Chapter IV. On Knowledge _A Priori_.

From the fact that we are able spontaneously to assign and determine the

laws of relations in space without having recourse to experience, Plato

concludes (_Meno_, p. 353, Bip.) that all learning is mere recollection.

Kant, on the other hand, concludes that space is subjectively conditioned,

and merely a form of the faculty of knowledge. How far, in this regard,

does Kant stand above Plato!

_Cogito, ergo sum_, is an analytical judgment. Indeed Parmenides held it

to be an identical judgment: “το γαρ αυτο νοειν εστι τε και ειναι” (_nam

intelligere et esse idem est_, _Clem. Alex. Strom._, vi. 2, § 23). As

such, however, or indeed even as an analytical judgment, it cannot contain

any special wisdom; nor yet if, to go still deeper, we seek to deduce it

as a conclusion from the major premise, _non-entis nulla sunt prædicata_.

But with this proposition what Descartes really wished to express was the

great truth that immediate certainty belongs only to self-consciousness,

to what is subjective. To what is objective, on the other hand, thus to

everything else, only indirect certainty belongs; for it is arrived at

through self-consciousness; and being thus merely at second hand, it is to

be regarded as problematical. Upon this depends the value of this

celebrated proposition. As its opposite we may set up, in the sense of the

Kantian philosophy, _cogito, ergo est_, that is, exactly as I think

certain relations in things (the mathematical), they must always occur in

all possible experience;—this was an important, profound, and a late

_apperçu_, which appeared in the form of the problem as to the

_possibility of synthetic judgments a priori_, and has actually opened up

the way to a deeper knowledge. This problem is the watchword of the

Kantian philosophy, as the former proposition is that of the Cartesian,

and shows εξ οἱων εισ οἱα.

Kant very fitly places his investigations concerning time and space at the

head of all the rest. For to the speculative mind these questions present

themselves before all others: what is time?—what is this that consists of

mere movement, without anything that moves it?—and what is space? this

omnipresent nothing, out of which nothing that exists can escape without

ceasing to be anything at all?

That time and space depend on the subject, are the mode in which the

process of objective apperception is brought about in the brain, has

already a sufficient proof in the absolute impossibility of thinking away

time and space, while we can very easily think away everything that is

presented in them. The hand can leave go of everything except itself.

However, I wish here to illustrate by a few examples and deductions the

more exact proofs of this truth which are given by Kant, not for the

purpose of refuting stupid objections, but for the use of those who may

have to expound Kant’s doctrine in future.

“A right-angled equilateral triangle” contains no logical contradiction;

for the predicates do not by any means cancel the subject, nor are they

inconsistent with each other. It is only when their object is constructed

in pure perception that the impossibility of their union in it appears.

Now if on this account we were to regard this as a contradiction, then so

would every physical impossibility, only discovered to be such after the

lapse of centuries, be a contradiction; for example, the composition of a

metal from its elements, or a mammal with more or fewer than seven

cervical vertebra,(14) or horns and upper incisors in the same animal. But

only _logical_ impossibility is a contradiction, not physical, and just as

little mathematical. Equilateral and rectangled do not contradict each

other (they coexist in the square), nor does either of them contradict a

triangle. Therefore the incompatibility of the above conceptions can never

be known by mere _thinking_, but is only discovered by perception—merely

mental perception, however, which requires no experience, no real object.

We should also refer here to the proposition of Giordano Bruno, which is

also found in Aristotle: “An infinitely large body is necessarily

immovable”—a proposition which cannot rest either upon experience or upon

the principle of contradiction, since it speaks of things which cannot

occur in any experience, and the conceptions “infinitely large” and

“movable” do not contradict each other; but it is only pure perception

that informs us that motion demands a space outside the body, while its

infinite size leaves no space over. Suppose, now, it should be objected to

the first mathematical example that it is only a question of how complete

a conception of a triangle the person judging has: if the conception is

quite complete it will also contain the impossibility of a triangle being

rectangular and also equilateral. The answer to this is: assume that his

conception is not so complete, yet without recourse to experience he can,

by the mere construction of the triangle in his imagination, extend his

conception of it and convince himself for ever of the impossibility of

this combination of these conceptions. This process, however, is a

synthetic judgment _a priori_, that is, a judgment through which,

independently of all experience, and yet with validity for all experience,

we form and perfect our conceptions. For, in general, whether a given

judgment is analytical or synthetical can only be determined in the

particular case according as the conception of the subject in the mind of

the person judging is more or less complete. The conception “cat” contains

in the mind of a Cuvier a hundred times more than in that of his servant;

