_Cogito, ergo sum_, is an a.n.a.lytical judgment. Indeed Parmenides held it to be an identical judgment: "t? ?a? a?t? ??e?? est? te ?a? e??a?" (_nam intelligere et esse idem est_, _Clem. Alex. Strom._, vi. 2, -- 23). As such, however, or indeed even as an a.n.a.lytical judgment, it cannot contain any special wisdom; nor yet if, to go still deeper, we seek to deduce it as a conclusion from the major premise, _non-entis nulla sunt praedicata_.
But with this proposition what Descartes really wished to express was the great truth that immediate certainty belongs only to self-consciousness, to what is subjective. To what is objective, on the other hand, thus to everything else, only indirect certainty belongs; for it is arrived at through self-consciousness; and being thus merely at second hand, it is to be regarded as problematical. Upon this depends the value of this celebrated proposition. As its opposite we may set up, in the sense of the Kantian philosophy, _cogito, ergo est_, that is, exactly as I think certain relations in things (the mathematical), they must always occur in all possible experience;-this was an important, profound, and a late _appercu_, which appeared in the form of the problem as to the _possibility of synthetic judgments a priori_, and has actually opened up the way to a deeper knowledge. This problem is the watchword of the Kantian philosophy, as the former proposition is that of the Cartesian, and shows e? ???? e?s ??a.
Kant very fitly places his investigations concerning time and s.p.a.ce at the head of all the rest. For to the speculative mind these questions present themselves before all others: what is time?-what is this that consists of mere movement, without anything that moves it?-and what is s.p.a.ce? this omnipresent nothing, out of which nothing that exists can escape without ceasing to be anything at all?
That time and s.p.a.ce depend on the subject, are the mode in which the process of objective apperception is brought about in the brain, has already a sufficient proof in the absolute impossibility of thinking away time and s.p.a.ce, while we can very easily think away everything that is presented in them. The hand can leave go of everything except itself.
However, I wish here to ill.u.s.trate by a few examples and deductions the more exact proofs of this truth which are given by Kant, not for the purpose of refuting stupid objections, but for the use of those who may have to expound Kant"s doctrine in future.
"A right-angled equilateral triangle" contains no logical contradiction; for the predicates do not by any means cancel the subject, nor are they inconsistent with each other. It is only when their object is constructed in pure perception that the impossibility of their union in it appears.
Now if on this account we were to regard this as a contradiction, then so would every physical impossibility, only discovered to be such after the lapse of centuries, be a contradiction; for example, the composition of a metal from its elements, or a mammal with more or fewer than seven cervical vertebra,(14) or horns and upper incisors in the same animal. But only _logical_ impossibility is a contradiction, not physical, and just as little mathematical. Equilateral and rectangled do not contradict each other (they coexist in the square), nor does either of them contradict a triangle. Therefore the incompatibility of the above conceptions can never be known by mere _thinking_, but is only discovered by perception-merely mental perception, however, which requires no experience, no real object.
We should also refer here to the proposition of Giordano Bruno, which is also found in Aristotle: "An infinitely large body is necessarily immovable"-a proposition which cannot rest either upon experience or upon the principle of contradiction, since it speaks of things which cannot occur in any experience, and the conceptions "infinitely large" and "movable" do not contradict each other; but it is only pure perception that informs us that motion demands a s.p.a.ce outside the body, while its infinite size leaves no s.p.a.ce over. Suppose, now, it should be objected to the first mathematical example that it is only a question of how complete a conception of a triangle the person judging has: if the conception is quite complete it will also contain the impossibility of a triangle being rectangular and also equilateral. The answer to this is: a.s.sume that his conception is not so complete, yet without recourse to experience he can, by the mere construction of the triangle in his imagination, extend his conception of it and convince himself for ever of the impossibility of this combination of these conceptions. This process, however, is a synthetic judgment _a priori_, that is, a judgment through which, independently of all experience, and yet with validity for all experience, we form and perfect our conceptions. For, in general, whether a given judgment is a.n.a.lytical or synthetical can only be determined in the particular case according as the conception of the subject in the mind of the person judging is more or less complete. The conception "cat" contains in the mind of a Cuvier a hundred times more than in that of his servant; therefore the same judgments about it will be synthetical for the latter, and only a.n.a.lytical for the former. But if we take the conceptions objectively, and now wish to decide whether a given judgment is a.n.a.lytical or synthetical, we must change the predicate into its contradictory opposite, and apply this to the subject without a copula. If this gives a _contradictio in adjecto_, then the judgment was a.n.a.lytical; otherwise it was synthetical.
That Arithmetic rests on the pure intuition or perception of time is not so evident as that Geometry is based upon that of s.p.a.ce.(15) It can be proved, however, in the following manner. All counting consists in the repeated affirmation of unity. Only for the purpose of always knowing how often we have already affirmed unity do we mark it each time with another word: these are the numerals. Now repet.i.tion is only possible through succession. But succession, that is, being after one another, depends directly upon the intuition or perception of _time_. It is a conception which can only be understood by means of this; and thus counting also is only possible by means of time. This dependence of all counting upon time is also betrayed by the fact that in all languages multiplication is expressed by "time," thus by a time-concept: _s.e.xies_, ??a???, _six fois_, _s.e.x mal_. But simple counting is already a multiplication by one, and for this reason in Pestalozzi"s educational establishment the children are always made to multiply thus: "Two times two is four times one." Aristotle already recognised the close relationship of number and time, and expounded it in the fourteenth chapter of the fourth book of the "Physics." Time is for him "the number of motion" ("? ?????? a????? est?
