Riddles of Philosophy
Part II
GA 18
III. The World as Illusion
[ 1 ] Besides the current of world conception that, through the idea of evolution, wants to bring the conception of the phenomena of nature and that of the spirit into complete unity, there is another that expresses their opposition in the strongest possible form. This current also springs from natural science. Its followers ask, “What is our basis as we construct a world conception by means of thinking? We hear, see and touch the physical world through our senses. We then think about the facts that our senses supply concerning that world. We form our thoughts accordingly concerning the world at the testimony of the senses. But are the statements of our senses really to be trusted?”
Let us consult actual observations. The eye conveys to us the phenomena of light. We say an object sends us red light when the eye has the sensation of red. But the eye conveys sensations of light to us also in other cases. When it is pushed or pressed, or when an electric current flows through our head, the eye also has sensations of light. It is, therefore, possible that in cases in which we have the sensation of a light-sending body, something could go on in that object that has no semblance to our sensation of light. The eye, nevertheless, would transmit light to us.
The physiologist, Johannes Mueller (1801–58), drew the conclusion from these facts that what man has as his actual sensation does not depend on the external processes but on his organization. Our nerves transmit sensations to us. As we do not have the sensation of the knife that cuts us but a state of our nerves that appears to us as pain, so we also do not have a sensation of the external world when something appears to us as light. What we then really have is a state of our optic nerve. Whatever may happen outside, the optic nerve translates this external event into the sensation of light. “The sensation is not a process that transmits a quality or a state of an external object to our consciousness but one that transmits a quality, a state of our nerves caused by an external event, to our consciousness. This Johannes Mueller called “the law of specific sense energies.” If that is correct, then our observations contain nothing of the external world but only the sum of our own inner conditions. What we perceive has nothing to do with the external world; it is a product of our own organization. We really perceive only what is in us.
[ 2 ] Natural scientists of great renown regarded this thought as an irrefutable basis of their world conception. Hermann Helmholtz (1821–94) considered it as the Kantian thought—that all our knowledge had reference only to processes within ourselves, not to things in themselves—translated into the language of natural science (compare Vol. I of this book). Helmholtz was of the opinion that the world of our sensations supplies us merely with the signs of the physical processes in the world outside.
I have been convinced that it is necessary to formulate the relation between the sensation and its object by declaring the sensation to be merely the sign of the effect of the object. The nature of the sign demands only that the same sign be always given to the same object. Beyond this requirement there is no more similarity necessary between the sensation and its object than between the spoken word and the object that we denote with it. We cannot even call our sense impression pictures, for a picture depicts the same by the same. In a statue we represent one bodily form through another bodily form; in a drawing we express the perspective view of an object by the same perspective in the picture; in a painting we depict color through color.
[ 3 ] Our sensations, therefore, must differ more from the events they represent than pictures differ from the objects they depict. In our sensual world picture we have nothing objective but a completely subjective element, which we ourselves produce under the stimulation of the effects of an external world that never penetrates into us. This mode of conception is supported from another side by the physicist's view of the phenomena of sensation. A sound that we hear draws our attention to a body in the external world, the parts of which are in a certain state of motion. A stretched string vibrates and we hear a tone. The string transmits the vibrations to the air. They spread and reach our ear; a tone sensation is transmitted to us. The physicist investigates the laws according to which the physical particles outside move while we hear these tones. He finds that the subjective tone sensation is based on the objective motion of the physical particles. Similar relations are observed by the physicist with respect to the sensations of light. Light is also based on motion, only this motion is not transmitted by the vibrating particles of the air, but by the vibrations of the ether, the thinnest matter that fills the whole space of the universe. By every light-emitting body, the ether is put into the state of undulatory vibrations that spread and meet the retina of our eye and excite the optic nerve, which then produces the sensation of light within us. What in our world picture appears as light and color is motion outside in space. Schleiden expresses this view in the following words:
The light outside ourselves in nature is motion of the ether. A motion can be slow and fast; it can have this or that direction, but there is obviously no sense in speaking of light or dark, of green or red motion. In short, outside ourselves, outside the beings who have the sensation, there is no such thing as bright and dark, nor are there any colors.
[ 4 ] The physicist expels colors and light from the external world because he finds only motion in it. The physiologist feels that he is forced to withdraw them into the soul because he is of the opinion that the nerve indicates only its own state of irritation no matter what might have excited it. The view that is given with these presuppositions is sharply delineated by Hippolyte Taine (1828–93) in his book, Reason. The external perception is, according to his opinion, nothing but hallucination. A person who, under the influence of hallucination, perceives a death skull three steps in front of him, has exactly the same perception as someone who receives the light rays sent out by a real skull. It is the same inner phantom that exists within us no matter whether we are confronted with a real skull or whether we have a hallucination. The only difference between the one perception and the other is that in one case the hand stretched out toward the object will grasp empty air, whereas in the other case it will meet some solid resistance. The sense of touch then supports the sense of sight. But does this support really represent an irrefutable testimony? What is correct for one sense is also valid for the other. The sensations of touch can also turn out to be hallucinations.
The anatomist Henle expresses the same view in his Anthropological Lectures (1876) in the following way:
Everything through which we believe to be informed about an external world consists merely of forms of our consciousness for which the external world supplies merely the exciting cause, the stimulus, in the language of the physiologists. The external world has no colors, tones and tastes. What it really contains we learn only indirectly or not at all. How the external world affects a sense, we merely conclude from its behavior toward the other senses. We can, for instance, in the case of a tone, see the vibrations of the tuning fork with our eyes and feel it with our fingers. The nature of certain stimuli, which reveal themselves only to the one sense, as, for instance, the stimuli of the sense of smell, is still inaccessible to us. The number of the properties of matter depends on the number and on the keenness of the senses. Whoever lacks a sense loses a group of properties without a chance of regaining them. A person who would have an extra sense would have an organ to grasp qualities of which we have no other inkling than the blind man has of color.
[ 5 ] If one glances over the physiological literature from the second half of the nineteenth century, one sees that this view of the subjective nature of the world picture of our perceptions has gained increasing acceptance. Time and again one comes across variations of the thought that is expressed by J. Rosenthal in his General Physiology of Muscles and Nerves (1877). “The sensations that we receive through external impressions are not dependent on the nature of these impressions but on the nature of our nerve cells. We have no sensation of what exerts its effect on our body but only of the processes in our brain.”
[ 6 ] To what extent our subjective world picture can be said to give us an indication of the objective external world, is expressed by Helmholtz in his Physiological Optics:
To ask the question if cinnabar is really red as we see it or if this is only a sense deception is meaningless. A red-blind person will see cinnabar as black or in a dark yellow-gray shade; this is also a correct reaction for the special nature of his eye. He must only know that his eye happens to be different from that of other people. In itself one sensation is neither more nor less correct or incorrect than the other, even if the people who see the red have the great majority on their side. The red color of cinnabar exists only insofar as the majority of men have eyes that are of a similar nature. One can say with exactly the same right that it is a quality of cinnabar to be black for red-blind people. It is a different question, however, if we maintain that the wave length of light that is reflected by cinnabar has a certain length. This statement, which we can make without reference to the special nature of our eye, is only concerned with the relations of the substance and the various systems of ether waves.
[ 7 ] It is apparent that for such a conception all phenomena of the world are divided into two completely separated parts, into a world of motions that is independent of the special nature of our faculty of perception, and a world of subjective states that are there only within the perceiving subjects. This view has been expressed sharply and pointedly by the physiologist, Du Bois-Reymond (1818–96), in his lecture, On the Limits of Natural Science, which he gave at the forty-fifth assembly of German naturalists and physicians on August 14, 1872 in Leipzig. Natural science is the reduction of processes we perceive in the world to motions of the smallest physical particles of a “dissolution of natural processes into mechanics of atoms,” for it is a “psychological fact of experience that, wherever such a dissolution is successful” our need for explanation is for the time being satisfied. Moreover, it is a known fact that our nervous system and our brain are of a material nature. The processes that take place within them can also be only processes of motion. When sound or light waves are transmitted to my sense organs and from there to my brain, they can here also be nothing but motions. I can only say that in my brain a certain process of motion goes on, and I have simultaneously the sensation “red.” For if it is meaningless to say of cinnabar that it is red, it is not less meaningless to say of a motion of the brain particles that it is bright or dark, green or red. “Mute and dark in itself, that is to say, without qualities,” such is the world according to the view that has been obtained through the natural scientific conception, which
...knows instead of sound and light only vibrations of a property-free fundamental matter that now can be weighed and then again is imponderable. . . . The Mosaic word, “And there was light,” is physiologically incorrect. Light came into being only when the first red eye spot of the infusoria differentiated for the first time between light and darkness. Without the substance of the optic and auditory sense this world, glowing in colors and resounding around us, would be dark and silent. (Limits of Natural Science.)
Through the processes in the substance of our optic and auditory senses a resounding and colorful world is, according to this view, magically called into existence. The dark and silent world is physical; the sounding and colorful one is psychic. Whereby does the latter arise out of the former; how does motion change into sensation? This is where we meet, according to Du Bois-Reymond, one of the “limits of natural science.” In our brain and in the external world there are only motions; in our soul, sensations appear. We shall never be able to understand how the one can arise out of the other.
At first sight it appears is if, through the knowledge of material processes in the brain, certain processes and latent abilities can become understandable. I am thinking of our memory, the stream of the association of our thought pictures, the effect of exercise, specific talents and so forth. But a little concentration at this point tells us that this view is an error. We would only learn something concerning the inner conditions of our mental life that are approximately of the same nature as our sense impressions, but we should learn nothing that would explain how the mental life comes into existence through these conditions. What possible connections can there be between certain motions of certain atoms in my brain, on the one hand, and, on the other, such undeniable and undefinable facts expressed by the words: I feel pain; I am delighted; I taste something sweet, smell the scent of roses, hear the sound of an organ, see red, and also the certainty that immediately follows from all this, Therefore I am. It is altogether incomprehensible that it should not be a matter of perfect indifference to a number of atoms of carbon, hydrogen, nitrogen, oxygen, etc., what their position is and how they move, how this has been and how it will be.
There is no bridge for our knowledge that leads from motion to sensation. This is the credo of Du Bois-Reymond. From motion in the material world we cannot come into the psychical world of sensations. We know that sensation arises from matter in motion, but we do not know how this is possible. Also, in the world of motion we cannot go beyond motion. For our subjective perceptions we can point at certain forms of motions because we can infer the course of these motions from the process of our perceptions, but we have no conception of what it is that is moving outside in space. We say that matter moves. We follow its motions as we watch the reactions of our sensations, but as we do not observe the object in motion but only a subjective sign of it, we can never know what matter is. Du Bois-Reymond is of the opinion that we might be able to solve the riddle of sensation if the riddle of matter were disclosed. If we knew what matter is, we should probably also know how it produces sensations, but both riddles are inaccessible to our knowledge. Du Bois-Reymond meant to check those who wanted to go beyond this limit with the words, “Just let them try the only alternative that is left, namely, supra-naturalism, but be sure that science ends where supra-naturalism begins.”
[ 8 ] The results of modern natural science are two sharply marked opposites. One of them is the current of monism. It gives the impression of penetrating directly from natural science to the most significant problems of world conception. The other declares itself incapable of proceeding any further with the means of natural science than to the insight that to a certain subjective state there is a certain corresponding process of motion. The representatives of the two currents vehemently oppose each other. Du Bois-Reymond rejected Haeckel's History of Creation as fiction (compare Du Bois-Reymond's speech, Darwin versus Galiani). The ancestral trees that Haeckel constructs on the basis of comparative anatomy, ontogeny and paleontology appear to Du Bois-Reymond to be of “approximately the same value as are the ancestral trees of the Homeric heroes in the eyes of historical criticism.” Haeckel, on the other hand, considers the view of Du Bois-Reymond to be an unscientific dilettantism that must naturally give support to the reactionary world conceptions. The jubilation of the spiritualists over Du Bois-Reymond's “Limitation Speech” was so much the more resonant and justified, as Du Bois-Reymond had, up to that time, been considered an important representative of the principle of scientific materialism.
[ 9 ] What captivates many people in the idea of dividing the world dualistically into external processes of motion and inner, subjective processes of sensation and perception is the possibility of an application of mathematics to the external processes. If one assumes material particles (atoms) with energies to exist, one can calculate in which way such atoms have to move under the influence of these energies. What is so attractive in astronomy with its methods of strict calculations is carried into the smallest elements. The astronomer determines the motion of the celestial bodies by calculating the laws of the mechanics of the heavens. In the discovery of the planet Neptune we experienced a triumph of the mechanism of the heavens. One can also reduce the motions that take place in the external world when we hear a tone and see a color to laws that govern the motions of the celestial bodies. Possibly one will be able in the future to calculate the motion that goes on in our brain while we form the judgment, two times two is four. The moment when everything that can be expressed in mathematical formulas has been calculated will be the one in which the world has been explained mathematically. Laplace has given a captivating description of the ideal of such an explanation of the world in his Essai Philosophique sur les Probabilités (1814):
A mind that would know for a given moment all forces that activate nature as well as the mutual position of the entities of which nature consists would, if its power of comprehension were otherwise sufficient, comprehend in the same formula the motions of the largest celestial body and of the lightest atom. Nothing would be uncertain for such a mind, and the future as well as the past would be within the scope of its perfect and immediate knowledge. Man's power of reasoning offers, with the perfection that it has given to astronomy, a feeble imitation of such a mind.
Du Bois-Reymond says in connection with these words:
As the astronomer predicts the day on which a comet reemerges from the depth of world space after years in the firmament of heaven, so would this mind read in its calculation the day when the Greek cross will shine from the mosque of the Hagia Sophia and when England will burn its last coal.
[ 10 ] There can be no doubt that even the most perfect mathematical knowledge of a process of motion would not enlighten me with regard to the question of why this motion appears to me as a red color. When one ball hits another, we can explain the direction of the second ball but we cannot in this way determine how a certain motion produces the red color. All we can say is that when a certain motion is given, a certain color is also given. While we can explain, apparently, as opposed to merely describe, what can be determined through calculation, we cannot go beyond a mere description in anything that defies calculation.
[ 11 ] A significant confession was made by Gustav Robert Kirchhoff (1824–87) when, in 1874, he defined the task of mechanics: “It is to describe the motions occurring in nature in the most complete and simple way.” Mechanics applies mathematics. Kirchhoff confesses that with the help of mathematics no more can be obtained than a complete and simple description of the processes in nature.
To those personalities who demand of an explanation something essentially more than just a description according to certain points of view, the confession of Kirchhoff could serve as a confirmation of their belief that there are “limits to our knowledge of nature.” Referring to Kirchhoff, Du Bois-Reymond praises the wise reserve of the master, who characterizes the task of mechanics as that of describing the motions of the bodies, and places this in contrast to Ernst Haeckel, who “speaks of atom souls.”
[ 12 ] An important attempt to base his world conception on the idea that all our perceptions are merely the result of our own organization has been made by Friedrich Albert Lange (1828–73) with his History of Materialism (1864). He had the boldness and consistency of thought that does not allow itself to be blocked by any obstacle but follows its fundamental conception to its last conclusion. Lange's strength lay in a forceful character that was expressed in many directions. His was a personality able to take up many things, and he had sufficient ability to carry them out.
[ 13 ] One important enterprise was his renewal of Kant's conception that, with the support of modern natural science, we perceive things not as they require it, but as our organization demands it. Lange did not really produce any new conceptions, but he did throw light into given thought worlds that is rare in its brightness. Our organization, our brain, in connection with our senses, produces the world of sensation. I see “blue,” or I feel “hardness,” because I am organized in this particular way. I combine the sensations into objects. By combining the sensations of “white” and “soft,” etc., I produce, for instance, the conception of wax. When I follow my sensation with my thoughts, I do not move in the external world. My intellect produces connections within the world of my sensations according to the laws of my reason. When I saw that the qualities I perceive in a body presuppose a matter with laws of motion, I also do not go outside of myself. I find that I am forced through my organization to add the thoughts of processes of motion to my sensations.
The same mechanism that produces our sensations also produces our conception of matter. Matter, equally, is only a product of my organization, just as color and tone. Even when we speak of things in themselves, we must be clearly aware of the fact that we cannot go beyond our own realm. We are so organized that we cannot possibly go beyond ourselves. Even what lies beyond our realm can be represented to ourselves only through our conception. We become aware of a limit to our world. We argue that there must be something beyond the limit that causes sensations in us. But we can only go as far as to that limit, even the limit we set ourselves because we can go no further. “A fish can swim in water in the pond, not in the earth, but it can hit its head against the bottom and the walls.” In the same way we live within the realm of our conceptions and sensations, but not in the external things. We hit against a limit, however, where we cannot go any further, where we must say no more than that beyond this is the unknown. All conceptions we produce concerning this unknown are unjustified because we cannot do anything but relate the conceptions we have obtained within ourselves to the unknown. If we wanted to do this, we should be no wiser than a fish that would say, “Here I cannot go any further. Therefore, I want to go into some other kind of water in which I will try to swim in some other way.” But the fact is that the fish can swim only in water and nowhere else.
[ 14 ] This is supplemented by another thought that belongs with the first line of reasoning. Lange, as the spirit of an inexorable desire for consistency, linked them together. In what situation am I when I contemplate myself? Am I not as much bound to the laws of my own organization as I am when I consider something else? My eye observes an object. Without an eye there is no color. I believe that there is an object in front of me, but on closer inspection I find that it is my eye, that is to say, I, myself, that produces the object. Now I turn my observation to my eye itself. Can I do this in any other way except by means of my organs? Is not the conception that I obtain of myself also just my idea? The world of the senses is the product of our organization. Our visible organs are like all other parts of the phenomenal world, only pictures of an unknown object. Our real organization remains, therefore, as unknown to us as the objects of the external world. What we have before us is merely the product of both. Affected by an unknown world through an unknown ego, we produce a world of conceptions that is all we have at our disposal.
[ 15 ] Lange asks himself the question: Where does a consistent materialism lead? Let all our mental conclusions and sense perceptions be produced by the activity of our brain, which is bound to material conditions, and our sense organs, which are also material. We are then confronted with the necessity of investigating our organism in order to see how it functions, but we can do this only by means of our organs. No color without an eye, but also no eye without an eye.
The consistently materialistic view is immediately reversed into a consistently idealistic one. There is no break to be assumed in our nature. We must not attribute some functions of our being to a physical nature and others to a spiritual one, but we are justified to assume physical conditions for everything, including the mechanism of our thinking, and we should not rest until we have found them. But we are as much justified if we consider as mere pictures of the really existing world, not only the external world as it appears to us, but also the organs with which we apprehend this world. The eye with which we believe we see is itself only a product of our imagination. When we find that our visual pictures are produced by the structure and function of the eye, we must never forget that the eye with all its contrivances—the optic nerve as well as the brain and the structures we may still discover in it as causes of our thinking—are only ideas that, to be sure, form a world that is consistent and interconnected in itself, but merely a world that points beyond itself. . The senses supply us, as Helmholtz says, with the effects of the things, not with faithful pictures, and certainly not with the things themselves. Among these effects are also the senses themselves as well as the brain and the molecular movements assumed in it. (History of Materialism, 1887.)
Lange, therefore, assumes a world beyond our world that may consist of the things in themselves or that may not even have anything to do with this “thing in itself,” since even this concept, which we form at the limit of our own realm, belongs merely to the world of our ideas.
[ 16 ] Lange's world conception, then, leads to the opinion that we have only a world of ideas. This world, however, forces us to acknowledge something beyond its own sphere. It also is completely incapable of disclosing anything about this something. This is the world conception of absolute ignorance, of agnosticism.
[ 17 ] It is Lange's conviction that all scientific endeavor that does not limit itself to the evidence of the senses and the logical intellect that combines these elements of evidence must remain fruitless. That the senses and the intellect together, however, do not supply us with anything but a result of our own organization, he accepts as evidently following from his analysis of the origin of knowledge. The world is for him fundamentally a product of the fiction of our senses and of our intellects. Because of this opinion, he never asks the question of truth with regard to the ideas. A truth that could enlighten us about the essence of the world is not recognized by Lange. He believes he has obtained an open road for the ideas and ideals that are formed by the human mind and that he has accomplished this through the very fact that he no longer feels the need of attributing any truth to the knowledge of the senses and the intellect. Without hesitation he considered everything that went beyond sensual observation and rational combination to be mere fiction. No matter what the idealistic philosophers had thought concerning the nature of facts, for him it belonged to the realm of poetic fiction.
Through this turn that Lange gave to materialism there arose necessarily the question: Why should not the higher imaginative creations be valid if even the senses are creative? What is the difference between these two kinds of creation? A philosopher who thinks like this must have a reason for admitting certain conceptions that is quite different from the reason that influences a thinker who acknowledges a conception because he thinks it is true. For Lange, this reason is given by the fact that a conception has value for life. For him, the question is not whether or not a conception is true, but whether it is valuable for man. One thing, however, must be clearly recognized: That I see a rose as red, that I connect the effect with the cause, is something I have in common with all creatures endowed with the power of perception and thinking. My senses and my reason cannot produce any additional values, but if I go beyond the imaginative product of senses and reason, then I am no longer bound to the organization of the whole human species. Schiller, Hegel and every Tom, Dick and Harry sees a flower in the same way. What Schiller weaves in poetic imagination around the flower, what Hegel thinks about it, is not imagined by Tom, Dick and Harry in the same way. But just as Tom, Dick and Harry are mistaken when they think that the flower is an entity existing externally, so Schiller and Hegel would be in error if they took their ideas for anything more than poetic fiction that satisfied their spiritual needs. What is poetically created through the senses and the intellect belongs to the whole human race, and no one in this respect can be different from anybody else. What goes beyond the creation of the senses and of reason is the concern of the individual. Nevertheless, this imaginative creation of the individual is also granted a value by Lange for the whole human race, provided that the individual creator “who produces it is normal, richly gifted and typical in his mode of thinking, and is, through his force of spirit, qualified to be a leader.”
In this way, Lange believes that he can secure for the ideal world its value by declaring that also the so-called real world is a product of poetic creation. Wherever he may look, Lange sees only fiction, beginning with the lowest stage of sense perception where “the individual still appears subject to the general characteristics of the human species, and culminating with the creative power in poetry.”
The function of the senses and of the combining intellect, which produce what is reality for us, can be called a lower function if one compares them with the soaring flight of the spirit in the creative arts. But, in general and in their totality, these functions cannot be classified as a principally different activity of the mind. As little as our reality is a reality according to our heart's desire, it is nevertheless the firm foundation of our whole spiritual existence. The individual grows out of the soil of the species, and the general and necessary process of knowledge forms the only secure foundation for the individual's rise to an esthetic conception of the world. (History of Materialism.)
[ 18 ] What Lange considers to be the error of the idealistic world conception is not that it goes beyond the world of the senses and the intellect with its ideas, but that it believes it possesses in these ideas more than the individual thinker's poetic fantasy. One should build up for oneself an ideal world, but one should be aware that this ideal world is no more than poetic imagination. If this idealism maintains it is more than that, materialism will rise time and again with the claim: I have the truth; idealism is poetry. Be that so, says Lange: Idealism is poetry, but materialism is also poetry. In idealism the individual is the creator, in materialism, the species. If they both are aware of their natures, everything is in its right place: the science of the senses and the intellect that provide proofs for the whole species, as well as the poetry of ideas with all its conceptions that are produced by the individual and still retain their value for the race.
One thing is certain: Man is in need of an ideal world created by himself as a supplement of reality, and the highest and noblest functions of his spirit are actively combined in such creations. But is this free activity of the spirit to be allowed repeatedly to assume the deceptive form of a proof-establishing science? If so, materialism will emerge again and again to destroy the bolder speculations and try to satisfy reason's demand for unity with a minimum of elevation above the real and actually provable. (History of Materialism.)
[ 19 ] In Lange's thinking, complete idealism is combined with a complete surrender of truth itself. The world for him is poetry, but a poetry that he does not value any less than he would if he could acknowledge it as reality.
Thus, two currents of a distinctly natural scientific character can be distinguished as abruptly opposing each other in the development of modern world conception: The monistic current in which Haeckel's mode of conception moved, and the dualistic one, the most forceful and consistent defender of which was Friedrich Albert Lange. Monism considers the world that man can observe to be a true reality and has no doubt that a thinking process that depends on observation can also obtain knowledge of essential significance concerning this reality. Monism does not imagine that it is possible to exhaust the fundamental nature of the world with a few boldly thought out formulas. It proceeds as it follows the facts, and forms new ideas in regard to the connections of these facts. It is convinced, however, that these ideas do supply a knowledge of a true reality. The dualistic conception of Lange divides the world into a known and an unknown part. It treats the first part in the same fashion as monism, following the lead of observation and reflective thought, but it believes that nothing at all can be known concerning the true essential core of the world through this observation and through this thought. Monism believes in the truth of the real and sees the human world of ideas best supported if it is based on the world of observations. In the ideas and ideals that the monist derives from natural existence, he sees something that is fully satisfactory to his feeling and to his moral need. He finds in nature the highest existence, which he does not only want to penetrate with his thinking for the purpose of knowledge, but to which he surrenders with all his knowledge and with all his love.
In Lange's dualism nature is considered to be unfit to satisfy the spirit's highest needs. Lange must assume a special world of higher poetry for this spirit that leads beyond the results of observation and its corresponding thought. For monism, true knowledge represents a supreme spiritual value, which, because of its truth, grants man also the purest moral and religious pathos. To dualism, knowledge cannot present such a satisfaction. Dualism must measure the value of life by other things, not by the truth it might yield. The ideas are not valuable because they participate in the truth. They are of value because they serve life in its highest forms. Life is not valued by means of the ideas, but the ideas are appreciated because of their fruitfulness for life. It is not for true knowledge that man strives but for valuable thoughts.
[ 20 ] In recognizing the mode of thinking of natural science Friedrich Albert Lange agrees with monism insofar as he denies the uses of all other sources for the knowledge of reality, but he also denies this mode of thinking any possibility to penetrate into the essential of things. In order to make sure that he himself moves on solid ground he curtails the wings of human imagination. What Lange is doing in such an incisive fashion corresponds to an inclination of thought that is deeply ingrained in the development of modern world conception. This is shown with perfect clarity also in another sphere of thinking of the nineteenth century. This thinking developed, through various stages, viewpoints from which Herbert Spencer (1820–1903) started as he laid the foundations for a dualism in England. Spencer's dualism appeared at approximately the same time as Lange's in Germany, which strove for natural scientific knowledge of the world on the one hand and, on the other, confessed to agnosticism so far as the essence of things is concerned. When Darwin published his work, The Origin of Species, he could praise the natural scientific mode of thought of Spencer:
Mr. Herbert Spencer, in an Essay (1852), has contrasted the theories of the Creation and the Development of organic beings with remarkable skill and force. He argues from the analogy of domestic production, from the changes which the embryos of many species undergo, from the difficulty of distinguishing species and varieties, and from the principle of general gradation that species have been modified; and he attributes the modification to the change of circumstances. The author (1855) has also treated Psychology on the principle of the necessary requirement of each mental power and capacity by gradation. (The Origin of Species, Historical Sketch.)