therefore the same judgments about it will be synthetical for the latter,

and only analytical for the former. But if we take the conceptions

objectively, and now wish to decide whether a given judgment is analytical

or synthetical, we must change the predicate into its contradictory

opposite, and apply this to the subject without a copula. If this gives a

_contradictio in adjecto_, then the judgment was analytical; otherwise it

was synthetical.

That Arithmetic rests on the pure intuition or perception of time is not

so evident as that Geometry is based upon that of space.(15) It can be

proved, however, in the following manner. All counting consists in the

repeated affirmation of unity. Only for the purpose of always knowing how

often we have already affirmed unity do we mark it each time with another

word: these are the numerals. Now repetition is only possible through

succession. But succession, that is, being after one another, depends

directly upon the intuition or perception of _time_. It is a conception

which can only be understood by means of this; and thus counting also is

only possible by means of time. This dependence of all counting upon time

is also betrayed by the fact that in all languages multiplication is

expressed by “time,” thus by a time-concept: _sexies_, ἑξακις, _six fois_,

_sex mal_. But simple counting is already a multiplication by one, and for

this reason in Pestalozzi’s educational establishment the children are

always made to multiply thus: “Two times two is four times one.” Aristotle

already recognised the close relationship of number and time, and

expounded it in the fourteenth chapter of the fourth book of the

“Physics.” Time is for him “the number of motion” (“ὁ χρονος αριθμος εστι

κινησεως”). He very profoundly suggests the question whether time could be

if the soul were not, and answers it in the negative. If arithmetic had

not this pure intuition or perception of time at its foundation, it would

be no science _a priori_, and therefore its propositions would not have

infallible certainty.

Although time, like space, is the form of knowledge of the subject, yet,

just like space, 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. Anticipating 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

identity 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 Considérations 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 asserted 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 crass 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 substituted 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, space 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 space, 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 assistance 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 assertion 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 assertion 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 assume 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 assert 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 assertion 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

assumption that cause and effect are simultaneous, the course of the world

shrinks up into an affair of a moment. This proof is analogous 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 God” (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 nobilior 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

“_Institutio Theologica_,” § 76: “Παν το απο ακινητου γιγνομενον αιτιας,

αμεταβλητον εχει την ὑπαρξιν; παν δε το απο κινουμενης, μεταβλητην; ει γαρ

ακινητον εστι παντῃ το ποιουν, ου δια κινησεως, αλλ᾽ αυτῳ τῳ ειναι παραγει

το δευτερον αφ᾽ ἑαυτου.” (_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 space. More than this the

law of causality does not assert. 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 assumption 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

constitutes 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 assuming 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 passed 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 assumption 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 analysis

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 assigns 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 (_Über den Einzig Möglichen 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 classes which are utterly falsely, and

indeed crudely conceived. Compare with it my classification 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 (ενεργεια = 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 asserted 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 assertion

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: “σωμα μεν ουκ αν ειη,

σωματικη δε” (_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 space 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 space 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 propædutic 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 space and time. In agreement with this, we find that what

geometry is for the pure perception or intuition of space, 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 space. 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 assumes 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 illustrate it

specially by an example. Aristotle’s book “_De Xenophane_,” &c., commences

with these weighty words of Xenophanes: “Αϊδιον ειναι φησιν, ει τι εστιν,

ειπερ μη ενδεχεται γενεσθαι μηδεν εκ μηδενος.” (_Æternum 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

analogy; 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 constitution 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, space, 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 _Prædicabilia a priori_ of time, space, and matter is to be taken:—

Prædicabilia _A Priori_.

Of Time. Of Space. Of Matter.