????se??"). He very profoundly suggests the question whether time could be if the soul were not, and answers it in the negative. If arithmetic had not this pure intuition or perception of time at its foundation, it would be no science _a priori_, and therefore its propositions would not have infallible certainty.
Although time, like s.p.a.ce, is the form of knowledge of the subject, yet, just like s.p.a.ce, it presents itself as independent of the subject and completely objective. Against our will, or without our knowledge, it goes fast or slow. We ask what o"clock it is; we investigate time, as if it were something quite objective. And what is this objective existence? Not the progress of the stars, or of the clocks, which merely serve to measure the course of time itself, but it is something different from all things, and yet, like them, independent of our will and knowledge. It exists only in the heads of percipient beings, but the uniformity of its course and its independence of the will give it the authority of objectivity.
Time is primarily the form of inner sense. Antic.i.p.ating the following book, I remark that the only object of inner sense is the individual will of the knowing subject. Time is therefore the form by means of which self-consciousness becomes possible for the individual will, which originally and in itself is without knowledge. In it the nature of the will, which in itself is simple and identical, appears drawn out into a course of life. But just on account of this original simplicity and ident.i.ty of what thus exhibits itself, its _character_ remains always precisely the same, and hence also the course of life itself retains throughout the same key-note, indeed its multifarious events and scenes are at bottom just like variations of one and the same theme.
The _a priori nature of the law of causality_ has, by Englishmen and Frenchmen, sometimes not been seen at all, sometimes not rightly conceived of; and therefore some of them still prosecute the earlier attempts to find for it an _empirical_ origin. Maine de Biran places this in the experience that the act of will as cause is followed by the movement of the body as effect. But this fact itself is untrue. We certainly do not recognise the really immediate act of will as something different from the action of the body, and the two as connected by the bond of causality; but both are one and indivisible. Between them there is no succession; they are simultaneous. They are one and the same thing, apprehended in a double manner. That which makes itself known to inner apprehension (self-consciousness) as the real _act of will_ exhibits itself at once in external perception, in which the body exists objectively as an _action_ of the body. That physiologically the action of the nerve precedes that of the muscle is here immaterial, for it does not come within self-consciousness; and we are not speaking here of the relation between muscle and nerve, but of that between the act of will and the action of the body. Now this does not present itself as a causal relation. If these two presented themselves to us as cause and effect their connection would not be so incomprehensible to us as it actually is; for what we understand from its cause we understand as far as there is an understanding of things generally. On the other hand, the movement of our limbs by means of mere acts of will is indeed a miracle of such common occurrence that we no longer observe it; but if we once turn our attention to it we become keenly conscious of the incomprehensibility of the matter, just because in this we have something before us which we do _not_ understand as the effect of a cause. This apprehension, then, could never lead us to the idea of causality, for that never appears in it at all. Maine de Biran himself recognises the perfect simultaneousness of the act of will and the movement (_Nouvelles Considerations des Rapports du Physique au Moral_, p.
377, 378). In England Thomas Reid (On the First Principles of Contingent Truths, Essay IV. c. 5) already a.s.serted that the knowledge of the causal relation has its ground in the nature of the faculty of knowledge itself.
Quite recently Thomas Brown, in his very tediously composed book, "Inquiry into the Relation of Cause and Effect," 4th edit., 1835, says much the same thing, that that knowledge springs from an innate, intuitive, and instinctive conviction; thus he is at bottom upon the right path. Quite unpardonable, however, is the cra.s.s ignorance on account of which in this book of 476 pages, of which 130 are devoted to the refutation of Hume, absolutely no mention is made of Kant, who cleared up the question more than seventy years ago. If Latin had remained the exclusive language of science such a thing would not have occurred. In spite of Brown"s exposition, which in the main is correct, a modification of the doctrine set up by Maine de Biran, of the empirical origin of the fundamental knowledge of the causal relation, has yet found acceptance in England; for it is not without a certain degree of plausibility. It is this, that we abstract the law of causality from the perceived effect of our own body upon other bodies. This was already refuted by Hume. I, however, have shown that it is untenable in my work, "_Ueber den Willen in der Natur_"
(p. 75 of the second edition, p. 82 of the third), from the fact that since we apprehend both our own and other bodies objectively in spatial perception, the knowledge of causality must already be there, because it is a condition of such perception. The one genuine proof that we are conscious of the law of causality _before all experience_ lies in the necessity of making a _transition_ from the sensation, which is only empirically given, to its _cause_, in order that it may become perception of the external world. Therefore I have subst.i.tuted this proof for the Kantian, the incorrectness of which I have shown. A most full and thorough exposition of the whole of this important subject, which is only touched on here, the _a priori_ nature of the law of causality and the intellectual nature of empirical perception, will be found in my essay on the principle of sufficient reason, -- 21, to which I refer, in order to avoid the necessity of repeating here what is said there. I have also shown there the enormous difference between the mere sensation of the senses and the perception of an objective world, and discovered the wide gulf that lies between the two. The law of causality alone can bridge across this gulf, and it presupposes for its application the two other forms which are related to it, s.p.a.ce and time. Only by means of these three combined is the objective idea attained to. Now whether the sensation from which we start to arrive at apprehension arises through the resistance which is suffered by our muscular exertion, or through the impression of light upon the retina, or of sound upon the nerves of the brain, &c. &c., is really a matter of indifference. The _sensation_ always remains a mere _datum_ for the _understanding_, which alone is capable of apprehending it as the effect of a cause different from itself, which the understanding now perceives as external, _i.e._, as something occupying and filling s.p.a.ce, which is also a form inherent in the intellect prior to all experience. Without this intellectual operation, for which the forms must lie ready in us, the perception of an _objective, external world_ could never arise from a mere _sensation_ within our skin. How can it ever be supposed that the mere feeling of being hindered in intended motion, which occurs also in lameness, could be sufficient for this? We may add to this that before I attempt to affect external things _they_ must necessarily have affected me as motives. But this almost presupposes the apprehension of the external world. According to the theory in question (as I have remarked in the place referred to above), a man born without arms and legs could never attain to the idea of causality, and consequently could never arrive at the apprehension of the external world.