Also, other thinkers who followed the method of natural science felt attracted to Spencer because he tried to explain all reality from the inorganic to the psychological in the manner expressed in Darwin's words above. But Spencer also sides with the agnostics, so that Lange is justified when he says, “Herbert Spencer, whose philosophy is closely related to ours, believes in a materialism of the phenomenal world, the relative justification of which, within the realm of natural science, finds its limit in a thought of an unknowable absolute.”
[ 21 ] It is quite likely that Spencer arrived at his viewpoint from assumptions similar to those of Lange. He had been preceded in England by thinkers who were guided by a twofold interest. They wanted to determine what it is that man really possesses with his knowledge, but they also were resolved not to shatter by doubt or reason the essential substance of the world. They were all more or less dominated by the sentiment that Kant described when he said, “I had to suspend knowledge in order to make room for belief.” (Compare the first volume of this book.)
[ 22 ] The beginning of the development of the world conception of the nineteenth century in England is marked by the figure of Thomas Reid (1710–96). The fundamental conviction of this man can be expressed in Goethe's words as he describes his own activity as a scientist as non-speculative: “In the last analysis it seems to me that my method consists merely m the practical and self-rectifying operations of common sense that dares to practice its function in a higher sphere.” (Compare Goethe's Werke, Vol. 38, p. 595 in Kürschner's Deutsche National Literatur.) This common sense does not doubt in any way that it is confronted with real essential things and processes as it contemplates the world. Reid believes that a world conception is viable only if it upholds this basic view of a healthy common sense. Even if one admitted the possibility that our observation could be deceptive and that the true nature of things could be different from the picture that is supplied to us by our senses and our intellect, it would not be necessary to pay any attention to such a possibility. We find our way through life only if we believe in our observation; nothing beyond that is our concern.
In taking this point of view Reid is convinced that he can arrive at really satisfactory truths. He makes no attempt to obtain a conception of things through complicated thought operations but wants to reach his aim by going back to the basic principles that the soul instinctively assumes. Instinctively, unconsciously, the soul possesses what is correct, before the attempt is made to illumine the mind's own nature with the torch of consciousness. It knows instinctively what to think in regard to the qualities and processes of the physical world, and it is endowed instinctively with the direction of moral behavior, of a judgment concerning good and evil. Through his reference to the truths innate in “common sense,” Reid directs the attention of thought toward an observation of the soul. This tendency toward a psychological observation becomes a lasting and characteristic trait in the development of the English world conception.
Outstanding personalities within this development are William Hamilton (1788–1856), Henry Mansel (1820–71), William Whewell (1794–1866), John Herschel (1792 – 1871), James Mill (1773–1836), John Stuart Mill (1806 – 73), Alexander Bain (1818–1903) and Herbert Spencer (1820–1903). They all place psychology in the center of their world conception.
[ 23 ] William Hamilton also recognizes as truth what the soul from the beginning feels inclined to accept as true. With respect to fundamental truths proofs and comprehension ceases. All one can do is observe their emergence at the horizon of our consciousness. In this sense they are incomprehensible. But one of the fundamental manifestations of our consciousness is also that everything in this world depends on something that is unknown to us. We find in this world in which we live only dependent things, but not absolutely independent ones. Such independent things must exist, however. When a dependent thing is found, an independent thing is assumed. With our thinking we do not enter the independent entity. Human knowledge is meant for the dependent and it becomes involved in contradictions if its thoughts, which are well-suited to the dependent, are applied to the independent. Knowledge, therefore, must withdraw as we approach the entrance toward the independent. Religious belief is here in its place. It is only through his admission that he cannot know anything of the essential core of the world that man can be a moral being. He can accept a God who causes a moral order in the world. As soon as it has been understood that all logic has exclusively to do with the dependent, not the independent, no logic can destroy this belief in an infinite God.
Henry Mansel was a pupil and follower of Hamilton, but he expressed Hamilton's view in still more extreme forms. It is not going too far to say that Mansel was an advocate of belief who no longer judged impartially between religion and knowledge, but who defended religious dogma with partiality. He was of the opinion that the revealed truths of religion involve our knowledge necessarily in contradictions. This is not supposed to be the fault of the revealed truths but has its cause in the limitation of the human mind, which can never penetrate into regions from which the statements of revelation arise.
William Whewell believed that he could best obtain a conception concerning the significance, origin and value of human knowledge by investigating the method through which leading men of science arrived at their insights. In his History of the Inductive Sciences (1840), he set out to analyze the psychology of scientific investigation. Thus, by studying outstanding scientific discoveries, he hoped to find out how much of these accomplishments was due to the external world and how much to man himself. Whewell finds that the human mind always supplements its scientific observations. Kepler, for example, had the idea of an ellipse before he found that the planets move in ellipses. Thus, the sciences do not come about through a mere reception from without but through the active participation of the human mind that impresses its laws on the given elements. These sciences do not extend as far as the last entities of things. They are concerned with the particulars of the world. Just as everything, for instance, is assumed to have a cause, such a cause must also be presupposed for the whole world. Since knowledge fails us with respect to that cause, the dogma of religion must step in as a supplement. Herschel, like Whewell, also tried to gain an insight into the genesis of knowledge in the human mind through the observation of many examples. His Preliminary Discourse on the Study of Natural Philosophy appeared in 1831.
[ 24 ] John Stuart Mill belongs with those thinkers who are deeply imbued with the conviction that one cannot be cautious enough in determining what is certain and uncertain in human knowledge. The fact that he was introduced to the most diversified branches of knowledge in his boyhood, most likely gave his mind its characteristic turn. As a child of three he received instructions in the Greek language, and soon afterwards was taught arithmetic. He was exposed to the other fields of instruction at a correspondingly early age. Of even greater importance was the method of instruction used by his father, James Mill, who was himself an important thinker. Through him vigorous logic became the second nature of John Stuart. From his autobiography we learn: “Anything which could be found out by thinking I was never told until I had exhausted my efforts to find it out for myself.” The things that occupy the thinking of such a person must become his destiny in the proper sense of the word. “I have never been a child, I have never played cricket. It is, after all, better to let nature take its own course,” says John Stuart Mill as one whose destiny had so uniquely been to live almost exclusively in thinking. Because of his development, he had to experience to the fullest the problems concerning the significance of knowledge. How can knowledge, which for him was life, lead also to the source of the phenomena of the world? The direction in which Mill's thought developed in order to obtain clarity concerning these problems was probably determined early by his father. James Mill had proceeded by starting from psychological experience. He had observed the process by which idea is linked to idea in man's mind. Through connecting one concrete idea to another we obtain our knowledge of the world. We must then ask ourselves: What is the relation between the order in which the ideas are linked and the order of the things in the world? Through such a mode of conception our thinking begins to distrust its own power because man can associate ideas in a manner that is entirely different from the connection of the things in the external world. This mistrust is the basis of John Stuart Mill's logic, which appeared in 1843 as his chief work under the title, System of Logic.
[ 25 ] In matters of world conception a more pronounced contrast is scarcely thinkable than that between Mill's Logic and Hegel's Science of Logic, which appeared twenty-seven years earlier. In Hegel we find the highest confidence in thinking, the full assurance that we cannot be deceived by what we experience within ourselves. Hegel experiences himself as a part, a member of the world, and what he experiences within himself must also belong to the world. Since he has the most direct knowledge of himself, he believes in the content of this knowledge and judges the rest of the world accordingly. He argues as follows: When I perceive an external thing, it is possible that the thing shows only its surface to me and that its essence remains concealed. This is not possible in my own case. I understand my own being. I can then compare the things outside with my own being. If they reveal some element of my own essence on their surface, I am justified in attributing to them something of my own nature. It is for this reason that Hegel expects confidently to find outside in nature the very spirit and the thought connections that he finds within himself.
Mill, however, experiences himself not as a part of the world but as a spectator. The things outside are an unknown element to him and the thoughts that man forms concerning them are met by Mill with distrust. One observes men and learns from his observations that all men die. One forms the judgment that all men are mortal. The Duke of Wellington is a man; therefore, the Duke of Wellington is mortal. This is the conclusion the observer comes to. What gives him the right to do so? This is the question John Stuart Mill asks. If a single human being would prove to be immortal, the whole judgment would be upset. Are we justified in supposing that, because all men up to this time have died, they will continue to do so in the future? All knowledge is uncertain because we draw conclusions from observations we have made and transfer them to things we cannot know anything about, since we have not observed them directly. What would somebody who thinks like Hegel have to say about such a conception? It is not difficult to imagine the answer. We know from definite concepts that in every circle all diameters are equal. If we find a circle in the real world, we maintain that its diameters, too, are equal. If we observe it a quarter of an hour later and find that its diameters are unequal, we do not decide [ 26 ] that under certain circumstances the diameter of a circle can also be unequal. But we say that what was formerly a circle has for some reason been elongated into an ellipse.
If we think like Hegel, this is the attitude we take toward the judgment, all men are mortal. It is not through observation but through an inner thought experience that we form the concept of man. For the concept of man, mortality is as essential as the equality of the diameters is for the concept of the circle. If we find a being in the real world that has all the other characteristics of man, we conclude that this being must also have that of mortality, in the same way that all other properties of the circle allow us to conclude that it has also that of the equality of diameters. If Hegel came across a being that did not die, he could only say, “That is not a man.” He could not say, “A man can also be immortal.” Hegel makes the assumption that the concepts in us are not arbitrarily formed but have their root in the essence of the world, as we ourselves belong to this essence. Once the concept of man has formed within us, it is clear that it has its origin in the essence of things, and we are fully justified in applying it to this essence. Why has this concept of mortal man formed within us? Surely only because it has its ground in the nature of things. A person who believes that man stands entirely outside of the order of things and forms his judgments as an outsider can argue that we have until now seen men die, and therefore we form the spectator concept: mortal men. The thinker who is aware that he himself belongs to the order of things and that it is they that are manifested within his thoughts, forms the judgment that up to this time all men have died; to die, then, is something that belongs to their nature, and if somebody does not die, he is not a man but something else. Hegel's logic has become a logic of things: For Hegel, the manifestation of logic is an effect of the essence of the world; it is not something that the human mind has added from an outside source to this essence. Mill's logic is the logic of a bystander, of a mere spectator who starts out by cutting the thread through which it is connected with the world.
[ 27 ] Mill points out that the thoughts, which in a certain age appear as absolutely certain inner experiences, are nevertheless reversed in a later time. In the Middle Ages it was, for instance, believed that there could not possibly be antipodes and that the stars would have to drop from the sky if they did not cling to fixed spheres. Man will, therefore, only be capable of the right attitude toward his knowledge if he, in spite of his awareness that the logic of the world is expressed in this knowledge, forms in every individual case his judgment through a careful methodical examination of his conceptual connections guided by observation, a judgment that is always in need of correction.
It is the method of observation that John Stuart Mill attempts to determine with cool detachment and calculation. Let us take an example. [ 28 ] Suppose a phenomenon had always occurred under certain conditions. In a given case a number of these conditions appear again, but a few of them are now missing. The phenomenon in question does not occur. We are forced to conclude that the conditions that were not provided and the phenomenon that failed to occur stood in a causal relationship. If two substances have always combined to form a chemical compound and this result fails to be obtained in a given case, it is necessary to inquire what condition is lacking that had always been present before. Through a method of this kind we arrive at conceptions concerning connections of facts that can be rightly considered as being grounded in the nature of things. Mill wants to follow the methods of observation in his analysis. Logic, which Kant maintained had not progressed a single step since Aristotle, is a means of orientation within our thinking itself. It shows how to proceed from one correct thought to the next. Mill's logic is a means of orientation within the world of facts. It intends to show how one obtains valid judgments about things from observation. He does not even admit mathematics as an exception. Mathematics must also derive its basic insights from observation. For example, in all observed cases we have seen that two intersecting straight lines diverge and do not intersect again. Therefore we conclude that they will never intersect again, but we do not have a perfect proof for this statement. For John Stuart Mill, the world is thus an alien element. Man observes its phenomena and arranges them according to what they announce to his conceptual life. He perceives regularities in the phenomena and through logical, methodical investigations of these regularities he arrives at the laws of nature. But there is nothing that leads him to the principle of the things themselves. One can well imagine that the world could also be entirely different. Mill is convinced that everybody who is used to abstraction and analysis and who seriously uses his abilities will, after a sufficient exercise of his imagination, have no difficulty with the idea that there could be another stellar system in which nothing could be found of the laws that have application to our own.
Mill is merely consistent in his bystander viewpoint of the world when he extends it to man's own ego. Mental pictures come and go, are combined and separated within his inner life; this is what man observes. He does not observe a being that remains identical with itself as “ego” in the midst of this constant flow of ideas. He has observed that mental pictures emerge within him and he assumes that this will continue to be the case. From this possibility, namely, that a world of perceptions can be grouped around a center, arises the conception of an “ego.” Thus, man is a spectator also with respect to his own “ego.” He has his conceptions tell him what he can know about himself. Mill reflects on the facts of memory and expectation. If everything that I know of myself is to consist of conceptual presentations, then I cannot say: I remember a conception that I have had at an earlier time, or I expect the occurrence of a certain experience, but I must say: A present conception remembers itself or expects its future occurrence. If we speak, so Mill argues, of the mind as of a sequence of perceptions, we must also speak of a sequence of perceptions that is aware of itself as becoming and passing. As a result, we find ourselves in the dilemma of having to say that either the “ego” or the mind is something to be distinguished from the perceptions, or else we must maintain the paradox that a mere sequence of perceptions is capable of an awareness of its past and future. Mill does not overcome this dilemma. It contains for him an insoluble enigma. The fact is that he has torn the bond between himself, the observer, and the world, and he is not capable of restoring the connection. The world for him remains an unknown beyond himself that produces impressions on man. All man knows of this transcendent unknown is that it can produce perceptions in him. Instead of having the possibility of knowing real things outside himself, he can only say in the end that there are opportunities for having perceptions. Whoever speaks of things in themselves uses empty words. We move on the firm ground of facts only as long as we speak of the continuous possibility of the occurrence of sensations, perceptions and conceptions.
[ 29 ] John Stuart Mill has an intense aversion to all thoughts that are gained in any way except through the comparison of facts, the observation of the similar, the analogous, and the homogeneous elements in all phenomena. He is of the opinion that the human conduct of life can only be harmed if we surrender to the belief that we could arrive at any truth in any way except through observation. This disinclination of Mill demonstrates his hesitation to relate himself in his striving for knowledge to the things of reality in any other way than by an attitude of passivity. The things are to dictate to man what he has to think about them. If man goes beyond this state of receptivity in order to say something out of his own self about the things, then he lacks every assurance that this product of his own activity has anything to do with the things. What is finally decisive in this philosophy is the fact that the thinker who maintains it is unable to count his own spontaneous thinking as belonging to the world. The very fact that he himself is active in this thinking makes him suspicious and misleads him. He would best of all like to eliminate his own self completely, to be absolutely sure that no erroneous element is mixed into the objective statements of the phenomena. He does not sufficiently appreciate the fact that his thinking is a part of nature as much as the growth of a leaf of grass. It is evident that one must also examine one's own spontaneous thinking if one wants to find out something concerning it.
How is man, to use a statement of Goethe, to become acquainted with his relation to himself and to the external world if he wants to eliminate himself completely in the cognitive process? Great as Mill's merits are for finding methods through which man can learn those things that do not depend on him, a view concerning man's relation to himself and of his relation to the external world cannot be obtained by his methods. All these methods are valid only for the special sciences, not, however, for a comprehensive world conception. No observation can teach what spontaneous thinking is; only thinking can experience this in itself. As this thinking can only obtain information concerning its own nature through its own power, it is also the only source that can shed light on the relation between itself and the external world. Mill's method of investigation excludes the possibility of obtaining a world conception because a world conception can be gained only through thinking that is concentrated in itself and thereby succeeds in obtaining an insight into its own relation to the external world. The fact that John Stuart Mill had an aversion to this kind of self-supporting thinking can be well understood from his character. Gladstone said in a letter (compare Gompertz: John Stuart Mill, Vienna, 1889) that in conversation he used to call Mill the “Saint of Rationalism.” A person who practices thinking in this way imposes rigorous demands on thinking and looks for the greatest possible precautionary measures so that it cannot deceive him. He becomes thereby mistrustful with respect to thinking itself. He believes that he will soon stand on insecure ground if he loses hold of external points of support. Uncertainty with regard to all problems that go beyond strictly observational knowledge is a basic trait in Mill's personality. In reading his books we see everywhere that Mill treats such problems as open questions concerning which he does not risk a sure judgment.
[ 30 ] The belief that the true nature of things is unknowable is also maintained by Herbert Spencer. He proceeds by asking: How do I obtain what I call truths concerning the world? I make certain observations concerning things and form judgments about them. I observe that hydrogen and oxygen under certain conditions combine to form water. I form a judgment concerning this observation. This is a truth that extends only over a small circle of things. I then observe under what circumstances other substances combine. I compare the individual observations and thereby arrive at more comprehensive, more general truths concerning the process in which substances in general form chemical compounds. All knowledge consists in this; we proceed from particular truths to more comprehensive ones. We finally arrive at the highest truth, which cannot be subordinated to any other and which we therefore must accept without further explanation. In this process of knowledge we have, however, no means of penetrating to the absolute essence of the world, for thinking can, according to this opinion, do no more than compare the various things with one another and formulate general truths with respect to the homogeneous element in them. But the ultimate nature of the world cannot, because of its uniqueness, be compared to any other thing. This is why thinking fails with regard to the ultimate nature. It cannot reach it.
[ 31 ] In such modes of conception we always sense, as an undertone, the thinking that developed from the basis of the physiology of the senses (compare above to the first part of this Chapter). In many philosophers this thought has inserted itself so deeply into their intellectual life that they consider it the most certain thought possible. They argue as follows: One can know things only by becoming aware of them. They then change this thought, more or less unconsciously, into: One can know only of those things that enter our consciousness, but it remains unknown how the things were before they entered our consciousness. It is for this reason that sense perceptions are considered as if they were in our consciousness, for one is of the opinion that they must first enter our consciousness and must become part of it in the form of conceptions if we are to be aware of them.
[ 32 ] Also, Spencer clings to the view that the possibility of the process of knowledge depends on us as human beings. We therefore must assume an unknowable element beyond that which can be transmitted to us by our senses and our thinking. We have a clear consciousness of everything that is present in our mind. But an indefinite consciousness is associated with this clear awareness that claims that everything we can observe and think has as its basis something we can no longer observe and think. We know that we are dealing with mere appearances and not with full realities existing independently by themselves. But this is just because we know definitely that our world is only appearance, that we also know that an unimaginable real world is its basis. Through such turns of thought Spencer believes it possible to arrange a complete reconciliation between religion and knowledge. There is something that religion can grasp in belief, in a belief that cannot be shaken by an impotent knowledge.
[ 33 ] The field, however, that Spencer considers to be accessible to knowledge must, for him, entirely take on the form of natural scientific conceptions. When Spencer himself ventures to explain, he does so in the sense of natural science.
[ 34 ] Spencer uses the method of natural science in thinking of the process of knowledge. Every organ of a living being has come into existence through the fact that this being has adapted itself to the conditions under which it lives. It belongs to the human conditions of life that man finds his way through the world with the aid of thinking. His organ of knowledge develops through the adaptation of his conceptual life to the conditions of his external life. By making statements concerning things and processes, man adjusts himself to the surrounding world. All truths have come into being through this process of adaptation, and what is acquired in this way can be transmitted through inheritance to the descendants. Those who think that man, through his nature, possesses once and for all a certain disposition toward general truths are wrong. What appears to be such a disposition did not exist at an earlier stage in the ancestors of man, but has been acquired by adaptation and transmitted to the descendants. When some philosophers speak of truths that man does not have to derive from his own individual experience but that are given a priori in his organization, they are right in a certain respect. While it is obvious that such truths are acquired, it must be stressed that they are not acquired by man as an individual but as a species. The individual has inherited the finished product of an ability that has been acquired at an earlier age.
Goethe once said that he had taken part in many conversations on Kant's Critique of Pure Reason and that he had noticed how on those occasions the old basic problem had been renewed, “How much does our inner self contribute to our spiritual existence, how much the external world?” And Goethe goes on to say, “I had never separated the two; when I was philosophizing in my own way on things, I did so with an unconscious naïveté and was really convinced that I saw with my eyes my opinion before me.”
[ 35 ] Spencer looks at this “old basic problem” from the point of view of natural science. He believed he could show that the developed human being also contributed to his spiritual existence through his own self. This self, is also made up of the inherited traits that had been acquired by our ancestors in their struggle with the external world. If we today believe we see with our eyes our opinions before us, we must remember that they were not always our opinions but that they were once observations that were really made by our eyes in the external world. Spencer's way of thinking, then, is, like that of John Stuart Mill, one that proceeds from psychology. But Mill does not go further than the psychology of the individual. Spencer goes from the individual back to his ancestors. The psychology of the individual is in the same position as the ontogenesis of zoology. Certain phenomena of the history of the individual are explainable only if they are referred back to phenomena of the history of the species. In the same way, the facts of the individual's consciousness cannot be understood if taken alone. We must go back to the species. We must, indeed, go back beyond the human species to acquisitions of knowledge that were accomplished by the animal ancestors of man. Spencer uses his great acumen to support this evolutionary history of the process of cognition. He shows in which way the mental activities have gradually developed from low stages at the beginning, through ever more accurate adaptations of the human mind to the external world and through inheritance of these adaptation. Every insight that the individual human being obtains through pure thought and without experience about things has been obtained by humanity or its ancestors through observation or experience. Leibniz thought he could explain the correspondence of man's inner life with the external world by assuming a harmony between them that was pre-established by the creator. Spencer explains this correspondence in the manner of natural science. The harmony is not pre-established, but gradually developed. We here find the continuation of natural scientific thinking to the highest aspects of human existence. Linnaeus had declared that every living organic form existed because the creator had made it as it is. Darwin maintained that it is as it is because it had gradually developed through adaptation and inheritance. Leibniz declared that thinking is an agreement with the external world because the creator had established this agreement. Spencer maintained that this agreement is there because it has gradually developed through adaptations and inheritance of the thought world.
[ 36 ] Spencer was motivated in his thought by the need for a naturalistic explanation of spiritual phenomena. He found the general direction for such an explanation in Lyell's geology (compare in Part 2 Chapter I). In this geology, to be sure, the idea is still rejected that organic forms have gradually developed one from another. It nevertheless receives a powerful support through the fact that the inorganic (geological) formations of the earth's surface are explained through such a gradual development and through violent catastrophes. Spencer, who had a natural scientific education and who had for a time also been active as a civil engineer, recognized at once the full extent of the idea of evolution, and he applied it in spite of Lyell's opposition to it. He even applied this idea to spiritual processes. As early as 1850, in his book, Social Statistics, he described social evolution in analogy with organic evolution. He also acquainted himself with the studies of Harvey and Wolff in embryonic development (compare Part I, Chapter IX of this book), and he plunged into the works of Karl Ernst von Baer (compare above in Part II Chapter II), which showed him that evolution proceeded from the development of a homogeneous uniform state to one of variety, diversity and abundance. In the early stages of embryological development the organisms are very similar; later they become different from one another (compare above in Part II Chapter II). Through Darwin this evolutionary thought was completely confirmed. From a few original organic forms the whole wealth of the highly diversified world of formations has developed.
From the idea of evolution, Spencer wanted to proceed to the most general truths, which, in his opinion, constituted the aim of all human striving for knowledge. He believed that one could discover manifestations of this evolutionary thought in the simplest phenomena. When, from dispersed particles of water, a cloud is formed in the sky, when a sand pile is formed from scattered grains of sand, Spencer saw the beginnings of an evolutionary process. Dispersed matter is contracted and concentrated to a whole. It is just this process that is presented to us in the Kant-Laplace hypothesis of world evolution. Dispersed parts of a chaotic world nebula have contracted. The organism originates in just this way. Dispersed elements are concentrated in tissues. The psychologist can observe that man contracts dispersed observations into general truths. Within this concentrated whole, articulation and differentiation take place. The original homogeneous mass is differentiated into the individual heavenly bodies of the solar system; the organism differentiates itself into the various organs.
[ 37 ] Concentration alternates with dissolution. When a process of evolution has reached a certain climax, an equilibrium takes place. Man, for instance, develops until he has evolved a maximum of harmonization of his inner abilities with external nature. Such a state of equilibrium, however, cannot last; external forces will effect it destructively. The evolutionary process must be followed by a process of dissolution; what had been concentrated is dispersed again; the cosmic again becomes chaotic. The process of evolution can begin anew. Thus, Spencer sees the process of the world as a rhythmic play of motion. [ 38 ] It is certainly not an uninteresting observation for the comparative history of the evolution of world conception that Spencer, from the observation of the genesis of world phenomena, reaches here a conclusion that is similar to one Goethe expressed in connection with his ideas concerning the genesis of life. Goethe describes the growth of a plant in the following way:
May the plant sprout, blossom or bear fruit, it is always by the same organs that the prescription of nature is fulfilled in various functions and under frequently changing forms. The same organ, which at the stem expands as a leaf and takes on a most differentiated shape, now contracts again in the calyx, spreads out in the petal, epitomizes in the organs of reproduction and finally once more swells as fruit.
If one thinks of this conception as being transferred to the whole process of the world, one arrives as Spencer's contraction and dispersion of matter.
[ 39 ] Spencer and Mill exerted a great influence on the development of world conception in the second half of the nineteenth century. The rigorous emphasis on observation and the one-sided elaboration of the methods of observational knowledge of Mill, along with the application of the conceptions of natural science to the entire scope of human knowledge by Spencer could not fail to meet with the approval of an age that saw in the idealistic world conception of Fichte, Schelling and Hegel nothing but degeneration of human thinking. It was an age that showed appreciation only for the successes of the research work of natural science. The lack of unity among the idealistic thinkers and what seemed to many a perfect fruitfulness of a thinking that was completely concentrated and absorbed in itself, had to produce a deep-seated suspicion against idealism. One may say that a widespread view of the last four decades of the nineteenth century is clearly expressed in words spoken by Rudolf Virchow in his address, The Foundation of the University of Berlin and the Transition from the Age of Philosophy into that of Natural Science (1893): “Since the belief in magic formulas has been forced back into the most backward circles of the people, the formulas of the natural philosopher have met with little approval.” And one of the most significant philosophers of the second half of the century, Eduard von Hartmann, sums up the character of his world conception in the motto he placed at the head of his book, Philosophy of the Unconscious: Speculative Results Obtained by the Inductive Method of Natural Science. He is of the opinion that it is necessary to recognize “the greatness of the progress brought about by Mill, through which all attempts of a deductive method of philosophy have been defeated and made obsolete for all times.” (Compare Eduard von Hartmann, Geschichte der Metaphysik, 2 part, page 479.)