(1) There is only (1) There is only (1) There is only

_one_ Time, and all _one_ Space, and all _one_ Matter, and

different times are different spaces 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 spaces (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) Space 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) Space 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 space and throughout

constitute 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) Space is (5) Matter is

infinitely infinitely infinitely

divisible. divisible. divisible.

(6) Time is (6) Space is (6) Matter is

homogeneous and a homogeneous and a homogeneous 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 (_homoiomeria_) or

anything that is not anything that is not originally separated

time. space. 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) Space 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 passing

in it. away are in it.

(8) By reason of (8) By reason of (8) By reason of

time we count. space we measure. matter we weigh.

(9) Rhythm is only (9) Symmetry is only (9) Equilibrium is

in time. in space. only in matter.

(10) We know the (10) We know the (10) We know the

laws of time _a laws of space _a laws of the

priori_. priori_. substance of all

accidents _a

priori_.

(11) Time can be (11) Space 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) Space can never (12) The accidents

permanence, but pass away, but change; the

passes away as soon endures through all substance remains.

as it is there. time.

(13) Time never (13) Space 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 space has material has the

duration. a position. capacity for action.

(15) Time has no (15) Space 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 space; 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. space. matter.

(17) Velocity is, in (17) Velocity is, in (17) The magnitude

equal spaces, in equal times, in of the motion, the

inverse proportion direct proportion to velocity being

to the time. the space. equal, is in direct

geometrical

proportion to the

matter (mass).

(18) Time is not (18) Space is (18) Matter as such

measurable directly measurable directly (mass) is

through itself, but through itself, and measurable, _i.e._,

only indirectly indirectly through determinable as

through motion, motion, which is in regards its quantity

which is in space time and space 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) Space 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 space, at passes away, and

once. thus its quantity

can neither be

increased nor

diminished.

(20) In time taken (20) In space 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 space; 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

space, and

constitutes the

whole nature of

matter.

(21) Time makes the (21) Space 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 space contains the both permanent and

parts of matter. same matter as impenetrable.

another.

(23) Time is the (23) Space 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) Space 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, space 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 space.) a beginning of time

or a limit of space.

(Principle of

sufficient reason of

becoming.)

(27) Time makes (27) Space makes (27) Matter, as that

arithmetic possible. geometry possible. which is movable in

space, 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 passes 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 κατ᾽ ενεργειαν, in

opposition to κατα δυναμιν, reveals the same source, for ενεργεια

signifies action in general; so also with _actu_ in opposition to

_potentia_, and the English “actually” for “_wirklich_.” What is called

space-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 analysed this space-occupation of the

mechanical mode of activity into repulsive and attractive force, just as a

given mechanical force is analysed into two others by means of the

parallelogram of forces. But this is really only the thoughtful analysis

of the phenomenon into its two constituent 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 space 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 assumed in

the case of subsidiary thoughts, flashes of wit, comparisons, &c., but not

in the case of the principal 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

space 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 Frauenstädt’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 principal 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 Système 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 möglichen 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 Constitution de l’Univers_). We are

therefore obliged to assume 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_?

the discovery of which is on the Continent of Europe always ascribed to

Newton, while in England the learned at least know very well that it

belongs to Robert Hooke, who in the year 1666, in a “Communication to the

Royal Society,” expounds it quite distinctly, although only as an

hypothesis and without proof. The principal passage of this communication

is quoted in Dugald Stewart’s “Philosophy of the Human Mind,” and is

probably taken from Robert Hooke’s Posthumous Works. The history of the

matter, and how Newton got into difficulty by it, is also to be found in

the “_Biographie Universelle_,” article Newton. Hooke’s priority is

treated as an established fact in a short history of astronomy, _Quarterly

Review_, August 1828. Further details on this subject are to be found in

my “_Parerga_,” vol. ii., § 86 (second edition, § 88). The story of the

fall of an apple is a fable as groundless as it is popular, and is quite

without authority.

(2) To No. 18 of Matter.

_The quantity of a motion_ (_quantitas motus_, already in Descartes) is

the product of the mass into the velocity.

