It is true of spiritual things as well as of physical ones, in fact it is true of all things, metaphysically speaking, that they are what they are, not "in themselves," not in their abstract nature, but in contact with other things, in reality. In this sense one might say that things are not what they seem, but manifest themselves because they are existent, and they manifest themselves in as many different ways as there are other things with which they enter into relations of time and space. But the statement that things are not what they seem requires, in order to be rightly understood, the modification that whatever manifests itself, exists in nature, and its existence is limited by its manifestations. "We cannot perceive heat itself," says a book on physics written by Professor Koppe, "we merely conclude from its manifestations that it is present in nature." Thus reasons a naturalist whoseeks to understand a thing by practical and diligent study of its manifestations, but who seeks refuge in the speculative belief in a hidden "thing itself" whenever a lack of understanding of the fundamentals of logic embarrasses him. We, on the contrary, conclude that there is no such thing as "heat itself," since it cannot be found, in nature, and we conceive of heat as effects of matter which the human brain translated into the conception of "heat itself." Because science was, perhaps, as yet unable to analyse this conception, the professor says we cannot perceive the natural object which gives rise to this conception. "Heat itself" is simply composed of the sum total of its manifold effects, and there is nothing else to it. The faculty of thought generalizes this variety of effects under the concept of heat in general. The analysis of this conception, the discovery of the general character of the various manifestations of heat, is the function of inductive science. But the conception of heat separated from its effects is a speculative idea, similar to Lichtenberg's knife without handle and blade.
The faculty of thought in touch with sense perceptions produces the nature of things. But it produces them no more independently of things outside than do the eye, the ear, or any other sense of man. It is not the "things themselves" which we see or feel, but their effects on our eyes, hands, etc. The faculty of reason to generalize different perceptions of the eye permits us to distinguish between concrete sights and sight in general. The faculty of thought conceives of any concrete sight as an object of sight in general. It furthermore distinguishes between subjective and objective sight perceptions, the latter being sights which arevisible not alone to the individual eye, but to eyesight in general. Even the visions of a spiritualist, or such subjective impressions as forked lightning, circles of fire, caused by excited blood of closed eyes, serve as objects for the critical consciousness. A glittering object revealed by bright sunlight miles away is no more and no less tangible in substance, no more and no less true, than any optical illusion. A man whose ear is tingling hears something, though it is not the tinkling of bells. Every sense perception is an object, and every object is a sense perception. The object of any subjective mind is a passing manifestation, and every objective perception is but a perishable subject. The object of observation may exist in a more tangible, less approachable, more stable, or more general form, but it is not a "thing itself." It may be perceived not alone by my eyes, but also by those of others, not by the eyes, but also by the feeling, the hearing, the taste, etc. And it may be noticed not alone by men, but also by other objects. But nevertheless it appears only as a manifestation, it is different in different places, it is not today what it is tomorrow. Every existence is relative, in touch with other things, and entering into different relations of time and space with them.
Every sense perception is an actual and natural object. Truth exists in the form of natural phenomena, and whatever is, is true. Substance and attribute are only terms for certain relations. They are not contradictions, and, as a matter of fact, all contradictions disappear before our faculty of generalization and differentiation. For this faculty reconciles all contradictions by finding a general quality in all differences. Existence, or universal truth, is the general object, theraw material, of the faculty of thought. This material is of the utmost variety and supplied by the senses. The senses reveal to us the substance of the universe in the forms of concrete qualities, in other words, the nature of perceptible matter is revealed to the faculty of thought through a variety of concrete forms. It is not perceived as a general essence, but only through interdependent phenomena. Out of the interdependence of the sense perceptions with our faculty of thought there arise quantities, general concepts, things, true perceptions, or understood truths.
Essence and truth are two terms for the same thing. Truth, or the essence and nature of things, is a theoretical concept. As we have seen, we receive impressions of things in two ways, viz., a sense impression and a mental impression, the one practical, the other theoretical. Practice furnishes us with the sense impression, theory with the mental nature of things.
Practice is the premise of theory, sense perception the premise of the nature which is also called the truth. The same truth manifests itself in practice either simultaneously or consecutively in the same place or in different places. It exists theoretically as a homogeneous conception.
Practice, phenomena, sense perceptions, are absolute qualities, that is to say they have no quantitative limitation, they are not restricted by time or space. They are absolute and infinite qualities. The qualities of a thing are as infinite as its parts. On the other hand, the work of the faculty of thought, of theory, creates at will an infinite number of quantities, and it conceives every quality of senseperceptionsin the form of quantities, as the essential nature of things, astruths. Every conception has a quality of some sense perception for its object. Every object can be conceived by the faculty of thought only as a quantitative unit, as true nature, as truth.
The faculty of thought produces in contact with sense perceptions that which manifests itself as true nature, as a general truth. A primitive concept accomplishes this at first only instinctively, while a scientific concept is a conscious and voluntary repetition of this primitive act. Scientific understanding wanting to know an object, such as for instance heat, is not hunting after the phenomena themselves. It does not aim to see or hear how heat melts iron or wax, how it benefits in one case or injures in another, how it makes eggs solid or ice liquid, nor does it concern itself with the difference between the heat of an animal, of the sun, or of a stove. All these things are from the point of view of the faculty of understanding, only effects, phenomena, qualities. It desires to get at the essence, the true nature of things, it strives to find a general law, a concise scientific extract, of things seen, heard, and felt. The abstract nature of things cannot be a tangible object. It is a concept of theory, of science, of the faculty of thought. The understanding of heat consists in singling out that which is common to all phenomena of heat, which is essential or true for all heat.Practically the nature of heat consists of the sum total of all its manifestations, theoretically in its concept, scientifically in the analysis of this concept. To analyze the concept of heat means to ascertain that which is common to all manifestations of heat.
The general nature of the thing is its true nature,the general quality its true quality. We define rain more truly as being wet than as being fertilizing, because it gives moisture wherever it falls, while it fertilizes only under certain circumstances and in certain places. My true friend is one who is constant and loyal to me all my life under all circumstances. Of course, we must not believe in any absolute and unconditional friendship any more than in any absolute and eternal truth. Perfectly true, perfectly universal, is only the general existence, the universe, the absolute quantity. But the real world is absolutely relative, absolutely perishable, an infinity of manifestations, an infinity of qualities. All truths are simply parts of this world, partial truths. Semblance and truth flow dialectically into one another like hard and soft, good and bad, right and wrong, but at the same time they remain different. Even though I know that there is no rain which is "fertile in itself," and no friend who is true in an absolute sense, I may nevertheless refer to a certain rain as fertile in relation to certain crops, and I may distinguish between my more or less true friends.