But that this is not the case is proved by a fact communicated in Froriep"s _Notizen_, July 1838, No. 133-the detailed account, accompanied by a likeness, of an Esthonian girl, Eva Lauk, then fourteen years old, who was born entirely without arms or legs. The account concludes with these words: "According to the evidence of her mother, her mental development had been quite as quick as that of her brothers and sisters; she attained just as soon as they did to a correct judgment of size and distance, yet without the a.s.sistance of hands.-Dorpat, 1st March 1838, Dr.
A. Hueck."
Hume"s doctrine also, that the conception of causality arises from the custom of seeing two states constantly following each other, finds a practical refutation in the oldest of all successions, that of day and night, which no one has ever held to be cause and effect of each other.
And the same succession also refutes Kant"s false a.s.sertion that the _objective_ reality of a succession is only known when we apprehend the two succeeding events as standing in the relation of cause and effect to each other. Indeed the converse of this doctrine of Kant"s is true. We know which of the two connected events is the cause and which the effect, _empirically_, only in the succession. Again, on the other hand, the absurd a.s.sertion of several professors of philosophy in our own day that cause and effect are simultaneous can be refuted by the fact that in cases in which the succession cannot be perceived on account of its great rapidity, we yet a.s.sume it with certainty _a priori_, and with it the lapse of a certain time. Thus, for example, we know that a certain time must elapse between the falling of the flint and the projection of the bullet, although we cannot perceive it, and that this time must further be divided between several events that occur in a strictly determined succession-the falling of the flint, the striking of the spark, ignition, the spread of the fire, the explosion, and the projection of the bullet.
No man ever perceived this succession of events; but because we know which is the cause of the others, we thereby also know which must _precede the others in time_, and consequently also that during the course of the whole series a certain time must elapse, although it is so short that it escapes our empirical apprehension; for no one will a.s.sert that the projection of the bullet is actually simultaneous with the falling of the flint. Thus not only the law of causality, but also its relation to _time_, and the necessity of the _succession_ of cause and effect, is known to us _a priori_. If we know which of two events is the cause and which is the effect, we also know which precedes the other in time; if, on the contrary, we do not know which is cause and which effect, but only know in general that they are causally connected, we seek to discover the succession empirically, and according to that we determine which is the cause and which the effect. The falseness of the a.s.sertion that cause and effect are simultaneous further appears from the following consideration.
An unbroken chain of causes and effects fills the whole of time. (For if this chain were broken the world would stand still, or in order to set it in motion again an effect without a cause would have to appear.) Now if every effect were simultaneous with its cause, then every effect would be moved up into the time of its cause, and a chain of causes and effects containing as many links as before would fill no time at all, still less an infinite time, but would be all together in one moment. Thus, under the a.s.sumption that cause and effect are simultaneous, the course of the world shrinks up into an affair of a moment. This proof is a.n.a.logous to the proof that every sheet of paper must have a certain thickness, because otherwise the whole book would have none. To say _when_ the cause ceases and the effect begins is in almost all cases difficult, and often impossible. For the _changes_ (_i.e._, the succession of states) are continuous, like the time which they fill, and therefore also, like it, they are infinitely divisible. But their succession is as necessarily determined and as unmistakable as that of the moments of time itself, and each of them is called, with reference to the one which precedes it, "effect," and with reference to the one which follows it, "cause."
_Every change in the material world can only take place because another has immediately preceded it_: this is the true and the whole content of the law of causality. But no conception has been more misused in philosophy than that of _cause_, by means of the favourite trick or blunder of conceiving it too widely, taking it too generally, through abstract thinking. Since Scholasticism, indeed properly since Plato and Aristotle, philosophy has been for the most part a _systematic misuse of general conceptions_. Such, for example, are substance, ground, cause, the good, perfection, necessity, and very many others. A tendency of the mind to work with such abstract and too widely comprehended conceptions has shown itself almost at all times. It may ultimately rest upon a certain indolence of the intellect, which finds it too difficult a task to be constantly controlling thought by perception. By degrees such unduly wide conceptions come to be used almost like algebraical symbols, and tossed about like them, and thus philosophy is reduced to a mere process of combination, a kind of reckoning which (like all calculations) employs and demands only the lower faculties. Indeed there finally results from this a mere juggling with words, of which the most shocking example is afforded us by the mind-destroying Hegelism, in which it is carried to the extent of pure nonsense. But Scholasticism also often degenerated into word-juggling. Nay even the "Topi" of Aristotle-very abstract principles, conceived with absolute generality, which one could apply to the most different kinds of subjects, and always bring into the field in arguing either _pro_ or _contra_-have also their origin in this misuse of general conceptions. We find innumerable examples of the way the Schoolmen worked with such abstractions in their writings, especially in those of Thomas Aquinas. But philosophy really pursued the path which was entered on by the Schoolmen down to the time of Locke and Kant, who at last bethought themselves as to the origin of conceptions. Indeed we find Kant himself, in his earlier years, still upon that path, in his "Proof of the Existence of G.o.d" (p. 191 of the first volume of Rosenkranz"s edition), where the conceptions substance, ground, reality, are used in such a way as would never have been possible if he had gone back to the _source_ of these conceptions and to their _true content_ which is determined thereby. For then he would have found as the source and content of _substance_ simply matter, of ground (if things of the real world are in question) simply cause, that is, the prior change which brings about the later change, &c.
