# Philosophical Works of the Late James Frederick Ferrier/Philosophical Remains (1883)/The Crisis of Modern Speculation

Philosophical Remains, Philosophical Works of the Late James Frederick Ferrier (1883 ed., Vol. 3). (E. L. Lushington, & A. Grant, Eds.) Edinburgh: William Blackwood and Sons. pp. 259-288
THE
CRISIS OF MODERN SPECULATION
THE
CRISIS OF MODERN SPECULATION
The great endeavour of philosophy, in all ages, has been to explain the nature of the connection which subsists between the mind of man and the external universe; but it is to speculation of a very late date that we owe the only approach that has been made to a satisfactory solution of this problem. In the following remarks on the state of modern speculation, we shall attempt to unfold this explanation, for it forms, we think, the very pith of the highest philosophy of recent times.
It will be seen that the question is resolved, not so much by having any positive answer given to it, as by being itself made to assume a totally new aspect. We shall find, upon reflection, that it is not what, at first sight, and on a superficial view, we imagined it to be. A change will come over the whole spirit of the question. Facts will arise, forcing it into a new form, even in spite of our efforts to keep it in its old ​shape. The very understanding of it will alter it from what it was. It will not be annihilated—it will not be violently supplanted—but it will be gradually transformed; and this transformation will be seen to arise out of the very nature of thought, out of the very exercise of reason upon the question. It will be granted that, before a question can become a question, it must first of all be conceived. Therefore, before the question respecting the intercourse between mind and matter can be asked, it must be thought. Now, the whole drift of our coming argument is to show that this question, in the very thinking of it, necessarily passes into a new question. And then, perhaps, the difficulty of answering this new question will be found to be not very great
This consideration may, perhaps, conciliate forbearance at the outset of our inquiry at least. Any objections levelled against the question as it now stands, would evidently be premature. For the present question is but the mask of another question; and unless it be known what that other question is, why should its shell be thrown aside as an unprofitable husk? Reader! spare the chrysalis for the sake of the living butterfly which perhaps may yet spring from its folds. The transformation we are going to attempt to describe, forms the most vital crisis in the whole history of speculation.
It must be kept in mind that our perception of an external universe is a phenomenon of a profounder and more vital character than is generally supposed. ​Besides having perceptions, the mind, it is said, is modified in a hundred other ways: by desires, passions, and emotions; and these, it is thought, contribute to form its reality, just as much as the perception of outward things does. But this is a mistake. Perception, the perception of an external universe, is the groundwork and condition of all other mental phenomena. It is the basis of the reality of mind. It is this reality itself. Through it, mind is what it is; and without it, mind could not be conceived to exist. Since, therefore, perception is the very life of man, when we use the word mind in this discussion we shall understand thereby the percipient being, or the perceiver. The word mind and the word precipient we shall consider convertible terms.
The earliest, and, in France and this country, the still dominant philosophy explains the connection between mind and matter by means of the relation of cause and effect. Outward things present to the senses are the causes of our perceptions, our perceptions are the effects of their proximity. "The presence of an external body," says Dr Brown, "an organic change immediately consequent on its presence, and a mental affection;" these, according to him, form three terms of a sequence, the statement of which is thought sufficiently to explain the phenomenon of perception, and to illustrate the intercourse which takes place between ourselves and outward objects.
This doctrine is obviously founded on a distinction laid down between objects as they are in themselves ​and objects as they are in our perceptions of them; in other words, between real objects and our perceptions of objects. For, unless we made a discrimination between these two classes, we could have no ground for saying that the former were the causes of the latter.
Now, when any distinction is established, the tendency of the understanding is to render it as definite, complete, and absolute as it admits of being made. And, with regard to the present distinction, the understanding was certainly not idle. It took especial pains to render this distinction real and precise; and, by doing so, it prepared a building-ground for the various philosophical fabrics that were to follow for many generations. It taught that the object in itself must be considered something which stood quite aloof from our perception of it, that our perception of the object must be considered something of which the real object formed no part. Had it been otherwise, the understanding would have pronounced the discrimination illogical, and consequently null and void.
