multifarious and finely distinguished data, out of which it constructs in our head the marvellous objective world, by the application of the law of causality upon the foundation of the pure perceptions of space and time.
Just that freedom from affecting the will which is characteristic of sensations of colour enables them, when their energy is heightened by transparency, as in the glow of an evening sky, in painted glass, and the like, to raise us very easily into the state of pure objective will-less perception, which, as I have shown in my third book, is one of the chief constituent elements of the æsthetic impression. Just this indifference with regard to the will fits sounds to supply the material for denoting the infinite multiplicity of the conceptions of the reason.
_Outer sense_, that is, receptivity for external impressions as pure data for the understanding, is divided into _five senses_, and these accommodate themselves to the four elements, _i.e._, the four states of aggregation, together with that of imponderability. Thus the sense for what is firm (earth) is touch; for what is fluid (water), taste; for what is in the form of vapour, _i.e._, volatile (vapour, exhalation), smell; for what is permanently elastic (air), hearing; for what is imponderable (fire, light), sight. The second imponderable, heat, is not properly an object of the senses, but of general feeling, and therefore always affects the _will_ directly, as agreeable or disagreeable. From this classification there also follows the relative dignity of the senses.
Sight has the highest rank, because its sphere is the widest and its susceptibility the finest. This rests upon the fact that what affects it is an imponderable, that is, something which is scarcely corporeal, but is _quasi_ spiritual. Hearing has the second place, corresponding to air.
However, touch is a more thorough and well-informed sense. For while each of the other senses gives us only an entirely one-sided relation to the object, as its sound, or its relation to light, touch, which is closely bound up with general feeling and muscular power, supplies the understanding with the data at once for the form, magnitude, hardness, softness, texture, firmness, temperature, and weight of bodies, and all this with the least possibility of illusion and deception, to which all the other senses are far more subject. The two lowest senses, smell and taste, are no longer free from a direct affection of the will, that is, they are always agreeably or disagreeably affected, and are therefore more subjective than objective.
Sensations of hearing are exclusively in _time_, and therefore the whole nature of music consists in degrees of time, upon which depends both the quality or pitch of tones, by means of vibrations, and also their quantity or duration, by means of time. The sensations of sight, on the other hand, are primarily and principally in _space_; but secondarily, by reason of their duration, they are also in time.
Sight is the sense of the understanding which perceives; hearing is the sense of the reason which thinks and apprehends. Words are only imperfectly represented by visible signs; and therefore I doubt whether a deaf and dumb man, who can read, but has no idea of the sound of the words, works as quickly in thinking with the mere visible signs of conceptions as we do with the real, _i.e._, the audible words. If he cannot read, it is well known that he is almost like an irrational animal, while the man born blind is from the first a thoroughly rational being.
Sight is an _active_, hearing a _passive_ sense. Therefore sounds affect our mind in a disturbing and hostile manner, and indeed they do so the more in proportion as the mind is active and developed; they distract all thoughts and instantly destroy the power of thinking. On the other hand, there is no analogous disturbance through the eye, no direct effect of what is seen, _as such_, upon the activity of thought (for naturally we are not speaking here of the influence which the objects looked at have upon the will); but the most varied multitude of things before our eyes admits of entirely unhindered and quiet thought. Therefore the thinking mind lives at peace with the eye, but is always at war with the ear. This opposition of the two senses is also confirmed by the fact that if deaf and dumb persons are cured by galvanism they become deadly pale with terror at the first sounds they hear (Gilbert’s “_Annalen der Physik_,” vol. x. p. 382), while blind persons, on the contrary, who have been operated upon, behold with ecstasy the first light, and unwillingly allow the bandages to be put over their eyes again. All that has been said, however, can be explained from the fact that hearing takes place by means of a mechanical vibration of the nerve of hearing which is at once transmitted to the brain, while seeing, on the other hand, is a real _action_ of the retina which is merely stimulated and called forth by light and its modifications; as I have shown at length in my physiological theory of colours. But this whole opposition stands in direct conflict with that coloured-ether, drum-beating theory which is now everywhere unblushingly served up, and which seeks to degrade the eye’s sensation of light to a mechanical vibration, such as primarily that of hearing actually is, while nothing can be more different than the still, gentle effect of light and the alarm-drum of hearing. If we add to this the remarkable circumstance that although we hear with two ears, the sensibility of which is often very different, yet we never hear a sound double, as we often see things double with our two eyes, we are led to the conjecture that the sensation of hearing does not arise in the labyrinth or in the cochlea, but deep in the brain where the two nerves of hearing meet, and thus the impression becomes simple. But this is where the _pons Varolii_ encloses the _medulla oblongata_, thus at the absolutely lethal spot, by the injury of which every animal is instantly killed, and from which the nerve of hearing has only a short course to the labyrinth, the seat of acoustic vibration. Now it is just because its source is here, in this dangerous place, in which also all movement of the limbs originates, that we start at a sudden noise; which does not occur in the least degree when we suddenly see a light; for example, a flash of lightning. The optic nerve, on the contrary, proceeds from its _thalami_ much further forward (though perhaps its source lies behind them), and throughout its course is covered by the anterior lobes of the brain, although always separated from them till, having extended quite out of the brain, it is spread out in the retina, upon which, on stimulation by light, the sensation first arises, and where it is really localised. This is shown in my essay upon sight and colour. This origin of the auditory nerve explains, then, the great disturbance which the power of thinking suffers from sound, on account of which thinking men, and in general all people of much intellect, are without exception absolutely incapable of enduring any noise. For it disturbs the constant stream of their thoughts, interrupts and paralyses their thinking, just because the vibration of the auditory nerve extends so deep into the brain, the whole mass of which feels the oscillations set up through this nerve, and vibrates along with them, and because the brains of such persons are more easily moved than those of ordinary men.