[ 40 ] The recognition of certain limits of human knowledge that was shown by many naturalists was also received favorably by many religiously attuned souls. They argued as follows: The natural scientists observe the inorganic and organic facts of nature and they attempt to find general laws by combining the individual phenomena. Through these laws processes can be explained, and it is even possible to predetermine thereby the regular course of future phenomena. A comprehensive world conception should proceed in the same way; it should confine itself to the facts, establish general truths within moderate limits and not maintain any claim to penetrate into the realm of the “unknowable.” Spencer, with his complete separation of the “knowable” and the “unknowable,” met the demand of such religious needs to a high degree. The idealistic mode of thought was, on the other hand, considered by such religiously inclined spirits to be a fantastic aberration. As a matter of principle, the idealistic mode of conception cannot recognize an “unknowable,” because it has to uphold the conviction that through the concentrated penetration into the inner life of man a knowledge can be attained that covers not merely the outer surface of the world but also its real core.
[ 41 ] The thought life of some influential naturalists, such as Thomas Henry Huxley, moved entirely in the direction of such religiously inclined spirits. Huxley believed in a complete agnosticism with regard to the essence of the world. He declared that a monism, which is in general agreement with Darwin's results, is applicable only to external nature. Huxley was one of the first to defend the Darwinian conceptions, but he is at the same time one of the most outspoken representatives of those thinkers who believed in the limitation of that mode of conception. A similar view is also held by the physicist Johaan Tyndall (1820–93) who considered the world process to be an energy that is completely inaccessible to the human intellect. According to him, it is precisely the assumption that everything in the world comes into existence through a natural evolution that makes it impossible to accept the thought that matter, which is, after all, the carrier of the whole evolution, should be no more than what our intellect can comprehend of it.
[ 42 ] A characteristic phenomenon of his time is the personality of the English statesman, James Balfour (1840–1930). In 1879, in his book, A Defense of Philosophical Doubt, Being an Essay on the Foundations of Belief, he expressed a credo that is doubtless similar to that held by many other thinkers. With respect to everything that man is capable of explaining he stands completely on the ground of the thought of natural science. For him, there is no other knowledge but natural science, but he maintains at the same time that his knowledge of natural science is only rightly understood if it is clear that the needs of man's soul and reason can never be satisfied by it. It is only necessary to understand that, in the last analysis even in natural science, everything depends on faith in the ultimate truths for which no further proof is possible. But no harm is done in that this trend of thoughts leads us only to belief, because this belief is a secure guide for our action in daily life. We believe in the laws of nature and we master them through this belief. We thereby force nature to serve us for our purpose. Religious belief is to produce an agreement between the actions of man and his higher needs that go beyond his everyday life.
[ 43 ] The world conceptions that have been discussed under the title, “The World as Illusion,” show that they have as their basis a longing for a satisfactory relationship of the self-conscious ego to the general world picture. It is especially significant that they do not consciously consider this search as their philosophical aim, and therefore do not expressly turn their inquiry toward that purpose. Instinctively as it were, they permit their thinking to be influenced by the direction that is determined by this unconscious search. The form that this search takes is determined by the conceptions of modern natural science. We approach the fundamental character of these conceptions if we fix our attention on the concept of “consciousness.” This concept was introduced to the life of modern philosophy by Descartes. Before him, it was customary to depend more on the concept of the “soul” as such. Little attention was paid to the fact that only a part of the soul's life is spent in connection with conscious phenomena. During sleep the soul does not live consciously. Compared to the conscious life, the nature of the soul must therefore consist of deeper forces, which in the waking state are merely lifted into consciousness. The more one asked the question of the justification and the value of knowledge in the light of clear and distinct ideas, however, the more it was also felt that the soul finds the most certain elements of knowledge when it does not go beyond its own limits and when it does not delve deeper into itself than consciousness extends. The opinion prevailed that everything else may be uncertain, but what my consciousness is, at least, as such is certain. Even the house I pass may not exist without me; that the image of this house is now in my consciousness: this I may maintain. But as soon as we fix our attention on this consciousness, the concept of the ego inevitably grows together with that of the consciousness. Whatever kind of entity the “ego” may be outside the consciousness, the realm of the “ego” can be conceived as extending as far as the consciousness. There is no possibility of denying that the sensual world picture, which the soul experiences consciously, has come into existence through the impression that is made on man by the world. But as soon as one clings to this statement, it becomes difficult to rid oneself of it, for there is a tendency thereby to imply the judgment that the processes of the world are the causes, and that the content of our consciousness is the effect. Because one thinks that only the effect is contained in the consciousness, it is believed that the cause must be in a world outside man as an imperceptible “thing in itself.” The presentation that is given above shows how the results of modern physiological research lead to an affirmation of such an opinion. It is just this opinion through which the “ego” finds itself enclosed with its subjective experiences within its own boundaries. This subtly produced intellectual illusion, once formed, cannot be destroyed as long as the ego does not find any clues within itself of which it knows that they refer to a being outside the subjective consciousness, although they are actually depicted within that consciousness. The ego must, outside the sensual consciousness, feel a contact with entities that guarantee their being by and through themselves. It must find something within that leads it outside itself. been said here concerning thoughts that are brought to life can have this effect. As long as the ego has experienced thought only within itself, it feels itself confined with it within its own boundary. As thought is brought to life it emancipates the ego from a mere subjective existence. A process takes place that is, to be sure, experienced subjectively by the ego, but by its own nature is an objective process. This breaks the “ego” loose from everything that it can feel only as subjective.
So we see that also the conceptions for which the world is illusion move toward a point that is reached when Hegel's world picture is so transformed that its thought comes to life. These conceptions take on the form that is necessary for a world picture that is unconsciously driven by an impulse in that direction. But in them, thinking still lacks the power to work its way through to that aim. Even in their imperfection, however, these conceptions receive their general character from this aim, and the ideas that appear are the external symptoms of active forces that remain concealed.
Die Welt als Illusion
[ 1 ] Neben der Weltanschauungsströmung, die durch den Entwickelungsgedanken eine volle Einheit in die Auffassung von Natur- und Geisteserscheinungen bringen will, läuft eine andere, die diesen Gegensatz in der denkbar schärfsten Form wieder zur Geltung bringt. Auch sie ist aus der Naturwissenschaft heraus geboren. Ihre Bekenner fragen sich: Worauf stützen wir uns denn, die wir aus der Beobachtung durch Denken eine Weltanschauung aufbauen? Wir hören, sehen und tasten die Körperwelt durch unsere Sinne. Wir denken dann über dasjenige nach, was uns die Sinne über die Welt sagen. Wir machen uns also unsere Gedanken über die Welt auf das Zeugnis der Sinne hin. Aber sind denn die Aussagen unserer Sinne untrüglich? Fragen wir die Beobachtung. Das Auge bringt uns die Lichterscheinungen. Wir sagen, ein Körper sende uns rotes Licht, wenn das Auge rot empfindet. Aber das Auge überliefert uns eine Lichtempfindung auch in anderen Fällen. Wenn es gestoßen oder gedrückt wird, wenn ein elektrischer Strom den Kopf durchfließt, so hat das Auge auch eine Lichtempfindung. Es könnte somit auch in den Fällen, in denen wir einen Körper als leuchtend empfinden, in dem Körper etwas vorgehen, was gar keine Ähnlichkeit hat mit unserer Empfindung des Lichtes: das Auge würde uns doch Licht übermitteln. Der Physiologe Johannes Müller (1801-1858) hat aus diesen Tatsachen gefolgert, daß es nicht von den äußeren Vorgängen abhängt, was der Mensch empfinde, sondern von dessen Organisation. Unsere Nerven vermitteln uns die Empfindungen. So wie wir nicht das Messer empfinden, das uns schneidet, sondern einen Zustand unserer Nerven, der uns schmerzhaft erscheint; so empfinden wir auch nicht einen Vorgang der Außenwelt, wenn uns Licht erscheint, sondern einen Zustand unseres Sehnerven. Draußen mag vorgehen, was will: der Sehnerv übersetzt diesen außer uns liegenden Vorgang in Lichtempfindung. «Die Empfindung ist nicht die Leitung einer Qualität oder eines Zustandes der äußeren Körper zum Bewußtsein, sondern die Leitung einer Qualität, eines Zustandes unserer Nerven zum Bewußtsein, veranlaßt durch eine äußere Ursache.» Dies Gesetz hat Johannes Müller das der spezifischen Sinnesenergien genannt. Ist es richtig, so haben wir in unseren Beobachtungen nichts von der Außenwelt gegeben, sondern nur die Summe unserer eigenen Zustände. Was wir wahrnehmen, hat mit der Außenwelt nichts zu tun; es ist ein Erzeugnis unserer eigenen Organisation. Wir nehmen im Grunde nur wahr, was in uns ist.
[ 2 ] Bedeutende Naturforscher sehen in diesen Gedanken eine unwiderlegliche Grundlage ihrer Weltauffassung. Hermann Helmholtz (1821-1894) fand in ihr den Kantschen Gedanken, daß sich alle unsere Erkenntnisse nicht auf Dinge außer uns beziehen, sondern auf Vorgänge in uns (vgl. 1. Band dieser Weltanschauungsgeschichte) ins Naturwissenschaftliche übersetzt. Er ist der Ansicht, daß unsere Empfindungswelt uns nur Zeichen gibt von den Vorgängen in den Körpern draußen in der Welt. «Ich habe die Beziehung zwischen der Empfindung und ihrem Objekte so formulieren zu müssen geglaubt, daß ich die Empfindung nur für ein Zeichen von der Einwirkung des Objekts erklärte. Zum Wesen eines Zeichens gehört nur, daß für das gleiche Objekt immer dasselbe Zeichen gegeben werde. Übrigens ist gar keine Art von Ähnlichkeit zwischen ihm und seinem Objekt nötig, ebensowenig wie zwischen dem gesprochenen Worte und dem Gegenstand, den wir dadurch bezeichnen. - Wir können unsere Sinneseindrücke nicht einmal Bilder nennen; denn das Bild bildet Gleiches durch Gleiches ab. In einer Statue geben wir Körperform durch Körperform, in einer Zeichnung den perspektivischen Anblick des Objekts durch den gleichen des Bildes, in einem Gemälde Farbe durch Farbe.» Verschiedener als Bilder von dem Abgebildeten müssen somit unsere Empfindungen von dem sein, was draußen in der Welt vorgeht. Wir haben es in unserem sinnlichen Weltbild nicht mit etwas Objektivem, sondern mit einem ganz und gar Subjektiven zu tun, das wir selbst aus uns aufbauen auf Grund der Wirkungen einer nie in uns dringenden Außenwelt.
[ 3 ] Dieser Vorstellungsweise kommt die physikalische Betrachtung der Sinneserscheinungen von einer anderen Seite entgegen. Ein Schall, den wir hören, weist uns auf einen Körper in der Außenwelt, dessen Teile sich in einem bestimmten Bewegungszustande befinden. Eine gespannte Saite schwingt, und wir hören einen Ton. Die Saite versetzt die Luft in Schwingungen. Die breiten sich aus, gelangen bis zu unserem Ohre: uns teilt sich eine Tonempfindung mit. Der Physiker untersucht die Gesetze, nach denen draußen die Körperteile sich bewegen, während wir diese oder jene Töne hören. Man sagt, die subjektive Tonempfindung beruht auf der objektiven Bewegung der Körperteilchen. Ähnliche Verhältnisse sieht der Physiker in bezug auf die Lichtempfindungen. Auch das Licht beruht auf Bewegung. Nur wird diese Bewegung nicht durch die schwingenden Luftteilchen uns überbracht, sondern durch die Schwingungen des Äthers, dieses feinsten Stoffes, der alle Räume des Weltalls durchflutet. Durch jeden selbstleuchtenden Körper wird der Äther in wellenförmige Schwingungen versetzt, die bis zur Netzhaut unseres Auges sich ausbreiten und den Sehnerv erregen, der dann die Empfindung des Lichtes in uns hervorruft. Was in unserem Weltbilde sich als Licht und Farbe darstellt, das ist draußen im Raume Bewegung. Schleiden drückt diese Ansicht mit den Worten aus: «Das Licht außer uns in der Natur ist Bewegung des Äthers, eine Bewegung kann langsam und schnell sein, diese oder jene Richtung haben, aber es hat offenbar keinen Sinn, von einer hellen oder dunklen, von einer grünen oder roten Bewegung zu sprechen; kurz: außer uns, den empfindenden Wesen, gibt es kein Hell und Dunkel, keine Farben.»
[ 4 ] Der Physiker drängt also die Farben und das Licht aus der Außenwelt heraus, weil er in ihr nur Bewegung findet; der Physiologe sieht sich genötigt, sie in die Seele hereinzunehmen, weil er der Ansicht ist, daß der Nerv nur seinen eigenen Zustand anzeigt, mag er von was immer erregt sein. Scharf spricht die dadurch gegebene Anschauung H. Taine in seinem Buche «Der Verstand» (Deutsche Ausgabe, Bonn 1880) aus. Die äußere Wahrnehmung ist, seiner Meinung nach, eine Halluzination. Der Halluzinär, der drei Schritte weit von sich entfernt einen Totenkopf sieht, macht genau die gleiche Wahrnehmung wie derjenige, der die Lichtstrahlen empfängt, die ihm ein wirklicher Totenkopf zusendet. Es ist in uns dasselbe innere Phantom vorhanden, gleichgültig, ob wir einen wirklichen Totenkopf vor uns haben oder ob wir eine Halluzination haben. Der einzige Unterschied zwischen der einen und der anderen Wahrnehmung ist der, daß in dem einen Fall die ausgestreckte Hand ins Leere tappt, in dem anderen auf einen festen Widerstand stößt. Der Tastsinn unterstützt also den Gesichtssinn. Aber ist die Unterstützung wirklich so, daß durch sie ein untrügliches Zeugnis überliefert wird? Was für den einen Sinn gilt, gilt natürlich auch für den anderen. Auch die Tastempfindungen erweisen sich als Halluzinationen. Der Anatom Henle bringt dieselbe Anschauung in seinen «Anthropologischen Vorträgen» (1876) auf den Ausdruck: «Alles, wodurch wir von einer Außenwelt unterrichtet zu sein glauben, sind Formen des Bewußtseins, zu welcher die Außenwelt sich nur als anregende Ursache, als Reiz im Sinne der Physiologen verhält. Die Außenwelt hat nicht Farben, nicht Töne, nicht Geschmäcke; was sie wirklich hat, erfahren wir nur auf Umwegen oder gar nicht; was das sei, wodurch sie einen Sinn affiziert, erschließen wir nur aus ihrem Verhalten gegen die anderen, wie wir beispielsweise den Ton, d. h. die Schwingungen der Stimmgabel mit dem Auge sehen und mit den Fingern fühlen; das Wesen mancher Reize, die nur einem Sinne sich offenbaren, zum Beispiel der Reize des Geruchsinns, ist uns noch heute unzugänglich. Die Zahl der Eigenschaften der Materie richtet sich nach der Zahl und der Schärfe der Sinne; wem ein Sinn gebricht, dem ist eine Gruppe von Eigenschaften unersetzlich verloren; wer einen Sinn mehr hätte, besäße ein Organ zum Erfassen von Qualitäten, die wir so wenig ahnen, wie der Blinde die Farbe.»
[ 5 ] Eine Umschau auf dem Gebiete der physiologischen Literatur aus der zweiten Hälfte des neunzehnten Jahrhunderts zeigt, daß diese Anschauung von der subjektiven Natur des Wahrnehmungsbildes weite Kreise gezogen hat. Man wird da immer wieder auf Variationen des Gedankens stoßen, den J. Rosenthal in seiner «Allgemeinen Physiologie der Muskeln und Nerven» (1877) ausgesprochen hat: «Die Empfindungen, welche wir durch äußere Eindrücke erhalten, sind nicht abhängig von der Natur dieser Eindrücke, sondern von der Natur unserer Nervenzellen. Wir empfinden nicht, was auf unseren Körper einwirkt, sondern nur, was in unserem Gehirn vorgeht.»
[ 6 ] Inwiefern unser subjektives Weltbild uns Zeichen von der objektiven Außenwelt gibt, davon gibt Helmholtz in seiner «Physiologischen Optik» eine Vorstellung: «Die Frage zu stellen, ob der Zinnober wirklich rot sei, wie wir ihn sehen, oder ob dies nur eine sinnliche Täuschung sei, ist sinnlos. Die Empfindung von Rot ist die normale Reaktion normal gebildeter Augen für das von Zinnober reflektierte Licht. Ein Rotblinder wird den Zinnober schwarz oder dunkelgraugelb sehen; auch dies ist die richtige Reaktion für sein besonders geartetes Auge. Er muß nur wissen, daß sein Auge eben anders geartet ist, als das anderer Menschen. An sich ist die eine Empfindung nicht richtiger und nicht falscher als die andere, wenn auch die Rotsehenden eine große Majorität für sich haben. Überhaupt existiert die rote Farbe des Zinnobers nur, insofern es Augen gibt, die denen der Majorität der Menschen ähnlich beschaffen sind. Genau mit demselben Rechte ist es eine Eigenschaft des Zinnobers, schwarz zu sein, nämlich für die Rotblinden. Überhaupt ist das vom Zinnober zurückgeworfene Licht an sich durchaus nicht rot zu nennen, es ist nur für bestimmte Arten von Augen rot. - Etwas anderes ist es, wenn wir behaupten, daß die Wellenlängen des vom Zinnober zurückgeworfenen Lichtes eine gewisse Länge haben. Das ist eine Aussage, die wir unabhängig von der besonderen Natur unseres Auges machen können, bei der es sich dann aber auch nur um Beziehungen der Substanz und den verschiedenen Ätherwellensystemen handelt.»
[ 7 ] Es ist klar, daß für eine solche Anschauung die gesamte Summe der Welterscheinungen in eine Zweiheit auseinanderfällt, in eine Welt der Bewegungszustände, die unabhängig von der besonderen Natur unseres Wahrnehmungsvermögens ist, und in eine Welt subjektiver Zustände, die nur innerhalb der wahrnehmenden Wesen sind. Scharf pointiert hat diese Anschauung der Physiologe Du Bois-Reymond in seinem Vortrag «Über die Grenzen des Naturerkennens» auf der fünfundvierzigsten Versammlung deutscher Naturforscher und Ärzte in Leipzig am 14. August 1872 zur Darstellung gebracht. Naturerkennen ist Zurückführen der von uns wahrgenommenen Vorgänge in der Welt auf Bewegungen der kleinsten Körperteile, «oder Auflösung der Naturvorgänge in Mechanik der Atome». Denn es ist «eine psychologische Erfahrungstatsache, daß, wo solche Auflösung gelingt», unser Erklärungsbedürfnis vorläufig befriedigt ist. Nun sind unser Nervensystem und unser Gehirn auch körperlicher Natur. Die Vorgänge, die sich in ihnen abspielen, können auch nur Bewegungsvorgänge sein. Wenn sich Ton- oder Lichtschwingungen bis zu meinen Sinnesorganen, und von da bis in mein Gehirn fortpflanzen, so können sie hier auch nichts sein als Bewegungen. Ich kann nur sagen: in meinem Gehirn findet ein bestimmter Bewegungsvorgang statt; und dabei empfinde ich «rot». Denn wenn es sinnlos ist, vom Zinnober zu sagen: er sei rot, so ist es nicht minder sinnlos, von einer Bewegung der Gehirnteile zu sagen, sie sei hell oder dunkel, grün oder rot. «Stumm und finster an sich, das heißt eigenschaftslos» ist die Welt für die durch naturwissenschaftliche Betrachtung gewonnene Anschauung, welche «statt Schalles und Lichtes nur Schwingungen eines eigenschaftlosen, dort zur wägbaren, hier zur unwägbaren Materie gewordenen Urstoffes kennt... . Das mosaische: Es ward Licht, ist physiologisch falsch. Licht ward erst, als der erste rote Augenpunkt eines Infusoriums zum ersten Mal Hell und Dunkel unterschied. Ohne Seh- und ohne Gehörsinnsubstanz wäre diese farbenglühende, tönende Welt um uns her finster und stumm.» (Grenzen des Naturerkennens, S. 6f.) Durch die Vorgänge in unserer Seh- und Gehörsinnsubstanz wird also aus der stummen und finsteren Welt - dieser Ansicht gemäß - eine tönende und in Farben leuchtende hervorgezaubert. Die finstere und stumme Welt ist körperlich; die tönende und farbige Welt ist seelisch. Wodurch erhebt sich die letztere aus der ersteren; wodurch wird aus Bewegung Empfindung? Hier zeigt sich uns, meint Du Bois-Reymond, eine «Grenze des Naturerkennens». In unserem Gehirn und in der Außenwelt gibt es nur Bewegungen; in unserer Seele erscheinen Empfindungen. Nie werden wir begreifen können, wie das eine aus dem anderen entsteht. «Es scheint zwar bei oberflächlicher Betrachtung, als könnten durch die Kenntnis der materiellen Vorgänge im Gehirne gewisse geistige Vorgänge und Anlagen uns verständlich werden. Ich rechne dahin das Gedächtnis, den Fluß und die Assoziation der Vorstellungen, die Folgen der Übung, die spezifischen Talente und dergleichen mehr. Das geringste Nachdenken lehrt, daß dies Täuschung ist. Nur über gewisse innere Bedingungen des Geisteslebens, weiche mit den äußeren durch die Sinneseindrücke gesetzten etwa gleichbedeutend sind, würden wir unterrichtet sein, nicht über das Zustandekommen des Geisteslebens durch diese Bedingungen. - Welche denkbare Verbindung besteht zwischen bestimmten Bewegungen bestimmter Atome in meinem Gehirn einerseits, anderseits in den für mich ursprünglichen, nicht weiter definierbaren, nicht wegzuleugnenden Tatsachen: Ich fühle Schmerz, fühle Lust, ich schmecke süß, rieche Rosenduft, höre Orgelton, sehe Rot, und der ebenso unmittelbaren daraus fließenden Gewißheit: Also bin ich? Es ist eben durchaus und für immer unbegreiflich, daß es einer Anzahl von Kohlenstoff-, Wasserstoff-, Stickstoff-, Sauerstoff- usw. Atomen nicht solle gleichgültig sein, wie sie liegen und sich bewegen, wie sie lagen und sich bewegten, wie sie liegen und sich bewegen werden.» Es gibt für die Erkenntnis keine Brücke von der Bewegung zur Empfindung: das ist Du Bois-Reymonds Glaubensbekenntnis. Wir kommen aus der Bewegung in der materiellen Welt nicht herein in die seelische Welt der Empfindungen. Wir wissen, daß durch bewegte Materie Empfindung entsteht; jedoch wissen wir nicht, wie das möglich ist. Aber wir kommen in der Welt der Bewegung auch nicht über die Bewegung hinaus. Wir können für unsere subjektiven Wahrnehmungen gewisse Bewegungsformen angeben, weil wir aus dem Verlauf der Wahrnehmungen auf den Verlauf der Bewegungen schließen können. Doch haben wir keine Vorstellung, was sich draußen im Raume bewegt. Wir sagen: die Materie bewegt sich. Wir verfolgen ihre Bewegungen an den Aussagen unserer seelischen Zustände. Da wir aber das Bewegte selbst nicht wahrnehmen, sondern nur ein subjektives Zeichen davon, können wir auch nie wissen, was Materie ist. Vielleicht würden wir, meint Du Bois-Reymond, auch das Rätsel der Empfindung lösen können, wenn erst das der Materie offen vor uns läge. Wüßten wir, was Materie ist, so wüßten wir vermutlich auch, wie sie empfindet. Beides sei unserer Erkenntnis unzugänglich. Die über diese Grenze hinwegkommen wollen, die sollen Du Bois-Reymonds Worte treffen: «Mögen sie es doch mit dem einzigen Ausweg versuchen, dem des Supranaturalismus. Nur daß, wo Supranaturalismus anfängt, Wissenschaft aufhört.»
[ 8 ] In zwei scharfen Gegensätzen lebt sich die neuere Na-turwissenschaft aus. Die eine, die monistische Strömung, scheint auf dem Wege zu sein, aus dem Gebiete der Naturerkenntnis heraus zu den wichtigsten Weltanschauungsfragen vorzudringen; die andere erklärt sich außerstande, mit naturwissenschaftlichen Mitteln weiter zu kommen als bis zu der Erkenntnis: diesem oder jenem subjektiven Zustand entspricht dieser oder jener Bewegungsvorgang. Und scharf stehen sich die Vertreter beider Strömungen gegenüber. Du Bois-Reymond hat Haeckels «Schöpfungsgeschichte» als einen Roman abgetan. (Vgl. Du Bois-Reymonds Rede «Darwin versus Galiani».) Die Stammbäume, die Haeckel auf Grund der vergleichenden Anatomie, der Keimungsgeschichte und der Paläontologie entwirft, sind ihm «etwa so viel wert, wie in den Augen der historischen Kritik die Stammbäume homerischer Helden». Haeckel aber sieht in Du Bois-Reymonds Anschauung einen unwissenschaftlichen Dualismus, der naturgemäß den rückschrittlichen Weltbetrachtungen eine Stütze liefern muß. «Der Jubel der Spiritualisten über Du Bois-Reymonds ,Grenzrede war um so heller und berechtigter, als E. Du Bois-Reymond bis dahin als bedeutender prinzipieller Vertreter des wissenschaftlichen Materialismus gegolten hat.»