It was this procedure of the understanding with respect to the above-mentioned distinction which led to the universal adoption of a representative theory of perception. We are far from thinking that any of its authors adopted or promulgated this doctrine under that gross form of it against which Dr Reid and other philosophers have directed their shafts; under the form, namely, which holds that outward ​things are represented by little images in the mind. Unquestionably, that view is a gross exaggeration of the real opinion. All that philosophers meant was, that we had perceptions of objects, and that these perceptions were not the objects themselves. Yet even this, the least exceptionable form of the theory that can be maintained) was found sufficient to subvert the foundations of all human certainty.
Here, then, it was that doubts and difficulties began to break in upon philosophical inquiry. It was at this juncture that the schism between common sense and philosophy, which has not yet terminated, began. People had hitherto believed that they possessed an immediate or intuitive knowledge of an external universe; but now philosophers assured them that no such immediate knowledge was possible. All that man could immediately know was either the object itself, or his perception of it. It could not be both of these in one, for this explanation of perception was founded on the admitted assumption that these two were distinct, and were to be kept distinct. Now, it could not be the object itself, for man knows the object only by knowing that he perceives it—in other words, by knowing his own perception of it; and the object and his perception being different, he could know the former only through his knowledge of the latter. Hence, knowing it through this vicarious phenomenon, namely, his own perception of it, he could only know it mediately; and therefore it was merely his own perceptions of an external ​universe, and not an external universe itself, that he was immediately cognisant of.
The immediate knowledge of an external universe being disproved, its reality was straightway called in question. For the existence of that which is not known immediately, or as it is in itself, requires to be established by an inference of reason. Instead, therefore, of asking, How is the intercourse carried on between man's mind and the external world? the question came to be this, Is there any real external world at all?
Three several systems undertook to answer this question: Hypothetical Realism, which defended the reality of the universe; Idealism, which denied its reality; and Scepticism, which maintained that if there were an external universe, it must be something very different from what it appears to us to be.
Hypothetical Realism was the orthodox creed, and became a great favourite with philosophers. It admitted that an outward world could not be immediately known; that we could be immediately and directly cognisant of nothing but our own subjective states—in other words, of nothing but our perceptions of this outward world; but, at the same time, it held that it must be postulated as a ground whereby to account for these impressions. This system was designed to reconcile common sense with philosophy, but it certainly had not the desired effect. The convictions of common sense repudiated the decrees of so hollow a philosophy. The belief which this ​system aimed at creating was not the belief in which common sense rejoiced. To the man who thought and felt with the mass, the universe was no hypothesis, no inference of reason, but a direct reality which he had immediately before him. His perception of the universe, that is, the universe as he was cognisant of it in perception, was, he felt convinced, the very universe as it was in itself.
Idealism did not care to conciliate common sense; but it maintained that if we must have recourse to an hypothesis to explain the origin of our perceptions, it would be a simpler one to say that they arose in conformity with the original laws of our constitution, or simply because it was the will of our Creator that they should arise in the way they do. Thus, a real external world called into existence by hypothetical Realism (no other Realism was at present possible), merely to account for our perceptions, was easily dispensed with as a very unnecessary encumbrance.
Scepticism assumed various modifications, but the chief guise in which it sought to outrage the convictions of mankind was, by first admitting the reality of an external world, and then by proving that this world could not correspond with our perceptions of it. Because, in producing these perceptions, its effects were, of necessity, modified by the nature of the percipient principle on which it operated; and hence our perceptions being the joint result of external nature and our own nature, they could not possibly ​be true and faithful representatives of the former alone. They could not but convey a false and perverted information. Thus, man's primary convictions, which taught him that the universe was what it appeared to be, were placed in direct opposition to the conclusions of his reason, which now informed him that it must be something very different from what he took it for.