The universe is the truth. The universe is that which is universal, that is, things which exist and are perceived. The general mark of truth is existence, because universal existence is truth. Now, existence is not a general abstraction, but a reality in the concrete form of sense perceptions. The world of sense perceptions has its true and perceptible existence in the passing and manifold manifestations of nature and life. Therefore all manifestations are recognized as relative truths, all truths as concrete and temporal manifestations. The manifestation of practice isconsidered as a truth in theory, and vice versa, the truth of theory is manifested in practice. Opposites are mutually relative. Truth and error differ only comparatively, in volume of degree, like being and seeming, life and death, light and dark, like all other opposites in the world. It is a matter of course that all things of this world are worldly, consequently are of the same matter, the same nature, the same family, the same quality. In other words, every volume of perceptible manifestation forms in contact with the human faculty of thought a being, a truth, a general thing. For our consciousness, every particle of dust as well as every dust cloud, or any other mass of material manifestations, is on the one hand an abstract "thing in itself," and on the other a passing phenomenon of the absolute object, the universe. Inside of this universe the various manifestations are systematized or generalized at will and on purpose by means of our mind. The chemical element is as much a manysided system as the organic cell or the whole vegetable kingdom. The smallest and the largest being is divided into individuals, species, families, classes, etc. This systematization, this generalization, this generation of beings is continued in an ascending scale up to the infinity of the universe, and in the descending scale down to the infinity of the parts. In the eyes of the faculty of thought all qualities become abstract things, all things relative qualities.
Every thing, every sense perception, no matter how subjective or shortlived it may be, is true, is a certain part of truth. In other words, the truth exists, not only in the general existence, but every concrete existence has also its own distinct generality or truth. Everyobject, whether it be a mere passing idea, or a volatile scent, or some tangible matter, constitutes a sum of manifold phenomena. The faculty of thought turns various quantities into one, discerns the equality in different things, seeks the unity in the multiplicity. Mind and matter have at least actual existence in common. Organic nature agrees with inorganic nature in being material. It is true that there are wide divergences between man, monkey, elephant, and plants attached to the soil, but even greater differences are reconciled under the term "organism." However much a stone may differ from a human heart, thinking reason will discover innumerable similarities in them. They at least agree in being matter, they are both visible, tangible, and may be weighed, etc. Their differences are as manifold as their likenesses. Solomon truly says that there is nothing new under the sun, and Schiller also says truly that the world grows old and again grows young. What abstract thing, being, existence, generality is there that is not manifold in its sense manifestations, and individually different from all other things? There are no two drops of water alike. I am now in many respects different from what I was an hour ago, and the likeness between my brother and myself is only relatively greater than the likeness between a watch and an oyster. In short, the faculty of thought is a faculty of absolute generalization, it classes all things without exception under one head, it comprises and understands everything uniformly, while sense perceptions show absolutely everything in a different, new and individual light.
If we apply this metaphysics[1]to our study, thefaculty of thought, we see that its functions, like all other things, are material manifestations, which are all equally true. All manifestations of the mind, all ideas, opinions, errors, partake of a certain truth, all of them have a kernel of truth. Just as inevitably as a painter derives all forms of his creation from perceptible objects around him, so are all ideas, images of true things, theories of true objects. So far as perceptions are perceptions, it is a matter of course that all perceptions perceive something. So far as knowledge is knowledge, it requires no explanation that all knowledge knows something. This follows from the rule of identity, according to which a equals a, or from the rule of contradiction, according to which 100 is not 1,000.
All perceptions are thoughts. One might claim, on the other hand, that all thoughts are not perceptions. One might define "perceiving" as a special kind of thought, as real objective thought in distinction from supposing, believing, or imagining. But it cannot be denied that all thoughts have a common nature, in spite of their many differences. Thought is treated in the court of the faculty of thought like all other things, it is made uniform. No matter how different the thoughts I had yesterday may be from those I have to-day, no matter how much the thoughts of different human beings may vary at different times, no matter how clearly we may distinguish between such thoughts as those expressed by the terms idea, conception, judgment, conclusion, impression, etc., they each and all possess the same common and universal nature, because all of them are manifestations of mind.
It follows, then, that the difference between true and erroneous thoughts, between understanding and misunderstanding, like all other differences, is only relative. A thought "in itself" is neither false nor true, it is either of these only in relation to some other object. Thoughts, conceptions, theories, natures, truths, all have this in common that they belong to some object. We have seen that any object is a part of the multiplicity of sense perceptions in the world outside of our brains. After as much of the universal being as constitutes the object which is to be understood has been defined by some customary term of language, truth is to be found in the discovery of the general nature of this perceptible part of being.
The perceptible parts of being which constitute the things of this world have not only a semblance and manifestation, but also a true nature which is given by means of their manifestation. The nature of things is as infinite in number as the world of sense perceptions is infinitely divisible in space and time. Every part of any phenomenon has its own nature, every special phenomenon has its general truth. A phenomenon is perceived in touch with the senses, while the true or essential nature of things is perceived in contact with our faculty of thought. In this way we find ourselves face to face with the necessity of speaking here, where the nature of things is up for discussion, simultaneously of the faculty of thought, and on the other hand of dealing with the nature of things when the faculty of thought is our main subject.
We said at the outset: The criterion of truth includes the criterion of reason. Truth, like reason,consists in developing a general concept, or an abstract theory, from a given sum of sense perceptions. Therefore it is not abstract truth which is the criterion of true understanding, but we rather refer to that understanding as being true which produces the truth, or the general hall-mark of any concrete object. Truth must be objective, that is to say it must be the truth about some concrete object. Perceptions cannot be true to themselves, they are true only in relation to some definite object, and to some outside facts. The work of understanding consists in the abstraction of the general hall-mark from concrete objects. The concrete is the measure of the general, the standard of truth. Whatever is, is true, no matter how much or how little true it may be. Once we have found existence, its general nature follows as truth itself. The difference between that which is more or less general, between being and seeming, between truth and error, is limited to definite conditions, for it presupposes the relation to some special object. Whether a perception is true or false will, therefore, depend not so much on perception as on the scope of the question which perception tries to solve of its own accord or which it is called upon to solve by external circumstances. A perfect understanding is possible only within definite limits. A perfect truth is one which is always aware of its imperfection. For instance, it is perfectly true that all bodies have weight only because the concept of "body" has previously been limited to things which have weight. After reason has assigned the conception of "body in general" to things of various weights, it is no longer a matter for surprise to find that bodies must inevitably haveweight. Once it is assumed that the term "bird" was abstracted exclusively from flying animals, we may be sure that all birds fly, whether they are in heaven, on earth, or in any other place. And to explain this we do not require the belief ina prioriconceptions which are supposed to differ from empirical conceptions by their strict necessity and generality. Truths are valid only under certain conditions, and under certain conditions errors may be true. It is a true perception that the sun is shining, provided we understand that the sky is not covered by clouds. And it is no less true that a straight stick becomes crooked in flowing water, provided we understand that this truth is an optical one.Truth is that which is common or general to our reasoning faculty within a given circle of sense perceptions. To call within a definite circle of sense perceptions that which is exceptional or special the rule or the general, is error.Error, the opposite of truth, arises when the faculty of thought, or consciousness, inadvertently or shortsightedly and without previous experience concedes to certain phenomena a more general scope than is supported by the senses, for instance when it hastily attributes to what is in fact only an optical existence, a supposed plastic existence also.