[ 9 ] Was viele für die Zweiteilung der Welt in äußere Vorgänge der Bewegungen und in innere (subjektive) der Empfindung und Vorstellung gefangen nimmt, das ist die Anwendbarkeit der Mathematik auf die erste Art von Vorgängen. Wenn man materielle Teile (Atome) mit Kräften annimmt, so kann man berechnen, wie sich diese Atome unter dem Einfluß dieser Kräfte bewegen müssen. Man hat das Anziehende, das die Astronomie mit ihren strengen rechnerischen Methoden hat, in das Kleinste der Körper hineingetragen. Der Astronom berechnet aus den Gesetzen der Himmelsmechanik die Art, wie sich die Weltkörper bewegen. In der Entdeckung des Neptun hat man einen Triumph dieser Himmelsmechanik erlebt. Auf solche Gesetze, wie die Bewegungen der Himmelskörper, kann man nun auch die Bewegungen bringen, welche in der äußeren Welt vor sich gehen, wenn wir einen Ton hören, eine Farbe sehen; man wird vielleicht einmal die Bewegungen, die sich in unserem Gehirn abspielen, berechnen können, während wir das Urteil fällen: zweimal zwei ist vier. In dem Augenblicke, wo man alles berechnen kann, was sich auf Rechnungsformeln bringen läßt, ist die Welt mathematisch erklärt. Laplace hat in seinem «Essai philosophique sur les Probabilités» (1814) eine bestrickende Schilderung des Ideals einer solchen Welterklärung gegeben: «Ein Geist, der für einen gegebenen Augenblick alle Kräfte kennt, welche die Natur beleben, und die gegenseitige Lage der Wesen, aus denen sie besteht, wenn sonst er umfassend genug wäre, um diese Angaben der Analyse zu unterwerfen, würde in derselben Formel die Bewegungen der größten Weltkörper und des leichtesten Atoms begreifen: nichts wäre ungewiß für ihn, und Zukunft wie Vergangenheit wäre seinem Blicke gegenwärtig. Der menschliche Verstand bietet in der Vollendung, die er der Astronomie zu geben gewußt hat, ein schwaches Abbild eines solchen Geistes dar.» Und Du Bois-Reymond sagt anschließend an diese Worte: «Wie der Astronom den Tag vorhersagt, an dem nach Jahren ein Komet aus den Tiefen des Weltraumes am Himmelsgewölbe wieder auftaucht, so läse jener Geist in seinen Gleichungen den Tag, da das griechische Kreuz von der Sophienmoschee blitzen und da England seine letzte Steinkohle verbrennen wird.»
[ 10 ] Es kann nicht bezweifelt werden, daß ich auch durch die vollkommenste mathematische Kenntnis eines Bewegungsvorgangs nichts gewinne, was mich darüber aufklärt, warum dieser Bewegungsvorgang als rote Farbe auftritt. Wenn eine Kugel an eine andere stößt, so können wir - so scheint es - die Richtung der zweiten Kugel erklären. Wir können mathematisch angeben, was für eine Bewegung aus einer anderen entsteht. Wir können aber nicht in dieser Weise angeben, wie aus einer bestimmten Bewegung die rote Farbe hervorgeht. Wir können nur sagen: Wenn diese oder jene Bewegung vorhanden ist, ist diese oder jene Farbe vorhanden. Wir können in diesem Falle nur eine Tatsache beschreiben. Während wir also das rechnerisch Bestimmbare - scheinbar im Gegensatze zur bloßen Beschreibung - erklären können, kommen wir allem gegenüber, was sich der Rechnung entzieht, nur zu einer Beschreibung.
[ 11 ] Ein bedeutungsvolles wissenschaftliches Bekenntnis hat Kirchhoff getan, als er 1874 die Aufgabe der Mechanik in die Worte faßte, sie solle «die in der Natur vor sich gehenden Bewegungen vollständig und auf die einfachste Weise beschreiben.» Die Mechanik bringt die Mathematik zur Anwendung. Kirchhoff bekennt, daß mit Hilfe der Mathematik nichts erreicht werden kann, als eine vollständige und einfache Beschreibung der Vorgänge in der Natur. Für diejenigen Persönlichkeiten, die von einer Erklärung etwas wesentlich anderes verlangen als eine Beschreibung nach gewissen Gesichtspunkten, konnte das Kirchhoffsche Bekenntnis als eine Bestätigung ihrer Ansicht dienen, daß es «Grenzen des Naturerkennens» gäbe. Du Bois-Reymond preist die «weise Zurückhaltung des Meisters» (Kirchhoffs), der als Aufgabe der Mechanik hinstellt, die Bewegungen der Körper zu beschreiben, und stellt sie in Gegensatz zu Ernst Haeckel, der von «Atom-Seelen» spreche.
[ 12 ] Einen bedeutungsvollen Versuch, die Weltanschauung auf die Vorstellung aufzubauen, daß alles, was wir wahrnehmen, nur das Ergebnis unserer eigenen Organisation sei, hat Friedrich Albert Lange (1828-1875) mit seiner «Geschichte des Materialismus» (1864) gemacht Er hatte die Kühnheit und vor nichts haltmachende Konsequenz, diese Grundvorstellung wirklich zu Ende zu denken. Langes Stärke lag in einem scharf und möglichst allseitig sich auslebenden Charakter. Er war eine von den Persönlichkeiten, die vieles ergreifen können und für das Ergriffene mit ihrem Können ausreichen.
[ 13 ] Und bedeutend wurde die mit Zuhilfenahme der neueren Naturwissenschaft von ihm besonders wirksam erneuerte Kantsche Vorstellungsart, daß wir die Dinge wahrnehmen, nicht wie sie es verlangen, sondern wie es von unserer Organisation gefordert wird. Lange hat im Grunde keine neuen Vorstellungen produziert; aber er hat in gegebene Gedankenwelten mit einem Licht hineingeleuchtet, das an Helligkeit etwas Seltenes hat. Unsere Organisation, unser Gehirn mit den Sinnen bringt die Welt unserer Empfindungen hervor. Ich sehe «blau», ich fühle «Härte», weil ich so und so organisiert bin. Aber ich verbinde auch die Empfindungen zu Gegenständen. Aus den Empfindungen des «Weißen» und «Weichen» usw. verbinde ich zum Beispiel die Vorstellung des Wachses. Wenn ich meine Empfindungen denkend betrachte, so bewege ich mich in keiner Außenwelt. Mein Verstand bringt Zusammenhang in meine Empfindungswelt, nach meinen Verstandesgesetzen. Wenn ich sage, die Eigenschaften, die ich an einem Körper wahrnehme, setzen eine Materie voraus mit Bewegungsvorgängen, so komme ich auch nicht aus mir heraus. Ich finde mich durch meine Organisation genötigt, zu den Empfindungen, die ich wahrnehme, materielle Bewegungsvorgänge hinzuzudenken. Derselbe Mechanismus, welcher unsere sämtlichen Empfindungen hervorbringt, erzeugt auch unsere Vorstellung von der Materie. Die Materie ist ebensogut nur Produkt meiner Organisation wie die Farbe oder der Ton. Auch wenn wir von Dingen an sich sprechen, müssen wir uns klar darüber sein, daß wir damit nicht aus unserem eigenen Bereiche hinauskommen können. Wir sind so eingerichtet, daß wir unmöglich aus uns heraus können. Ja, wir können uns auch das, was jenseits unseres Bereiches liegt, nur durch unsere Vorstellung vergegenwärtigen. Wir spüren eine Grenze unseres Bereiches; wir sagen uns, jenseits der Grenze muß etwas sein, was in uns Empfindungen bewirkt. Aber wir kommen nur bis zur Grenze. Auch diese Grenze setzen wir uns selbst, weil wir nicht weiter können. «Der Fisch im Teiche kann im Wasser schwimmen, nicht in der Erde; aber er kann doch mit dem Kopf gegen Boden und Wände stoßen.» So können wir innerhalb unseres Vorstellungs- und Empfindungswesens leben, nicht aber in äußeren Dingen; aber wir stoßen an eine Grenze, wo wir nicht weiter können, wo wir uns nicht mehr sagen dürfen als: Jenseits liegt das Unbekannte. Alle Vorstellungen, die wir uns über dieses Unbekannte machen, sind unberechtigt; denn wir könnten doch nichts tun, als die in uns gewonnenen Vorstellungen auf das Unbekannte übertragen. Wir wären, wenn wir solches tun wollten, genau so klug wie der Fisch, der sich sagt: Hier kann ich nicht weiter, also ist von da ab ein anderes Wasser, in dem ich anders zu schwimmen probieren will. Er kann eben nur im Wasser schwimmen und nirgends anders.
[ 14 ] Nun aber kommt eine andere Wendung des Gedankens. Sie gehört zu der ersten. Lange hat sie als Geist von unerbittlichem Folgerichtigkeitsdrang herangezogen. Wie steht es denn mit mir, wenn ich mich selbst betrachte? Bin ich denn dabei nicht ebensogut an die Gesetze meiner eigenen Organisation gebunden, wie wenn ich etwas anderes betrachte? Mein Auge betrachtet den Gegenstand, vielmehr: es erzeugt ihn. Ohne Auge keine Farbe. Ich glaube einen Gegenstand vor mir zu haben und finde, wenn ich genauer zusehe, daß mein Auge, also ich, den Gegenstand erzeuge. Nun aber will ich mein Auge selbst betrachten. Kann ich das anders als wieder mit meinen Organen? Ist also nicht auch die Vorstellung, die ich mir von mir selbst mache, nur meine Vorstellung? Die Sinnenwelt ist Produkt unserer Organisation. Unsere sichtbaren Organe sind gleich allen anderen Teilen der Erscheinungswelt nur Bilder eines unbekannten Gegenstandes. Unsere wirkliche Organisation bleibt uns daher ebenso verborgen wie die wirklichen Außendinge. Wir haben stets nur das Produkt von beiden vor uns. Wir erzeugen auf Grund einer uns unbekannten Welt aus einem uns unbekannten Ich heraus eine Vorstellungswelt, die alles ist, womit wir uns beschäftigen können.
[ 15 ] Lange fragt sich: Wohin führt der konsequente Materialismus? Es sei, daß alle unsere Verstandesschlüsse und Sinnesempfindungen durch die Tätigkeit unseres an materielle Bedingungen gebundenen Gehirnes und der ebenfalls materiellen Organe hervorgebracht werden. Dann stehen wir vor der Notwendigkeit, unseren Organismus zu untersuchen, um zu sehen, wie er tätig ist. Das können wir nur wieder mit unseren Organen. Keine Farbe ohne Auge; aber auch kein Auge ohne Auge. «Die konsequent materialistische Betrachtung schlägt dadurch sofort um in eine konsequent idealistische. Es ist keine Kluft in unserem Wesen anzunehmen. Wir haben nicht einzelne Funktionen unseres Wesens einer physischen, andere einer geistigen Natur zuzuschreiben, sondern wir sind in unserem Recht, wenn wir für alles, auch für den Mechanismus des Denkens, physische Bedingungen voraussetzen und nicht rasten, bis wir sie gefunden haben. Wir sind aber nicht minder in unserem Recht, wenn wir nicht nur die uns erscheinende Außenwelt, sondern auch die Organe, mit denen wir diese auffassen, als bloße Bilder des wahrhaft Vorhandenen betrachten. Das Auge, mit dem wir zu sehen glauben, ist selbst nur ein Produkt unserer Vorstellung, und wenn wir finden, daß unsere Gesichtsbilder durch die Einrichtung des Auges hervorgerufen werden, so dürfen wir nie vergessen, daß auch das Auge samt seinen Einrichtungen, der Sehnerv samt dem Hirn und all den Strukturen, die wir dort noch etwa als Ursachen des Denkens entdecken möchten, nur Vorstellungen sind, die zwar eine in sich selbst zusammenhängende Welt bilden, jedoch eine Welt, die über sich selbst hinausweist... . Die Sinne geben uns, wie Helmholtz sagt, Wirkungen der Dinge, nicht getreue Bilder, oder gar die Dinge selbst. Zu diesen bloßen Wirkungen gehören aber auch die Sinne selbst samt dem Hirn und den in ihm gedachten Molekularbewegungen». (Geschichte des Materialismus, S. 734 f.) Lange nimmt deshalb eine Welt jenseits der unsrigen an, möge diese nun auf Dingen an sich selbst beruhen, oder möge sie in irgend etwas bestehen, was nicht einmal mit dem «Ding an sich» etwas zu tun hat, da ja selbst dieser Begriff, den wir uns an der Grenze unseres Bereiches bilden, nur unserer Vorstellungswelt angehört.
[ 16 ] Langes Weltanschauung führt also zu der Meinung, daß wir nur eine Vorstellungswelt haben. Diese aber zwingt uns, ein Etwas jenseits ihrer selbst gelten zu lassen; sie erweist sich aber auch ganz ungeeignet, über dieses Etwas eine irgendwie geartete Aussage zu machen. Dies ist die Weltanschauung des absoluten Nichtwissens, des Agnostizismus.
[ 17 ] Daß alles wissenschaftliche Streben unfruchtbar bleiben muß, das sich nicht an die Aussagen der Sinne und an den logischen Verstand hält, der diese Aussagen verknüpft: dies ist Langes Überzeugung. Daß aber Sinne und Verstand zusammen uns nichts liefern als ein Ergebnis unserer eigenen Organisation, ist ihm aus seinen Betrachtungen über den Ursprung der Erkenntnis klar. Die Welt ist ihm also im Grunde eine Dichtung der Sinne und des Verstandes. Diese Meinung bringt ihn dazu, den Ideen gegenüber gar nicht mehr die Frage nach ihrer Wahrheit aufzuwerfen. Eine Wahrheit, die uns über das Wesen der Welt aufklärt, erkennt Lange nicht an. Nun glaubt er gerade dadurch, daß er den Erkenntnissen der Sinne und des Verstandes keine Wahrheit zuzugestehen braucht, auch die Bahn frei zu bekommen für die Ideen und Ideale, die sich der menschliche Geist über das hinaus bildet, was ihm Sinne und Verstand geben. Unbedenklich hält er alles, was über die sinnliche Beobachtung und verstandesmäßige Erkenntnis hinausgeht, für Erdichtung. Was immer ein idealistischer Philosoph erdacht hat über das Wesen der Tatsachen: es ist Dichtung. Notwendig entsteht durch die Wendung, die Lange dem Materialismus gegeben hat, die Frage: Warum sollten die höheren Ideendichtungen nicht gelten, da doch die Sinne selbst dichten? Wodurch unterscheidet sich die eine Dichtungsart von der anderen? Es muß für den, der so denkt, ein ganz anderer Grund vorhanden sein, warum er eine Vorstellung gelten läßt, als für den, der glaubt, sie gelten lassen zu müssen, weil sie wahr ist. Und Lange findet diesen Grund darin, daß eine Vorstellung Wert für das Leben hat. Nicht darauf komme es an, daß eine Vorstellung wahr ist; sondern darauf, daß sie für den Menschen wertvoll ist. Nur eines muß deutlich erkannt werden: daß ich eine Rose rot sehe, daß ich die Wirkung mit der Ursache verknüpfe, habe ich mit allen empfindenden und denkenden Geschöpfen gemein. Meine Sinne und mein Verstand können sich keine Extrawerte schaffen. Gehe ich aber über dasjenige hinaus, was Sinne und Verstand dichten, dann bin ich nicht mehr an die Organisation der ganzen menschlichen Gattung gebunden. Schiller, Hegel Hinz und Kunz sehen eine Blume auf gleiche Weise was Schiller über die Blume dichtet was Hegel über sie denkt, dichten und denken Hinz und Kunz nicht in der gleichen Weise So wie aber Hinz und Kunz im Irrtum sind wenn sie ihre Vorstellung von der Blume für eine außer ihnen befindliche Wesenheit halten so waren Schiller und Hegel im Irrtum, wenn sie ihre Ideen für etwas anderes ansähen, denn als Dichtungen, die ihrem geistigen Bedürfnisse entsprechen. Was die Sinne und der Verstand dichten, gehört der ganzen menschlichen Gattung an; keiner kann da von dem anderen abweichen. Was über Sinnes- und Verstandesdichtung hinausgeht, ist Sache des einzelnen Individuums. Aber dieser Dichtung des Individuums spricht Lange doch einen Wert auch für die ganze menschliche Gattung zu, wenn der einzelne, welcher «sie erzeugt, reich und normal begabt und in seiner Denkweise typisch, durch seine Geisteskraft zum Führer berufen ist». So vermeint Lange dadurch der idealen Welt ihren Wert zu sichern, daß er auch die sogenannte wirkliche zur Dichtung macht. Er sieht überall, wohin wir blicken können, nur Dichtung, von der untersten Stufe der Sinnesanschauung, auf der «das Individuum noch ganz an die Grundzüge der Gattung gebunden erscheint, bis hinauf zu dem schöpferischen Walten in der Poesie». «Man kann die Funktionen der Sinne und des verknüpfenden Verstandes, welche uns die Wirklichkeit erzeugen, im einzelnen niedrig nennen gegenüber dem hohen Fluge des Geistes in der frei schaffenden Kunst. Im ganzen aber und in ihrem Zusammenhange lassen sie sich keiner anderen Geistestätigkeit unterordnen. So wenig unsere Wirklichkeit eine Wirklichkeit nach dem Wunsche unseres Herzens ist, so ist sie doch die feste Grundlage unserer ganzen geistigen Existenz. Das Individuum wächst aus dem Boden der Gattung hervor, und das allgemeine und notwendige Erkennen bildet die einzig sichere Grundlage für die Erhebung des Individuums zu einer ästhetischen Auffassung der Welt.» (Geschichte des Materialismus, 1887, S. 824 f.)
[ 18 ] Nicht das sieht Lange als den Irrtum der idealistischen Weltanschauungen an, daß diese mit ihren Ideen über die Sinnes- und Verstandeswelt hinausgegangen sind, sondern ihren Glauben, daß mit diesen Ideen mehr erreicht ist als individuelle Dichtung. Man soll sich eine ideale Welt aufbauen; aber man soll sich bewußt sein, daß diese Idealwelt nichts weiter ist als Dichtung. Behauptet man, sie sei mehr, so wird immer wieder und wieder der Materialismus auftauchen, der da sagt: Ich habe die Wahrheit; der Idealismus ist Dichtung. Wohlan, sagt Lange, der Idealismus ist Dichtung, aber auch der Materialismus ist Dichtung. Im Idealismus dichtet das Individuum, im Materialismus die Gattung. Sind sich beide ihrer Wesenheit bewußt, so ist alles in Ordnung: die Sinnes- und Verstandeswissenschaft mit ihren strengen, für die ganze Gattung bindenden Beweisen, die Ideendichtung mit ihren vom Individuum erzeugten, aber doch für die Gattung wertvollen höheren Vorstellungswelten. «Eins ist sicher: daß der Mensch einer Ergänzung der Wirklichkeit durch eine von ihm selbst geschaffene Idealwelt bedarf, und daß die höchsten und edelsten Funktionen seines Geistes in solchen Schöpfungen zusammenwirken. Soll aber diese freie Tat des Geistes immer und immer wieder die Truggestalt einer beweisenden Wissenschaft annehmen? Dann wird auch der Materialismus immer wieder hervortreten und die kühneren Spekulationen zerstören, indem er dem Einheitstriebe der Vernunft mit einem Minimum von Erhebung über das Wirkliche und Beweisbare zu entsprechen sucht». (Geschichte des Materialismus, S. 828.)
[ 19 ] Ein vollständiger Idealismus geht bei Lange neben einem vollständigen Aufgeben der Wahrheit einher. Die Welt ist ihm Dichtung, aber eine Dichtung, die er als solche nicht geringer schätzt, als wenn er sie für Wirklichkeit erkennen könnte. Zwei Strömungen mit scharf ausgeprägtem naturwissenschaftlichen Charakter stehen innerhalb der modernen Weltanschauungsentwickelung einander schroff gegenüber. Die monistische, in der sich die Vorstellungsart Haeckels bewegt, und eine dualistische, deren energischster und konsequentester Verteidiger Friedrich Albert Lange ist. Der Monismus sieht in der Welt, die der Mensch beobachten kann, eine wahre Wirklichkeit und zweifelt nicht daran, daß er mit seinem an die Beobachtung sich haltenden Denken auch Erkenntnisse von wesenhafter Bedeutung über diese Wirklichkeit gewinnen kann. Er bildet sich nicht ein, mit einigen kühn erdachten Formeln das Grundwesen der Welt erschöpfen zu können; er schreitet an der Hand von Tatsachen vorwärts und bildet sich Ideen über die Zusammenhänge dieser Tatsachen. Von diesen seinen Ideen ist er aber überzeugt, daß sie ihm ein Wissen von einem wahren Dasein geben. Die dualistische Anschauung Langes teilt die Welt in ein Bekanntes und in ein Unbekanntes. Das erste behandelt sie in ebenderselben Art wie der Monismus, am Leitfaden der Beobachtung und des betrachtenden Denkens. Aber sie hat den Glauben, daß durch diese Beobachtung und durch dieses Denken über den wahren Wesenskern der Welt nicht das Geringste gewußt werden kann. Der Monismus glaubt an die Wahrheit des Wirklichen und sieht die beste Stütze für die menschliche Ideenwelt darin, daß er diese fest auf die Beobachtungswelt gründet. In den Ideen und Idealen, die er aus dem natürlichen Dasein schöpft, sieht er Wesenheiten, die sein Gemüt, sein sittliches Bedürfnis voll befriedigen. In der Natur findet er das höchste Dasein, das er nicht nur denkend erkennen will, sondern an das er eine herzliche Hingabe, seine ganze Liebe verschenkt. Langes Dualismus hält die Natur für ungeeignet, des Geistes höchste Bedürfnisse zu befriedigen. Er muß für diesen Geist eine besondere Welt der höheren Dichtung annehmen, die ihn über das hinausführt, was Beobachtung und Denken offenbaren. Dem Monismus ist in der wahren Erkenntnis ein höchster Geisteswert gegeben, der wegen seiner Wahrheit dem Menschen auch das reinste sittliche und religiöse Pathos verleiht. Dem Dualismus kann die Erkenntnis eine solche Befriedigung nicht gewähren. Er muß den Wert des Lebens an anderen Wesenheiten als an der Wahrheit abmessen. Die Ideen haben nicht Wert, weil sie aus der Wahrheit sind. Sie haben Wert, weil sie dem Leben in seinen höchsten Formen dienen. Das Leben wird nicht an den Ideen gewertet, sondern die Ideen werden an ihrer Fruchtbarkeit für das Leben bewertet. Nicht wahre Erkenntnisse strebt der Mensch an, sondern wertvolle Gedanken.
[ 20 ] In der Anerkennung der naturwissenschaftlichen Denkweise stimmt Friedrich Albert Lange mit dem Monismus insofern überein, als er jeder anderen Quelle für die Erkenntnis des Wirklichen ihre Berechtigung bestreitet; nur spricht er dieser Denkweise jede Fähigkeit ab, ins Wesenhafte der Dinge zu dringen. Damit er sich auf sicherem Boden bewege, beschneidet er der menschlichen Vorstellungsart die Flügel. Was Lange auf eindringliche Art tut, entspricht einer tief in der Weltanschauungsentwickelung der neueren Zeit wurzelnden Gedankenneigung. Dies zeigt sich mit vollkommener Klarheit auch auf einem anderen Gebiet der Ideenwelt des neunzehnten Jahrhunderts. Durch verschiedene Phasen hindurch entwickelt sich diese Ideenwelt zu Gesichtspunkten, von denen aus Herbert Spencer ungefähr um dieselbe Zeit in England wie Lange in Deutschland einen Dualismus begründet, der auf der einen Seite vollständige naturwissenschaftliche Welterkenntnis anstrebt, auf der anderen Seite gegenüber dem Wesen des Daseins sich zum Agnostizismus bekennt. Als Darwin sein Werk von der «Entstehung der Arten» erscheinen ließ und damit dem Monismus eine seiner festen Stützen überlieferte, konnte er die naturwissenschaftliche Denkart Spencers rühmend anerkennen: «In einem seiner Essays (1852) stellt Herbert Spencer die Theorie der Schöpfung und die der organischen Entwickelung in merkwürdig geschickter und wirksamer Weise einander gegenüber. Er schließt aus der Analogie mit den Züchtungsprodukten, aus der Veränderung, der die Embryonen vieler Arten unterliegen, aus der Schwierigkeit, Art von Varietät zu unterscheiden, und aus dem Grundsatz einer allgemeinen Stufenreihe, daß Arten abgeändert worden sind. Diese Abänderungen macht er von den veränderten Verhältnissen abhängig. Der Verfasser hat auch (1855) die Psychologie nach dem Prinzip der notwendig stufenweisen Erwerbung jeder geistigen Kraft und Fähigkeit behandelt.» Wie der Begründer der modernen Ansicht von den Lebensvorgängen, so fühlen sich auch andere naturwissenschaftlich Denkende zu Spencer hingezogen, der die Wirklichkeit von der unorganischen Tatsache bis in die Psychologie herauf in der Richtung zu erklären strebt, die in obigem Ausspruch Darwins zum Ausdruck kommt. Spencer steht aber auch auf der Seite der Agnostiker, so daß Friedrich Albert Lange sagen darf: «Herbert Spencer huldigt, unserem eignen Standpunkt verwandt, einem Materialismus der Erscheinung, dessen relative Berechtigung in der Naturwissenschaft ihre Schranken findet an dem Gedanken eines unerkennbaren Absoluten.»
[ 21 ] Man darf sich vorstellen, daß Spencer von ähnlichen Ausgangspunkten wie Lange zu seinem Standpunkt geführt worden ist. Ihm gingen in der Gedankenentwickelung Englands Geister voran, die von einem doppelten Interesse geleitet waren. Sie wollten bestimmen, was der Mensch an seiner Erkenntnis eigentlich besitzt. Sie wollten aber auch das Wesenhafte der Welt durch keine Zweifel und durch keine Vernunft erschüttern. In mehr oder weniger ausgesprochener Weise waren sie alle von der Empfindung beherrscht, die Kant zum Ausdruck bringt, wenn er sagt: «Ich mußte das Wissen aufheben, um zum Glauben Platz zu bekommen.» (Vgl. Band I. dieser Weltanschauungsgeschichte, S. 149 ff.)
