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The Boundaries of Natural Science
GA 322

27 September 1920, Dornach

Lecture I

The theme of this cycle of lectures was not chosen because it is traditional within academic or philosophical disciplines, as though we thought epistemology or the like should appear within our courses. Rather, it was chosen as the result of what I believe to be an open-minded consideration of the needs and demands of our time. The further evolution of humanity demands new concepts, new notions, and new impulses for social life generally: we need ideas which, when realized, can create social conditions offering to human beings of all stations and classes an existence that seems to them humane. Already, to be sure, it is being said in the widest circles that social renewal must begin with a renewal of our thinking.1“... that social renewal must begin with the renewal of our thinking.” The original German (“... dass die soziale Erneuerung vom Geiste ausgehen musse”) might be translated alternately “that social renewal must proceed from the spirit.” The German word “Geist”—bane of all who would translate German into English—embraces two meanings that remain in English quite distinct “mind” and “spirit.” The translator must choose one, even though the German always implies both. If he chooses the former, he runs the risk of seriously distorting the author's intentions (as did the man who translated Hegel's Phanomenologie des Geistes as The Phenomenology of Mind). If he chooses the latter, he flies in the face of the dubious connotations that “spirit” and “spiritual” convey—no doubt as a result of the basically empirical cast of English thought. Although “Geist” as Steiner uses it should almost invariably be translated “spirit” (which of course comprehends “wind”), here the context has led us to choose the more restricted meaning. Yet not everyone in these widest circles imagines something clear and distinct when speaking in this way. One does not ask: whence shall come the ideas upon which one might found a social economy offering man a humane existence? That portion of humanity which has received an education in the last three to four centuries, but particularly since the nineteenth century, has been raised with certain ideas that are outgrowths of the scientific world view or entirely schooled in it. This is particularly true of those who have undergone some academic training. Only those working in fields other than the sciences believe that natural science has had little influence on their pursuits. Yet it is easy to demonstrate that even in the newer, more progressive theology, in history and in jurisprudence—everywhere can be found scientific concepts such as those that arose from the scientific experiments of the last centuries, so that traditional concepts have in a certain way been altered to conform to the new. One need only allow the progress of the new theological developments in the nineteenth century to pass before the mind's eye. One sees, for example, how Protestant theology has arrived at its views concerning the man, Jesus, and the nature of Christ, because at every turn it had in mind certain scientific conceptions that it wanted to satisfy, against which it did not want to sin. At the same time, the old, instinctive ties within the social order began to slacken: they gradually ceased to hold human life together. In the course of the nineteenth century it became increasingly necessary to replace the instincts according to which one class subordinated itself to another, the instincts out of which the new parliamentary institutions, with all their consequences, have come with more-or-less conscious concepts. Not only in Marxism but in many other movements as well there has come about what one might call a transformation of the old social instincts into conscious concepts.

But what was this new element that had entered into social science, into this favorite son of modern thought? It was the conceptions, the new mode of thinking that had been developed in the pursuit of natural science. And today we are faced with the important question: how far shall we be able to progress within a web of social forces woven from such concepts? If we listen to the world's rumbling, if we consider all the hopeless prospects that result from the attempts that are made on the basis of these conceptions, we are confronted with a dismal picture indeed. One is then faced with the portentous question: how does it stand with those very concepts that we have acquired from natural science and now wish to apply to our lives, concepts that—this has become clearly evident in many areas already—are actually rejected by life itself? This vital question, this burning question with which our age confronts us, was the occasion of my choosing the theme, “The Boundaries of Natural Science.” Just this question requires that I treat the theme in such a way that we receive an overview of what natural science can and cannot contribute to an appropriate social order and an idea of the kind of scientific research, the kind of world view to which one would have to turn in order to confront seriously the demands made upon us by our time.

What is it we see if we consider the method according to which one thinks in scientific circles and how others have been influenced in their thinking by those circles? What do we see? We see first of all that an attempt is made to acquire data and to order it in a lucid system with the help of clear concepts. We see how an attempt is made to order the data gathered from inanimate nature by means of the various sciences—mechanics, physics, chemistry, etc.—to order them in a systematic manner but also to permeate the data with certain concepts so that they become intelligible. With regard to inanimate nature, one strives for the greatest possible clarity, for crystal-clear concepts. And a consequence of this striving for lucid concepts is that one seeks, if it is at all possible, to permeate everything that one finds in one's environment with mathematical formulae. One wants to translate data gathered from nature into clear mathematical formulae, into the transparent language of mathematics.