Thus, in consequence of one fatal and fundamental oversight, the earlier philosophy was involved in inextricable perplexities in its efforts to unravel the mysteries of perception. But we are now approaching times in which this oversight was retrieved, and in which, under the scrutiny of genuine speculation, the whole character and bearings of the question became altered. Its old features were obliterated, and out of the crucible of thought it came forth in a new form, a form which carries its solution on its very front. How has this change been brought about?
We have remarked that all preceding systems were founded on a distinction laid down between objects themselves and our perception of objects. And we have been thus particular in stating this principle, and in enumerating a few of its consequences, because it is by the discovery of a law directly opposed to it that the great thinkers of modern times have revolutionised the whole of philosophy, and escaped the calamitous conclusions into which former systems were precipitated. ​In the olden days of speculation, this distinction was rendered real and absolute by the logical understanding. The objective and the subjective of human knowledge (i.e., the reality and our perception of it) were permanently severed from one another; and while all philosophers were disputing as to the mode in which these two could again intelligibly coalesce, not one of them thought of questioning the validity of the original distinction—the truth of the alleged and admitted separation. Not one of them dreamt of asking whether it was possible for human thought really to make and maintain this discrimination. It was reserved for the genius of modern thought to disprove the distinction in question, or at least to qualify it most materially by the introduction of a directly antagonist principle. By a more rigorous observation of facts, modern inquirers have been led to discover the radical identity of the subjective and the objective of human consciousness, and the impossibility of thinking them asunder. In our present inquiry, we shall restrict ourselves to the consideration of the great change which the question regarding man's intercourse with the external world has undergone, in consequence of this discovery; but its consequences are incalculable, and we know not where they are to end.
In attempting, then, to interpret the spirit of this new philosophy, we commence by remarking that the distinction which lay at the foundation of all the older philosophies is not to be rejected and set aside ​altogether. Unless we made some sort of discrimination between our perceptions and outward objects, no consciousness or knowledge would be possible. This principle is one of the laws of human thought, one of the first conditions of intelligence. But we allow it only a relative validity. It gives us but one-half of the truth. We deny that it is an absolute, final, and permanent distinction; and we shall show that, if by one law of intelligence we constantly separate the subject and the object, so by another law we as constantly blend them into one. If by one principle of our nature we are continually forced to make this separation, we are just as continually forced, by another principle of our nature, to repair it. It is this latter principle which is now to engage our research. But here we must have recourse to facts and illustrations; for it is only by the aid of these that we can hope to move in an intelligible course through so abstruse an investigation.
We shall illustrate our point by first appealing to the sense of sight. Light or colour is the proper object of this perception. That which is called, in the technical language of philosophy, the objective, is the light; that which is called, in the same phraseology, the subjective, is the seeing. We shall frequently make use of these words in the sense thus indicated. Now, admitting, in a certain sense, this discrimination between the objective and subjective in the case of vision, we shall make it our business to show that it undoes itself, by each of these terms ​or extremes necessarily becoming, when thought, both the subjective and the objective in one.
Let us begin with the consideration of the objective—light. It is very easy to say that light is not seeing. But, good reader, we imagine you will be considerably puzzled to think light without allowing the thought of seeing to enter into the thinking of it. Just try to do so. Think of light without thinking of seeing; think the pure object without permitting any part of your subjective nature to be blended with it in that thought. Attempt to conjure up the thought of light without conjuring up along with it in indissoluble union the thought of seeing. Attempt this in every possible way, then reflect for a moment; and as sure as you are a living and percipient being, you will find that, in all your efforts to think of light, you invariably begin and end in thinking of the seeing of light. You think of light by and through the thought of seeing, and you can think of it in no other way. By no exertion of the mind can you separate these two. They are not two, but one. The objective light, therefore, when thought, ceases to be purely objective; it becomes both subjective and objective, both light and seeing in one. And the same truth holds good with regard to all lighted or coloured objects, such as trees, houses, &c.; we can think of these only by thinking of our seeing of them.