The judgment of error is a prejudice. Truth and error, understanding and misunderstanding, knowing and not knowing, have their common habitation in the faculty of thought which is the organ of science. Thought at large is the general expression of experienced facts perceived by the senses, and it includes errors as well. Error is distinguished from truth in that the former assigns to any definite fact of whichit is a manifestation, a wider and more general existence than is supported by sense perceptions and experience. Unwarranted assumption is the nature of error. A glass bead does not become a counterfeit, until it pretends to be a genuine pearl.
Schleiden says of the eye: "When the excited blood expands the veins and presses on the nerves, we feel it in the fingers as pain, we see it in the eyes as forked lightning. And thus we obtain the irrefutable proof that our conceptions are free creations of the mind, that we do not perceive the external world as it really is, but that its reflex actions on us simply give rise to a peculiar brain activity, on our part. The products of this activity are frequently connected with certain processes of the external world, but frequently they are not. We close our eyes and we see a circle of light, but there is in reality no shining body. It is easy to see that this may be a great and dangerous source of errors of all kinds. From the teasing forms of a misty moonlight night to the threatening and insanity-producing visions of the believer in ghosts we meet a series of illusions which are not derived from any direct processes of external nature, but belong to the field of the free activity of the mind which is subject to error. It requires great judgment and wide education, before the mind learns to break away from all its own errors and to control them. Reading in general seems so easy, and yet it is a difficult art. It is only by degrees that the mind learns to understand which of the messages of the nerves may be trusted and used as a basis for conceptions. The light, if we consider it entirely by itself, is not clear, not yellow, nor blue nor red. The light is amovement of a very fine and everywhere diffused substance, the ether."
The beautiful world of light and splendor, of color and form, is supposed not to be a perception of something which really is. "Through the thick covering of the grape arbor, a ray of sunlight undulates into the cooling shadows. You think you see the ray of light itself, but what you really see is nothing but a flock of dust particles." The truth about light and color is said to be that they are "waves rushing through ether in restless succession at the rate of 160,000 miles per second." This true physical nature of light and color is supposed to be so illusive, that "it required the sharp intellects of the greatest thinkers to reveal to us this true nature of light. We find that every one of our senses is susceptible only to definite external influences, and that the stimulation of different senses produces different conceptions in our mind. Thus the sense organs are the mediators between the external soulless world (undulations of the ether), which is revealed to us by science, and the beautiful world of sense perceptions in which we find ourselves with our minds."
Schleiden thus gives an illustration of the fact that there is still a great deal of embarrassment, even in our times, when the understanding of these two worlds is under discussion, that there is still much helpless groping to explain the connection between the world of thought, of knowledge or science, which is in this case represented by undulations of the ether, and between the world of our five senses, represented by the bright and colored lights of the eyes or of reality. At the same time this illustration shows howqueer the traditional survivals of speculative philosophy sound in the mouth of a modern scientist. The confused condition of this mode of thought is seen in the distinction between "an external sense-perceived world of science" and another one, "in which we find ourselves with our minds." The distinction between the senses and the mind, between theory and practice, between the special and the general, between truth and error, has been noticed by such thinkers, but they have no solution for it. They know there is something missing, but they do not know where to look for it, and therefore they are confused.
The great scientific achievement of the XIXth century consists in the victory over speculation, over knowledge without sense perception, in the delivery of the senses from the thraldom of such knowledge, and in the foundation of empirical investigation. To acknowledge the theoretical value of this achievement means to come to an understanding about the source of error. Contrary to a philosophy that tries to discover truth with the mind, and error with the senses, we seek for truth with the senses and regard the mind as the source of errors. The belief in certain messages of the nerves which are alone worthy of confidence and which can be understood only by degrees without any specific mark of distinction, is a superstition. Let us have confidence in all testimonials of the senses. There is nothing false to be separated from the genuine. The supernatural mind idea is the only deceiver whenever it undertakes to disregard the sense perceptions, and, instead of being the interpreter of the senses, tries to enlarge their statements and repeat what has not been dictated. The eye, in seeing forkedlightning or radiant circles when the blood is excited or a pressure exerted on it, perceives no more errors than it does in perceiving any other manifestation of the external world. It is our faculty of thought which makes a mistake, by regarding without further inquiry such subjective events as objective bodies. One who sees ghosts does not commit any mistake, until he claims that his personal apparition is a general phenomenon, until he prematurely takes something for an experience which he has not experienced. Error is an offense against the law of truth which prescribes to our consciousness that it must remember the limits within which a perception is true, or general. Error makes out of something special a generality, out of a predicate a subject, and takes the part for the whole. Error makesa prioriconclusions, while truth, its opposite, arrives at understanding bya posteriorireasoning.
A priorianda posterioriunderstanding are related in the same way as philosophy and natural science, taking the latter in the widest meaning of the term, that of science in general. The contrast between believing and knowing is duplicated in that between philosophy and natural science. Speculative philosophy, like religion, lives on faith. The modern world has transformed faith into science. The reactionists in politics who demand that science retrace its steps desire its return to faith. The content of faith is acquired without exertion. Faith makesa prioriperceptions, while science arrives at its knowledge by harda posterioristudy. To give up faith means to give up taking things easy. And to confine science toa posterioriknowledge means to decorate it with the characteristic mark of modern times, work.
It is not a result of scientific study, but merely a freak of philosophy on the part of Schleiden to deny the reality and truth of light phenomena, to call them fantasmagoria created by the free play of the mind. His superstitious belief in philosophical speculation misleads him into abandoning the scientific method of induction and speaking of "waves rushing through ether in restless succession at the rate of 160,000 miles per hour" as being the real and true nature of light and color, in contradistinction to the color phenomena of light. The perversion of this mode of procedure becomes evident by his referring to the material world of the eyes as a "creation of the mind" and to the undulations of the ether, revealed by the "sharp intellect of the greatest thinkers" as "physical nature."
