–in–itself. That relative increase and decrease of clearness in inverse proportion of causality and of the will, that mutual advancing and receding of both, depends consequently upon the fact, that the more a thing is given us as mere phenomenon, i.e. as representation, the more clearly does the a priori form of representation, i.e. causality, manifest itself: this is the case in inanimate Nature; conversely, the more immediate our knowledge of the will, the more does the form of representation recede into the background: this is the case with ourselves. That is : the nearer one side of the world approaches to us, the more do we lose sight of the other.