It is true that in this case such an investigation would not have led to the intended result. But everywhere, as here, such unduly wide conceptions, under which, therefore, more was subsumed than their true content would have justified, there have arisen false principles, and from these false systems. Spinoza"s whole method of demonstration rests upon such uninvestigated and too widely comprehended conceptions. Now here lies the great merit of Locke, who, in order to counteract all that dogmatic unreality, insisted upon the investigation of the _origin of the conceptions_, and thus led back to _perception and experience_. Bacon had worked in a similar frame of mind, yet more with reference to Physics than to Metaphysics. Kant followed the path entered upon by Locke, but in a higher sense and much further, as has already been mentioned above. To the men of mere show who succeeded in diverting the attention of the public from Kant to themselves the results obtained by Locke and Kant were inconvenient. But in such a case they know how to ignore both the dead and the living. Thus without hesitation they forsook the only right path which had at last been found by those wise men, and philosophised at random with all kinds of indiscriminately collected conceptions, unconcerned as to their origin and content, till at last the substance of the Hegelian philosophy, wise beyond measure, was that the conceptions had no origin at all, but were rather themselves the origin and source of things. But Kant has erred in this respect. He has too much neglected empirical perception for the sake of _pure_ perception-a point which I have fully discussed in my criticism of his philosophy. With me perception is throughout the source of all knowledge. I early recognised the misleading and insidious nature of abstractions, and in 1813, in my essay on the principle of sufficient reason, I pointed out the difference of the relations which are thought under _this_ conception. General conceptions must indeed be the material in which philosophy deposits and stores up its knowledge, but not the source from which it draws it; the _terminus ad quem_, not _a quo_. It is not, as Kant defines it, a science _drawn from_ conceptions, but a science _in_ conceptions. Thus the conception of causality also, with which we are here concerned, has always been taken far too widely by philosophers for the furtherance of their dogmatic ends, and much was imported into it which does not belong to it at all. Hence arose propositions such as the following: "All that is has its cause"-"the effect cannot contain more than the cause, thus nothing that was not also in the cause"-"_causa est n.o.bilior suo effectu_," and many others just as unwarranted. The following subtilty of that insipid gossip Proclus affords an elaborate and specially lucid example of this. It occurs in his "_Inst.i.tutio Theologica_," -- 76: "?a? t? ap? a????t?? ?????e??? a?t?a?, aeta??t?? e?e? t?? ?pa????; pa? de t? ap? ?????e???, eta??t??; e? ?a?
a????t?? est? pa?t? t? p?????, ?? d?a ????se??, a??? a?t? t? e??a? pa?a?e?
t? de?te??? af? ?a?t??." (_Quidquid ab immobili causa manat, immutabilem habet essentiam [substantiam]. Quidquid vero a mobili causa manat, essentiam habet mutabilem. Si enim illud, quod aliquid facit, est prorsus immobile, non per motum, sed per ipsum Esse producit ipsum secundum ex se ipso._) Excellent! But just show me a cause which is not itself set in motion: it is simply impossible. But here, as in so many cases, abstraction has thought away all determinations down to that one which it is desired to make use of without regard to the fact that the latter cannot exist without the former. The only correct expression of the law of causality is this: _Every change has its cause in another change which immediately precedes it_. If something _happens_, _i.e._, if a new state of things appears, _i.e._, if something is _changed_, then something else must have _changed_ immediately before, and something else again before this, and so on _ad infinitum_, for a _first_ cause is as impossible to conceive as a beginning of time or a limit of s.p.a.ce. More than this the law of causality does not a.s.sert. Thus its claims only arise in the case of _changes_. So long as nothing changes there can be no question of a cause. For there is no _a priori_ ground for inferring from the existence of given things, _i.e._, states of matter, their previous non-existence, and from this again their coming into being, that is to say, there is no _a priori_ ground for inferring a change. Therefore the mere existence of a thing does not justify us in inferring that it has a cause. Yet there may be _a posteriori_ reasons, that is, reasons drawn from previous experience, for the a.s.sumption that the present state or condition did not always exist, but has only come into existence in consequence of another state, and therefore by means of a change, the cause of which is then to be sought, and also the cause of this cause. Here then we are involved in the _infinite regressus_ to which the application of the law of causality always leads. We said above: "_Things_, _i.e._, _states or conditions of matter,_" for _change_ and _causality_ have only to do with states or conditions. It is these states which we understand by _form_, in the wider sense; and only the forms change, the matter is permanent. Thus it is only the form which is subject to the law of causality. But the form const.i.tutes the _thing_, _i.e._, it is the ground of _the difference_ of things; while matter must be thought as the same in all. Therefore the Schoolmen said, "_Forma dat esse rei;_" more accurately this proposition would run: _Forma dat rei essentiam, materia existentiam_. Therefore the question as to the cause of a _thing_ always concerns merely its form, _i.e._, its state or quality, and not its matter, and indeed only the former so far as we have grounds for a.s.suming that it has not _always_ existed, but has come into being by means of a _change_. The union of _form_ and _matter_, or of _essentia_ and _existentia_, gives the _concrete_, which is always particular; thus, the _thing_. And it is the _forms_ whose union with _matter_, _i.e._, whose appearance in matter by means of a _change_, are subject to the law of causality. By taking the conception _too widely_ in the abstract the mistake slipped in of extending causality to the thing absolutely, that is, to its whole inner nature and existence, thus also to matter, and ultimately it was thought justifiable to ask for a cause of the world itself. This is the origin of the _cosmological proof_. This proof begins by inferring from the existence of the world