The truth of science maintains the same relation to the sense perception that the general does to the special. Waves of light, the so-called truth of light and color, represent the "true" nature of light only in so far as they represent what is common to all light phenomena, whether they are white, yellow, blue, or any other color. The world of the mind, or of science finds its raw material, its premise, its proof, its beginning, and its boundary in sense perception.
When we have learned that the nature, or the truth, of things is not back of their phenomena, but can be perceived only by the help of phenomena, and that it does not exist "in itself," but only in connection with the faculty of understanding, that the nature is separated from the phenomena only by thought; and when we see on the other hand, that the faculty of understanding does not derive conceptions out of itself, but only out of their relations with somephenomenon; then this discussion of the "nature of things" is an evidence that the nature of the faculty of thought is a conception which we have obtained from its sense manifestations. To understand that the faculty of thought, although universal in the choice of its objects, is nevertheless limited in that it requires some object; to recognize that the true thought process, that is to say the thought with a scientific result, differs from unscientific thinking by consciously attaching itself to some external object; to realize that truth, or universality, is not perceived "in itself," but can be perceived only by means of some given object; this frequently varied statement reveals the nature of the faculty of thought. This statement re-appears at the end of every chapter, because all special truths, all special chapters, serve only to demonstrate the general chapter of universal truth.
FOOTNOTE:[1]E. g., this all-embracing physics.—Editor.
[1]E. g., this all-embracing physics.—Editor.
[1]E. g., this all-embracing physics.—Editor.
Although we know that reason is attached to perceptible matter, to physical objects, so that science can never be anything else but the science of the physical, still we may, according to the prevailing ideas and usage of language, separate physics from logic and ethics, and thus distinguish them as different forms of science. The problem is then to demonstrate that in physics as well as in logic, as also in ethics, the general or intellectual perceptions can be practically obtained only on the basis of concrete perceptible facts.
This practice of reason, to generate thought from matter, to arrive at understanding by sense perceptions, to produce the general out of the concrete, has been universally accepted in physical investigation, but only in practice. The inductive method is employed, and one is aware of this fact, but it is not understood that the nature of inductive science is the nature of science in general, of reason. The process of thought is misunderstood. Physical science lacks the theory of understanding and for this reason often falls out of its practical step. The faculty of thought is still an unknown, mysterious, mystical being for natural science. Either it confounds the function with the organ, the mind with the brain, as do thematerialists, or it thinks with the idealists that the faculty of thought is an imperceptible object outside of its field. We see modern investigators marching toward their goal with firm and uniform steps, so far as physical matters are concerned. But they aimlessly grope around in the abstract relations of these things. The inductive method has been practically adopted by natural science and its successes have secured a great reputation for it. On the other hand, the speculative method has become discredited by its failures. There is, however, no conscious understanding of these various methods of thought. We see the men of physical research, when they are outside of their special field, offer lawyer-like speculations in lieu of scientific facts. While they arrive at the special truths of their chosen fields by sense perceptions, they still pretend to derive speculative truths out of the depths of their own minds.
Listen to the following statements of Alexander von Humboldt, which he makes in the initial argument of his "Cosmos" in regard to speculation: "The most important result of physical research by sense perception is this: that it finds the element of unity in a multitude of forms; that it grasps all the individual manifestations offered by the discoveries of recent times, carefully scrutinizes and distinguishes them; yet does not succumb under their mass; that it fulfills the sublime mission of the human being, of understanding the nature of things which is hidden under the cover of phenomena. In this way our aim reaches beyond the narrow limits of the senses, and we may succeed in grasping the nature by controlling the raw material of empirical observation throughideas. In my observations of the scientific treatment of general cosmic phenomena, I am not deriving unity out of a few fundamental principles found by speculative reason. My work is the expression of a thoughtful observation of empirical phenomena seen as one and the same nature. I am not going to venture into a field which is foreign to me. What I call physical cosmology does not, therefore, aspire to the rank of a rational science of nature.... True to the character of my former occupation and writings, which were devoted to experiments, measurements, and investigations of facts, I confine myself in this work to empirical observations. It is the only ground on which I can move with a measure of security." In the same breath Humboldt says that "without the earnest desire for the knowledge of concrete facts any great and universal world philosophy would be merely a castle in the air" and in another place that "an understanding of the universe by speculative and introspective reason would represent a still more sublime aim" than understanding by empirical thought. And on page 68 of volume I. he says: "I am far from finding fault with endeavors of others the success of which still remains in doubt, when I have had no practical experience with them."
Now natural science shares with Humboldt the consciousness that the practice of reason in physical research consists exclusively in "perceiving the element of unity in a multitude of forms." But on the other hand, though it does not always admit its belief in speculative introspection as frankly as Humboldt does, it nevertheless proves that it does not fully understand the practice of science and that it believesin a metaphysical as well as a physical science by using the speculative method in the treatment of so-called philosophical topics, in which the element of unity is supposed to be discovered by introspective reason instead of an analysis of multiform sense perceptions, and it demonstrates its lack of unity by being unaware of the unscientific character of disagreements, by believing in a metaphysical science outside of the physical domain. The relations between phenomenon and its nature, cause and effect, matter and force, substance and spirit, are certainly physical ones. But what is there of unity that science teaches about them? Plainly then, the work of science, like that of the farmer, has so far been done only practically, but not scientifically, not with a predetermination of success. Understanding, that is to say the practice of understanding, is well applied in science, I readily admit. But the instrument of this understanding, the faculty of thought, is misunderstood. We find that natural science, instead of applying this faculty scientifically, simply experiments with it. What is the reason for this? Natural science has neglected the critique of reason, the theory of science, logic.
Just as the handle and the blade of a knife constitute its general content, so we found that the general content of reason was the universal, the general "itself." We know that it does not produce this content out of itself, but out of given objects, and these objects are the sum of all natural or physical things. The object of reason is, therefore, an infinite, unlimited, absolute quantity. This infinite quantity manifests itself in finite quantities. In the treatment of relatively small quantities of nature the true essence of reason,the true method of understanding, is well recognized. It remains to be demonstrated that the great relations of the world, the treatment of which is still doubtful, are likewise intelligible by the same method. Cause and effect, mind and matter, matter and force, are such great world problems, and they are of a physical character. We shall demonstrate that the most general distinction between reason and its object furnishes the key to the solution of the great world problems.