But you will perhaps say that, by leaving the sunshine, and going into a dark room, you are able ​to effect an actual and practical separation between these two things, light and seeing. By taking this step, you put an end to your perception; but you do not put an end, you say, to the real objective light which excited it. The perception has vanished, but the light remains, a permanent existence outside of your dark chamber. Now here we must beware of dogmatising, that is, of speaking either affirmatively or negatively, about anything, without first of all having thought about it. Before we can be entitled to speak of what is, we must ascertain what we can think. When, therefore, you talk of light as an outward permanent existence, we neither affirm nor deny it to be so. We give no opinion at all upon the matter. All that we request and expect of both of us is, that we shall think it before we talk of it. But we shall find that, the moment we think this outward permanent existence, we are forced, by the most stringent law of our intelligence, to think sight along with it; and it is only by thinking these two in inseparable unity, that light can become a conceivability at all, or a comprehensible thought.
Perhaps you will here remind us that light exists in many inaccessible regions, where it is neither seen nor was ever thought of as seen. It may be so; we do not deny it. But we answer that, before this light can be spoken of, it must be thought; and that it cannot be thought unless it be thought of as seen, unless we think an ideal spectator of it; in other words, unless a subjective be inseparably added unto ​it. Perhaps, again, in order to show that the objective may be conceived as existing apart from the subjective, you will quote the lines of the poet—
" Full many a flower is born to blush unseen, And waste its sweetness on the desert air."
We reply that it may be very true that many a flower is born so to do. We rather admit the fact. But we maintain that, in order to speak of the fact, you must think of it; and in order to think of the fact, you must think of the flower; and in order to think of the flower, and of its blushing unseen, you must think of the seeing of the flower, and of the seeing of its blushing. All of which shows that here, as in every other supposable case, it is impossible to think the objective without thinking the subjective as its inseparable concomitant, which is the only point we are at present endeavouring to establish.
It will not do to say that this light may be something which may exist, outwardly, and independently of all perception of it, though, in consequence of the limitation of our faculties, it may not be possible for us to conceive how, or in what way, its existence is maintained. Reader! put no faith in those who preach to you about the limited nature of the human faculties, and of the things which lie beyond their bounds. For one instance in which this kind of modesty keeps people right in speculative matters, there are a thousand in which it puts them wrong; and the present case is one of those in which it endeavours to prevail upon us to practise a gross ​imposition upon ourselves. For this light, which is modestly talked of as something which lies, or may lie, altogether out of the sphere of the subjective, will be found, upon reflection, to be conceived only by thinking back, and blending inseparably with it the very subjective (i.e., the seeing) from which it had been supposed possible for thought to divorce it.
Precisely the same thing holds good in the case of sound and hearing. Sound is here the objective, and hearing the subjective; but the objective cannot be conceived, unless we comprehend both the subjective and it in one and the same conception. It is true that sounds may occur (thunder, for instance, in lofty regions of the sky) which are never heard; but we maintain that, in thinking such sounds, we necessarily think the hearing of them; in other words, we think that we would have heard them, had we been near enough to the spot where they occurred, which is exactly the same thing as imagining ourselves, or some other percipient being, present at that spot. We establish an ideal union between them and hearing. In respect to thought, they are as nothing unless thought of as heard. Thus only do we, or can we, conceive them. Whenever, therefore, the objective is here thought of, the same ideal and indissoluble union ensues between it and the subjective, which we endeavoured to show took place between light and vision, whenever the objective of that perception was thought of.
The consideration of these two senses, sight and ​hearing, with their appropriate objects, light and sound, sufficiently explains and illustrates our point. For what holds good with regard to them, holds equally good with regard to all our other perceptions. The moment the objective part of any one of them is thought, we are immediately constrained by a law of our nature which we cannot transgress, to conceive as one with it the subjective part of the perception. We think objective weight only by thinking the feeling of weight. We think hardness, solidity, and resistance, in one and the same thought with touch or some subjective effort. But it would be tedious to multiply illustrations; and our doing so would keep us back too long from the important conclusion towards which we are hastening. Every illustration, however, that we could instance would only help to establish more and more firmly the great truth, that no species or form of the objective, throughout the wide universe, can be conceived of at all, unless we blend with it in one thought its appropriate subjective—that every objective, when construed to the intellect, is found to have a subjective clinging to it, and forming one with it, even when pursued in imagination unto the uttermost boundaries of creation.