its non-existence, which preceded its existence, and such an inference is quite unjustifiable; it ends, however, with the most fearful inconsistency, for it does away altogether with the law of causality, from which alone it derives all its evidencing power, for it stops at a first cause, and will not go further; thus ends, as it were, by committing parricide, as the bees kill the drones after they have served their end. All the talk about the _absolute_ is referable to a shamefast, and therefore disguised cosmological proof, which, in the face of the "Critique of Pure Reason," has pa.s.sed for philosophy in Germany for the last sixty years. What does the absolute mean? Something that is, and of which (under pain of punishment) we dare not ask further whence and why it is. A precious rarity for professors of philosophy! In the case, however, of the honestly expressed cosmological proof, through the a.s.sumption of a first cause, and therefore of a first beginning in a time which has absolutely no beginning, this beginning is always pushed further back by the question: Why not earlier? And so far back indeed that one never gets down from it to the present, but is always marvelling that the present itself did not occur already millions of years ago. In general, then, the law of causality applies to all things in the world, but not to the world itself, for it is _immanent_ in the world, not _transcendent; with_ it it comes into action, and _with_ it it is abolished. This depends ultimately upon the fact that it belongs to the mere form of our understanding, like the whole of the objective world, which accordingly is merely phenomenal, and is conditioned by the understanding. Thus the law of causality has full application, without any exception, to all things in the world, of course in respect of their form, to the variation of these forms, and thus to their changes. It is valid for the actions of men as for the impact of a stone, yet, as we have said always, merely with regard to events, to _changes_. But if we abstract from its origin in the understanding and try to look at it as purely objective, it will be found in ultimate a.n.a.lysis to depend upon the fact that everything that acts does so by virtue of its original, and therefore eternal or timeless, power; therefore its present effect would necessarily have occurred infinitely earlier, that is, before all conceivable time, but that it lacked the temporal condition. This temporal condition is the occasion, _i.e._, the cause, on account of which alone the effect only takes place _now_, but now takes place necessarily; the cause a.s.signs it its place in time.
But in consequence of that unduly wide view in abstract thought of the conception _cause_, which was considered above, it has been confounded with the conception of _force_. This is something completely different from the cause, but yet is that which imparts to every cause its causality, _i.e._, the capability of producing an effect. I have explained this fully and thoroughly in the second book of the first volume, also in "The Will in Nature," and finally also in the second edition of the essay on the principle of sufficient reason, -- 20, p. 44 (third edition, p. 45).
This confusion is to be found in its most aggravated form in Maine de Biran"s book mentioned above, and this is dealt with more fully in the place last referred to; but apart from this it is also very common; for example, when people seek for the cause of any original force, such as gravitation. Kant himself (_uber den Einzig Moglichen Beweisgrund_, vol.
i. p. 211-215 of Rosenkranz"s edition) calls the forces of nature "efficient causes," and says "gravity is a cause." Yet it is impossible to see to the bottom of his thought so long as force and cause are not distinctly recognised as completely different. But the use of abstract conceptions leads very easily to their confusion if the consideration of their origin is set aside. The knowledge of causes and effects, always _perceptive_, which rests on the form of the understanding, is neglected in order to stick to the abstraction _cause_. In this way alone is the conception of causality, with all its simplicity, so very frequently wrongly apprehended. Therefore even in Aristotle ("Metaph.," iv. 2) we find causes divided into four cla.s.ses which are utterly falsely, and indeed crudely conceived. Compare with it my cla.s.sification of causes as set forth for the first time in my essay on sight and colour, chap. 1, and touched upon briefly in the sixth paragraph of the first volume of the present work, but expounded at full length in my prize essay on the freedom of the will, p. 30-33. Two things in nature remain untouched by that chain of causality which stretches into infinity in both directions; these are matter and the forces of nature. They are both conditions of causality, while everything else is conditioned by it. For the one (matter) is that _in_ which the states and their changes appear; the other (forces of nature) is that by virtue of which alone they can appear at all. Here, however, one must remember that in the second book, and later and more thoroughly in "The Will in Nature," the natural forces are shown to be identical with the will in us; but matter appears as the mere _visibility of the will_; so that ultimately it also may in a certain sense be regarded as identical with the will.
On the other hand, not less true and correct is what is explained in -- 4 of the first book, and still better in the second edition of the essay on the principle of sufficient reason at the end of -- 21, p. 77 (third edition, p. 82), that matter is causality itself objectively comprehended, for its entire nature consists in _acting in general_, so that it itself is thus the activity (e?e??e?a = reality) of things generally, as it were the abstraction of all their different kinds of acting. Accordingly, since the essence, _essentia_, of matter consists in _action in general_, and the reality, _existentia_, of things consists in their materiality, which thus again is one with action in general, it may be a.s.serted of matter that in it _existentia_ and _essentia_ unite and are one, for it has no other attribute than _existence itself_ in general and independent of all fuller definitions of it. On the other hand, all _empirically_ given matter, thus all material or matter in the special sense (which our ignorant materialists at the present day confound with matter), has already entered the framework of the _forms_ and manifests itself only through their qualities and accidents, because in experience every action is of quite a definite and special kind, and is never merely general.