[ 22 ] Vor dem Eingange der Weltanschauungsentwickelung des neunzehnten Jahrhunderts steht in England Thomas Reid (1710-1796). Es bildet den Grundzug der Überzeugung dieses Mannes, was auch Goethe als seine Anschauung mit den Worten ausspricht: «Es sind doch am Ende nur, wie mich dünkt, die praktischen und sich selbst rektifizierenden Operationen des gemeinen Menschenverstandes, der sich in einer höheren Sphäre zu üben wagt.» (Vgl. Goethes Werke, Band 36, S. 595 in Kürschners Deutscher National-Literatur.) Dieser gemeine Menschenverstand zweifelt nicht daran, daß er es mit wirklichen, wesenhaften Dingen und Vorgängen zu tun habe, wenn er die Tatsachen der Welt betrachtet. Reid sieht nur eine solche Weltanschauung für lebensfähig an, die an dieser Grundansicht des gesunden Menschenverstandes festhält. Wenn man selbst zugäbe, daß uns unsere Beobachtung täuschen könne, und das wahre Wesen der Dinge ein ganz anderes wäre als uns Sinne und Verstand sagen, so brauchten wir uns um eine solche Möglichkeit nicht zu kümmern. Wir kommen im Leben nur zurecht, wenn wir unserer Beobachtung glauben; alles weitere geht uns nichts an. Von diesem Gesichtspunkte aus glaubt Reid zu wirklich befriedigenden Wahrheiten zu kommen. Er sucht nicht durch komplizierte Denkverrichtungen zu einer Anschauung über die Dinge zu kommen, sondern durch Zurückgehen auf die von der Seele instinktiv angenommenen Ansichten. Und instinktiv, unbewußt, besitzt die Seele schon das Richtige, bevor sie es unternimmt, mit der Fackel des Bewußtseins in ihre eigene Wesenheit hineinzuleuchten. Instinktiv weiß sie, was sie von den Eigenschaften und Vorgängen in der Körperwelt zu halten hat; instinktiv ist ihr aber auch die Richtung ihres moralischen Verhaltens, ein Urteil über Gut und Böse eigen. Reid lenkt das Denken durch seine Berufung auf die dem gesunden Menschenverstand eingeborenen Wahrheiten auf die Beobachtung der Seele hin. Dieser Zug nach Seelenbeobachtung bleibt fortan der englischen Weltanschauungsentwickelung eigen. Hervorragende Persönlichkeiten, die innerhalb dieser Entwickelung stehen, sind William Hamilton (1788-1856), Henry Mansel (1820-1871), William Whewell (,794 bis 1866), John Herschel (1792-1871), James Mill (1773 bis 1836), John Stuart Mill (1806-1873), Alexander Bair (1818-1903), Herbert Spencer (1820-1903). Sie alle stellen die Psychologie in den Mittelpunkt ihrer Weltanschauung.
[ 23 ] Auch für Hamilton gilt als wahr, was die Seele ursprünglich als wahr anzunehmen sich genötigt findet. Ursprünglichen Wahrheiten gegenüber hört das Beweisen und Begreifen auf; man kann einfach ihr Auftauchen am Horizonte des Bewußtseins feststellen. Sie sind in diesem Sinne unbegreiflich. Aber es gehört zu den ursprünglichen Aussagen des Bewußtseins auch die, daß ein jegliches Ding in dieser Welt von etwas abhängig ist, das wir nicht kennen. Wir finden in der Welt, in der wir leben, nur abhängige Dinge, nirgends ein unbedingt unabhängiges. Ein solches muß es aber doch geben. Wenn Abhängiges angetroffen wird, muß ein Unabhängiges vorausgesetzt werden. Mit unserem Denken kommen wir in das Unabhängige nicht hinein. Das menschliche Wissen ist auf das Abhängige berechnet und verwickelt sich in Widersprüche, wenn es seine Gedanken, die für Abhängiges sehr wohl geeignet sind, auf Unabhängiges anwendet. Das Wissen muß also abtreten, wenn wir an den Eingang zum Unabhängigen kommen. Der religiöse Glaube ist da an seinem Platze. Durch das Bekenntnis, daß er von dem Wesenskern der Welt nichts wissen kann, kann der Mensch erst ein moralisches Wesen sein. Er kann einen Gott annehmen, der in der Welt eine moralische Ordnung bewirkt. Keine Logik kann diesen Glauben an einen unendlichen Gott rauben, sobald erkannt ist, daß alle Logik sich nur auf Abhängiges, nicht auf Unabhängiges richtet. - Mansel ist Schüler und Fortsetzer Hamiltons. Er kleidet dessen Ansichten nur in noch extremere Formen. Man geht nicht zu weit, wenn man sagt, Mansel ist ein Advokat des Glaubens, der nicht unparteiisch zwischen Religion und Wissen urteilt, sondern parteiisch für das religiöse Dogma eintritt. Er ist der Ansicht, daß die religiösen Offenbarungswahrheiten unbedingt das Erkennen in Widersprüche verwickeln. Das rühre aber nicht von einem Mangel in den Offenbarungswahrheiten her, sondern davon, daß der menschliche Geist begrenzt sei und niemals in die Regionen kommen könne, über die die Offenbarung Aussagen macht. - William Whewell glaubt am besten dadurch eine Ansicht für die Bedeutung, den Ursprung und Wert des menschlichen Wissens zu erlangen, daß er untersucht, wie bahnbrechende Geister der Wissenschaften zu ihren Erkenntnissen gelangt sind. Seine «Geschichte der induktiven Wissenschaften» (1837) und seine «Philosophie der induktiven Wissenschaften» (1840) gehen darauf aus, die Psychologie des wissenschaftlichen Forschens zu durchschauen. An den hervorragenden wissenschaftlichen Entdeckungen sucht er zu erkennen, wieviel von unseren Vorstellungen der Außenwelt und wieviel dem Menschen selbst angehört. Whewell findet, daß die Seele in jeglicher Wissen-schaft die Beobachtung aus eigenem ergänzt. Kepler hatte den Begriff der Ellipse, bevor er fand, daß die Planeten sich in Ellipsen bewegen. Die Wissenschaften kommen also nicht durch bloßes Empfangen von außen, sondern durch tätiges Eingreifen des Menschengeistes zustande, der seine Gesetze dem Empfangenen einprägt. Aber die Wissenschaften reichen nicht bis zu den letzten Wesenheiten der Dinge. Sie beschäftigen sich mit den Einzelheiten der Welt. Wie man aber für jedes einzelne Ding zum Beispiel eine Ursache annimmt, muß man eine solche auch für die ganze Welt voraussetzen. Da einer solchen gegenüber das Wissen versagt, muß das religiöse Dogma ergänzend eintreten. Wie Whewell sucht auch Herschel eine Ansicht über das Zustandekommen des Wissens im menschlichen Geiste durch Betrachtung zahlreicher Beispiele zu gewinnen. («A Preliminary Discourse on the Study of Natural Philosophy» ist 1831 erschienen.)
[ 24 ] John Stuart Millgehört zum Typus derjenigen Denker, die von der Empfindung durchdrungen sind: man könne nicht vorsichtig genug sein, wenn es sich um Feststellung dessen handelt, was in der menschlichen Erkenntnis gewiß, was ungewiß ist. Daß er schon im Knabenalter in die verschiedensten Zweige des Wissens eingeführt wurde, dürfte seinem Geiste das ihm eigentümliche Gepräge gegeben haben. Er empfing als dreijähriges Kind Unterricht im Griechischen, bald darauf wurde er in der Arithmetik unterwiesen. Die anderen Unterrichtsgebiete traten entsprechend früh an ihn heran. Noch mehr wirkte wohl die Art des Unterrichtes, die sein Vater, der als Denker bedeutende James Mill so gestaltete, daß John Stuart die schärfste Logik wie zur Natur wurde. Aus der Selbstbiographie erfahren wir: «Was sich durch Denken ausfindig machen ließ, das sagte mein Vater mir nie, bevor ich meine Kräfte erschöpft hatte, um auf alles selbst zu kommen.» Bei einem solchen Menschen müssen die Dinge, die sein Denken beschäftigen, im eigentlichsten Sinne des Wortes das Schicksal seines Leben werden. «Ich bin nie Kind gewesen, habe nie Kricket gespielt; es ist doch besser, die Natur ihre eigenen Bahnen wandeln zu lassen», sagt John Stuart Mill, nicht ohne Beziehung auf die Erfahrungen, die jemand macht, dessen Schicksal so einzig das Denken ist. Mit aller Stärke mußten auf ihm, der diese Entwickelung durchgemacht hat, die Fragen nach der Bedeutung des Wissens lasten. Inwiefern kann die Erkenntnis, die ihm das Leben ist, auch zu den Quellen der Welterscheinungen führen? Die Richtung, die Mills Gedankenentwickelung nahm, um über diese Fragen Aufschluß zu gewinnen, ist wohl auch frühzeitig von seinem Vater bestimmt worden. James Mills Denken ging von der psychologischen Erfahrung aus. Er beobachtete, wie sich im Menschen Vorstellung an Vorstellung angliedert. Durch die Angliederung einer Vorstellung an die andere gewinnt der Mensch sein Wissen von der Welt. Er muß sich also fragen: In welchem Verhältnis steht die Gliederung der Vorstellungen zu der Gliederung der Dinge in der Welt? Durch eine solche Betrachtungsweise wird das Denken mißtrauisch gegen sich selbst. Im Menschen könnten sich die Vorstellungen möglicherweise in einer ganz anderen Weise verknüpfen, als draußen in der Welt die Dinge. Auf dieses Mißtrauen ist John Stuart Mills Logik aufgebaut, die 1843 als sein Hauptwerk, unter dem Titel «System of Logic» erschienen ist.
[ 25 ] Man kann sich in Dingen der Weltanschauung kaum einen schärferen Gegensatz denken, als diese Milische «Logik» und die siebenundzwanzig Jahre früher erschienene «Wissenschaft der Logik» Hegels. Bei Hegel findet man das höchste Vertrauen in das Denken, die volle Sicherheit darüber, daß uns das nicht täuschen kann, was wir in uns selbst erleben. Hegel fühlt sich als Glied der Welt. Was er in sich erlebt, muß also auch zu der Welt gehören. Und da er am unmittelbarsten sich selbst erkennt, so glaubt er an dieses in sich Erkannte und beurteilt danach die ganze übrige Welt. Er sagt sich: Wenn ich ein äußeres Ding wahrnehme, so kann es mir vielleicht nur seine Außenseite zeigen, und sein Wesen bleibt verhüllt. Bei mir selbst ist das unmöglich. Mich durchschaue ich. Ich kann aber dann die Dinge draußen mit meinem eigenen Wesen vergleichen. Wenn sie in ihrer Außenseite etwas von meinem eigenen Wesen verraten, dann darf ich ihnen auch etwas von meinem Wesen zusprechen. Deshalb sucht Hegel vertrauensvoll den Geist, die Gedankenverbindungen, die er in sich findet, auch draußen in der Natur. Mill fühlt sich zunächst nicht als Glied, sondern als Zuschauer der Welt. Die Dinge draußen sind ihm ein Unbekanntes, und den Gedanken, die der Mensch sich über diese Dinge macht, begegnet er mit Mißtrauen. Man nimmt Menschen wahr. Man hat bisher immer die Beobachtung gemacht, daß die Menschen gestorben sind. Deshalb hat man sich das Urteil gebildet: Alle Menschen sind sterblich. «Alle Menschen sind sterblich; der Herzog von Wellington ist ein Mensch; also ist der Herzog von Wellington sterblich.» So schließen die Menschen. Was gibt ihnen ein Recht dazu? fragt John Stuart Mill. Wenn sich einmal ein einziger Mensch als unsterblich erwiese, so wäre das ganze Urteil umgestoßen. Dürfen wir deshalb, weil bis jetzt alle Menschen gestorben sind, auch voraussetzen, daß sie dies auch in Zukunft tun werden? Alles Wissen ist unsicher. Denn wir schließen von Beobachtungen, die wir gemacht haben, auf Dinge, über die wir nichts wissen können, solange wir nicht die betreffenden Beobachtungen auch an ihnen gemacht haben. Was müßte jemand, der im Sinne Hegels denkt, zu einer solchen Anschauung sagen? Man kann sich unschwer darüber eine Vorstellung bilden. Man weiß aus sicheren Begriffen, daß in jedem Kreise alle Halbmesser gleich sind. Trifft man in der Wirklichkeit auf einen Kreis, so behauptet man von diesem wirklichen Kreise auch, daß seine Halbmesser gleich seien. Beobachtet man denselben Kreis nach einer Viertelstunde und findet man seine Halbmesser ungleich, so entschließt man sich nun nicht zu dem Urteile:
[ 26 ] In einem Kreise können unter Umständen auch die Halbmesser ungleich sein, - sondern man sagt sich: Was ehedem Kreis war, hat sich aus irgendwelchen Gründen zu einer Ellipse verlängert. So etwa stellte sich ein in Hegels Sinn Denkender zu dem Urteile: Alle Menschen sind sterblich. Der Mensch hat sich nicht durch Beobachtung, sondern als inneres Gedankenerlebnis den Begriff des Menschen gebildet, wie er sich den Begriff des Kreises gebildet hat. Zu dem Begriff des Menschen gehört die Sterblichkeit, wie zu dem des Kreises die Gleichheit der Halbmesser. Trifft man in der Wirklichkeit auf ein Wesen, das alle anderen Merkmale des Menschen hat, so muß dieses Wesen auch das der Sterblichkeit haben, wie alle anderen Merkmale des Kreises das der Halbmessergleichheit nach sich ziehen. Hegel könnte, wenn er auf ein Wesen träfe, das nicht stirbt, sich nur sagen: Das ist kein Mensch, - nicht aber: Ein Mensch kann auch unsterblich sein. Er setzt eben voraus, daß sich die Begriffe in uns nicht willkürlich bilden, sondern daß sie im Wesen der Welt wurzeln, wie wir selbst diesem Wesen angehören. Hat sich der Begriff des Menschen in uns einmal gebildet, so stammt er aus dem Wesen der Dinge; und wir haben das volle Recht, ihn auch auf dieses Wesen anzuwenden. Warum ist in uns der Begriff des sterblichen Menschen entstanden? Doch nur, weil er seinen Grund in der Natur der Dinge hat. Wer glaubt, daß der Mensch ganz außerhalb der Dinge stehe und sich als Außenstehender seine Urteile bilde, kann sich sagen: Wir haben bisher die Menschen sterben sehen, also bilden wir den Zuschauerbegriff: sterbliche Menschen. Wer sich bewußt ist, daß er selbst zu den Dingen gehört, und diese sich in seinen Gedanken aussprechen, der sagt sich: bisher sind alle Menschen gestorben; also gehört es zu ihrem Wesen, zu sterben; und wer nicht stirbt, der ist eben kein Mensch, sondern etwas anderes. Hegels Logik ist eine Logik der Dinge geworden; denn Hegel ist die Sprache der Logik eine Wirkung des Wesens der Welt; nicht etwas zu diesem Wesen von dem menschlichen Geiste von außen Hinzugefügtes. Mills Logik ist eine Zuschauerlogik, die zunächst den Faden zerschneidet, der sie mit der Welt verbindet.
[ 27 ] Mill weist darauf hin, wie Gedanken, die einem gewissen Zeitalter als unbedingt sichere innere Erlebnisse erscheinen, doch von einem folgenden umgestoßen werden. Zum Beispiel hat man im Mittelalter daran geglaubt, daß es unmöglich Gegenfüßler geben könne, und daß die Sterne herunterfallen müßten, wenn sie nicht an festen Sphären hingen. Der Mensch wird also ein rechtes Verhältnis zu seinem Wissen nur gewinnen können, wenn er sich, trotz des Bewußtseins, daß die Logik der Welt sich in ihm ausspricht, im einzelnen nur durch methodische Prüfung seiner Vorstellungszusammenhänge an der Hand der Beobachtung ein der fortwährenden Korrektur bedürftiges Urteil bildet. Und die Methoden der Beobachtung sind es, die John Stuart Mill in kalt berechnender Weise in seiner Logik festzustellen sucht. Ein Beispiel dafür ist dieses:
[ 28 ] Man nehme an, eine Erscheinung wäre unter gewissen Bedingungen immer eingetreten. In einem bestimmten Falle treten von diesen Bedingungen eine ganze Reihe wieder ein; nur einzelne fehlen. Die Erscheinung tritt nicht ein. Dann muß man schließen, daß die nicht eingetretenen Bedingungen mit der nicht eingetretenen Erscheinung in einem ursächlichen Zusammenhange stehen. Wenn zwei Stoffe sich stets zu einer chemischen Verbindung zusammengefügt haben, und sie dies einmal nicht tun, so muß man nachforschen, was diesmal nicht da ist und sonst immer da war. Durch eine solche Methode kommen wir zu Vorstellungen über Tatsachenzusammhänge, welche mit Berechtigung von uns als solche angesehen werden, die ihren Grund in der Natur der Dinge haben. Den Beobachtungsmethoden will Mill nachgehen. Die Logik, von der Kant gesagt hat, daß sie seit Aristoteles um keinen Schritt weiter gekommen sei, ist ein Orientierungsmittel innerhalb des Denkens selbst. Sie zeigt, wie man von einem richtigen Gedanken auf den anderen kommt. Mills Logik ist ein Orientierungsmittel innerhalb der Welt der Tatsachen. Sie will zeigen, wie man aus Beobachtungen zu gültigen Urteilen über die Dinge gelangt. Mill macht keinen Unterschied zwischen den menschlichen Urteilen. Ihm geht alles aus der Beobachtung hervor, was der Mensch über die Dinge denkt. Nicht einmal bezüglich der Mathematik läßt er eine Ausnahme gelten. Auch sie muß ihre Grunderkenntnisse aus der Beobachtung gewinnen. Wir haben in allen Fällen, die wir bisher beobachtet haben, gesehen, daß zwei gerade Linien, die sich einmal geschnitten haben, auseinanderlaufen (divergieren) und sich nicht ein zweites Mal geschnitten haben. Daraus schließen wir, daß sie sich nicht schneiden können. Aber einen vollkommenen Beweis dafür haben wir nicht. Für John Stuart Mill ist also die Welt ein dem Menschen Fremdes. Der Mensch betrachtet ihre Erscheinungen und ordnet sie nach den Aussagen, die sie ihm in seinem Vorstellungsleben macht. Er nimmt Regelmäßigkeit in den Erscheinungen wahr und gelangt durch logisch-methodische Untersuchungen dieser Regelmäßigkeiten zu Naturgesetzen. Aber nichts führt in den Grund der Dinge selbst. Man kann deshalb ganz gut sich vorstellen, daß alles in der Welt auch anders sein könnte. Mill ist überzeugt, daß jeder, der an Abstraktion und Analyse gewöhnt ist, und seine Fähigkeiten redlich anwendet, nach genügender Übung seiner Vorstellungskraft keine Schwierigkeit in der Idee findet, es könne in einem anderen Sternsystem als dem unsrigen nichts von den Gesetzen zu finden sein, die im unsrigen gelten. Es ist nur konsequent, wenn dieser Weltzuschauerstandpunkt von Mill auch auf das eigene Ich des Menschen ausgedehnt wird. Vorstellungen kommen und gehen, verknüpfen sich und trennen sich in seinem Innern; das nimmt der Mensch wahr. Ein Wesen, das sich als «Ich» gleich bleibt in diesem Kommen und Gehen, Trennen und Verbinden der Vorstellungen, nimmt er nicht wahr. Er hat bisher Vorstellungen in sich auftauchen sehen und setzt voraus, daß dies auch weiter der Fall sein werde. Aus diesem Möglichkeit, daß sich um einen Mittelpunkt herum eine Vorstellungswelt gliedert, entsteht die Vorstellung des «Ich». Auch seinem eigenen «Ich» gegenüber ist der Mensch also Zuschauer. Er läßt sich von seinen Vorstellungen sagen, was er über sich wissen kann. Mill betrachtet die Tatsachen der Erinnerung und der Erwartung. Wenn alles, was ich von mir weiß, sich in Vorstellungen erschöpfen soll, so kann ich nicht sagen: Ich erinnere mich an eine früher von mir gehabteVorstellung, oder ich erwarte den Eintritt eines gewissen Erlebnisses; sondern: eine Vorstellung erinnert sich an sich selbst oder erwartet ihr zukünftiges Auftreten. «Wenn wir» - sagt Mill - «vom Geiste als von einem Reihe von Wahrnehmungen sprechen, dann müssen wir von einer Wahrnehmungsreihe sprechen, die sich selbst als werdend und vergangen bewußt ist. Und nun befinden wir uns in dem Dilemma, entweder zu sagen, das ,Ich' oder der Geist sei etwas von den Wahrnehmungen Verschiedenes; oder das Paradoxon zu behaupten, eine bloße Vorstellungsreihe könne ein Bewußtsein von ihrer Vergangenheit und Zukunft haben.» Mill kommt über dieses Dilemma nicht hinaus. Für ihn birgt es ein unlösbares Rätsel. Er hat eben das Band zwischen sich, dem Beobachter, und dem Welt zerrissen, und ist nicht imstande, es wieder zu knüpfen. Die Welt bleibt ihm das jenseitige Unbekannte, das auf den Menschen Eindrücke macht. Alles, was dieser von dem jenseitigen Unbekannten weiß, ist, daß die Möglichkeit vorhanden ist, es könne in ihm Wahrnehmungen hervorrufen. Statt also von wirklichen Dingen außer sich, kann der Mensch im Grunde nur davon sprechen, daß Wahrnehmungsmöglichkeiten vorhanden sind. Wer von Dingen an sich spricht, ergeht sich in leeren Worten; nur wer von der beständigen Möglichkeit des Eintretens von Empfindungen, Wahrnehmungen, Vorstellungen spricht, bewegt sich auf dem Boden des Tatsächlichen.
[ 29 ] John Stuart Mill hat eine heftige Abneigung gegen alle Gedanken, die auf anderem Wege gewonnen sind als durch Vergleichung der Tatsachen, durch Verfolgen des Ähnlichen, Analogen und Zusammengehörigen in den Erscheinungen. Er meint, der menschlichen Lebensführung könne nur der größte Schaden zugefügt werden, wenn man sich in dem Glauben wiege, man könne zu irgendeiner Wahrheit auf eine andere Weise gelangen als durch Beobachtung. Man fühlt in dieser Abneigung Mills die Scheu davor, sich bei allem Erkenntnisstreben anders als rein empfangend (passiv) den Dingen gegenüber zu verhalten. Sie sollen dem Menschen diktieren, was er über sie zu denken hat. Sucht er über das Empfangen hinauszugehen und aus sich selbst heraus etwas über die Dinge zu sagen, so fehlt ihm jede Garantie dafür, daß dieses sein eigenes Erzeugnis auch wirklich etwas mit den Dingen zu tun habe. Zuletzt kommt es bei dieser Anschauung darauf an, daß ihr Bekenner sich nicht entschließen kann, sein eigenes selbsttätiges Denken mit zu der Welt zu rechnen. Gerade, daß er dabei selbsttätig ist, das beirrt ihn. Er möchte sein Selbst am liebsten ganz ausschalten, um nur ja nichts Falsches in das einzumischen, was die Erscheinungen über sich sagen. Er würdigt die Tatsache nicht in richtiger Weise, daß sein Denken ebenso zur Natur gehört wie das Wachsen eines Grashalmes. So klar es nun ist, daß man den Grashalm beobachten muß, wenn man etwas von ihm wissen will, so klar sollte es sein, daß man auch sein eigenes selbsttätiges Denken befragen muß, wenn man über dasselbe etwas erfahren will. Wie soll man, nach dem Goetheschen Worte, sein Verhältnis zu sich selbst und zur Außenwelt kennenlernen, wenn man im Erkenntnisprozesse sich selbst ganz ausschalten will? Wie groß die Verdienste Mills auch sind um die Auffindung der Methoden, durch die der Mensch alles das erkennt, was von ihm nicht abhängt: eine Ansicht darüber, in welchem Verhältnisse der Mensch zu sich selbst und mit seinem Selbst zur Außenwelt steht, kann durch keine solche Methode gewonnen werden. Alle diese Methoden haben ihre Gültigkeit daher für die einzelnen Wissenschaften, nicht aber für eine umfassende Weltanschauung. Was das selbsttätige Denken ist, kann keine Beobachtung lehren; das kann nur das Denken aus sich selbst erfahren. Und da das Denken über sich nur durch sich etwas aussagen kann, so kann es sich auch nur selbst etwas über sein Verhältnis zur Außenwelt sagen. Mills Vorstellungsart schließt also die Gewinnung einer Weltanschauung vollständig aus. Eine solche kann nur durch ein sich in sich versenkendes und dadurch sich und seine Beziehung zur Außenwelt überschauendes Denken gewonnen werden. Daß John Stuart Mill eine Antipathie gegen ein solches auf sich selbst bauendes Denken hegte, ist aus seinem Charakter wohl zu begreifen. Gladstone hat in einem Briefe (vgl. Gomperz, John Stuart Mill, Wien 1889) gesagt, daß er Mill in Gesprächen den «Heiligen des Rationalismus» zu nennen pflegte. Ein Mann, der in dieser Weise sich ganz im Denken auslebt, stellt an das Denken große Anforderungen und sucht nach den größtmöglichen Vorsichtsmaßregeln, daß es ihn nicht täuschen könne. Er wird dadurch dem Denken gegenüber mißtrauisch. Er glaubt, leicht ins Unsichere zu kommen, wenn er feste Anhaltspunkte verliert. Und Unsicherheit gegenüber allen Fragen, die über das strenge Beobachtungswissen hinausgehen, ist einGrundzug in Mills Persönlichkeit. Wer seine Schriften verfolgt, wird überall sehen, wie Mill solche Fragen als offene betrachtet, über die er ein sicheres Urteil nicht wagt.
[ 30 ] An der Unerkennbarkeit des wahren Wesens der Dinge hält auch Herbert Spencer fest. Er fragt sich zunächst: Wodurch komme ich zu dem, was ich Wahrheiten über die Welt nenne? Ich beobachte einzelnes an den Dingen und bilde mir über diese Urteile. Ich beobachte, daß Wasserstoff und Sauerstoff unter gewissen Bedingungen sich zu Wasser verbinden. Ich bilde mir ein Urteil darüber. Das ist eine einzelne Wahrheit, die sich nur über einen kleinen Kreis von Dingen erstreckt. Ich beobachte dann auch, unter welchen Verhältnissen sich andere Stoffe verbinden. Ich vergleiche die einzelnen Beobachtungen und komme dadurch zu umfassenderen, allgemeineren Wahrheiten darüber, wie sich Stoffe überhaupt chemisch verbinden. Alles Erkennen beruht darauf, daß der Mensch von einzelnen Wahrheiten zu immer allgemeineren Wahrheiten übergeht, um zuletzt bei der höchsten Wahrheit zu endigen, die er auf keine andere zurückführen kann; die er also hinnehmen muß, ohne sie weiter begreifen zu können. In diesem Erkenntnisweg haben wir aber kein Mittel, zum absoluten Wesen der Welt vorzudringen. Das Denken kann ja, nach dieser Meinung, nichts tun, als die verschiedenen Dinge miteinander vergleichen und sich über das, was in ihnen Gleichartiges ist, sich allgemeine Wahrheiten bilden. Das unbedingte Weltwesen kann aber, in seiner Einzigartigkeit, mit keinem anderen Ding verglichen werden. Deshalb versagt das Denken ihm gegenüber. Es kommt an dasselbe nicht heran.