In the last third of the nineteenth century, scientists already believed themselves very close to being able to give a mathematical-mechanical explanation of natural phenomena that would be thoroughly transparent. It remained for them only to explain the little matter of the atom. They wanted to reduce it to a point-force [Kraftpunkt] in order to be able to express its position and momenta in mathematical formulae. They believed they would then be justified in saying: I contemplate nature, and what I contemplate there is in reality a network of interrelated forces and movements wholly intelligible in terms of mathematics. Hence there arose the ideal of the so-called “astronomical explanation of nature,” which states in essence: just as one brings to expression the relationships between the various heavenly bodies in mathematical formulae, so too should one be able to compute everything within this smallest realm, within the “little cosmos” of atoms and molecules, in terms of lucid mathematics. This was a striving that climaxed in the last third of the nineteenth century: it is now on the decline again. Over against this striving for a crystal-clear, mathematical view of the world, however, there stands something entirely different, something that is called forth the moment one tries to extend this striving into realms other than that of inanimate nature. You know that in the course of the nineteenth century the attempt was made to carry this point of view, at least to some extent, into the life sciences. And though Kant had said that a second Newton would never be found who could explain living organisms according to a causal principle similar to that used to explain inorganic nature, Haeckel could nevertheless claim that this second Newton had been found in Darwin, that Darwin had actually tried, by means of the principle of natural selection, to explain how organisms evolve in the same “transparent” terms. And one began to aim for just such a clarity, a clarity at least approaching that of mathematics, in all explanations, proceeding all the way up to the explanation of man himself. Something thereby was fulfilled which certain scientists explained by saying that man's need to understand the causes of phenomena is satisfied only when he arrives at such a transparent, lucid view of the world.

And yet over against this there stands something entirely different. One comes to see that theory upon theory has been contrived in order to construct a view of the world such as I have just described, and ever and again those who strove for such a view of the world called forth—often immediately—their own opposition. There always arose the other party, which demonstrated that such a view of the world could never produce valid explanations, that such a view of the world could never ultimately satisfy man's need to know. On the one hand it was argued how necessary it is to keep one's world view within the lucid realm of mathematics, while on the other hand it was shown that such a world view would, for example, remain entirely incapable of constructing even the simplest living organism in thought of mathematical clarity or, indeed, even of constructing a comprehensible model of organic substance. It was as though the one party continually wove a tissue of ideas in order to explain nature, and the other party—sometimes the same party—continually unraveled it.

It has been possible to follow this spectacle—for it seems just that to anyone who is able to view it with an unprejudiced eye—within the scientific work and striving of the last fifty years especially. If one has sensed the full gravity of the situation, that with regard to this important question nothing but a weaving and unraveling of theories has taken place, one can pose the question: is not the continual striving for such a conceptual explanation of phenomena perhaps superfluous? Is not the proper answer to any question that arises when one confronts phenomena perhaps that one should simply allow the facts to speak for themselves, that one should describe what occurs in nature and forgo any more detailed accounting? Is it not possible that all such explanations show only that humanity is still tied to its mother's apron strings, that humanity in its infancy sought a kind of luxury? Would not humanity, come of age, have to say to itself: we must not strive at all for such explanation; we get nowhere in that way and must simply extirpate the need to know? Why not? As we become older we outgrow the need to play; why, if we were justified in doing so, should we not simply outgrow the need for explanations?

Just such a question could already emerge in the most extraordinarily significant way when, on August 14, 1872, du Bois-Reymond stood before the Second General Meeting of the Association of German Scientists and Physicians to deliver his famous address, “The Boundaries of Natural Science” [“Grenzen des Naturerkennens”], an address still worthy of consideration today. Yet despite the amount that has been written about this address by the important physiologist, du Bois-Reymond, many still do not realize that it represents one of the important junctures in the evolution of the modern world view.