Therefore pure matter is an object of _thought_ alone, not of _perception_, which led Plotinus (_Enneas II._, lib. iv., c. 8 & 9) and Giordano Bruno (_Della Causa_, dial. 4) to make the paradoxical a.s.sertion that matter has no extension, for extension is inseparable from the form, and that therefore it is _incorporeal_. Yet Aristotle had already taught that it is not a body although it is corporeal: "s?a e? ??? a? e??, s?at??? de" (_Stob. Ecl._, lib. i., c. 12, -- 5). In reality we think under _pure matter_ only action, in the abstract, quite independent of the _kind_ of action, thus _pure causality_ itself; and as such it is not an _object_ but a _condition_ of experience, just like s.p.a.ce and time. This is the reason why in the accompanying table of our pure _a priori_ knowledge matter is able to take the place of causality, and therefore appears along with s.p.a.ce and time as the third pure form, and therefore as dependent on our intellect.
This table contains all the fundamental truths which are rooted in our perceptive or intuitive knowledge _a priori_, expressed as first principles independent of each other. What is special, however, what forms the content of arithmetic and geometry, is not given here, nor yet what only results from the union and application of those formal principles of knowledge. This is the subject of the "Metaphysical First Principles of Natural Science" expounded by Kant, to which this table in some measure forms the propaedutic and introduction, and with which it therefore stands in direct connection. In this table I have primarily had in view the very remarkable _parallelism_ of those _a priori_ principles of knowledge which form the framework of all experience, but specially also the fact that, as I have explained in -- 4 of the first volume, matter (and also causality) is to be regarded as a combination, or if it is preferred, an amalgamation, of s.p.a.ce and time. In agreement with this, we find that what geometry is for the pure perception or intuition of s.p.a.ce, and arithmetic for that of time, Kant"s _phoronomy_ is for the pure perception or intuition of the two _united_. For matter is primarily that which is movable in s.p.a.ce. The mathematical point cannot even be conceived as movable, as Aristotle has shown ("Physics," vi. 10). This philosopher also himself provided the first example of such a science, for in the fifth and sixth books of his "Physics" he determined _a priori_ the laws of rest and motion.
Now this table may be regarded at pleasure either as a collection of the eternal laws of the world, and therefore as the basis of our ontology, or as a chapter of the physiology of the brain, according as one a.s.sumes the realistic or the idealistic point of view; but the second is in the last instance right. On this point, indeed, we have already come to an understanding in the first chapter; yet I wish further to ill.u.s.trate it specially by an example. Aristotle"s book "_De Xenophane_," &c., commences with these weighty words of Xenophanes: "??d??? e??a? f?s??, e? t? est??, e?pe? ? e?de?eta? ?e?es?a? ?de? e? ?de???." (_aeternum esse, inquit, quicquid est, siquidem fieri non potest, ut ex nihilo quippiam existat._) Here, then, Xenophanes judges as to the origin of things, as regards its possibility, and of this origin he can have had no experience, even by a.n.a.logy; nor indeed does he appeal to experience, but judges apodictically, and therefore _a priori_. How can he do this if as a stranger he looks from without into a world that exists purely objectively, that is, independently of his knowledge? How can he, an ephemeral being hurrying past, to whom only a hasty glance into such a world is permitted, judge apodictically, _a priori_ and without experience concerning that world, the possibility of its existence and origin? The solution of this riddle is that the man has only to do with his own ideas, which as such are the work of his brain, and the const.i.tution of which is merely the manner or mode in which alone the function of his brain can be fulfilled, _i.e._, the form of his perception. He thus judges only as to the _phenomena of his own brain_, and declares what enters into its forms, time, s.p.a.ce, and causality, and what does not. In this he is perfectly at home and speaks apodictically. In a like sense, then, the following table of the _Praedicabilia a priori_ of time, s.p.a.ce, and matter is to be taken:-
Praedicabilia _A Priori_.
Of Time. Of s.p.a.ce. Of Matter.
(1) There is only (1) There is only (1) There is only _one_ Time, and all _one_ s.p.a.ce, and all _one_ Matter, and different times are different s.p.a.ces are all different parts of it. parts of it. materials are different states of matter; as such it is called _Substance_.
(2) Different times (2) Different s.p.a.ces (2) Different are not simultaneous are not successive matters (materials) but successive. but simultaneous. are not so through substance but through accidents.
(3) Time cannot be (3) s.p.a.ce cannot be (3) Annihilation of thought away, but thought away, but matter is everything can be everything can be inconceivable, but thought away from thought away from annihilation of all it. it. its forms and qualities is conceivable.
(4) Time has three (4) s.p.a.ce has three (4) Matter exists, divisions, the past, dimensions-height, _i.e._, acts in all the present, and the breadth, and length. the dimensions of future, which s.p.a.ce and throughout const.i.tute two the whole length of directions and a time, and thus these centre of two are united and indifference. thereby filled. In this consists the true nature of matter; thus it is through and through causality.
(5) Time is (5) s.p.a.ce is (5) Matter is infinitely infinitely infinitely divisible. divisible. divisible.