Having seen, then, that the objective (the sum of which is the whole external universe) necessarily becomes when thought, both the objective and subjective in one, we now turn to the other side of the question, and we ask whether the subjective (the sum of which is the whole mind of man) does not ​also necessarily convert itself, when conceived, into the subjective and the objective in one. For the establishment of this point in the affirmative is necessary for the completion of our premises. But we have no fears about the result; for certainly a simple reference made by any one to his own consciousness will satisfy him that, as he could not think of light without thinking of seeing, or of sound without thinking of hearing, so now he cannot conceive seeing without conceiving light, or hearing without conceiving sound. Starting with light and sound, we found that these, the objective parts of perception, became, when construed to thought, both subjective and objective in one; so, now, starting with seeing and hearing, we find that each of these, the subjective parts of perception, become both subjective and objective when conceived. For, let us make the attempt as often as we will, we shall find that it is impossible to think of seeing without thinking of light, or of hearing without thinking of sound. Vision is thought through the thought of light, and hearing through the thought of sound, and they can be thought in no other manner, and these two are conceived not as two but as one.
​Again, perhaps you will maintain that the faculty of hearing may be thought of as something which exists anterior to the existence or application of sound; and that, being thought of as such, it must be conceived independently of all conception of its object, sound being, ex hypothesi, not yet in rerum natura. But let any one attempt to frame a conception of such an existence, and he will discover that it is possible for him to do so only by thinking back in union with that existence, the very sound which he pretended was not yet in thought or in being. Therefore, in this and every other case in which we commence by thinking the subjective of any perception, we necessarily blend with it the objective of that perception in one indivisible thought. It is both of these together which form a conceivability. Each of them, singly, is but half a thought, or, in other words, is no thought at all; is an abstraction, which may be uttered, but which certainly cannot be conceived.
We have now completed the construction of our premises. One or two condensed sentences will show the reader the exact position in which we stand. Our intercourse with the external universe was the given whole with which we had to deal. The older philosophies divided this given whole into the external universe on the one hand, and our perceptions of it on the other; but they were never able to show how these two, the objective and the subjective, could ​again be understood to coalesce. Like magicians with but half the powers of sorcery, they had spoken the dissolving spell which severed man's mind from the universe, but they were unable to articulate the binding word which again might bring them into union. It was reserved for the speculation of a later day to utter this word. And this it did by admitting in limine the distinction; but, at the same time, by showing that each of the divided members again resolves itself into both the factors, into which the original whole was separated; and that in this way the distinction undoes itself, while the subjective and the objective, each of them becoming both of them in one thought, are thus restored to their original indissoluble unity. An illustration will make this plain. In treating of mind and matter and their connection, the old philosophy is like a chemistry which resolves a neutral salt into an acid and an alkali, and is then unable to show how these two separate existences may be brought together. The new philosophy is like a chemistry which admits, at the outset, the analysis of the former chemistry, but which then shows that the acid is again both an acid and an alkali in one; and that the alkali is again both an alkali and an acid in one: in other words, that instead of having, as we supposed, a separate acid and a separate alkali under our hand, we have merely two neutral salts instead of one. The new philosophy then shows that the question respecting perception answers itself in this way, that there is no occasion for ​thought to explain how that may be united into one, which no effort of thought is able to put asunder into two.