[ 31 ] Wir hören in solchen Vorstellungsarten immer den Gedanken mitsprechen, der auch auf Grund der Sinnesphysiologie sich ausgebildet hat (vgl. oben S. 422 ff.). Bei vielen Denkern ist dieser Gedanke so mit ihrem geistigen Leben verwachsen, daß sie ihn für das Gewisseste halten, das es geben kann. Sie sagen sich, der Mensch erkennt die Dinge nur dadurch, daß er sich ihrer bewußt wird. Sie verwandeln nun, mehr oder weniger unwillkürlich, diesen Gedanken in den anderen: Man kann nur von dem wissen, was in das Bewußtsein eintritt; es bleibt aber unbekannt, wie die Dinge waren, bevor sie in das Bewußtsein eingetreten sind. Deshalb sieht man auch die Sinnesempfindungen so an, als wären sie im Bewußtsein; denn man meint, sie müssen doch erst in dasselbe eintreten, also Teile desselben (Vorstellungen) werden, wenn man von ihnen etwas wissen will.
[ 32 ] Auch Spencer hält daran fest, daß es von uns Menschen abhängt, wie wir erkennen können und daß wir deshalb jenseits dessen, was unsere Sinne und unser Denken uns übermitteln, ein Unerkennbares annehmen müssen. Wir haben ein klares Bewußtsein von allem, was uns unsere Vorstellungen sagen. Aber diesem klaren ist ein unbestimmtes Bewußtsein beigemischt, das besagt, daß allem, was wir beobachten und denken, etwas zugrunde liegt, was wir nicht mehr beobachten und denken können. Wir wissen, daß wir es mit bloßen Erscheinungen, nicht mit vollen für sich bestehenden Realitäten zu tun haben. Aber eben weil wir genau wissen, daß unsere Welt nur Erscheinung ist, so wissen wir auch, daß ihr eine unvorstellbare wirkliche zugrunde liegt. Durch solche Wendungen seines Denkens glaubt Spencer die volle Versöhnung von Religion und Erkenntnis herbeiführen zu können. Es gibt etwas, das keinem Erkennen zugänglich ist; also gibt es auch etwas, was die Religion in Glauben fassen kann; in einen Glauben, den die ohnmächtige Erkenntnis nicht erschüttern kann.
[ 33 ] Dasjenige Gebiet nun, das Spencer der Erkenntnis zugänglich hält, macht er völlig zum Felde naturwissenschaftlicher Vorstellungen. Wo er zu erklären unternimmt, tut er das nur in naturwissenschaftlichem Sinne.
[ 34 ] Naturwissenschaftlich denkt sich Spencer den Erkenntnisprozeß. Ein jegliches Organ eines Lebewesens ist dadurch entstanden, daß sich dieses Wesen den Bedingungen angepaßt hat, unter denen es lebt. Zu den menschlichen Lebensbedingungen gehört, daß sich der Mensch denkend in der Welt zurechtfindet. Sein Erkenntnisorgan entsteht durch Anpassung seines Vorstellungslebens an die Bedingungen der Außenwelt. Wenn der Mensch über ein Ding oder einen Vorgang etwas aussagt, so bedeutet dies nichts anderes als: er paßt sich der ihn umgebenden Welt an. Alle Wahrheiten sind auf diesem Wege der Anpassung entstanden. Was aber durch Anpassung erworben ist, kann sich auf die Nachkommen vererben. Diejenigen haben nicht recht, die behaupten, dem Menschen komme durch seine Natur ein für allemal eine gewisse Disposition zu allgemeinen Wahrheiten zu. Was als solche Disposition erscheint, war einmal bei den Vorfahren des Menschen nicht da, sondern ist durch Anpassung erworben worden und hat sich auf die Nachkommen vererbt. Wenn gewisse Philosophen von Wahrheiten sprechen, die der Mensch nicht aus seiner eigenen individuellen Erfahrung zu schöpfen braucht, sondern die von vornherein in seiner Organisation liegen, so haben sie in gewisser Beziehung recht. Aber solche Wahrheiten sind doch auch erworben, nur nicht von dem Menschen als Individuum, sondern als Gattung. Der einzelne hat das in früherer Zeit Erworbene fertig ererbt. - Goethe sagt, daß er manchem Gespräch über Kants «Kritik der reinen Vernunft» beigewohnt und dabei gesehen habe, daß die alte Hauptfrage sich erneuere, «wieviel unser Selbst und wieviel die Außenwelt zu unserem geistigen Dasein beitrage?» Und er fährt fort: «Ich hatte beide niemals gesondert, und wenn ich nach meiner Weise über Gegenstände philosophierte, so tat ich es mit unbewußter Naivität und glaubte wirklich, ich sähe meine Meinungen vor Augen.» Spencer rückte diese «alte Hauptfrage» in das Licht der naturwissenschaftlichen Anschauungsart. Er glaubte, zu zeigen, daß der entwickelte Mensch allerdings auch aus seinem Selbst zu seinem geistigen Dasein beizutragen hat; aber dieses Selbst setzt sich doch auch aus den Erbstücken zusammen, die unsere Vorfahren im Kampfe mit der Außenwelt erworben haben. Wenn wir heute unsere Meinungen vor Augen zu sehen glauben, so waren dies nicht immer unsere Meinungen, sondern sie waren einst Beobachtungen, die wirklich mit den Augen an der Außenwelt gemacht worden sind. Spencers Weg ist also wie der Mills ein solcher, der von der Psychologie ausgeht. Aber Mill bleibt bei der Psychologie des Individuums stehen. Spencer steigt von dem Individuum zu dessen Vorfahren auf. Die Individualpsychologie ist in derselben Lage wie die Keimesgeschichte der Zoologie. Gewisse Erscheinungen der Keimung sind nur erklärlich, wenn man sie zuruckführt auf Erscheinungen der Stammesgeschichte. Ebenso sind die Tatsachen des individuellen Bewußtseins aus sich selbst nicht verständlich. Man muß aufsteigen zu der Gattung, ja über die Menschengattung noch hinausgehen bis zu den Erkenntniserwerbungen, welche die tierischen Vorfahren des Menschen schon gemacht haben. Spencer wendet seinen großen Scharfsinn an, um diese seine Entwickelungsgeschichte des Erkenntnis-prozesses zu stützen. Er zeigt, wie die geistigen Fähigkeiten aus niedrigen Anfängen sich allmählich entwickelt haben durch immer entsprechendere Anpassungen des Geistes an die Außenwelt und durch Vererbung dieser Anpassungen. Alles, was der einzelne Mensch ohne Erfahrung, durch reines Denken über die Dinge gewinnt, hat die Menschheit oder haben deren Voreltern durch Beobachtung, durch Erfahrung gewonnen. Leibniz hat die Übereinstimmung des menschlichen Innern mit der Außenwelt nur dadurch erklären zu können geglaubt, daß er eine vom Schöpfer vorherbestimmte Harmonie angenommen hat. Spencer erklärt diese Übereinstimmung naturwissenschaftlich. Sie ist nicht vorher bestimmt, sondern geworden. Man hat hier die Fortsetzung des naturwissenschaftlichen Denkens bis in die höchsten, dem Menschen gegebenen Tatsachen. Linné erklärt, jede lebendige Wesensform sei vorhanden, weil der Schöpfer sie so geschaffen hat, wie sie ist. Darwin erklärt, sie sei so, wie sie sich durch Anpassung und Vererbung allmählich entwickelt hat. Leibniz erklärt, das Denken stimme mit der Außenwelt überein, weil der Schöpfer die Übereinstimmung geschaffen hat. Spencer erklärt, diese Übereinstimmung sei vorhanden, weil sie sich durch Anpassung und Vererbung der Gedankenwelt entwickelt hat.
[ 35 ] Von dem Bedürfnis nach einer naturgemäßen Erklärung der geistigen Erscheinungen ist Spencer ausgegangen. Die Richtung auf eine solche hat ihm Lyells Geologie gegeben (vgl. S. 360). In ihr wird zwar der Gedanke noch bekämpft, daß die organischen Formen sich durch allmähliche Entwickelung auseinander gebildet haben; aber er erfährt doch eine wichtige Stütze dadurch, daß die unorganischen (geologischen) Bildungen der Erdoberfläche durch eine solche allmähliche Entwickelung, nicht durch gewaltsame Katastrophen, erklärt werden. Spencer, der eine naturwissenschaftliche Bildung hatte, sich auch einige Zeit als Zivilingenieur betätigt hatte, erkannte die volle Tragweite des Entwickelungsgedankens sofort und wendete ihn an, trotz der Bekämpfung durch Lyell. Ja, er wendete ihn sogar auf die geistigen Vorgänge an. Schon 1850, in seiner Schrift «Social Statics», beschrieb er die soziale Entwickelung in Analogie mit der organischen. Er machte sich auch mit Harveys und Wolffs (vgl. Bd. I, S. 286 ff.) Studien über Keimesgeschichte der Organismen bekannt und vertiefte sich in die Arbeiten Carl Ernst von Baers (vgl. oben S.397 f.), die ihm zeigten, wie die Entwickelung darin bestehe, daß aus einem Zustande der Gleichartigkeit, der Einförmigkeit ein solcher der Verschiedenheit, der Mannigfaltigkeit, des Reichtums sich entwickele. In den ersten Keimstadien sehen sich die Organismen ähnlich; später' werden sie voneinander verschieden (vgl. oben S. 397 ff.). Durch Darwin erfuhr dieser Entwickelungsgedanke dann eine vollkommene Bekräftigung. Aus einigen wenigen Urorganismen hat sich der ganze Reichtum der heutigen mannigfaltigen Formenwelt entwickelt.
[ 36 ] Von dem Entwickelungsgedanken aus wollte Spencer aufsteigen zu den allgemeinsten Wahrheiten, die nach seiner Meinung das Ziel des menschlichen Erkenntnisstrebens ausmachen. In den einfachsten Erscheinungen glaubte er den Entwickelungsgedanken schon zu finden. Wenn aus zerstreuten Wasserteilchen sich eine Wolke am Himmel, aus zerstreuten Sandkörpern ein Sandhaufen sich bildet, so hat man es mit einem Entwickelungsprozesse zu tun. Zerstreuter Stoff wird zusammengezogen (konzentriert) zu einem Ganzen. Keinen anderen Prozeß hat man in der Kant-Laplaceschen Weltbildungshypothese vor sich. Zerstreute Teile eines chaotischen Weltnebels haben sich zusammengezogen. Der Organismus entsteht auf eben diese Weise. Zerstreute Elemente werden in Geweben konzentriert. Der Psychologe kann beobachten, wie der Mensch zerstreute Beobachtungen zu allgemeinen Wahrheiten zusammenzieht. Innerhalb des konzentrierten Ganzen gliedert sich dann das Zusammengezogene (es differenziert sich). Die Urmasse gliedert sich zu den einzelnen Himmelskörpern des Sonnensystems; der Organismus differenziert sich zu mannigfaltigen Organen.
[ 37 ] Mit der Zusammenziehung wechselt die Auflösung ab. Wenn ein Entwickelungsprozeß einen gewissen Höhepunkt erreicht hat, dann tritt ein Gleichgewicht ein. Der Mensch entwickelt sich zum Beispiel so lange, bis sich eine möglichst große Harmonie seiner inneren Fähigkeiten und der äußeren Natur herausgebildet hat. Ein solcher Gleichgewichtszustand kann aber nicht dauern; äußere Kräft8 werden zerstörend an ihn herantreten. Auf die Entwickelung muß der absteigende, der Auflösungsprozeß folgen; das Zusammengezogene dehnt sich wieder aus; das Kosmische wird wieder zum Chaos. Der Prozeß der Entwickelung kann von neuem beginnen. Ein rhythmisches Bewegungsspiel sieht Spencer also im Weltprozeß.
[ 38 ] Es ist eine gewiß nicht uninteressante Beobachtung für die vergleichende Entwickelungsgeschichte der Weltanschauungen, daß Spencer hier aus der Betrachtung des Werdens der Welterscheinungen zu einem ähnlichen Gedanken kommt, den auch Goethe auf Grund seiner Ideen über das Werden des Lebens ausgesprochen hat. Dieser beschreibt das Wachstum der Pflanze so: «Es mag die Pflanze sprossen, blühen oder Früchte tragen, so sind es doch immer nur dieselbigen Organe, welche in vielfältigen Bestimmungen und unter oft veränderten Gestalten die Vorschrift der Natur erfüllen. Dasselbe Organ, welches am Stengel als Blatt sich ausgedehnt und eine höchst mannigfaltige Gestalt angenommen hat, zieht sich nun im Kelche zusammen, dehnt sich im Blumenblatte wieder aus, zieht sich in den Geschlechtswerkzeugen zusammen, um sich als Frucht zum letztenmal auszudehnen.» Man denke sich diese Vorstellung auf den ganzen Weltprozeß übertragen, so gelangt man zu Spencers Zusammenziehung und Zerstreuung des Stoffes.
[ 39 ] Spencer und Mill haben auf die Weltanschauungsentwickelung der letzten Jahrhunderthälfte einen großen Einfluß geübt. Das strenge Betonen der Beobachtung und die einseitige Bearbeitung der Methoden des beobachtenden Erkennens durch Mill; die Anwendung naturwissenschaftlicher Vorstellungen auf den ganzen Umfang des menschlichen Wissens durch Spencer: sie mußten den Empfindungen eines Zeitalters entsprechen, das in den idealistischen Weltanschauungen Fichtes, Schellings, Hegels nur Entartungen des menschlichen Denkens sah und dem die Erfolge der naturwissenschaftlichen Forschung alleinige Schätzung abgewannen, während die Uneinigkeit der idealistischen Denker und die, nach Meinung vieler, völlige Unfruchtbarkeit des in sich selbst sich vertiefenden Denkens ein tiefes Mißtrauen gegenüber dem Idealismus erzeugten. Man darf wohl behaupten, daß eine in den letzten vier Jahrzehnten weit verbreitete Anschauung zum Ausdruck bringt, was Rudolf Virchow 1893 in seiner Rede «Die Gründung der Berliner Universität und der Übergang aus dem philosophischen in das naturwissenschaftliche Zeitalter» sagt: «Seitdem der Glaube an Zauberformeln in die äußersten Kreise des Volkes zurückgedrängt war, fanden auch die Formeln der Naturphilosophen wenig Anklang mehr.» Und einer der bedeutendsten Philosophen von der zweiten Hälfte des Jahrhunderts, Eduard von Hartmann, faßt den Charakter seiner Weltanschauung in dem Motto zusammen, das er an die Spitze seines Buches «Philosophie des Unbewußten» gestellt hat: «Spekulative Resultate nach induktiv-naturwissenschaftlicher Methode.» Ja, er ist der Meinung, man müsse die «Größe des von Mill bewirkten Fortschrittes» anerkennen, durch « den alle Versuche eines deduktiven Philosophierens für immer überwunden sind». (Vgl. E. von Hartmann, Geschichte der Metaphysik. 2. Teil, S. 479.)
[ 40 ] Auch wirkte die Anerkennung gewisser Grenzen des menschlichen Erkennens, die viele Naturforscher zeigten, auf religiös gestimmte Gemüter sympathisch. Sie sagten sich: Die Naturforscher beobachten die unorganischen und organischen Tatsachen und suchen durch Verknüpfung der einzelnen Erscheinungen allgemeine Gesetze zu finden, mit deren Hilfe sich Vorgänge erklären lassen, ja sogar der regelmäßige Verlauf zukünftiger Erscheinungen vorausbestimmt werden kann. Ebenso soll die zusammenfassende Weltanschauung vorgehen; sie soll sich an die Tatsachen halten, aus ihnen allgemeine Wahrheiten innerhalb bescheidener Grenzen erforschen und keinen Anspruch darauf machen, in das Gebiet des «Unbegreiflichen» zu dringen. Spencer mit seiner vollkommenen Scheidung des «Begreiflichen» und des «Unbegreiflichen» kam solchen religiösen Bedürfnissen im höchsten Maße entgegen. Dagegen betrachteten diese religiös gestimmten Geister die idealistische Vorstellungsart als eine Verstiegenheit. Diese kann eben im Prinzip ein Unbegreifliches nicht anerkennen, weil sie daran festhalten muß, daß durch die Versenkung in das menschliche Innenleben die Erkenntnis nicht nur der Außenseite des Weltdaseins, sondern auch des wirklichen Kernes desselben möglich ist.
[ 41 ] Ganz in der Richtung solcher religiös gestimmten Geister bewegt sich auch das Denken einflußreicher Naturforscher, wie das Huxleys, der sich zu einem vollkommenen Agnostizismus gegenüber dem Weltwesen bekennt und einen im Sinne der Darwinschen Erkenntnisse gehaltenen Monismus nur für die dem Menschen gegebene Außenseite der Natur für anwendbar erklärt. Er ist als einer der ersten für die Darwinschen Vorstellungen eingetreten; ist aber zugleich einer der entschiedensten Vertreter der Beschränktheit dieser Vorstellungsart. Zu einer ähnlichen Ansicht bekannte sich der Physiker John Tyndall (1820-1893), der in dem Weltprozesse eine dem menschlichen Verstande vollkommen unzugängliche Kraft anerkennt. Denn gerade, wenn man annehme, daß in der Welt alles durch natürliche Entwickelung entstehe, könne man nimmermehr zugeben, daß der Stoff, der doch der Träger der ganzen Entwickelung ist, nichts weiter sei als das, was unser Verstand von ihm begreifen kann.
[ 42 ] Eine für seine Zeit charakteristische Erscheinung ist die Persönlichkeit des englischen Staatsmannes James Balfour (1848-1930), der 1879 (in seinem Buche «A defence of philosophic doubt, being an Essay on the foundations of belief») ein Glaubensbekenntnis ablegte, das demjenigen weiter Kreise zweifellos ähnlich ist. Er stellt sich in bezug auf alles, was der Mensch erklären kann, ganz auf den Boden des naturwissenschaftlichen Denkens. Er läßt im Naturerkennen sich die gesamte Erkenntnis erschöpfen. Aber er behauptet zugleich, daß nur derjenige das naturwissenschaftliche Erkennen recht verstehe, der einsehe, daß die Gemüts- und Vernunftbedürfnisse des Menschen durch dasselbe niemals befriedigt werden können. Man brauche nur einzusehen, daß zuletzt alles auch in der Naturwissenschaft darauf ankomme, die letzten Wahrheiten, die man nicht mehr beweisen kann, zu glauben. Es schadet aber nichts, daß wir in dieser Richtung bloß zu einem Glauben kommen, denn dieser Glaube leitet uns sicher bei unseren Handlungen im täglichen Leben. Wir glauben an die Naturgesetze und beherrschen sie durch diesen Glauben; wir zwingen durch ihn die Natur, uns für unsere Zwecke zu dienen. Der religiöse Glaube soll eine gleiche Übereinstimmung zwischen den Handlungen des Menschen und den höheren, über das Alltägliche hinausgehenden Bedürfnissen herstellen.
[ 43 ] Die Weltanschauungen, welche hier zusammengefaßt erscheinen durch die Bezeichnung «Die Welt als Illusion», zeigen, daß ihnen ein Suchen nach dem befriedigenden Verhältnis der Vorstellung vorn selbstbewußten Ich zu einem Gesamtweltbilde zugrunde liegt. Sie erscheinen eben dadurch besonders bedeutsam, daß sie dieses Suchen nicht als ihr bewußtes philosophisches Ziel ansehen und ihre Untersuchungen nicht nach diesem Ziele hin ausgesprochen richten, sondern daß sie wie instinktiv ihrer Vorstellungsart das Gepräge geben, welches von diesem Suchen als unbewußtem Impuls bestimmt ist. Und es ist die Art dieses Suchens eine solche, wie sie durch die neueren naturwissenschaftlichen Vorstellungen bedingt werden mußte. - Man kommt dem Grundcharakter dieser Vorstellungen nahe, wenn man sich an den Begriff des «Bewußtseins» hält. Dieser Begriff ist deutlich erst seit Descartes in das neuere Weltanschauungsleben eingeströmt. Vorher hielt man sich an den Begriff der «Seele» als solcher. Daß die Seele nur einen Teil ihres Lebens in ihr bewußten Erscheinungen durchmacht, wurde weniger beachtet. Im Schlafe lebt die Seele doch nicht bewußt. Gegenüber dem bewußten Leben muß ihr Wesen also in tieferen Kräften bestehen, die sie aus dem Grunde dieses Wesens doch nur im Wachen zum Bewußtsein heraufhebt. Je mehr man aber dazu kam, nach der Berechtigung und dem Wert der Erkenntnis auf Grund einleuchtender Vorstellungen zu fragen, um so mehr kam man auch dazu, zu empfinden, daß das Gewisseste aus aller Erkenntnis die Seele dann findet, wenn sie über sich selbst nicht hinaus- und in sich selbst auch nicht tiefer hineingeht, als das Bewußtsein reicht. Man meinte: Möge auch alles andere ungewiß sein; was im Bewußtsein ist, das zum mindesten ist, als solches, gewiß. Mag selbst das Haus, an dem ich vorbeigehe, nicht außer mir existieren; daß das Bild dieses Hauses jetzt in meinem Bewußtsein lebt: das darf ich behaupten. Sobald man aber die Aufmerksamkeit auf das Bewußtsein richtet, kann es nicht ausbleiben, daß der Begriff des Ich mit dem des Bewußtseins zusammenwächst. Mag das «Ich» außer dem Bewußtsein was immer für ein Wesen sein: so weit das Bewußtsein geht, so weit darf der Bereich des «Ich» vorgestellt werden. Nun kann doch gar nicht geleugnet werden, daß sich von dem bewußt vor der Seele stehenden sinnlichen Weltbilde sagen läßt, es komme durch den Eindruck zustande, der von der Welt auf den Menschen gemacht wird. Sobald man sich aber an dieser Aussage festklammert' kommt man nicht leicht wieder von ihr los. Denn es unterschiebt sich das Urteil: Die Vorgänge der Welt sind Ursache; das, was im Bewußtsein sich darstellt, ist Wirkung. Da man so im Bewußtsein allein die Wirkung zu haben glaubt, meint man, die Ursache müsse ganz in einer außer dem Menschen liegenden Welt als unwahrnehmbares «Ding an sich» vorhanden sein. Die obigen Darstellungen zeigen, wie die neueren physiologischen Erkenntnisse zur Bekräftigung einer solchen Meinung führen. Es ist nun diese Meinung, durch welche sich das «Ich» mit seinen subjektiven Erlebnissen ganz in seiner eigenen Welt eingeschlossen findet. Diese intellektuelle, scharfsinnig erzeugte Illusion kann so lange nicht zerstört werden, wenn sie einmal gebildet ist, als das «Ich» nicht in sich selbst etwas findet, von dem es weiß, daß es, obwohl es im Bewußtsein abgebildet ist, doch außerhalb des subjektiven Bewußtseins sein Wesen hat. Das Ich muß sich außerhalb des sinnlichen Bewußtseins von Wesen berührt fühlen, die ihr Sein durch sich selbst verbürgen. Es muß in sich etwas finden, das es außerhalb seiner selbst führt. Was von dem Lebendigwerden des Gedankens gesagt worden ist, kann solches bewirken. Hat das Ich den Gedanken nur in sich erlebt, so fühlt es sich mit ihm in sich selbst. Beginnt der Gedanke sein Eigenleben, so entreißt er das Ich seinem subjektiven Leben. Es vollzieht sich ein Vorgang, den das Ich zwar subjektiv erlebt, der jedoch durch seine eigene Natur objektiv ist, und der das «Ich» all dem entreißt, was es nur als subjektiv empfinden kann. Man sieht, daß auch die Vorstellungen, welchen die Welt Illusion wird, nach dem Ziele hindrängen, das in der Weiterführung des Hegelschen Weltbildes zum lebendig gewordenen Gedanken liegt. Diese Vorstellungen gestalten sich so, wie das Weltanschauungsbild werden muß, das von dem in diesem Ziele gelegenen Impuls unbewußt getrieben wird, doch aber nicht die Kraft hat, zu diesem Ziele sich hindurchzuarbeiten. Dieses Ziel waltet in den Untergründen der neueren Weltanschauungsentwickelung. Den Weltanschauungen, welche auftreten, fehlt die Kraft, zu ihm durchzubrechen. Sie erhalten auch in ihrer Unvollkommenheit ihr Gepräge von diesem Ziel; und die Ideen, welche auftreten, sind die äußeren Symptome verborgen bleibender Willenskräfte.
The world as illusion
[ 1 ] In addition to the worldview current that seeks to bring full unity to the conception of natural and spiritual phenomena through the idea of development, there is another current that emphasizes this contrast in the sharpest form imaginable. It too was born out of natural science. Its proponents ask themselves: What do we rely on when we build a world view from observation through thinking? We hear, see and feel the physical world through our senses. We then think about what the senses tell us about the world. So we form our thoughts about the world based on the testimony of the senses. But are the statements of our senses infallible? Let us ask observation. The eye brings us light phenomena. We say that a body sends us red light when the eye perceives red. But the eye also gives us a sensation of light in other cases. When it is pushed or pressed, when an electric current flows through the head, the eye also has a sensation of light. Thus, even in cases where we perceive a body as luminous, something could be going on in the body that bears no resemblance to our perception of light: the eye would still transmit light to us. The physiologist Johannes Müller (1801-1858) concluded from these facts that what a person feels does not depend on external processes, but on their organization. Our nerves convey the sensations to us. Just as we do not feel the knife that cuts us, but a state of our nerves that appears painful to us; just as we do not feel a process of the outside world when light appears to us, but a state of our optic nerves. Whatever may be going on outside, the optic nerve translates this external process into the sensation of light. "Sensation is not the conduction of a quality or a state of the external body to consciousness, but the conduction of a quality, a state of our nerves to consciousness, caused by an external cause." Johannes Müller called this law the law of specific sense energies. If it is correct, then we have given nothing of the external world in our observations, but only the sum of our own states. What we perceive has nothing to do with the outside world; it is a product of our own organization. Basically, we only perceive what is inside us.
[ 2 ] Significant natural scientists see this idea as an irrefutable basis for their understanding of the world. Hermann Helmholtz (1821-1894) found in it the Kantian idea that all our knowledge does not refer to things outside us, but to processes within us (cf. Volume 1 of this Weltanschauungsgeschichte) translated into the natural sciences. He is of the opinion that our sensory world only gives us signs of the processes in the bodies outside in the world. "I believed that I had to formulate the relationship between sensation and its object in such a way that I declared sensation to be only a sign of the influence of the object. The essence of a sign is only that the same sign is always given for the same object. Moreover, no kind of similarity is necessary between it and its object, any more than between the spoken word and the object which we designate by it. - We cannot even call our sensory impressions pictures; for the picture represents the same thing by the same thing. In a statue we give body form by body form, in a drawing the perspective view of the object by the same of the picture, in a painting color by color." Our perceptions of what is going on outside in the world must therefore be more different than images of what is depicted. In our sensory view of the world, we are not dealing with something objective, but with something entirely subjective, which we construct ourselves on the basis of the effects of an external world that never penetrates us.