(6) Time is (6) s.p.a.ce is (6) Matter is h.o.m.ogeneous and a h.o.m.ogeneous and a h.o.m.ogeneous and a _Continuum_, _i.e._, _Continuum_, _i.e._, _Continuum_, _i.e._, no one of its parts no one of its parts it does not consist is different from is different from of originally the rest, nor the rest, nor different separated from it by separated from it by (_h.o.m.oiomeria_) or anything that is not anything that is not originally separated time. s.p.a.ce. parts (atoms); it is therefore not composed of parts, which would necessarily be separated by something that was not matter.
(7) Time has no (7) s.p.a.ce has no (7) Matter has no beginning and no limits, but all origin and no end, end, but all limits are in it. but all coming into beginning and end is being and pa.s.sing in it. away are in it.
(8) By reason of (8) By reason of (8) By reason of time we count. s.p.a.ce we measure. matter we weigh.
(9) Rhythm is only (9) Symmetry is only (9) Equilibrium is in time. in s.p.a.ce. only in matter.
(10) We know the (10) We know the (10) We know the laws of time _a laws of s.p.a.ce _a laws of the priori_. priori_. substance of all accidents _a priori_.
(11) Time can be (11) s.p.a.ce is (11) Matter can only perceived _a immediately be thought _a priori_, although perceptible _a priori_.
only in the form of priori_.
a line.
(12) Time has no (12) s.p.a.ce can never (12) The accidents permanence, but pa.s.s away, but change; the pa.s.ses away as soon endures through all substance remains.
as it is there. time.
(13) Time never (13) s.p.a.ce is (13) Matter is rests. immovable. indifferent to rest and motion, _i.e._, it is originally disposed towards neither of the two.
(14) Everything that (14) Everything that (14) Everything exists in time has exists in s.p.a.ce has material has the duration. a position. capacity for action.
(15) Time has no (15) s.p.a.ce has no (15) Matter is what duration, but all motion, but all is permanent in time duration is in it, motion is in it, and and movable in and is the it is the change of s.p.a.ce; by the persistence of what position of what is comparison of what is permanent in moved, in contrast rests with what is contrast with its with its unbroken moved we measure restless course. rest. duration.
(16) All motion is (16) All motion is (16) All motion is only possible in only possible in only possible to time. s.p.a.ce. matter.
(17) Velocity is, in (17) Velocity is, in (17) The magnitude equal s.p.a.ces, in equal times, in of the motion, the inverse proportion direct proportion to velocity being to the time. the s.p.a.ce. equal, is in direct geometrical proportion to the matter (ma.s.s).
(18) Time is not (18) s.p.a.ce is (18) Matter as such measurable directly measurable directly (ma.s.s) is through itself, but through itself, and measurable, _i.e._, only indirectly indirectly through determinable as through motion, motion, which is in regards its quant.i.ty which is in s.p.a.ce time and s.p.a.ce only indirectly, and time together: together; hence, for only through the thus the motion of example, an hour"s amount of the motion the sun and of the journey, and the which it receives clock measure time. distance of the and imparts when it fixed stars is repelled or expressed as the attracted.
travelling of light for so many years.
(19) Time is (19) s.p.a.ce is (19) Matter is omnipresent. Every eternal. Every part absolute. That is, part of time is of it exists always. it neither comes everywhere, _i.e._, into being nor in all s.p.a.ce, at pa.s.ses away, and once. thus its quant.i.ty can neither be increased nor diminished.
(20) In time taken (20) In s.p.a.ce taken (20, 21) Matter by itself everything by itself everything unites the ceaseless would be in would be flight of time with succession. simultaneous. the rigid immobility of s.p.a.ce; therefore it is the permanent substance of the changing accidents.
Causality determines this change for every place at every time, and thereby combines time and s.p.a.ce, and const.i.tutes the whole nature of matter.
(21) Time makes the (21) s.p.a.ce makes the change of accidents permanence of possible. substance possible.
(22) Every part of (22) No part of (22) For matter is time contains all s.p.a.ce contains the both permanent and parts of matter. same matter as impenetrable.
another.
(23) Time is the (23) s.p.a.ce is the (23) Individuals are _principium _principium material.
individuationis_. individuationis_.
(24) The now has no (24) The point has (24) The atom has no duration. no extension. reality.
(25) Time in itself (25) s.p.a.ce in itself (25) Matter in is empty and without is empty and without itself is without properties. properties. form and quality, and likewise inert, _i.e._, indifferent to rest or motion, thus without properties.
(26) Every moment is (26) By the position (26) Every change in conditioned by the of every limit in matter can take preceding moment, s.p.a.ce with reference place only on and is only because to any other limit, account of another the latter has its position with change which ceased to be. reference to every preceded it; and (Principle of possible limit is therefore a first sufficient reason of precisely change, and thus existence in determined. also a first state time.-See my essay (Principle of of matter, is just on the principle of sufficient reason of as inconceivable as sufficient reason.) existence in s.p.a.ce.) a beginning of time or a limit of s.p.a.ce.
(Principle of sufficient reason of becoming.) (27) Time makes (27) s.p.a.ce makes (27) Matter, as that arithmetic possible. geometry possible. which is movable in s.p.a.ce, makes phoronomy possible.
(28) The simple (28) The simple (28) The simple element in element in geometry element in phoronomy arithmetic is unity. is the point. is the atom.
Notes to the Annexed Table.
(1) To No. 4 of Matter.