(a) Cause and Effect.
"The nature of natural history," says F. W. Bessell, "lies in the fact that it does not consider phenomena as facts in themselves, but looks for their causes. The knowledge of nature is thus reduced to the minimum number of facts." But the causes of the phenomena of nature had been investigated even before the age of natural history. The characteristic mark of natural history is not so much that it investigates causes, but that the causes which it investigates have a peculiar nature and a particular quality.
Inductive science has materially changed the conception of causes. It has retained the term, but uses it in a different sense from that employed by speculation. The naturalist conceives of causes differently within his special field and outside of it; here, outside of his specialty, he frequently indulges in introspective speculation, because he understands science and its cause in a concrete, but not in a general way. The unscientific forces are of a supernatural make-up, they are transcendental spirits, gods, forces, little and big goblins. The original conception of causes is an anthropomorphic one. In a state of inexperience, man measures the objectiveby a subjective standard, judges the world by himself. Just as he creates things with conscious intent, so he attributes to nature his human manner, imagines the existence of an external and creative cause of the phenomena of sense perception, similar to himself who is the special cause of his own creations. This subjective mood is to blame for the fact that the struggle for objective understanding has so long been in vain. The unscientifically conceived cause is a speculation of thea priorikind.
If the term understanding is retained for subjective understanding, then objective science differs from it in that such a science penetrates to the causes of its objects not by faith or introspective speculation, but by experience and induction, nota priori, buta posteriori. Natural science looks for causes not outside or back of nature's phenomena, but within or by means of them. Modern research seeks no external creator of causes, but rather the immanent system, the method or general mode of the various phenomena as they are given by succession in time. The unscientifically conceived cause is a "thing in itself," a little god who generates his effects independently and hides behind them. The scientific conception of causes, on the other hand, looks only for the theory of effects, the general element of phenomena. To investigate a cause means then to generalize a variety of phenomena, to arrange the multiplicity of experienced facts under one scientific rule. "The knowledge of nature is thus reduced to the minimum number of facts."
The commonplace and inept knowledge differs from the most exalted, rarest, and newly discovered science in the same way in which a petty and childishsuperstition differs from the historical superstition of a whole period. For this reason we may well choose our illustrations from our daily circle, instead of looking for them in the so-called higher regions of a remote science. Human common sense had long practiced the investigation of causes by inductive and scientific methods, before science realized that it would have to pursue its higher aims in the same way. Common sense does arrive at the faith in a mysterious cause of speculative reason, just like the naturalist, as soon as it leaves the field of its immediate environment. In order to stand firmly on the ground of real science, every one requires the understanding of the manner in which inductive reason investigates its causes.
To this end let us glance briefly at the outcome of the study of the nature of reason. We know that the faculty of understanding is not a "thing in and by itself," because it becomes real only in contact with some object. But whatever we know of any object, is known not alone through the object, but also through the faculty of reason. Consciousness, like all other being, is relative. Understanding is contact with a variety of objects. To knowledge there is attached distinction, subject and object, variety in unity. Thus things become mutual causes and mutual effects. The entire world of phenomena, of which thought is but a part, a form, is an absolute circle, in which the beginning and end is everywhere and nowhere, in which everything is at the same time essence and semblance, cause and effect, general and concrete. Just as all nature is in the last instance one sole general unity, in view of which all otherunities become a multitude, so this same nature, or objectivity, or world of sense perceptions, or whatever else we may call the sum of all phenomena or effects, is the final cause of all things, compared to which all other causes become effects. But we must remember that this cause of all causes is only the sum of all effects, not a transcendental or superior being. Every cause has its effect, every effect causes something.
A cause cannot be physically separated from its effect any more than the visible can be separated from the eye, the taste from the tongue, in brief the general from the concrete. Nevertheless, the faculty of thought may separate the one from the other. We must keep in mind that this separation is a mere formality of thought, although it is a formality which is necessary in order to be reasonable or conscious, in order to act scientifically. The practice of understanding, or scientific practice, derives the concrete from the general, the natural things from nature. But whoever has been behind the scenes, and has looked at the faculty of thought at work, knows that, conversely the general is derived from the concrete, the concept of nature from natural things. The theory of understanding or science teaches us that the antecedent is understood by its consequent, the cause by its effect, while our practical understanding regards the after as a consequence of the before, the effect as a result of the cause. The faculty of understanding, the organ of generalization, regards its opposite, the concrete, as secondary, while the faculty of thought which understands itself regards it as primary. However, the practice of understanding is not to be changed by itstheory, nor can it be; the theory intends simply to render the steps of consciousness firm. The scientific farmer differs from the practical farmer, not because he employs theory and method, for both do that, but because he understands the theory, while the practical man theorizes instinctively.
To continue: From a given multitude of facts, reason generates truth in general, and out of a succession of forms and transformations it abstracts the true cause, just as absolute multiplicity is the nature of space, so absolute variability is the nature of time. Every particle of time and space is new, original, and has never been there before. The faculty of thought enables us to find our way through this absolute medley by abstracting general concepts out of the multitude of things in space, and tracing the variations of time to general causes. The entire nature of reason consists in generalizing sense perceptions, in abstracting the common elements out of concrete things. Whoever does not fully understand reason by understanding that it is the organ of generalization forgets that understanding requires an object which must remain something outside of its conception, since such object cannot be dissolved by its conception. The being of the reasoning faculty cannot be understood any more than being in general. Or rather, being is understood when we take it in its generality. Not being itself, but the general element of being, is understood by the faculty of thought.
Let us realize, for instance, the process which takes place when reason understands something it did not know before. Think of some peculiar, unexpected and unknown chemical transformation which takesplace suddenly and without apparent cause in some mixture. Assume furthermore that the same reaction takes place more frequently after that, until experience demonstrates that this inexplicable change occurs whenever sunlight touches the mixture. This already constitutes a certain understanding of the process. Assume furthermore that subsequent experience teaches us that several other substances have the faculty of producing the same reaction in connection with sunlight. We have then arranged the new reaction in line with a number of phenomena of the same class, that is to say we have enlarged, deepened, completed our understanding of it still more. And if we finally discover that a special part of the sunlight unites with a special element of the mixture and thereby produces this new reaction, we have generalized this experience, or experienced this generalization, in a "pure" state, in other words, the theory of this reaction is complete, reason has solved its problem, and yet it has done nothing more than it did when it classified the animal and vegetable kingdoms in families, genera, species, etc. To find the species, the genus, the sex, etc., of anything means to understand it.