By appealing to the facts of our intelligence, then, we have found that, whenever we try to think what we heretofore imagined to be the purely objective part of any perception, we are forced, by an invincible law of our nature, to think the subjective part of the perception along with it; and to think these two not as two, but as constituting one thought. And we have also found that, whenever we try to think what we heretofore imagined to be the purely subjective part of any perception, we are forced by the same law of our nature, to think the objective part of the perception along with it; and to think these two, not as two, but as constituting one thought. Therefore the objective, which hitherto, through a delusion of thought, had been considered as that which excluded the subjective from its sphere, was found to embrace and comprehend the subjective, and to be nothing and inconceivable without it; while the subjective, which hitherto, through the same delusion of thought, had been considered as that which excluded the objective from its sphere, was found to embrace and comprehend the objective, and to be nothing and inconceivable without it. We have now reached the very acme of our speculation, and shall proceed to point out the very singular change which this discovery brings about, with regard to the question with which we commenced these remarks, the question ​concerning the intercourse between man and the external universe.
What was hitherto considered the objective, was the whole external universe; and what was hitherto considered the subjective, was the whole percipient power, or, in other words, the whole mind of man. But we have found that this objective, or the whole external universe, cannot become a thought at all, unless we blend and identify with it the subjective, or the whole mind of man. And we have also found that this subjective, or the whole mind of man, cannot become a thought at all, unless we blend and identify with it the objective, or the whole external universe. So that, instead of the question as it originally stood, What is the nature of the connection which subsists between the mind of man and the external world? in other words, between the subjective and the objective of perception? the question becomes this, and into this form it is forced by the laws of the very thought which thinks it, What is the nature of the connection which subsists between the mind of man plus the external universe on the one hand, and the mind of man plus the external universe on the other? Or differently expressed, What is the connection between mind-and-matter (in one), and mind-and-matter (in one)? Or differently still, What is the connection between the subjective subject-object and the objective subject-object?
This latter, then, is the question really asked. This is the form into which the original question is changed, ​by the very laws and nature of thought. We used no violence with the question, we made no effort to displace it, that we might bring forward the new question in its room; we merely thought it, and this is the shape which it necessarily assumed. In this new form the question is still the same as the one originally asked; the same, and yet how different!
But though this is the question really asked, it is not the one which the asker really wished or expected to get an answer to. No; what he wished to get explained was the nature of the connection between what was heretofore considered the subjective, and what was heretofore considered the objective part of perception. Now, touching this point, the following is the only explanation which it is possible to give him. Unless we are able to think two things as two and separated from each other, it is vain and unreasonable to ask how they can become one. Unless we are able to hold the subjective and the objective apart in thought, we cannot be in a position to inquire into the nature of their connection. But we have shown that it is not possible for us, by any effort of thought, to hold the subjective and the objective apart; that the moment the subjective is thought, it becomes both the subjective and the objective in one; and that the moment the objective is thought, it becomes both the subjective and the objective in one; and that, however often we may repeat the attempt to separate them, the result is invariably the same; each of the terms, mistakenly supposed to be but a member of ​one whole, is again found to be itself that very whole. Therefore we see that it is impossible for us to get ourselves into a position from which we might inquire into the nature of the connection between mind and matter, because it is not possible for thought to construe, intelligibly to itself, the ideal disconnection which must necessarily be presupposed as preceding such an inquiry. It must not be supposed, however, that this inability to separate the subject and object of perception argues any weakness on the part of human thought. Here reason merely obeys her own laws; and the just conclusion is, that these two are not really two, but are, in truth, fundamentally and originally one.