[ 3 ] The physical view of sensory phenomena approaches this conception from a different angle. A sound that we hear points us to a body in the outside world whose parts are in a certain state of motion. A taut string vibrates and we hear a sound. The string causes the air to vibrate. These vibrations spread out and reach our ears: a sound sensation is communicated to us. The physicist examines the laws according to which the parts of the body outside move while we hear this or that sound. It is said that the subjective perception of sound is based on the objective movement of body parts. The physicist sees similar relationships with regard to the perception of light. Light is also based on movement. However, this movement is not transmitted to us by the vibrating air particles, but by the vibrations of the ether, the finest substance that flows through all the spaces of the universe. Through every self-luminous body, the ether is set into wave-like vibrations that spread to the retina of our eye and excite the optic nerve, which then evokes the sensation of light in us. What appears as light and color in our image of the world is movement outside in space. Schleiden expresses this view with the words: "The light outside us in nature is movement of the ether, a movement can be slow and fast, have this or that direction, but it obviously makes no sense to speak of a light or dark, of a green or red movement; in short: apart from us, the sentient beings, there is no light and dark, no colors."
[ 4 ] The physicist thus pushes colors and light out of the external world because he finds only movement in it; the physiologist feels compelled to take them into the soul because he believes that the nerve only indicates its own state, no matter what excites it. The view thus given speaks sharply H. Taine in his book "The Mind" (German edition, Bonn 1880). In his opinion, external perception is a hallucination. The hallucinarian who sees a skull three steps away from him has exactly the same perception as the one who receives the rays of light sent to him by a real skull. The same inner phantom is present in us, regardless of whether we have a real skull in front of us or whether we have a hallucination. The only difference between the one and the other perception is that in the one case the outstretched hand gropes in the void, in the other it encounters a firm resistance. The sense of touch therefore supports the sense of sight. But is the support really such that it provides an infallible testimony? What applies to one sense naturally also applies to the other. The tactile sensations also prove to be hallucinations. The anatomist Henle expresses the same view in his "Anthropological Lectures" (1876): "Everything by which we believe to be informed of an external world are forms of consciousness to which the external world relates only as a stimulating cause, as a stimulus in the sense of physiologists. The external world has no colors, no sounds, no tastes; what it really has we learn only in a roundabout way or not at all; what it is by which it affects one sense we infer only from its relation to the others, as, for example, we see the sound, i.e., the vibrations of the tuning-fork, with the eye and feel it with the fingers; the nature of some stimuli which reveal themselves to only one sense, for example, the stimuli of the sense of smell, is still inaccessible to us today. The number of the properties of matter depends on the number and acuteness of the senses; if one sense is lacking, a group of properties is irreplaceably lost to him; if one sense were more, he would possess an organ for grasping qualities that we suspect as little as the blind man grasps color."
[ 5 ] A survey of physiological literature from the second half of the nineteenth century shows that this view of the subjective nature of the perceptual image has spread far and wide. One will repeatedly come across variations on the idea expressed by J. Rosenthal in his "General Physiology of Muscles and Nerves" (1877): "The sensations which we receive through external impressions are not dependent on the nature of these impressions, but on the nature of our nerve cells. We do not feel what acts on our body, but only what goes on in our brain."
[ 6 ] In his "Physiological Optics", Helmholtz gives us an idea of the extent to which our subjective view of the world gives us signs of the objective outside world: "It is pointless to ask whether vermilion is really red, as we see it, or whether this is merely a sensory illusion. The sensation of red is the normal reaction of normally formed eyes to the light reflected by cinnabar. A red-blind person will see the cinnabar as black or dark grayish-yellow; this is also the correct reaction for his specially formed eye. He only has to know that his eye is of a different nature than that of other people. In itself, the one sensation is no more correct and no more incorrect than the other, even if those who see red are in the majority. In general, the red color of vermilion exists only in so far as there are eyes similar to those of the majority of men. By exactly the same right it is a property of cinnabar to be black, namely for the red-blind. In general, the light reflected by cinnabar cannot be called red per se; it is only red for certain types of eyes. - It is a different matter if we claim that the wavelengths of the light reflected by cinnabar have a certain length. This is a statement that we can make independently of the particular nature of our eye, but which is then only a matter of relationships between the substance and the various ether wave systems."
[ 7 ] It is clear that for such a view the entire sum of world phenomena falls apart into a duality, into a world of states of motion, which is independent of the particular nature of our perceptive faculty, and into a world of subjective states, which are only within the perceiving beings. The physiologist Du Bois-Reymond expressed this view in a sharply pointed manner in his lecture "On the Limits of Natural Cognition" at the forty-fifth meeting of German naturalists and physicians in Leipzig on August 14, 1872. Recognizing nature is tracing the processes we perceive in the world back to the movements of the smallest parts of the body, "or dissolving natural processes into the mechanics of atoms". For it is "a fact of psychological experience that, where such a resolution succeeds", our need for explanation is satisfied for the time being. Now our nervous system and our brain are also of a physical nature. The processes that take place in them can also only be processes of movement. If sound or light vibrations propagate to my sensory organs and from there to my brain, they can also be nothing but movements. I can only say that a certain process of movement is taking place in my brain, and I feel "red". For if it is meaningless to say of cinnabar that it is red, it is no less meaningless to say of a movement of the parts of the brain that it is light or dark, green or red. The world is "mute and dark in itself, i.e. devoid of properties" for the view gained through scientific observation, which "instead of sound and light only knows vibrations of a property-less primordial substance that has become ponderable there and imponderable matter here.... . The Mosaic statement that there was light is physiologically false. Light only appeared when the first red eye spot of an infusorium distinguished light and dark for the first time. Without sight and without hearing, this glowing, colorful, sounding world around us would be dark and mute." (Grenzen des Naturerkennens, p. 6f.) According to this view, the processes in our visual and auditory senses conjure up a sounding and colorful world from the mute and dark world. The dark and mute world is physical; the sounding and colorful world is spiritual. How does the latter rise from the former; how does movement become sensation? Here, according to Du Bois-Reymond, we see a "limit to the recognition of nature". In our brain and in the outside world there are only movements; sensations appear in our soul. We will never be able to understand how one arises from the other. "On superficial observation, it does seem as if knowledge of the material processes in the brain could make certain mental processes and systems comprehensible to us. I include memory, the flow and association of ideas, the consequences of exercise, specific talents and the like. The slightest reflection teaches us that this is deception. We would only be informed about certain inner conditions of mental life, which are approximately equivalent to the outer conditions set by sense impressions, not about the coming into being of mental life through these conditions. - What conceivable connection exists between certain movements of certain atoms in my brain on the one hand, and on the other hand in the facts that are original to me, that cannot be further defined, that cannot be denied: I feel pain, I feel pleasure, I taste sweet, I smell the scent of roses, I hear the sound of an organ, I see red, and the equally immediate certainty that flows from this: So I am? It is absolutely and forever incomprehensible that a number of carbon, hydrogen, nitrogen, oxygen etc. atoms should not be indifferent. atoms should not be indifferent to how they lie and move, how they lay and moved, how they will lie and move." There is no bridge for knowledge from movement to sensation: that is Du Bois-Reymond's creed. We cannot get from movement in the material world into the spiritual world of sensations. We know that sensation arises through moving matter; but we do not know how this is possible. But in the world of movement we cannot get beyond movement either. We can indicate certain forms of movement for our subjective perceptions, because we can deduce the course of the movements from the course of the perceptions. But we have no idea what is moving outside in space. We say: matter is moving. We follow its movements through the statements of our mental states. But since we do not perceive the moving itself, but only a subjective sign of it, we can never know what matter is. Perhaps, says Du Bois-Reymond, we would also be able to solve the riddle of sensation if that of matter were first laid open before us. If we knew what matter is, we would probably also know how it feels. Both are inaccessible to our knowledge. Those who want to get over this boundary should meet Du Bois-Reymond's words: "Let them try the only way out, that of supranaturalism. Only that where supranaturalism begins, science ends."
[ 8 ] Modern natural science is characterized by two sharp contrasts. One, the monistic current, seems to be on the way to penetrating from the field of natural knowledge to the most important questions of worldview; the other declares itself unable to get any further with scientific means than the realization: this or that subjective state corresponds to this or that process of movement. And the representatives of both currents are sharply opposed to each other. Du Bois-Reymond dismissed Haeckel's "creation story" as a novel. (Cf. Du Bois-Reymond's speech "Darwin versus Galiani".) The family trees that Haeckel draws up on the basis of comparative anatomy, the history of germination and palaeontology are "worth about as much to him as the family trees of Homeric heroes" in the eyes of historical critics. Haeckel, however, sees Du Bois-Reymond's view as an unscientific dualism, which must naturally provide support for the regressive views of the world. "The jubilation of the spiritualists over Du Bois-Reymond's 'Grenzrede' was all the brighter and more justified because E. Du Bois-Reymond had until then been regarded as an important and principled representative of scientific materialism."
[ 9 ] What captivates many for the division of the world into external processes of movement and internal (subjective) processes of sensation and imagination is the applicability of mathematics to the first kind of processes. If one assumes material parts (atoms) with forces, one can calculate how these atoms must move under the influence of these forces. The attraction that astronomy has with its strict mathematical methods has been carried into the smallest of bodies. The astronomer uses the laws of celestial mechanics to calculate the way in which the world's bodies move. The discovery of Neptune was a triumph of this celestial mechanics. Such laws as the movements of the heavenly bodies can now be applied to the movements that take place in the outer world when we hear a sound or see a color; perhaps one day it will be possible to calculate the movements that take place in our brain while we make the judgment: two times two is four. The moment you can calculate everything that can be reduced to mathematical formulas, the world is mathematically explained. In his "Essai philosophique sur les Probabilités" (1814), Laplace gave a captivating description of the ideal of such an explanation of the world: "A mind that knows for a given moment all the forces that animate nature, and the mutual position of the beings that compose it, if otherwise it were comprehensive enough to subject these particulars to analysis, would comprehend in the same formula the movements of the largest bodies of the world and of the lightest atom: nothing would be uncertain to it, and future as well as past would be present to its gaze. The human mind, in the perfection which it has known how to give to astronomy, presents a faint image of such a spirit." And Du Bois-Reymond follows up these words by saying: "Just as the astronomer predicts the day when, after years, a comet will reappear from the depths of space in the firmament, so that spirit would read in its equations the day when the Greek cross will flash from St. Sophia's Mosque and when England will burn its last coal."
[ 10 ] It cannot be doubted that even by the most perfect mathematical knowledge of a process of motion I gain nothing which enlightens me as to why this process of motion appears as a red color. When one ball collides with another, we can - it seems - explain the direction of the second ball. We can specify mathematically what kind of movement arises from another. However, we cannot specify in the same way how the red color arises from a certain movement. We can only say: If this or that movement is present, this or that color is present. In this case, we can only describe a fact. So while we can explain what can be determined by calculation - seemingly in contrast to mere description - we can only arrive at a description of everything that eludes calculation.
[ 11 ] Kirchhoff made a significant scientific statement in 1874 when he summarized the task of mechanics in the words that it should "describe the movements occurring in nature completely and in the simplest possible way". Mechanics applies mathematics. Kirchhoff admits that nothing can be achieved with the help of mathematics other than a complete and simple description of the processes in nature. For those personalities who demand something essentially different from an explanation than a description according to certain points of view, Kirchhoff's confession could serve as a confirmation of their view that there are "limits to the knowledge of nature". Du Bois-Reymond praised the "wise restraint of the master" (Kirchhoff), who set the task of mechanics as describing the movements of bodies, and contrasted it with Ernst Haeckel, who spoke of "atomic souls".
[ 12 ] In his "History of Materialism" (1864), Friedrich Albert Lange (1828-1875) made a significant attempt to build the world view on the idea that everything we perceive is only the result of our own organization. He had the boldness and consistency to really think this basic idea through to the end. Lange's strength lay in his sharp and all-round character. He was one of those personalities who could grasp many things and whose skills were sufficient for what they grasped.
[ 13 ] And Kant's way of perceiving things, which he renewed particularly effectively with the help of modern natural science, became significant: we do not perceive things as they demand it, but as our organization demands it. Lange basically produced no new ideas; but he shone a light into given worlds of thought that has something rare in its brightness. Our organization, our brain with its senses, produces the world of our sensations. I see "blue", I feel "hardness" because I am organized in such and such a way. But I also connect the sensations to objects. For example, from the sensations of "white" and "soft" etc. I connect the idea of wax. When I think about my sensations, I am not moving in any external world. My mind brings coherence into my world of sensations, according to the laws of my mind. If I say that the qualities I perceive in a body presuppose matter with processes of movement, then I cannot get out of myself either. I find myself compelled by my organization to add material processes of movement to the sensations that I perceive. The same mechanism that produces all our sensations also produces our idea of matter. Matter is just as much a product of my organization as color or sound. Even when we speak of things in themselves, we must realize that we cannot get out of our own realm. We are so organized that we cannot possibly get out of ourselves. Indeed, we can only visualize that which lies beyond our realm through our imagination. We sense a boundary of our realm; we tell ourselves that there must be something beyond the boundary that causes sensations in us. But we only get as far as the boundary. We also set this limit for ourselves because we can go no further. "The fish in the pond can swim in the water, not in the earth; but it can still bump its head against the ground and walls." Thus we can live within our imaginative and sensory being, but not in external things; but we come up against a limit where we can go no further, where we cannot say more to ourselves than: Beyond lies the unknown. All ideas that we form about this unknown are unjustified; for we could do nothing but transfer the ideas we have gained within ourselves to the unknown. If we wanted to do this, we would be just as clever as the fish that says to itself: I can't go any further here, so from here on there is another water in which I want to try swimming differently. It can only swim in water and nowhere else.
[ 14 ] But now comes another turn of thought. It belongs to the first. It has long been used as a spirit of relentless consistency. What about me when I look at myself? Am I not just as well bound by the laws of my own organization as when I look at something else? My eye looks at the object, rather: it creates it. Without an eye there is no color. I believe I have an object before me and find, if I look more closely, that my eye, that is, I, produce the object. But now I want to look at my eye itself. Can I do this in any other way than with my organs? Is not the idea that I form of myself also only my imagination? The sensory world is a product of our organization. Our visible organs, like all other parts of the phenomenal world, are only images of an unknown object. Our real organization therefore remains just as hidden from us as the real external things. We only ever have the product of both before us. On the basis of a world unknown to us, we create an imaginary world out of a self unknown to us, which is all we can occupy ourselves with.
[ 15 ] Lange asks himself: Where does consistent materialism lead? Let it be that all our intellectual conclusions and sensory perceptions are produced by the activity of our brain, which is bound to material conditions, and the likewise material organs. Then we are faced with the necessity of examining our organism in order to see how it is active. Again, we can only do this with our organs. No color without an eye; but also no eye without an eye. "The consistently materialistic view immediately turns into a consistently idealistic one. There is no gap to be assumed in our being. We do not have to ascribe individual functions of our being to a physical nature and others to a spiritual nature, but we are in our right when we presuppose physical conditions for everything, even for the mechanism of thought, and do not rest until we have found them. We are no less in our right, however, if we regard not only the external world that appears to us, but also the organs with which we perceive it, as mere images of what is truly present. The eye with which we think we see is itself only a product of our imagination, and if we find that our visual images are produced by the equipment of the eye, we must never forget that the eye together with its equipment, the optic nerve together with the brain and all the structures which we would like to discover there as causes of thought, are also only ideas which form a world coherent in itself, but a world which points beyond itself.... . The senses give us, as Helmholtz says, effects of things, not faithful images, or even the things themselves. But these mere effects also include the senses themselves, together with the brain and the molecular movements conceived in it". (History of Materialism, p. 734 f.) Lange therefore assumes a world beyond ours, whether this is based on things in themselves or whether it consists in something that does not even have anything to do with the "thing in itself", since even this concept, which we form at the limit of our realm, belongs only to our imagination.
[ 16 ] Long worldview thus leads to the opinion that we only have a world of imagination. This, however, forces us to accept something beyond itself; but it also proves to be quite unsuitable for making any kind of statement about this something. This is the worldview of absolute ignorance, of agnosticism.
[ 17 ] That all scientific endeavor must remain unfruitful that does not adhere to the statements of the senses and to the logical understanding that links these statements: this is Lange's conviction. But that the senses and reason together provide us with nothing but a result of our own organization is clear to him from his reflections on the origin of knowledge. For him, therefore, the world is basically a fiction of the senses and the intellect. This opinion leads him to no longer raise the question of the truth of ideas. Lange does not recognize a truth that enlightens us about the nature of the world. Now he believes that precisely by not conceding any truth to the knowledge of the senses and the intellect, he also clears the way for the ideas and ideals that the human mind forms beyond what the senses and the intellect give it. He unhesitatingly considers everything that goes beyond sensory observation and rational cognition to be fiction. Whatever an idealist philosopher has conceived about the nature of facts: it is fiction. The turn that Lange gave to materialism necessarily raises the question: Why should the higher poetry of ideas not apply, since the senses themselves write poetry? How does one type of poetry differ from the other? There must be a quite different reason for the one who thinks in this way why he accepts an idea than for the one who believes that he must accept it because it is true. And Lange finds this reason in the fact that an idea has value for life. What matters is not that an idea is true, but that it is valuable for man. Only one thing must be clearly recognized: that I see a rose red, that I connect the effect with the cause, is something I have in common with all sentient and thinking creatures. My senses and my intellect cannot create extra values for themselves. But if I go beyond what my senses and intellect create, then I am no longer bound to the organization of the entire human species. Schiller, Hegel Hinz and Kunz see a flower in the same way what Schiller writes about the flower what Hegel thinks about it, Hinz and Kunz do not write and think in the same way But just as Hinz and Kunz are mistaken if they regard their idea of the flower as an entity outside themselves, so Schiller and Hegel were mistaken if they regarded their ideas as something other than poetry that corresponds to their spiritual needs. What the senses and the intellect compose belongs to the whole human species; neither can deviate from the other. What goes beyond the poetry of the senses and the intellect is a matter for the individual. But Lange ascribes this poetry of the individual a value for the whole human species, if the individual who "produces it, richly and normally gifted and typical in his way of thinking, is called to be a leader through his intellectual power". Lange thus believes that he is securing the value of the ideal world by also turning the so-called real world into poetry. He sees only poetry everywhere we can look, from the lowest level of sensory perception, where "the individual still appears to be completely bound to the basic features of the genre, right up to the creative workings of poetry". "One can call the functions of the senses and the connecting intellect, which produce reality for us, low in comparison with the high flight of the spirit in freely creative art. On the whole, however, and in their interrelation, they cannot be subordinated to any other mental activity. As little as our reality is a reality according to the desire of our heart, it is nevertheless the firm foundation of our entire spiritual existence. The individual grows out of the soil of the species, and general and necessary cognition forms the only sure basis for the elevation of the individual to an aesthetic conception of the world." (History of Materialism, 1887, p. 824 f.)
[ 18 ] Lange does not see this as the error of idealistic world views, that they have gone beyond the sensory and intellectual world with their ideas, but rather their belief that more can be achieved with these ideas than individual poetry. One should build up an ideal world; but one should be aware that this ideal world is nothing more than poetry. If one asserts that it is more than that, then materialism will always appear again and again, saying: I have the truth; idealism is fiction. Well, says Lange, idealism is poetry, but materialism is also poetry. In idealism the individual writes poetry, in materialism the genus. If both are aware of their essence, then everything is in order: the science of sense and understanding with its strict proofs that are binding for the whole species, the poetry of ideas with its higher worlds of imagination generated by the individual but nevertheless valuable for the species. "One thing is certain: that man needs to supplement reality with an ideal world created by himself, and that the highest and noblest functions of his spirit work together in such creations. But should this free act of the spirit take on the illusory form of a proving science again and again? Then materialism, too, will again and again come forward and destroy the bolder speculations by seeking to correspond to the unifying instinct of reason with a minimum of elevation above the real and provable". (History of Materialism, p. 828.)
[ 19 ] A complete idealism goes hand in hand with Lange's complete abandonment of truth. The world is poetry to him, but a poetry that he values as such no less than if he could recognize it as reality. Two currents with a sharply defined scientific character stand in stark contrast to each other within the modern development of worldview. The monistic one, in which Haeckel's way of thinking operates, and a dualistic one, whose most energetic and consistent defender is Friedrich Albert Lange. Monism sees a true reality in the world that man can observe and does not doubt that he can also gain knowledge of essential significance about this reality with his thinking based on observation. He does not imagine that he can exhaust the fundamental nature of the world with a few boldly conceived formulas; he proceeds on the basis of facts and forms ideas about the connections between these facts. But he is convinced that these ideas give him knowledge of a true existence. Lange's dualistic view divides the world into a known and an unknown. The former is treated in the same way as monism, on the basis of observation and contemplative thinking. But it has the belief that through this observation and through this thinking not the slightest thing can be known about the true essence of the world. Monism believes in the truth of the real and sees the best support for the human world of ideas in the fact that it bases it firmly on the world of observation. In the ideas and ideals that it draws from natural existence, it sees entities that fully satisfy its mind, its moral need. In nature he finds the highest existence, which he not only wants to recognize by thinking, but to which he gives his heartfelt devotion, his whole love. Lange's dualism considers nature unsuitable to satisfy the spirit's highest needs. It must assume a special world of higher poetry for this spirit, which leads it beyond what observation and thought reveal. Monism is given a supreme spiritual value in true knowledge, which, because of its truth, also gives man the purest moral and religious pathos. To dualism, knowledge cannot grant such satisfaction. It must measure the value of life by entities other than truth. Ideas do not have value because they are of truth. They have value because they serve life in its highest forms. Life is not judged by ideas, but ideas are judged by their fruitfulness for life. It is not true knowledge that man strives for, but valuable thoughts.
[ 20 ] In his recognition of the scientific way of thinking, Friedrich Albert Lange agrees with monism insofar as he denies the legitimacy of any other source for the knowledge of reality; he only denies this way of thinking any ability to penetrate into the essence of things. To ensure that he is on safe ground, he clips the wings of the human way of thinking. What Lange does in a forceful way corresponds to a tendency of thought deeply rooted in the development of the world view of modern times. This can also be seen with perfect clarity in another area of the nineteenth-century world of ideas. Through various phases, this world of ideas developed into points of view from which Herbert Spencer founded a dualism in England around the same time as Lange in Germany, which on the one hand strives for complete scientific knowledge of the world and on the other hand professes agnosticism towards the nature of existence. When Darwin published his work on the "Origin of Species" and thus gave monism one of its firm pillars, he was able to praise Spencer's scientific way of thinking: "In one of his essays (1852) Herbert Spencer contrasts the theory of creation and that of organic development in a strangely clever and effective way. He concludes from the analogy with the products of breeding, from the modification to which the embryos of many species are subject, from the difficulty of distinguishing species from variety, and from the principle of a general series of stages, that species have been modified. He makes these modifications dependent on the changed conditions. The author has also (1855) treated psychology according to the principle of the necessarily gradual acquisition of every mental power and faculty." Like the founder of the modern view of the processes of life, other scientific thinkers are also attracted to Spencer, who strives to explain reality from the inorganic fact up to psychology in the direction expressed in the above statement by Darwin. But Spencer is also on the side of the agnostics, so that Friedrich Albert Lange can say: "Herbert Spencer, related to our own point of view, pays homage to a materialism of appearance whose relative justification in natural science finds its limits in the idea of an unknowable absolute."
[ 21 ] It can be imagined that Spencer was led to his point of view from similar starting points as Lange. He was preceded in the development of English thought by spirits who were guided by a double interest. They wanted to determine what man actually possesses in his knowledge. But they also did not want to shake the essential nature of the world by any doubt or reason. In a more or less pronounced way, they were all dominated by the feeling that Kant expresses when he says: "I had to abolish knowledge in order to make room for faith." (Cf. Volume I. of this Weltanschauungsgeschichte, p. 149 ff.)
[ 22 ] In England, Thomas Reid (1710-1796) stands at the beginning of the development of the world view in the nineteenth century. The fundamental trait of this man's conviction is what Goethe also expressed as his view with the words: "In the end, it is only, methinks, the practical and self-rectifying operations of the common sense of man that dares to exercise itself in a higher sphere." (Cf. Goethe's Works, vol. 36, p. 595 in Kürschner's German National Literature). This common sense does not doubt that he is dealing with real, essential things and processes when he looks at the facts of the world. Reid considers only such a worldview viable that adheres to this basic view of common sense. If we ourselves admitted that our observation could deceive us, and that the true nature of things was quite different from what our senses and reason tell us, we would not need to worry about such a possibility. We can only get along in life if we believe our observation; everything else is none of our business. It is from this point of view that Reid believes he arrives at truly satisfying truths. He does not seek to arrive at a view of things by complicated reasoning, but by going back to the views instinctively accepted by the soul. And instinctively, unconsciously, the soul already possesses what is right before it undertakes to shine the torch of consciousness into its own being. Instinctively it knows what to think of the qualities and processes in the physical world; instinctively, however, it also has the direction of its moral behavior, a judgment of good and evil. Reid directs thought towards the observation of the soul by appealing to the truths inherent in common sense. From then on, this trait of soul observation remained characteristic of the development of the English world view. Outstanding personalities who stand within this development are William Hamilton (1788-1856), Henry Mansel (1820-1871), William Whewell (,794 to 1866), John Herschel (1792-1871), James Mill (1773 to 1836), John Stuart Mill (1806-1873), Alexander Bair (1818-1903), Herbert Spencer (1820-1903). They all put psychology at the center of their worldview.