Reason proceeds in the same way when it investigates the causes of certain transformations. Causes are, in the last instance, not noticed and furnished by means of sight, hearing, feeling, not by means of the sense perceptions. They are rather supplied by the faculty of thought. It is true, causes are not the "pure" products of the faculty of thought, but are produced by it in connection with sense perceptions and their material objects. This raw material givesthe objective existence to the causes produced by the mind. Just as we demand that a truth should be the truth about some objective phenomenon, so we also demand that a cause should be real, that it should be the cause of some objective effect.
The understanding of any concrete cause is conditioned on the empirical study of its material, while the understanding of any general cause is based on the study of the faculty of reason. In the understanding of concrete causes, the material of study varies, but reason maintains a constant or general attitude. The cause, as a general cause, is a pure conception, and it is based on the study of the multiformity of concrete understandings of causes, or on the multiplied study of concrete causes. Hence we are compelled to return to the concrete material of the general concept, to the understanding of concrete causes, if we wish to analyze the concept of a general cause.
When a stone falls into the water and causes ripples on the surface, the stone is no more the cause of the ripples than the liquid condition of the water. If the stone falls on solid substances, it causes no ripples. It is the contact of the falling stone with liquid substances which causes the ripples. The cause is itself an effect, and the effect, the ripples, become a cause when they carry a piece of cork ashore. But in either case the cause is based on a mutual effect, on the interaction of the waves with the light condition of the cork.
A stone falling into the water is not a cause "in itself," not a cause in general. We arrive at such a cause only, when the faculty of thought uses concrete causes for its raw material and constructs out of themthe "pure" concept of the cause in general. A stone falling into the water is only the cause of the subsequent ripples, and it becomes a general cause only through the experience that ripples always follow the falling of a stone into water.
We call cause that which generally precedes a certain manifestation, and effect that which generally follows it. We refer to the stone as the cause of ripples merely because we know that it always causes them when falling into water. But since ripples sometimes appear without being preceded by the fall of a stone, ripples have another general cause. So far as there is anything general in ripples which precedes them, it is the elasticity of the water itself which is the general cause of ripples. Circular ripples, which are a special form of ripples, are generally preceded by the falling of some body into the water, and this body is then considered as their cause. The cause is always different in proportion and to the extent of the phenomena under consideration.
We cannot ascertain causes by mere introspective reasoning, we cannot derive them out of our head. Matter, materials, sense perceptions are required for this purpose. A definite cause requires a definite material, a definite amount of sense perceptions. In the abstract unity of nature, the variations of matter are represented by the variations of concrete quantities. Every quantity is given in time before and after a certain other quantity, as antecedent and subsequent. The general element of the antecedent is called cause, the general element of the subsequent, effect.
When the wind sways a forest, the yielding character of the forest is as much instrumental in producingthis effect as the bending power of the wind. The cause of a thing is its connection with other things. The fact that the same wind leaves rocks and walls standing shows that the cause is not qualitatively different from the effect, but that it is a matter of aggregate effects. If nevertheless science or knowledge determines any special fact to be the cause of any change, that is to say of any succession of phenomena, this cause is no longer regarded as the external creator, but merely as the general mode, the immanent method of succession. A definite cause can be ascertained only when we have under consideration a definite circle, series, or number of changes, the cause of which is to be determined. And within a definite circle of succeeding phenomena, that which generally precedes is their cause.
The wind which sways a forest differs from wind as a general cause only in that the latter has other general effects, inasmuch as it howls in one place, stirs up dust in another, or acts in many different ways. In the special case of the forest, the wind is a cause only in so far as it precedes the swaying of the trees. But in the case of rocks and walls, the solidity precedes the wind and is therefore the general cause of their resistance to the swaying power of the wind. In a still wider circle of hurricane phenomena, a gentle wind may be regarded as a cause of the stability of the objects last mentioned.
Thequantityornumberof given objects varies the name of their cause. If a certain company of people return from a walk in a tired condition, this change of condition is just as much due to the physical weakness of the people as to the walk. In other words,a manifestation has in itself no cause which can be separated from it. Everything which was connected with a phenomenon has contributed toward its appearance. In the case of the promenaders, the physical constitution of their bodies has to be considered as well as the physical constitution and length of the road and duration of the walk. If reason is nevertheless called upon to determine the special cause of some concrete change, for instance, of a tired feeling, it is simply a question of determining which one of the various factors has contributed most to that feeling. In this case as well as in all others, the work of reason consists in developing the general from the concrete, that is to say in this case, singling out from a given number of tired sensations that which generally precedes the tired feeling. If most of the promenaders or all of them are found to be tired, the walk will be considered as the cause. But if only a few are tired, the weak constitution of these people will be considered as the general cause of their tired condition.
To use another illustration: If the discharge of a shot frightens some birds, this effect is due to the combined action of the shot and the timidity of the birds. If the majority of the birds fly away, the shot will be considered as the cause. But if the minority fly away, their timidity will be regarded as the cause.
Effects are subsequences. Since all things in nature follow other things and all things have an antecedent and a subsequent, we may call the natural, the real, the sense perceptions absolute effects, having no cause unless we find one with our faculty of thought by systematizing the given material. Causes are mental generalizations of perceptible changes. Thesupposed relation of cause and effect is a miracle, a creation of something out of nothing. For this reason this relation has been and still is an object of speculative reasoning. The speculative cause creates its effects. But in reality the effects are the material out of which the brain, or science, forms its causes. The cause concept is a product of reason; not of "pure" reason, but of reason married to the world of sense perceptions.
If Kant maintains that the statement: "Every change has its cause" is ana priori truthwhich we cannot experience because no one can possibly experience all changes, although every one has the irrefutable feeling of the correctness of this statement, we know now that this statement expresses merely the experience that the phenomenon which we call reason recognizes the uniform element in all multiformity. Or in other words, we now know that the development of the general element out of the concrete facts is called reason, thought, or mind. The secure knowledge that every change has its cause is nothing else but the conviction that we are thinking human beings.Cogito, ergo sum.I think, therefore I am. We have experienced the nature of our reason instinctively even if we have not analyzed it scientifically. We are as well aware of the faculty of our reason to abstract a cause out of every given change, as we are that every circle is round, that a is equal to a. We know that the general is the product of reason, and reason produces this general thing in contact with every given object. And since all objects before and after a certain other object are temporal changes, it follows that all changes which we as thinking beings experience must have a general antecedent, a cause.