Let us add, too, that when we use the words "connection between," we imply that there are two things to be connected. But here there are not two things, but only one. Let us again have recourse to our old illustration of the neutral salt. Our hypothesis (for the purpose of explaining the present question) is, with regard to this substance, that its analysis, repeated as often as it may be, invariably gives us, not an alkali and an acid, but what turns out to be an acid-alkali (an indivisible unit), when we examine what we imagined to be the pure acid; and also what turns out to be an acid-alkali (an indivisible unit), when we examine what we imagined to be the pure alkali; so that, supposing we should inquire into the connection between the acid and the alkali, the question would either be, What is the connection ​between an acid-alkali on the one hand, and an acid-alkali on the other? in other words, What is the connection between two neutral salts? or it would be this absurd one, What is the connection between one thing, the indivisible acid-alkali? In the same way, with respect to the question in hand. There is not a subjective and objective before us, but there is what we find to be an indivisible subjective-objective, when we commence by regarding what we imagined to be the pure subjective; and there is what we find to be an indivisible subjective-objective also, when we commence by regarding what we imagined to be the pure objective; so that the question respecting the nature of the connection between the subjective and the objective comes to be either this, What is the nature of the connection between two subjective-objectives? (but that is not the question to which an answer was wished), or else this, What is the nature of the connection between one thing, one thing which no effort of thought can construe as really two? Surely no one but an Irishman would think of asking, or expecting an answer to, such a question.
Now, with regard to the question in its new shape, it is obvious that it requires no answer; and that no answer given to it would be explanatory of any real difficulty. For, as in chemistry, no purpose would be gained; no new truth would be evolved by our explaining the connection between two neutral salts, except an observed increase of bulk in one neutral ​ salt; so in explaining the connection between two subject-objects (i.e., between mind-and-matter and mind-and-matter), no new truth could be elicited, no difficulty whatever would be solved, the quantum before us would be merely increased. Some allowance must be made for the imperfection of the above illustration, but we think that it may serve to indicate our meaning. The true state of the case, however, is that there are not really two subject-objects before us, but only one viewed under two different aspects. The subject-object viewed subjectively, is the whole mind of man, not without an external universe along with it, but with an external universe necessarily given in the very giving, in the very conception of that mind. In this case all external nature is our nature, is the necessary integration of man. The subject-object viewed objectively, is the whole external universe, not without mind along with it, but with mind necessarily given in the very giving, in the very conception of that external universe. In this case our nature is external nature, is the necessary integration of the universe. Beginning with the subjective subject-object (mind), we find that its very central and intelligible essence is to have an external world as one with it; beginning with the objective subject-object (the external world), we find that its very central and intelligible essence is to have a mind as one with it. He who can maintain his equilibrium between these two opposite views without falling over either into the one ​(which conducts to idealism) or into the other (which conducts to materialism), possesses the gift of genuine speculative insight.
One important result of this view of the question is, that it demolishes for ever that explanation of perception which is founded on the relation of cause and effect. Because it has been shown that the cause, that is, the object, cannot be conceived at all unless the effect, that is, the perception, be already conceived in inseparable union with it. Therefore, when we say that the object is the cause of our perception, we merely say that that which, when thought, becomes one with our perception, is the cause of our perception. In other words, we are guilty of the glaring petitio principii of maintaining that our perceptions of objects are the causes of our perceptions of objects.
Another important result of the new philosophy is the finishing stroke which it gives to the old systems of dogmatic Realism and dogmatic Idealism. The former of these maintains that an outward world exists, independent of our perceptions of it. The latter maintains that no such world exists, and that we are cognisant merely of our own perceptions. But this new doctrine shows that these systems are investigating a problem which cannot possibly be answered either in the affirmative or the negative; not on account of the limited nature of the human faculties, but because the question itself is an irrational and unintelligible one. For if we say, with ​dogmatic Realism, that an outward world does exist independent of our perception of it, this implies that we are able to separate, in thought, external objects and our perceptions of them. But such a separation we have shown to be impossible and inconceivable. And if, on the other hand, we say, with dogmatic Idealism, that an outward world does not exist independent of our perceptions of it, and that we are conscious only of these perceptions, this involves us in exactly the same perplexity. Because to think that there is no outward independent world, is nothing more than to think an outward independent world away, but to think an independent world away, we must first of all think it; but to think an outward independent world at all, is to be able to make the distinction which we have shown it is impossible for us to make, the distinction, namely, between objects and our perceptions of them. Therefore this question touching the reality or non-reality of an external world cannot be answered, not because it is unanswerable, but because it is unaskable.