In medieval Scholasticism all of man's thinking, all of his notional activity, was determined by the view that one could explain the broad realms of nature in terms of certain concepts but that one had to draw the line upon reaching the super-sensible. The super-sensible had to be the object of revelation. They felt that man should stand in a relation to the super-sensible in such a way that he would not even wish to penetrate it with the same concepts he formed concerning the realms of nature and external human existence. A limit was set to knowledge on the side of the super-sensible, and it was strongly emphasized that such a limit had to exist, that it simply lay within human nature and the order of the universe that such a limit be recognized. This placement of a limit to knowledge was then renewed from an entirely different side by thinkers and researchers such as du Bois-Reymond. They were no longer Schoolmen, no longer theologians, but just as the medieval theologian, proceeding according to his own mode of thinking, had set a limit to knowledge at the super-sensible, so these thinkers and researchers set a limit at the sensible. The limit was meant to apply above all to the realm of external sensory data.

There were two concepts in particular that du Bois-Reymond had in mind, which to him established the limits natural science could reach but beyond which it could not proceed. Later he increased that number by five in his lecture, “The Seven Enigmas of the World,” but in the first lecture he spoke of the two concepts, “matter” and “consciousness.” He said that when contemplating nature we are forced, in thinking systematically, to apply concepts in such a way that we eventually arrive at the notion of matter. Just what this mysterious entity in space we call “matter” is, however, we can never in any way resolve. We must simply assume the concept “matter,” though it is opaque. If only we assume this opaque concept “matter,” we can apply our mathematical formulae and calculate the movements of matter in terms of the formulae. The realm of natural phenomena becomes comprehensible if only we can posit this “opaque” little point millions upon millions of times. Yet surely we must also assume that it is this same material world that first builds up our bodies and unfolds its own activity within them, so that there rises up within us, by virtue of this corporeal activity, what eventually becomes sensation and consciousness. On the one hand we confront a world of natural phenomena requiring that we construct a concept of “matter,” while on the other hand we confront ourselves, experience the fact of consciousness, observe its phenomena, and surmise that whatever it is we assume to be matter must also lie at the foundation of consciousness. But how, out of these movements of matter, out of inanimate, dead movement, there arises consciousness, or even simple sensation, is a mystery that we cannot possibly fathom. This is the other pole of all the uncertainties, all the limits to knowledge: how can we explain consciousness, or even the simplest sensation?

With regard to these two questions, then—What is matter? How does consciousness arise out of material processes?—du Bois-Reymond maintains that as researchers we must confess: ignorabimus, we shall never know. That is the modern counterpart to medieval Scholasticism. Medieval Scholasticism stood at the limit of the super-sensible world. Modern natural science stands at the limit delineated in essence by two concepts: “matter,” which is everywhere assumed within the sensory realm but nowhere to be found, and “consciousness,” which is assumed to originate within the sense world, although one can never comprehend how.

If one considers this development of modern scientific thought, must one not then say to oneself that scientific research is entangling itself in a kind of web, and only outside of this web can one find the world? For in the final analysis it is there, where matter haunts space, that the external world lies. If this is the one place into which one cannot penetrate, one has no way in which to come to terms with life. Within man one finds the fact of consciousness. Does one come at all near to it with explanations conceived in observing external nature? If in one's search for explanations one pulls up short at human life, how, then, can one arrive at notions of how to live in a way worthy of a human being? How, if one cannot understand the existence or the essence of man according to the assumptions one makes concerning that existence?

As this course of lectures progresses it shall, I believe, become evident beyond any doubt that it is the impotence of the modern scientific method that has made us so impotent in our thinking about social questions. Many today still do not perceive what an important and essential connection exists between the two. Many today still do not perceive that when in Leipzig on August 14, 1872 du Bois-Reymond spoke his ignorabimus, this same ignorabimus was spoken also with regard to all social thought. What this ignorabimus actually meant was: we stand helpless in the face of real life; we have only shadowy concepts; we have no concepts with which to grasp reality. And now, almost fifty years later, the world demands just such concepts of us. We must have them. Such concepts, such impulses, cannot come out of lecture-halls still laboring in the shadow of this ignorabimus. That is the great tragedy of our time. Here lie questions that must be answered.