Already the English sceptic Hume felt that true causes are different from assumed causes. According to him the concept of a cause contains nothing but the experience of that which generally precedes a certain phenomenon. Kant rightfully remarks on the other hand that the conception of cause and effect expresses a far more intimate relation than that indicated by a loose and accidental succession, and that the concept of a cause rather comprises that of a certain effect as a necessity and strict general result. Therefore he claimed that there must be somethinga prioriin reason which cannot be experienced and which extends beyond experience.
We reply to the materialists who deny all autonomy of the mind and hope to detect causes by experience alone that the general necessity which presupposes the relation of cause and effect represents an impossible experience. And we reply to the idealists: Although reason explores causes which cannot be experienced, this research cannot take placea priori, but onlya posteriori, only on the basis of empirically given effects. It is true that the mind alone discovers the imperceptible and abstract generality, but it does so only within the circle of certain given sense perceptions.
(b) Matter and Mind.
The understanding of the general dependence of the faculty of thought on material sense perceptions will restore to objective reality that right which has long been denied to it by ideas and opinions. Nature with its varied concrete phenomena which had been crowded out of human considerations byphilosophical and religious imaginings, and which has been scientifically re-established again on special fields by the development of natural sciences, gains general theoretical recognition by the understanding of the functions of the brain. Hitherto natural science has chosen for its object only special matters, special causes, special forces, but has remained ignorant in general questions of so-called natural philosophy regarding the cause of all things, of matter, of force in general. The actual existence of this ignorance is revealed by that great contradiction between idealism and materialism which pervades all works of science like a red thread.
"May I succeed in this letter in strengthening the conviction that chemistry as an independent science represents one of the most powerful means for the higher cultivation of the mind, that its study is useful not alone for the promotion of the material interests of mankind, but because it permits a deeper penetration of the wonders of creation, with which our existence, our welfare, and our development are intimately connected."
In these words Liebig expresses the prevalent views which have accustomed themselves to look upon material and spiritual differences as absolute opposites. But the untenability of such a distinction is vaguely felt even by the just quoted advocate of this view, who speaks of material interests and of a mental penetration which is the condition for our existence, welfare, and development. But what else does the term material interests mean but the abstract expression of our existence, welfare, and development? Are not these the concrete content of our material interests?Does he not say explicitly that the penetration of the wonders of creation promotes our material interests? And on the other hand, does not the promotion of our material interests require a penetration on our part of the wonders of creation? In what respect are our material interests different from our mental penetration of things?
The superior, spiritual, ideal, which Liebig in conformity with the views of the world of naturalists opposes to our material interests, is only a special part of those interests. Mental penetration and material interests differ no more than the circle differs from the square. Circles and squares are contrasts, but at the same time they are but different and special classes of form in general.
It has been the custom, especially since the advent of Christian times, to speak contemptuously of material, perceptible, fleshly things which are destroyed by rust and moths. And nowadays people continue on this conservative track, although their antipathy against perceptible reality has long disappeared from their minds and actions. The Christian separation of mind and body has been practically abandoned in the age of natural science. But the theoretical solution of the contradiction, the demonstration that the spiritual is material and the material at the same time spiritual, by which the material interests would be freed from the stigma of inferiority, has not yet been forthcoming.
Modern science is natural science. Science is deemed worthy of its name only in so far as it is natural science. In other words, only that thought is scientific which consciously has real, perceptible,natural things for its object. For this reason representatives and friends of science can not be enemies of nature or of matter. Indeed they are not. But the very existence of science shows that this nature, this world of sense perceptions, this matter or substance, does alone and by itself not satisfy us. Science, or thought, which has material practice or being for its object, does not strive to reproduce nature in its integrity, in its entire perceptible substance, for these are already present. If science were to aim at nothing new, it would be superfluous. It is entitled to special recognition only to the extent that it carries a new element into matter. Science is not so much concerned in the material of its study as in understanding. Of course it is the understanding of this material which is desired, the understanding of its general character, of the fixed pole in the succession of phenomena. That which religion supernaturally separates from the material, which science opposes to the material as something higher, diviner, more spiritual, is in reality nothing but the faculty of rising above multiformity, of proceeding from the concrete to the general.
The nobler spiritual interests are not absolutely different from the material interests, they are not qualitatively different. The positive side of modern idealism does not consist in belittling eating and drinking, the pleasure in earthly possessions and in intercourse with the other sex, but rather in pleading for the recognition of other material enjoyments besides these, as for instance those of the eye, the ear, of art and science, in short of the whole man. You shall not indulge in the material revelries of passion, that is to say you shall not direct your thought one-sidedlyto any concrete lust, but rather consider your entire development, take into account the total general extension of your existence. The bare materialist principle is inadequate in that it does not appreciate the difference between the concrete and the general, because it makes the individual synonymous with the general. It refuses to recognize the quantitative superiority of the mind over the world of sense perceptions. Idealism, on the other hand, forgets the qualitative unity in the quantitative difference. It is transcendental and makes an absolute difference out of the relative one. The contradiction between these two camps is due to the misunderstood relation of our reason to its given object or material. The idealist regards reason alone as the source of all understanding, while the materialist looks upon the world of sense perceptions in the same way. Nothing is required for a solution of this contradiction but the comprehension of the relative interdependence of these two sources of understanding. Idealism sees only the difference, materialism sees only the uniformity of matter and mind, content and form, force and substance, sense perception and moral interpretation. But all these distinctions belong to the one common genus which constitutes the distinction between the special and the general.
Consistent materialists act like purely practical men without any science. But, since knowing and thinking are real attributes of man regardless of his party affiliation, purely practical men do not exist in reality. Even the merest attempt at practical experiment on the basis of experienced facts differs only in degree from scientific practice based on theoretical principles. Onthe other hand, consistent idealists are just as impossible as purely practical men. They would like to have the general without the special, the spirit without matter, force without substance, science without experience or material, the absolute without the relative. How can thinkers who search for truth, being, relative causes, such as naturalists, be idealists? They are so only outside of their specialties, never inside of them. The modern mind, the mind of natural science, is immaterial only so far as it embraces all matters. But men like the astronomer Madler find so little of the ridiculous in the current expectation of the materially increased spiritual power after our "emancipation from the bonds of matter," that he has nothing better to substitute for it and flatters himself with having defined the "bonds of matter" as material attraction. Truly, so long as mind is still conceived in the form of a religious ghost, the expectation of an increased mental power after the emancipation from the bonds of matter is not so much an object for ridicule as for compassion. But if we regard mind as the expression of modern science, we offer the better scientific explanation for the traditional faith. By bonds of matter we do not mean, in that case, the bond of gravitation, but the multiplicity of sense perceptions. And matter holds the mind in bondage only so long as the faculty of thought has not overcome the multiplicity of things. The emancipation of the mind from the bonds of matter consists in developing the general element out of the concrete multiplicity.