This law is the basis not only of the doctrine of impact in mechanics, but

also of that of equilibrium in statics. From the force of impact which two

bodies with the same velocity exert the relation of their masses to each

other may be determined. Thus of two hammers striking with the same

velocity, the one which has the greater mass will drive the nail deeper

into the wall or the post deeper into the earth. For example, a hammer

weighing six pounds with a velocity = 6 effects as much as a hammer

weighing three pounds with a velocity = 12, for in both cases the quantity

of motion or the momentum = 36. Of two balls rolling at the same pace, the

one which has the greater mass will impel a third ball at rest to a

greater distance than the ball of less mass can. For the mass of the first

multiplied by the same velocity gives a _greater quantity of motion_, or a

_greater momentum_. The cannon carries further than the gun, because an

equal velocity communicated to a much greater mass gives a much _greater

quantity of motion_, which resists longer the retarding effect of gravity.

For the same reason, the same arm will throw a lead bullet further than a

stone one of equal magnitude, or a large stone further than quite a small

one. And therefore also a case-shot does not carry so far as a ball-shot.

The same law lies at the foundation of the theory of the lever and of the

balance. For here also the smaller mass, on the longer arm of the lever or

beam of the balance, has a greater velocity in falling; and multiplied by

this it may be equal to, or indeed exceed, the _quantity of motion_ or the

_momentum_ of the greater mass at the shorter arm of the lever. In the

state of rest brought about by _equilibrium_ this velocity exists merely

in intention or virtually, _potentiâ_, not _actu_; but it acts just as

well as _actu_, which is very remarkable.

The following explanation will be more easily understood now that these

truths have been called to mind.

The quantity of a given matter can only be estimated in general according

to its force, and its force can only be known in its _expression_. Now

when we are considering matter only as regards its quantity, not its

quality, this expression can only be mechanical, _i.e._, it can only

consist in motion which it imparts to other matter. For only in motion

does the force of matter become, so to speak, _alive_; hence the

expression _vis viva_ for the manifestation of force of matter in motion.

Accordingly the only measure of the quantity of a given matter is the

_quantity of its motion_, or its _momentum_. In this, however, if it is

given, the _quantity_ of matter still appears in conjunction and

amalgamated with its other factor, _velocity_. Therefore if we want to

know the quantity of matter (the mass) this other factor must be

eliminated. Now the velocity is known directly; for it is _S/T_. But the

other factor, which remains when this is eliminated, can always be known

only _relatively_ in comparison with other masses, which again can only be

known themselves by means of the _quantity of their motion_, or their

_momentum_, thus in their combination with velocity. We must therefore

compare one _quantity of motion_ with the other, and then subtract the

velocity from both, in order to see how much each of them owed to its

mass. This is done by weighing the masses against each other, in which

that _quantity of motion_ is compared which, in each of the two masses,

calls forth the attractive power of the earth that acts upon both only in

proportion to their _quantity_. Therefore there are two kinds of weighing.

Either we impart to the two masses to be compared _equal_ velocity, in

order to find out which of the two now _communicates_ motion to the other,

thus itself _has_ a greater quantity of motion, which, since the velocity

is the same on both sides, is to be ascribed to the other factor of the

_quantity of motion_ or the _momentum_, thus to the mass (common balance).

Or we weigh, by investigating how much _more velocity_ the one mass must

receive than the other has, in order to be equal to the latter in

_quantity of motion_ or _momentum_, and therefore allow no more motion to

be communicated to itself by the other; for then in proportion as its

velocity must exceed that of the other, its mass, _i.e._, the quantity of

its matter, is less than that of the other (steelyard). This estimation of

masses by weighing depends upon the favourable circumstance that the

moving force, in itself, acts upon both quite equally, and each of the two

is in a position to _communicate_ to the other directly its surplus

_quantity of motion_ or _momentum_, so that it becomes visible.

The substance of these doctrines has long ago been expressed by Newton and

Kant, but through the connection and the clearness of this exposition I

believe I have made it more intelligible, so that that insight is possible

for all which I regarded as necessary for the justification of proposition

No. 18.

Second Half. The Doctrine of the Abstract Idea, or Thinking.

The World as Will and Idea (Vol. 2 of 3) · 第 4 / 20 章