The essence of matter is acting, it is acting itself, in the abstract, thus acting in general apart from all difference of the kind of action: it is through and through causality. On this account it is itself, as regards its existence, not subject to the law of causality, and thus has neither come into being nor pa.s.ses away, for otherwise the law of causality would be applied to itself. Since now causality is known to us _a priori_, the conception of matter, as the indestructible basis of all that exists, can so far take its place in the knowledge we possess _a priori_, inasmuch as it is only the realisation of an _a priori_ form of our knowledge. For as soon as we see anything that acts or is causally efficient it presents itself _eo ipso_ as material, and conversely anything material presents itself as necessarily active or causally efficient. They are in fact interchangeable conceptions. Therefore the word "actual" is used as synonymous with "material;" and also the Greek ?at? e?e??e?a?, in opposition to ?ata d??a??, reveals the same source, for e?e??e?a signifies action in general; so also with _actu_ in opposition to _potentia_, and the English "actually" for "_wirklich_." What is called s.p.a.ce-occupation, or impenetrability, and regarded as the essential predicate of body (_i.e._ of what is material), is merely that _kind of action_ which belongs to _all_ bodies without exception, the mechanical.
It is this universality alone, by virtue of which it belongs to the conception of body, and follows _a priori_ from this conception, and therefore cannot be thought away from it without doing away with the conception itself-it is this, I say, that distinguishes it from any other kind of action, such as that of electricity or chemistry, or light or heat. Kant has very accurately a.n.a.lysed this s.p.a.ce-occupation of the mechanical mode of activity into repulsive and attractive force, just as a given mechanical force is a.n.a.lysed into two others by means of the parallelogram of forces. But this is really only the thoughtful a.n.a.lysis of the phenomenon into its two const.i.tuent parts. The two forces in conjunction exhibit the body within its own limits, that is, in a definite volume, while the one alone would diffuse it into infinity, and the other alone would contract it to a point. Notwithstanding this reciprocal balancing or neutralisation, the body still acts upon other bodies which contest its s.p.a.ce with the first force, repelling them, and with the other force, in gravitation, attracting all bodies in general. So that the two forces are not extinguished in their product, as, for instance, two equal forces acting in different directions, or +E and -E, or oxygen and hydrogen in water. That impenetrability and gravity really exactly coincide is shown by their empirical inseparableness, in that the one never appears without the other, although we can separate them in thought.
I must not, however, omit to mention that the doctrine of Kant referred to, which forms the fundamental thought of the second part of his "Metaphysical First Principles of Natural Science," thus of the Dynamics, was distinctly and fully expounded before Kant by Priestley, in his excellent "Disquisitions on Matter and Spirit," -- 1 and 2, a book which appeared in 1777, and the second edition in 1782, while Kant"s work was published in 1786. Unconscious recollection may certainly be a.s.sumed in the case of subsidiary thoughts, flashes of wit, comparisons, &c., but not in the case of the princ.i.p.al and fundamental thought. Shall we then believe that Kant silently appropriated such important thoughts of another man? and this from a book which at that time was new? Or that this book was unknown to him, and that the same thoughts sprang up in two minds within a short time? The explanation, also, which Kant gives, in the "Metaphysical First Principles of Natural Science" (first edition, p. 88; Rosenkranz"s edition, p. 384), of the real difference between fluids and solids, is in substance already to be found in Kaspar Freidr. Wolff"s "Theory of Generation," Berlin 1764, p. 132. But what are we to say if we find Kant"s most important and brilliant doctrine, that of the ideality of s.p.a.ce and the merely phenomenal existence of the corporeal world, already expressed by Maupertuis thirty years earlier? This will be found more fully referred to in Frauenstadt"s letters on my philosophy, Letter 14.
Maupertuis expresses this paradoxical doctrine so decidedly, and yet without adducing any proof of it, that one must suppose that he also took it from somewhere else. It is very desirable that the matter should be further investigated, and as this would demand tiresome and extensive researches, some German Academy might very well make the question the subject of a prize essay. Now in the same relation as that in which Kant here stands to Priestley, and perhaps also to Kaspar Wolff, and Maupertuis or his predecessor, Laplace stands to Kant. For the princ.i.p.al and fundamental thought of Laplace"s admirable and certainly correct theory of the origin of the planetary system, which is set forth in his "_Exposition du Systeme du Monde_," liv. v. c. 2, was expressed by Kant nearly fifty years before, in 1755, in his "_Naturgeschichte und Theorie des Himmels_,"
and more fully in 1763 in his "_Einzig moglichen Beweisgrund des Daseyns Gottes_," ch. 7. Moreover, in the later work he gives us to understand that Lambert in his "_Kosmologischen Briefen_," 1761, tacitly adopted that doctrine from him, and these letters at the same time also appeared in French (_Lettres Cosmologiques sur la Const.i.tution de l"Univers_). We are therefore obliged to a.s.sume that Laplace knew that Kantian doctrine.
Certainly he expounds the matter more thoroughly, strikingly, and fully, and at the same time more simply than Kant, as is natural from his more profound astronomical knowledge; yet in the main it is to be found clearly expressed in Kant, and on account of the importance of the matter, would alone have been sufficient to make his name immortal. It cannot but disturb us very much if we find minds of the first order under suspicion of dishonesty, which would be a scandal to those of the lowest order. For we feel that theft is even more inexcusable in a rich man than in a poor one. We dare not, however, be silent; for here we are posterity, and must be just, as we hope that posterity will some day be just to us. Therefore, as a third example, I will add to these cases, that the fundamental thoughts of the "Metamorphosis of Plants," by Goethe, were already expressed by Kaspar Wolff in 1764 in his "Theory of Generation," p. 148, 229, 243, &c. Indeed, is it otherwise with the _system of gravitation_?