(c) Force and Matter.
The reader who has closely followed our main idea,which will be further illustrated, will anticipate that the question of matter and force finds its solution in the understanding of the relation between the general and the special. What is the relation of the concrete to the abstract? This is the common problem of those who see the active impulse of the world either in the spiritual force or in the material substance, who think to find the nature of things, thenon plus ultraof science, in either of these facts.
Liebig, who is especially fond of straying from his inductive science into the field of speculative thought, says in an idealist sense: "Force cannot be seen, we cannot grasp it with our hands; in order to understand its nature and peculiarities, we must investigate its effects." And if a materialist replies to him: "Matter is force, force is matter, no matter without force, no force without matter," it is plain that either has determined this relation only negatively. In certain shows, the clown is asked by the manager: "Clown, where have you been?" "With the others," answers the clown. "And where were the others?"—"With me."
In this case we have two answers with the same content, in the other we have two camps which quarrel with different words about an indisputable fact. And this dispute is so much more ridiculous because it is taken so seriously. If the idealist makes a distinction between matter and force, he does not mean to deny that the real phenomenon of force is inseparably linked with matter. And if the materialist claims that there is no matter without force and no force without matter, he does not mean to deny that matter and force are different, as his opponent claims.
The dispute exists for a good reason and has its object, but this object is not revealed in the dispute. It is instinctively kept under cover by both parties, so that they may not be in a position where they would have to acknowledge their own ignorance. Each wants to prove to the other that the other's explanations are inadequate, and both demonstrate this sufficiently. Büchner admits in the closing statements of his "Matter and Force" that the empirical material is insufficient to permit of definite answers to transcendental questions, and that therefore no positive answer can be given to them. And he furthermore says that the empirical material "is fully sufficient to answer them negatively and to do away with hypothesis." This is saying in so many words that the science of the materialist is adequate for the proof that his opponent knows nothing.
The spiritualist or idealist believes in a spiritual, which means in a ghostlike and inexplicable, nature of force. The materialist thinkers, on the other hand, are skeptical. A scientific proof of faith or of skepticism does not exist. The materialist has only this advantage over his idealist opponent, that he looks for the transcendental, the nature, the cause, the force, not back of the phenomenon, not outside of matter. But he remains behind the idealist when he ignores the difference between matter and force. The materialist dwells on the actual inseparability of matter and force and does not admit any other reason for a distinction between the two than "an external reason derived from the demand of our mind for systematization." Büchner says in "Nature and Mind," page 66: "Force and matter, separated from one another, are for menothing but thoughts, fantasies, ideas without any substance, hypotheses which do not exist for any healthy study of nature, because all phenomena of nature are rendered obscure and unintelligible by such a separation." But if Büchner deals with any special department of natural science in a productive way, instead of handling phrases of natural philosophy, his own practice will show him that the separation of forces from matter is not an "external," but an internal, an imminent necessity, by which alone we are enabled to elucidate and understand the phenomena of nature. Although the author of "Force and Matter" chose for his motto: "Now, what I want is—facts," we assure the reader that this device is more a thoughtless word than a serious opinion. Materialism is not so coarse-grained that it wants purely facts. Those facts which Büchner is looking for are by themselves not specifics for his desires. The idealist likewise wants such facts. No student of nature wants mere hypotheses. What all cultivators of the field of science want is not so much facts as explanations or an understanding of facts. Even the materialist will not deny that science, the "natural philosophy" of Büchner not excepted, is more concerned with mental forces than with bodily matter, that it cares more for force than for matter. The separation of force and matter is derived from "the demand of our mind for systematization." Very true! But so does all science emanate from the demand of our reason for systematization.
The contradistinction between force and matter is as old as that between idealism and materialism. The first conciliation between the two was attempted byimagination which, through the belief in spirits, suggested a secret nature as the cause of all natural phenomena. Science has of late expelled many of these special spirits by replacing the fantastic demons with scientific, or general, explanations. And after we have succeeded in explaining the demon of "pure" reason, it is not difficult to expel the special spirit of force by the general explanation of its nature and thus to reconcile scientifically the contradiction between spiritualism and materialism.
In the universe which constitutes the object of science and of the faculty of reason, both force and matter are unseparated. In the world of sense perceptions force is matter and matter is force. "Force cannot be seen." Oh, yes! Seeing itself is pure force. Seeing is as much an effect of its object as an effect of the eye, and this double effect and other effects are forces. We do not see the things themselves, but their effects on our eyes. We see their forces. And force cannot alone be seen, it can also be heard, smelled, tasted, felt. Who will deny that he can feel the force of heat, of cold, of gravitation? We have already quoted the words of Professor Koppe to the effect that we "cannot perceive heat itself, we merely conclude from its effects that this force exists in nature." This is saying in other words that we do not see, hear, or feel the things themselves, but their effects or forces.
It is just as true to say that we feel matter and not its force as it is to say that we feel force and not matter. Indeed, both are inseparable from the object, as we have already remarked. But by means of the faculty of thought we separate from thesimultaneously and successively occurring phenomena the general and the concrete. For instance, we abstract the general concept of sight from the various phenomena of our sight and distinguish it by the name of power of vision from the concrete objects, or substances, of our eyes. From a multitude of sense perceptions we develop by means of reason the general element. The general element of different water phenomena, for instance, is the water power distinguished from the substance of the water. If levers of different materials but of the same length have the same power, it is plain that in this case force is different from matter only in so far as it represents the general element of various substances. A horse does not pull without force, and this force does not pull without the horse. Indeed, in practice the horse is force and force is the horse. But nevertheless we may distinguish the power of pulling from other qualities of the horse, or we may refer to the common element in different services of horses as general horse power, without thereby starting from any other hypothesis than we do in distinguishing the sun from the earth. For in reality the sun does not exist without the earth, nor the earth without the sun.
The world of sense perceptions is made known to us only by our consciousness, but consciousness is conditioned on the world of sense perceptions. Nature is infinitely united or infinitely separated, according to whether we regard it from the standpoint of consciousness as an unconditional unit or from the standpoint of sense perceptions as an unconditional multiplicity. There is truth in both unity and multiplicity, but it is truth only relatively speaking, under certain conditions. It matters a great deal whether we lookabout with the eyes of the body or with the eyes of the mind. For the eyes of the mind, matter is force. For the eyes of the body, force is matter. The abstract matter is force, the concrete force is matter. Matter is represented by the objects of the hand, of practice, while force is an object of understanding, of science.