We want to proceed from fundamental principles to such an answer and above all to consider the question: is there not perhaps something more intelligent that we as human beings could do than what we have done for the last fifty years, namely tried to explain nature after the fashion of ancient Penelope, by weaving theories with one hand and unraveling them with the other? Ah yes, if only we could, if only we could stand before nature entirely without thoughts! But we cannot: to the extent that we are human beings and wish to remain human beings we cannot. If we wish to comprehend nature, we must permeate it with concepts and ideas. Why must we do that?

We must do that, ladies and gentlemen, because only thereby does consciousness awake, because only thereby do we become conscious human beings. Just as each morning upon opening our eyes we achieve consciousness in our interaction with the external world, so essentially did consciousness awake within the evolution of humanity. Consciousness, as it is now, was first kindled through the interaction of the senses and thinking with the outer world. We can watch the historical development of consciousness in the interaction of man's senses with outer nature. In this process consciousness gradually was kindled out of the dull, sleepy cultural life of primordial times. Yet one must only consider with an open mind this fact of consciousness, this interaction between the senses and nature, in order to observe something extraordinary transpiring within man. We must look into our soul to see what is there, either by remaining awhile before fully awakening within that dull and dreamy consciousness or by looking back into the almost dreamlike consciousness of primordial times. If we look within our soul at what lies submerged beneath the surface consciousness arising in the interaction between senses and the outer world, we find a world of representations, faint, diluted to dream-pictures with hazy contours, each image fading into the other. Unprejudiced observation establishes this. The faintness of the representations, the haziness of the contours, the fading of one representation into another: none of this can cease unless we awake to a full interaction with external nature. In order to come to this awakening which is tantamount to becoming fully human—our senses must awake every morning to contact with nature. It was also necessary, however, for humanity as a whole to awake out of a dull, dreamlike vision of primordial worlds within the soul to achieve the present clear representations.

In this way we achieve the clarity of representation and the sharply delineated concepts that we need in order to remain awake, to remain aware of our environment with a waking soul. We need all this in order to remain human in the fullest sense of the word. But we cannot simply conjure it all up out of ourselves. We achieve it only when our senses come into contact with nature: only then do we achieve clear, sharply delineated concepts. We thereby develop something that man must develop for his own sake—otherwise consciousness would not awake. It is thus not an abstract “need for explanations,” not what du Bois-Reymond and other men like him call “the need to know the causes of things,” that drives us to seek explanations but the need to become human in the fullest sense through observing nature. We thus may not say that we can outgrow the need to explain like any other child's play, for that would mean that we would not want to become human in the fullest sense of the word—that is to say, not want to awake in the way we must awake.

Something else happens in this process, however. In coming to such concepts as we achieve in contemplating nature, we at the same time impoverish our inner conceptual life. Our concepts become clear, but their compass becomes diminished, and if we consider exactly what it is we have achieved by means of these concepts, we see that it is an external, mathematical-mechanical lucidity. Within that lucidity, however, we find nothing that allows us to comprehend life. We have, as it were, stepped out into the light but lost the very ground beneath our feet. We find no concepts that allow us to typify life, or even consciousness, in any way. In exchange for the clarity we must seek for the sake of our humanity, we have lost the content of that for which we have striven. And then we contemplate nature around us with our concepts. We formulate such complex ideas as the theory of evolution and the like. We strive for clarity. Out of this clarity we formulate a world view, but within this world view it is impossible to find ourselves, to find man. With our concepts we have moved out to the surface, where we come into contact with nature. We have achieved clarity, but along the way we have lost man. We move through nature, apply a mathematical-mechanical explanation, apply the theory of evolution, formulate all kinds of biological laws; we explain nature; we formulate a view of nature—within which man cannot be found. The abundance of content that we once had has been lost, and we are confronted with a concept that can be formed only with the clearest but at the same time most desiccated and lifeless thinking: the concept of matter. And an ignorabimus in the face of the concept of matter is essentially the confession: I have achieved clarity; I have struggled through to an awakening of full consciousness, but thereby I have lost the essence of man in my thinking, in my explanations, in my comprehension.