On the same readiness to be set in motion, and capacity for transmission, which characterises their brains depends the fact that in the case of persons like these every thought calls forth so readily all those analogous or related to it whereby the similarities, analogies, and relations of things in general come so quickly and easily into their minds; that the same occasion which millions of ordinary minds have experienced before brings them to _the_ thought, to _the_ discovery, that other people are subsequently surprised they did not reach themselves, for they certainly can think afterwards, but they cannot think before. Thus the sun shone on all statues, but only the statue of Memnon gave forth a sound. For this reason Kant, Gœthe, and Jean Paul were highly sensitive to every noise, as their biographers bear witness.(13) Gœthe in his last years bought a house which had fallen into disrepair close to his own, simply in order that he might not have to endure the noise that would be made in repairing it. Thus it was in vain that in his youth he followed the drum in order to harden himself against noise. It is not a matter of custom. On the other hand, the truly stoical indifference to noise of ordinary minds is astonishing. No noise disturbs them in their thinking, reading, writing, or other occupations, while the finer mind is rendered quite incapable by it. But just that which makes them so insensible to noise of every kind makes them also insensible to the beautiful in plastic art, and to deep thought or fine expression in literary art; in short, to all that does not touch their personal interests. The following remark of Lichtenberg’s applies to the paralysing effect which noise has upon highly intellectual persons: “It is always a good sign when an artist can be hindered by trifles from exercising his art. F—— used to stick his fingers into sulphur if he wished to play the piano...Such things do not interfere with the average mind;...it acts like a coarse sieve” (_Vermischte Schriften_, vol. i. p. 398). I have long really held the opinion that the amount of noise which any one can bear undisturbed stands in inverse proportion to his mental capacity, and therefore may be regarded as a pretty fair measure of it. Therefore, if I hear the dogs barking for hours together in the court of a house without being stopped, I know what to think of the intellectual capacity of the inhabitants. The man who habitually slams the door of a room, instead of shutting it with his hand, or allows this to go on in his house, is not only ill-bred, but is also a coarse and dull-minded fellow. That in English “sensible” also means gifted with understanding is based upon accurate and fine observation. We shall only become quite civilised when the ears are no longer unprotected, and when it shall no longer be the right of everybody to sever the consciousness of each thinking being, in its course of a thousand steps, with whistling, howling, bellowing, hammering, whip-cracking, barking, &c. &c. The Sybarites banished all noisy trades without the town; the honourable sect of the Shakers in North America permit no unnecessary noise in their villages, and the Moravians have a similar rule. Something more is said upon this subject in the thirtieth chapter of the second volume of the “Parerga.”
The effect of music upon the mind, so penetrating, so direct, so unfailing, may be explained from the _passive_ nature of hearing which has been discussed; also the after effect which sometimes follows it, and which consists in a specially elevated frame of mind. The vibrations of the tones following in rationally combined numerical relations set the fibre of the brain itself in similar vibration. On the other hand, the _active_ nature of sight, opposed as it is to the passive nature of hearing, makes it intelligible why there can be nothing analogous to music for the eye, and the piano of colours was an absurd mistake. Further, it is just on account of the active nature of the sense of sight that it is remarkably acute in the case of beasts that hunt, _i.e._, beasts of prey, while conversely the _passive_ sense of hearing is specially acute in those beasts that are hunted, that flee, and are timid, so that it may give them timely warning of the pursuer that is rushing or creeping upon them.
Just as we have recognised in sight the sense of the understanding, and in hearing the sense of the reason, so we might call smell the sense of the memory, because it recalls to us more directly than any other the specific impression of an event or a scene even from the most distant past.
Chapter IV. On Knowledge _A Priori_.
From the fact that we are able spontaneously to assign and determine the laws of relations in space without having recourse to experience, Plato concludes (_Meno_, p. 353, Bip.) that all learning is mere recollection.
Kant, on the other hand, concludes that space is subjectively conditioned, and merely a form of the faculty of knowledge. How far, in this regard, does Kant stand above Plato!