[ 23 ] For Hamilton, too, what the soul originally finds itself compelled to accept as true is considered true. Proof and comprehension cease in the face of original truths; one can simply note their emergence on the horizon of consciousness. In this sense they are incomprehensible. But it also belongs to the original statements of consciousness that every thing in this world is dependent on something that we do not know. In the world in which we live we find only dependent things, nowhere an absolutely independent one. But there must be such a thing. When something dependent is encountered, an independent must be presupposed. We cannot enter the independent with our thinking. Human knowledge is calculated for the dependent and becomes entangled in contradictions when it applies its thoughts, which are very suitable for the dependent, to the independent. Knowledge must therefore give way when we reach the entrance to the independent. Religious faith is there in its place. Only by confessing that he can know nothing of the essence of the world can man be a moral being. He can accept a God who brings about a moral order in the world. No logic can rob this belief in an infinite God as soon as it is recognized that all logic is directed only to the dependent, not to the independent. - Mansel is a student and continuator of Hamilton. He only dresses his views in even more extreme forms. It is not going too far to say that Mansel is an advocate of faith, who does not judge impartially between religion and knowledge, but is biased in favor of religious dogma. He is of the opinion that the religious truths of revelation necessarily entangle cognition in contradictions. However, this does not stem from a deficiency in the truths of revelation, but from the fact that the human mind is limited and can never reach the regions about which revelation makes statements. - William Whewell believes that the best way to gain a view of the meaning, origin and value of human knowledge is to examine how pioneering minds in the sciences arrived at their findings. His "History of the Inductive Sciences" (1837) and his "Philosophy of the Inductive Sciences" (1840) aim to understand the psychology of scientific research. From the outstanding scientific discoveries he seeks to recognize how much of our ideas belong to the external world and how much to man himself. Whewell finds that the soul in all science supplements observation of its own accord. Kepler had the concept of the ellipse before he found that the planets move in ellipses. The sciences, therefore, do not come about by mere reception from without, but by the active intervention of the human spirit, which impresses its laws on what it receives. But the sciences do not reach to the ultimate essences of things. They deal with the details of the world. But just as one assumes a cause for every single thing, for example, one must also assume such a cause for the whole world. Since knowledge fails in the face of such a cause, religious dogma must step in to supplement it. Like Whewell, Herschel also seeks to gain a view of the origin of knowledge in the human mind by considering numerous examples. ("A Preliminary Discourse on the Study of Natural Philosophy" was published in 1831.)
[ 24 ] John Stuart Mill belongs to the type of thinkers who are imbued with the sentiment that one cannot be too careful when it comes to determining what is certain and what is uncertain in human knowledge. The fact that he was introduced to the most diverse branches of knowledge as a boy must have given his mind its peculiar character. He was taught Greek at the age of three, and soon afterwards arithmetic. The other subjects came to him at a correspondingly early age. His father, the eminent thinker James Mill, had an even greater influence on the way he was taught, so that the sharpest logic became second nature to John Stuart. From his biography we learn: "What could be found out by thinking, my father never told me until I had exhausted my powers to find it out for myself." For such a person, the things that occupy his thoughts must become the fate of his life in the truest sense of the word. "I have never been a child, I have never played cricket; it is better to let nature take its own course," says John Stuart Mill, not without reference to the experiences of one whose destiny is so solely to think. The questions about the meaning of knowledge must have weighed heavily on him, who had undergone this development. To what extent can the knowledge that is his life also lead to the sources of world phenomena? The direction that Mill's development of thought took in order to gain insight into these questions was probably also determined early on by his father. James Mill's thinking was based on psychological experience. He observed how, in man, conception attaches itself to conception. Man gains his knowledge of the world by attaching one idea to another. He must therefore ask himself: What is the relationship between the structure of ideas and the structure of things in the world? Through such an approach, thinking becomes suspicious of itself. In man the ideas could possibly be connected in a completely different way than the things outside in the world. John Stuart Mill's logic, which was published in 1843 as his main work under the title "System of Logic", is based on this mistrust.
[ 25 ] It is hard to imagine a sharper contrast in matters of worldview than this Milian "Logic" and Hegel's "Science of Logic", which appeared twenty-seven years earlier. In Hegel we find the highest confidence in thinking, the complete certainty that what we experience in ourselves cannot deceive us. Hegel feels himself to be a member of the world. What he experiences in himself must therefore also belong to the world. And since he recognizes himself most directly, he believes in what he recognizes in himself and judges the rest of the world by it. He says to himself: "When I perceive an external thing, it can perhaps only show me its outside, and its essence remains concealed. This is impossible with myself. I can see through myself. But then I can compare the things outside with my own being. If they reveal something of my own being on the outside, then I can also attribute something of my being to them. This is why Hegel confidently seeks the spirit, the connections of thought that he finds within himself, also outside in nature. Mill does not initially feel like a member of the world, but as a spectator. The things outside are unknown to him, and he is suspicious of the thoughts that people have about these things. One perceives people. Until now, we have always observed that people have died. That is why the judgment has been formed: All people are mortal. "All men are mortal; the Duke of Wellington is a man; therefore the Duke of Wellington is mortal." So people conclude. What gives them a right to do so? asks John Stuart Mill. If a single man were once proved to be immortal, the whole judgment would be overturned. Can we therefore assume, because all men have died so far, that they will do so in the future? All knowledge is uncertain. For we infer from observations we have made things about which we can know nothing until we have made the observations in question on them. What would someone who thinks in Hegel's sense have to say about such a view? It is not difficult to form an idea about it. We know from certain concepts that in every circle all radii are equal. If one encounters a circle in reality, one also asserts of this real circle that its radii are equal. If one observes the same circle after a quarter of an hour and finds its radii to be unequal, one does not decide to make the judgment:
[ 26 ] In a circle, under certain circumstances, the radii can also be unequal, - but one says to oneself: what was once a circle has for some reason lengthened into an ellipse. Thus, for example, someone thinking in Hegel's sense came to the judgment: All men are mortal. Man has not formed the concept of man through observation, but as an inner experience of thought, just as he has formed the concept of the circle. Mortality belongs to the concept of man, just as the equality of radii belongs to the concept of the circle. If one encounters a being in reality that has all the other characteristics of man, then this being must also have that of mortality, just as all the other characteristics of the circle entail that of equality of radii. If Hegel were to encounter a being that does not die, he could only say to himself: This is not a human being - but not: A human being can also be immortal. He presupposes that the concepts in us are not formed arbitrarily, but that they are rooted in the essence of the world, just as we ourselves belong to this essence. Once the concept of man has been formed in us, it comes from the essence of things; and we have the full right to apply it to this essence as well. Why has the concept of mortal man arisen in us? Only because it has its foundation in the nature of things. He who believes that man stands entirely outside things and forms his judgments as an outsider can say to himself: We have seen men die so far, so we form the concept of spectators: mortal men. He who is aware that he himself belongs to things, and that these things express themselves in his thoughts, says to himself: so far all men have died; therefore it is part of their nature to die; and he who does not die is not a man, but something else. Hegel's logic has become a logic of things; for Hegel the language of logic is an effect of the essence of the world; not something added to this essence by the human spirit from without. Mill's logic is a spectator logic, which initially cuts the thread that connects it to the world.
[ 27 ] Mill points out how thoughts that appear to be absolutely certain inner experiences to a certain age are nevertheless overturned by a subsequent one. For example, in the Middle Ages it was believed that it was impossible for there to be opposites, and that the stars would have to fall down if they were not attached to fixed spheres. Man will therefore only be able to gain a proper relationship to his knowledge if, despite the awareness that the logic of the world expresses itself in him, he forms a judgment that requires continual correction only by methodically examining his conceptual connections on the basis of observation. And it is the methods of observation that John Stuart Mill seeks to establish in a coldly calculating way in his logic. An example of this is the following:
[ 28 ] Suppose a phenomenon to have always occurred under certain conditions. In a certain case, a whole series of these conditions occur again; only some of them are missing. The phenomenon does not occur. Then one must conclude that the conditions that did not occur are causally related to the phenomenon that did not occur. If two substances have always combined to form a chemical compound, and they do not do so once, we must investigate what is not there this time and was always there otherwise. By such a method we arrive at ideas about factual connections which we justifiably regard as having their basis in the nature of things. Mill wants to pursue the methods of observation. Logic, of which Kant said that it had not advanced a single step since Aristotle, is a means of orientation within thought itself. It shows how to get from one correct thought to another. Mill's logic is a means of orientation within the world of facts. It aims to show how one arrives at valid judgments about things from observations. Mill makes no distinction between human judgments. For him, everything that man thinks about things emerges from observation. He does not even make an exception for mathematics. Mathematics, too, must gain its basic knowledge from observation. In all the cases we have observed so far, we have seen that two straight lines that have intersected once diverge and have not intersected a second time. From this we conclude that they cannot intersect. But we do not have perfect proof of this. For John Stuart Mill, then, the world is something alien to man. Man looks at its phenomena and orders them according to the statements it makes to him in his imagination. He perceives regularity in the phenomena and arrives at natural laws through logical and methodical investigations of these regularities. But nothing leads to the foundation of things themselves. It is therefore quite easy to imagine that everything in the world could be different. Mill is convinced that anyone who is accustomed to abstraction and analysis, and applies his faculties honestly, will, after sufficient exercise of his imagination, find no difficulty in the idea that in a star system other than our own there could be none of the laws that apply in our own. It is only logical for Mill to extend this view of the world to man's own ego. Ideas come and go, combine and separate within him; man perceives this. He does not perceive a being that remains the same as an "I" in this coming and going, separating and connecting of ideas. Up to now he has seen ideas emerge within himself and assumes that this will continue to be the case. The idea of the "I" arises from this possibility that a world of ideas is structured around a center. Man is also a spectator to his own "I". He lets his ideas tell him what he can know about himself. Mill looks at the facts of memory and expectation. If all that I know of myself is to be exhausted in ideas, I cannot say: I remember an idea I had of myself in the past, or I expect the occurrence of a certain experience; but: an idea remembers itself or expects its future occurrence. "When we speak," says Mill, "of the mind as a series of perceptions, we must speak of a series of perceptions which is conscious of itself as becoming and past. And now we are in the dilemma of either saying that the 'I' or the mind is something distinct from the perceptions; or of asserting the paradox that a mere series of perceptions can have a consciousness of its past and future." Mill does not get beyond this dilemma. For him it holds an unsolvable riddle. He has just torn the bond between himself, the observer, and the world, and is unable to tie it again. The world remains for him the unknown beyond, which makes impressions on man. All that he knows of the unknown beyond is that the possibility exists that it could evoke perceptions in him. So instead of speaking of real things outside himself, man can basically only speak of the fact that possibilities of perception exist. He who speaks of things in themselves is indulging in empty words; only he who speaks of the constant possibility of the occurrence of sensations, perceptions, ideas, moves on the ground of the actual.
[ 29 ] John Stuart Mill has a strong aversion to all thoughts that are gained in any other way than by comparing facts, by pursuing the similar, analogous and related in phenomena. He believes that the greatest harm can only be done to human life if one is lulled into the belief that one can arrive at any truth in any other way than through observation. In this aversion, one senses Mill's reluctance to behave towards things in any way other than in a purely receptive (passive) manner in the pursuit of knowledge. They should dictate to man what he should think about them. If he tries to go beyond receiving and say something about things out of himself, he lacks any guarantee that his own product really has anything to do with things. Ultimately, the point of this view is that its proponent cannot decide to include his own independent thinking in the world. It is precisely the fact that he is self-acting that disturbs him. He would prefer to eliminate his self altogether so as not to mix anything false into what the phenomena say about himself. He does not properly appreciate the fact that his thinking is as much a part of nature as the growth of a blade of grass. As clear as it is that one must observe the blade of grass if one wants to know something about it, it should be just as clear that one must also question one's own independent thinking if one wants to learn something about it. How, in Goethe's words, is one to get to know one's relationship to oneself and to the outside world if one wants to eliminate oneself completely in the process of cognition? However great the merits of Mill's discovery of the methods by which man recognizes all that does not depend on him, no such method can give a view of the relation of man to himself and of his self to the external world. All these methods are therefore valid for the individual sciences, but not for a comprehensive world view. No observation can teach what self-acting thinking is; only thinking can experience this from within itself. And since thinking can only say something about itself through itself, it can also only say something to itself about its relationship to the outside world. Mill's way of conceiving thus completely excludes the acquisition of a world view. Such a world view can only be gained through a way of thinking that immerses itself in itself and thereby surveys itself and its relationship to the outside world. The fact that John Stuart Mill harbored an antipathy to this kind of self-referential thinking is easy to understand from his character. Gladstone said in a letter (cf. Gomperz, John Stuart Mill, Vienna 1889) that he used to call Mill the "saint of rationalism" in conversations. A man who lives himself out entirely in thinking in this way makes great demands on thinking and seeks the greatest possible precautions to ensure that it cannot deceive him. He thus becomes suspicious of thinking. He believes that he can easily become uncertain if he loses firm points of reference. And uncertainty towards all questions that go beyond strict observational knowledge is a fundamental trait of Mill's personality. Anyone who follows his writings will see everywhere how Mill regards such questions as open questions, on which he does not dare to make a certain judgment.
[ 30 ] Herbert Spencer also holds fast to the unknowability of the true nature of things. He first asks himself: How do I arrive at what I call truths about the world? I observe individual things and form judgments about them. I observe that hydrogen and oxygen combine to form water under certain conditions. I form a judgment about this. This is a single truth that only applies to a small circle of things. I then also observe the conditions under which other substances combine. I compare the individual observations and thereby arrive at more comprehensive, more general truths about how substances combine chemically. All cognition is based on the fact that man proceeds from individual truths to ever more general truths in order to end up with the highest truth, which he cannot trace back to any other; which he must therefore accept without being able to comprehend it further. In this path of knowledge, however, we have no means of penetrating to the absolute essence of the world. Thinking, according to this opinion, can do nothing but compare the different things with each other and form general truths about what is similar in them. But the unconditioned world being, in its uniqueness, cannot be compared with any other thing. That is why thinking fails in relation to it. It does not come close to it.
[ 31 ] We always hear the thought that has also developed on the basis of the physiology of the senses (cf. above p. 422 ff.). For many thinkers this thought is so interwoven with their spiritual life that they consider it to be the most certain thing that can exist. They say to themselves that man only recognizes things by becoming conscious of them. They now, more or less involuntarily, transform this thought into the other: One can only know of that which enters consciousness; but it remains unknown how things were before they entered consciousness. That is why we regard sensations as if they were in consciousness, for we think that they must first enter it, i.e. become parts of it (ideas), if we want to know anything about them.
[ 32 ] Spencer also maintains that it depends on us humans how we can recognize and that we must therefore assume something unrecognizable beyond what our senses and our thinking convey to us. We have a clear awareness of everything that our perceptions tell us. But this clear consciousness is mixed with an indeterminate consciousness that says that everything we observe and think is based on something that we can no longer observe and think. We know that we are dealing with mere appearances, not with full realities existing for themselves. But precisely because we know that our world is only an appearance, we also know that it is based on an unimaginable reality. By such turns of thought Spencer believes he can bring about the full reconciliation of religion and knowledge. There is something that is not accessible to cognition; therefore there is also something that religion can grasp in faith; in a faith that impotent cognition cannot shake.
[ 33 ] Now that area which Spencer considers accessible to knowledge, he makes entirely the field of scientific ideas. Where he undertakes to explain, he does so only in a scientific sense.
[ 34 ] Spencer conceives of the process of cognition in scientific terms. Every organ of a living being has come into being because this being has adapted itself to the conditions under which it lives. One of the conditions of human life is that man finds his way in the world by thinking. His organ of cognition arises through the adaptation of his imaginative life to the conditions of the external world. When man says something about a thing or a process, this means nothing other than that he adapts himself to the world around him. All truths have arisen in this way of adaptation. But what is acquired through adaptation can be passed on to descendants. Those are not right who maintain that man, by his nature, has a certain disposition to general truths once and for all. What appears to be such a disposition was not once present in man's ancestors, but has been acquired by adaptation and has been passed on to descendants. When certain philosophers speak of truths which man does not need to draw from his own individual experience, but which are inherent in his organization from the outset, they are right to a certain extent. But such truths are also acquired, not by man as an individual, but as a species. The individual has fully inherited what he acquired in earlier times. - Goethe says that he attended many a conversation about Kant's Critique of Pure Reason and saw that the old main question was being renewed: "How much does our self and how much does the outside world contribute to our spiritual existence?" And he continues: "I had never separated the two, and when I philosophized in my own way about objects, I did so with unconscious naivety, and really believed that I saw my opinions before my eyes." Spencer placed this "old main question" in the light of the scientific way of looking at things. He believed he was showing that the developed human being does indeed have to contribute to his spiritual existence from his own self; but this self is also made up of the heirlooms that our ancestors acquired in the struggle with the outside world. If today we think we see our opinions before our eyes, these were not always our opinions, but were once observations that were really made with our eyes of the outside world. Spencer's path, like Mill's, is therefore one that starts from psychology. But Mill stops at the psychology of the individual. Spencer ascends from the individual to its ancestors. Individual psychology is in the same position as the germinal history of zoology. Certain phenomena of germination can only be explained if they are traced back to phenomena of phylogeny. In the same way, the facts of individual consciousness cannot be understood by themselves. One must ascend to the genus, indeed one must go beyond the human species as far as the acquisitions of knowledge which the animal ancestors of man have already made. Spencer uses his great acumen to support this history of the development of the cognitive process. He shows how the mental faculties have gradually developed from lowly beginnings through ever more appropriate adaptations of the mind to the external world and through the inheritance of these adaptations. Everything that the individual human being gains without experience, through pure thinking about things, has been gained by mankind or its ancestors through observation, through experience. Leibniz believed that he could only explain the correspondence of the human inner being with the outer world by assuming a harmony predetermined by the Creator. Spencer explains this harmony in scientific terms. It is not predetermined, but has become. Here we have the continuation of scientific thought up to the highest facts given to man. Linné explains that every living form of being exists because the Creator has made it as it is. Darwin explains that it is the way it has gradually developed through adaptation and heredity. Leibniz explains that thinking corresponds to the outside world because the Creator has created this correspondence. Spencer explains that this correspondence exists because it has developed through adaptation and inheritance of the world of thought.
[ 35 ] Spencer started from the need for a natural explanation of mental phenomena. Lyell's geology gave him the direction for such an explanation (cf. p. 360). In it the idea is still opposed that the organic forms have been formed by gradual evolution; but it receives an important support in that the inorganic (geological) formations of the earth's surface are explained by such gradual evolution, not by violent catastrophes. Spencer, who had a scientific education and had also worked for some time as a civil engineer, immediately recognized the full implications of the evolutionary idea and applied it, despite Lyell's opposition. Indeed, he even applied it to mental processes. As early as 1850, in his work "Social Statics", he described social development by analogy with organic development. He also familiarized himself with Harvey's and Wolff's (cf. vol. I, p. 286 ff.) studies on the germinal history of organisms and delved into the work of Carl Ernst von Baer (cf. p. 397 f. above), which showed him how development consists in the fact that from a state of uniformity, of uniformity, a state of diversity, of variety, of richness develops. In the first germinal stages, organisms resemble each other; later they become different from each other (cf. p. 397 ff. above). This idea of development was then fully confirmed by Darwin. The entire wealth of today's diverse world of forms has developed from a few primordial organisms.
[ 36 ] From the idea of development, Spencer wanted to ascend to the most general truths which, in his opinion, constitute the goal of human striving for knowledge. He believed that the idea of development could already be found in the simplest phenomena. When a cloud forms in the sky from scattered particles of water, or a heap of sand from scattered bodies of sand, we are dealing with a process of development. Scattered matter is drawn together (concentrated) into a whole. No other process is involved in the Kant-Laplace hypothesis of world formation. Scattered parts of a chaotic world nebula have been drawn together. The organism arises in precisely this way. Scattered elements are concentrated in tissues. The psychologist can observe how man draws together scattered observations into general truths. Within the concentrated whole, what has been drawn together is then structured (differentiated). The primordial mass divides itself into the individual celestial bodies of the solar system; the organism differentiates itself into manifold organs.
[ 37 ] Dissolution alternates with contraction. When a developmental process has reached a certain climax, equilibrium occurs. Man develops, for example, until the greatest possible harmony has been achieved between his inner abilities and his outer nature. However, such a state of equilibrium cannot last; external forces8 will approach it destructively. Development must be followed by the descending process of dissolution; the contracted expands again; the cosmic becomes chaos again. The process of development can begin anew. Spencer thus sees a rhythmic play of movement in the world process.
[ 38 ] It is certainly not an uninteresting observation for the comparative history of the development of world views that Spencer comes here from the observation of the becoming of world phenomena to a similar thought, which Goethe also expressed on the basis of his ideas about the becoming of life. The latter describes the growth of the plant as follows: "The plant may sprout, blossom or bear fruit, but it is always only the same organs that fulfill nature's prescription in manifold determinations and under often changed forms. The same organ that has expanded as a leaf on the stem and taken on a highly diverse form now contracts in the calyx, expands again in the petal, contracts in the reproductive organs and expands for the last time as fruit." If we transfer this idea to the whole world process, we arrive at Spencer's contraction and dispersion of matter.
[ 39 ] Spencer and Mill have had a great influence on the development of the world view in the last half of the century. The strict emphasis on observation and the one-sided treatment of the methods of observational cognition by Mill; the application of scientific ideas to the whole scope of human knowledge by Spencer: they must have corresponded to the sentiments of an age which saw in the idealistic world-views of Fichte, Schelling, and Hegel only degenerations of human thought, and from which the successes of scientific research alone were not appreciated, while the disunity of idealistic thinkers and the, in the opinion of many, utter unfruitfulness of self-deepening thought produced a profound distrust of idealism. It is fair to say that a widespread view over the last four decades expresses what Rudolf Virchow said in 1893 in his speech "The foundation of Berlin University and the transition from the philosophical to the scientific age": "Since the belief in magic formulas had been pushed back into the outermost circles of the people, the formulas of the natural philosophers also found little favor." And one of the most important philosophers of the second half of the century, Eduard von Hartmann, summarized the character of his world view in the motto he placed at the head of his book "Philosophy of the Unconscious": "Speculative results according to the inductive-natural scientific method." Indeed, he is of the opinion that one must recognize the "greatness of the progress brought about by Mill", through which "all attempts at deductive philosophizing have been overcome forever". (Cf. E. von Hartmann, Geschichte der Metaphysik. 2nd part, p. 479.)
[ 40 ] The recognition of certain limits of human cognition shown by many natural scientists also had a sympathetic effect on religiously-minded people. They said to themselves: "Natural scientists observe the inorganic and organic facts and, by linking the individual phenomena, seek to find general laws with the help of which processes can be explained and even the regular course of future phenomena can be predicted. The summarizing view of the world should proceed in the same way; it should stick to the facts, investigate general truths from them within modest limits and make no claim to penetrate into the realm of the "incomprehensible". Spencer, with his complete separation of the "comprehensible" and the "incomprehensible", met such religious needs to the highest degree. In contrast, these religiously-minded spirits regarded the idealistic mode of conception as an absurdity. In principle, it cannot acknowledge the incomprehensible, because it must hold on to the idea that by immersing oneself in human inner life, it is possible to recognize not only the outside of the world, but also the real core of it.
[ 41 ] The thinking of influential naturalists, such as Huxley, who professes a complete agnosticism towards the being of the world and declares a monism in the sense of Darwin's findings to be applicable only to the outside of nature given to man, also moves in the direction of such religiously inclined minds. He was one of the first to advocate Darwin's ideas, but at the same time he is one of the most resolute representatives of the limitations of this way of thinking. The physicist John Tyndall (1820-1893) professed a similar view, recognizing in the world process a force completely inaccessible to the human mind. For precisely when one assumes that everything in the world arises through natural development, one can never admit that the substance, which is the carrier of all development, is nothing more than what our intellect can comprehend of it.
[ 42 ] A phenomenon characteristic of his time is the personality of the English statesman James Balfour (1848-1930), who in 1879 (in his book "A defense of philosophic doubt, being an Essay on the foundations of belief") made a profession of faith that is undoubtedly similar to that of wider circles. With regard to everything that man can explain, he places himself entirely on the ground of scientific thinking. He allows all knowledge to be exhausted in the recognition of nature. At the same time, however, he maintains that only those who recognize that man's emotional and rational needs can never be satisfied by scientific knowledge can understand it correctly. One need only realize that in the end, even in the natural sciences, everything depends on believing the ultimate truths that can no longer be proven. But it does no harm that we merely arrive at a belief in this direction, for this belief guides us securely in our actions in daily life. We believe in the laws of nature and control them through this faith; through it we force nature to serve us for our purposes. Religious faith is meant to establish an equal correspondence between man's actions and the higher needs that transcend the mundane.
[ 43 ] The world views, which appear here summarized by the term "The World as Illusion", show that they are based on a search for the satisfying relationship of the idea of the self-conscious ego to an overall world view. They appear particularly significant precisely because they do not regard this search as their conscious philosophical goal and do not direct their investigations explicitly towards this goal, but rather because they instinctively give their way of conceiving the world the character that is determined by this search as an unconscious impulse. And the nature of this search is such as had to be determined by the newer scientific conceptions. - One comes close to the basic character of these ideas if one adheres to the concept of "consciousness". This concept has clearly only entered the newer worldview since Descartes. Before that, the concept of the "soul" as such was adhered to. Less attention was paid to the fact that the soul only lives part of its life in conscious phenomena. In sleep the soul does not live consciously. In contrast to conscious life, its essence must therefore consist of deeper forces, which it raises to consciousness from the basis of this essence only when awake. But the more one came to ask about the justification and value of knowledge on the basis of plausible ideas, the more one also came to feel that the most certain of all knowledge is found by the soul when it does not go beyond itself and does not go deeper into itself than consciousness reaches. One thought: "Even if everything else is uncertain, what is in consciousness is at least certain as such. Even if the house I pass by does not exist apart from me, I may claim that the image of this house now lives in my consciousness. But as soon as one turns one's attention to consciousness, it cannot fail to happen that the concept of the I grows together with that of consciousness. No matter what kind of being the "I" may be apart from consciousness: as far as consciousness goes, so far may the realm of the "I" be imagined. Now it cannot be denied that it can be said of the sensory image of the world standing consciously before the soul that it comes about through the impression made on man by the world. But as soon as one clings to this statement' one cannot easily get away from it. For the judgment is imposed: the processes of the world are cause; that which presents itself in consciousness is effect. Since one thus believes to have the effect in consciousness alone, one thinks that the cause must be present entirely in a world outside man as an imperceptible "thing in itself". The above descriptions show how the more recent physiological findings lead to the confirmation of such an opinion. It is now this opinion through which the "I" with its subjective experiences finds itself completely enclosed in its own world. This intellectual, astutely created illusion cannot be destroyed, once it has been formed, as long as the "I" does not find something in itself of which it knows that, although it is represented in consciousness, it nevertheless has its being outside of subjective consciousness. The ego must feel itself touched outside of sensual consciousness by beings that vouch for their being through themselves. It must find something in itself that leads it outside itself. What has been said about the thought coming to life can bring this about. If the ego has only experienced the thought within itself, it feels itself with it within itself. If the thought begins its own life, it snatches the ego from its subjective life. A process takes place which the ego experiences subjectively, but which is objective by its own nature, and which tears the "ego" away from everything it can only experience as subjective. It can be seen that the ideas to which the world becomes illusion also push towards the goal that lies in the further development of Hegel's world view into thought that has become alive. These conceptions form themselves in the way that the world view must become, which is unconsciously driven by the impulse lying in this goal, but does not have the strength to work its way through to this goal. This goal reigns in the subsoil of the newer world-view development. The world-views that appear lack the power to break through to it. Even in their imperfection they receive their character from this goal; and the ideas that arise are the external symptoms of will-powers that remain hidden.