And now we turn to look within. We turn away from matter to consider the inner realm of consciousness. We see how within this inner realm of consciousness representations pass in review, feelings come and go, impulses of will flash through us. We observe all this and notice that when we attempt to bring the inner realm into the same kind of focus that we achieved with regard to the external world, it is impossible. We seem to swim in an element that we cannot bring into sharp contours, that continually fades in and out of focus. The clarity for which we strive with regard to outer nature simply cannot be achieved within. In the most recent attempts to understand this inner realm, in the Anglo-American psychology of association, we see how, following the example of Hume, Mill, James, and others, the attempt was made to impose the clarity attained in observation of external nature upon inner sensations and feelings. One attempts to impose clarity upon sensation, and this is impossible. It is as though one wanted to apply the laws of flight to swimming. One does not come to terms at all with the element within which one has to move. The psychology of association never achieves sharpness of contour or clarity regarding the phenomenon of consciousness. And even if one attempts with a certain sobriety, as Herbart has done, to apply mathematical computation to human mental activity [das Vorstellen], to the human soul, one finds it possible, but the computations hover in the air. There is no place to gain a foothold, because the mathematical formulae simply cannot comprehend what is actually occurring within the soul. While one loses man in coming to clarity regarding the external world, one finds man, to be sure—it goes without saying that one finds man when one delves into consciousness—but there is no hope of achieving clarity, for one swims about, borne hither and thither in an insubstantial realm. One finds man, but one cannot find a valid image of man.

It was this that du Bois-Reymond felt very clearly but was able to express only much less clearly—only as a kind of vague feeling about scientific research on the whole—when in August 1872 he spoke his ignorabimus. What this ignorabimus wants to say in essence is that on the one hand, we have in the historical evolution of humanity arrived at clarity regarding nature and have constructed the concept of matter. In this view of nature we have lost man—that is, ourselves. On the other hand we look down into consciousness. To this realm we want to apply that which has been most important in arriving at the contemporary explanation of nature. Consciousness rejects this lucidity. This mathematical clarity is entirely out of place. To be sure, we find man in a sense, but our consciousness is not yet strong enough, not yet intensive enough to comprehend man fully.

Again, one is tempted to answer with an ignorabimus, but that cannot be, for we need something more than an ignorabimus in order to meet the social demands of the modern world. The limit that du Bois-Reymond had come up against when he spoke [about] his ignorabimus on August 14, 1872 lies not within the human condition as such but only within its present stage of historical human evolution. How are we to transcend this ignorabimus? That is the burning question.

Erster Vortrag

Das Thema dieses Vortragszyklus wurde gewählt nicht aus irgendeiner Tradition des philosophisch-akademischen Studiums, etwa aus dem Grunde, weil etwas Erkenntnistheoretisches oder dergleichen unter unseren Vorträgen vorkommen sollte, sondern es wurde gewählt aus einer, wie ich glaube, unbefangenen Beobachtung der Zeitbedürfnisse und Zeitforderungen. Wir brauchen für die nächste Entwickelung der Menschheit Begriffe, Vorstellungen, überhaupt Impulse des sozialen Lebens, wir brauchen Ideen, durch deren Verwirklichung wir soziale Zustände herbeiführen können, die den Menschen aller Stände, Klassen und so weiter ein ihnen menschenwürdig erscheinendes Dasein geben können. Wir sprechen ja heute auch schon in weitesten Kreisen davon, daß die soziale Erneuerung vom Geiste ausgehen müsse. Aber man stellt sich in diesen weitesten Kreisen nicht überall etwas Klares und Deutliches vor, wenn man so spricht. Man frägt sich nicht: Woher sollen die Vorstellungen, die Ideen kommen, durch die man eine Sozialökonomie begründen wollte, die dem Menschen ein menschenwürdiges Dasein bietet? Die Menschheit in ihrem gebildeten Teile ist ja seit den letzten drei bis vier Jahrhunderten, insbesondere aber seit dem 19. Jahrhundert in Vorstellungen, in Ideen erzogen — insbesondere ist das diejenige Menschheit, die durch das akademische Studium gegangen ist —, die eigentlich durchaus herangebildet, herangereift sind an der neueren naturwissenschaftlichen Betrachtungsweise. Man glaubt nur in den Kreisen, in denen man anderes treibt als Naturwissenschaft, daß die Naturwissenschaft auf dieses Treiben wenig Einfluß habe. Allein es ist leicht nachzuweisen, daß selbst zum Beispiel in der neueren, fortgeschritteneren Theologie, in der Historie, in der Jurisprudenz überall naturwissenschaftliche Begriffe, das heißt solche Begriffe, wie sie in den naturwissenschaftlichen Untersuchungen der letzten Jahrhunderte heranerzogen wurden, hineingekommen sind, daß die althergebrachten Begriffe nach diesen neuen in einer gewissen Weise umgeformt worden sind. Und man braucht ja zum Beispiel nur den Gang der neuen theologischen Entwickelung im 19. Jahrhundert vor seinem geistigen Auge vorübergehen zu lassen, so wird man sehen, wie zum Beispiel die evangelische Theologie durchaus zu ihren Anschauungen über die Persönlichkeit Jesu, über das Wesen des Christus dadurch gekommen ist, daß sie gewissermaßen überall im Hintergrunde hatte die naturwissenschaftlichen Begriffe, von denen sie sich kritisiert fühlte, die naturwissenschaftlichen Begriffe, denen sie genügen wollte, an denen sie sich nicht versündigen wollte. Und dann kam das andere: Die alten, instinktiven Zusammenhänge des sozialen Lebens, sie verloren allmählich ihre Spannkraft im Menschendasein. Es wurde immer mehr und mehr notwendig im Laufe des 19. Jahrhunderts, an die Stelle jener Instinkte, durch die eine Klasse sich den Anordnungen der andern gefügt hat, an die Stelle der Instinkte, aus denen auch die neueren parlamentarischen Einrichtungen mit ihren Ergebnissen hervorgegangen sind, an die Stelle dieser Instinkte mehr oder weniger bewußte Begriffe zu setzen. Es bildete sich nicht nur in der Strömung des Marxismus, sondern auch in vielen andern Strömungen das aus, was man nennen könnte Umwandelung der alten sozialen Instinkte in bewußte Begriffe.