_Cogito, ergo sum_, is an analytical judgment. Indeed Parmenides held it to be an identical judgment: “το γαρ αυτο νοειν εστι τε και ειναι” (_nam intelligere et esse idem est_, _Clem. Alex. Strom._, vi. 2, § 23). As such, however, or indeed even as an analytical judgment, it cannot contain any special wisdom; nor yet if, to go still deeper, we seek to deduce it as a conclusion from the major premise, _non-entis nulla sunt prædicata_.
But with this proposition what Descartes really wished to express was the great truth that immediate certainty belongs only to self-consciousness, to what is subjective. To what is objective, on the other hand, thus to everything else, only indirect certainty belongs; for it is arrived at through self-consciousness; and being thus merely at second hand, it is to be regarded as problematical. Upon this depends the value of this celebrated proposition. As its opposite we may set up, in the sense of the Kantian philosophy, _cogito, ergo est_, that is, exactly as I think certain relations in things (the mathematical), they must always occur in all possible experience;—this was an important, profound, and a late _apperçu_, which appeared in the form of the problem as to the _possibility of synthetic judgments a priori_, and has actually opened up the way to a deeper knowledge. This problem is the watchword of the Kantian philosophy, as the former proposition is that of the Cartesian, and shows εξ οἱων εισ οἱα.
Kant very fitly places his investigations concerning time and space at the head of all the rest. For to the speculative mind these questions present themselves before all others: what is time?—what is this that consists of mere movement, without anything that moves it?—and what is space? this omnipresent nothing, out of which nothing that exists can escape without ceasing to be anything at all?
That time and space depend on the subject, are the mode in which the process of objective apperception is brought about in the brain, has already a sufficient proof in the absolute impossibility of thinking away time and space, while we can very easily think away everything that is presented in them. The hand can leave go of everything except itself.
However, I wish here to illustrate by a few examples and deductions the more exact proofs of this truth which are given by Kant, not for the purpose of refuting stupid objections, but for the use of those who may have to expound Kant’s doctrine in future.
“A right-angled equilateral triangle” contains no logical contradiction; for the predicates do not by any means cancel the subject, nor are they inconsistent with each other. It is only when their object is constructed in pure perception that the impossibility of their union in it appears.
Now if on this account we were to regard this as a contradiction, then so would every physical impossibility, only discovered to be such after the lapse of centuries, be a contradiction; for example, the composition of a metal from its elements, or a mammal with more or fewer than seven cervical vertebra,(14) or horns and upper incisors in the same animal. But only _logical_ impossibility is a contradiction, not physical, and just as little mathematical. Equilateral and rectangled do not contradict each other (they coexist in the square), nor does either of them contradict a triangle. Therefore the incompatibility of the above conceptions can never be known by mere _thinking_, but is only discovered by perception—merely mental perception, however, which requires no experience, no real object.
We should also refer here to the proposition of Giordano Bruno, which is also found in Aristotle: “An infinitely large body is necessarily immovable”—a proposition which cannot rest either upon experience or upon the principle of contradiction, since it speaks of things which cannot occur in any experience, and the conceptions “infinitely large” and “movable” do not contradict each other; but it is only pure perception that informs us that motion demands a space outside the body, while its infinite size leaves no space over. Suppose, now, it should be objected to the first mathematical example that it is only a question of how complete a conception of a triangle the person judging has: if the conception is quite complete it will also contain the impossibility of a triangle being rectangular and also equilateral. The answer to this is: assume that his conception is not so complete, yet without recourse to experience he can, by the mere construction of the triangle in his imagination, extend his conception of it and convince himself for ever of the impossibility of this combination of these conceptions. This process, however, is a synthetic judgment _a priori_, that is, a judgment through which, independently of all experience, and yet with validity for all experience, we form and perfect our conceptions. For, in general, whether a given judgment is analytical or synthetical can only be determined in the particular case according as the conception of the subject in the mind of the person judging is more or less complete. The conception “cat” contains in the mind of a Cuvier a hundred times more than in that of his servant; therefore the same judgments about it will be synthetical for the latter, and only analytical for the former. But if we take the conceptions objectively, and now wish to decide whether a given judgment is analytical or synthetical, we must change the predicate into its contradictory opposite, and apply this to the subject without a copula. If this gives a _contradictio in adjecto_, then the judgment was analytical; otherwise it was synthetical.
That Arithmetic rests on the pure intuition or perception of time is not so evident as that Geometry is based upon that of space.(15) It can be proved, however, in the following manner. All counting consists in the repeated affirmation of unity. Only for the purpose of always knowing how often we have already affirmed unity do we mark it each time with another word: these are the numerals. Now repetition is only possible through succession. But succession, that is, being after one another, depends directly upon the intuition or perception of _time_. It is a conception which can only be understood by means of this; and thus counting also is only possible by means of time. This dependence of all counting upon time is also betrayed by the fact that in all languages multiplication is _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