Aber was war da in die Sozialwissenschaft, ich möchte sagen, in dieses Lieblingskind des neueren Denkens hineingekommen? Es waren diejenigen Begriffe, namentlich Begriffsformen, hineingekommen, die man an den naturwissenschaftlichen Studien herangebildet hatte. Und heute stehen wir vor der großen Frage: Wie weit kommen wir mit einer sozialen Wirksamkeit, die von solchen Begriffen ausgeht? Und wenn wir das Rumoren der Welt betrachten, wenn wir all die Aussichtslosigkeit ins Auge fassen, die sich ergibt aus den verschiedenen Versuchen, die gemacht werden, aus diesen Ideen, aus diesen Begriffen heraus, wir bekommen ein recht schlimmes Bild. Da entsteht denn die bedeutungsvolle Frage: Wie ist es denn überhaupt mit den Begriffen, die wir da aus der Naturwissenschaft heraus gewonnen haben, und die wir jetzt anwenden wollen im Leben und die uns — deutlich zeigt sich das auf vielen Gebieten bereits - vom Leben eigentlich zurückgewiesen werden? Diese Lebensfrage, diese brennende Zeitfrage ist es, welche mich veranlaßt hat, gerade dieses Thema über die Grenzen des Naturerkennens zu wählen, und welche mich veranlassen wird, dieses Thema gerade so zu behandeln, daß man eine Übersicht bekommen kann, was Naturwissenschaft vermag oder nicht vermag, um für eine entsprechende soziale Ordnung irgend etwas zu tun, und wohin man sich zu wenden hat im wissenschaftlichen Forschen, in Weltanschauungsvorstellungen, wenn man ernsthaft sich hineinstellen will in die Forderungen des menschlichen Daseins gerade in unserer Zeit.

Was sehen wir, wenn wir den Blick werfen auf die ganze Art, wie gedacht wird innerhalb naturwissenschaftlicher Kreise und wie dann denken gelernt haben alle diejenigen, die eben beeinflußt werden von diesen Kreisen, was sehen wir da? Wir sehen, da wird zunächst angestrebt, in einer durchsichtigen Weise mit Hilfe klarer Begriffe die Naturtatsachen zu erforschen, zu redigieren, in ein System zu bringen. Wir sehen, wie versucht wird, die Tatsachen der leblosen Natur durch die verschiedenen Wissenschaften, Mechanik, Physik, Chemie und so weiter, in systematischer Weise zu ordnen, aber auch mit gewissen Begriffen zu durchdringen, durch die sie uns in einer gewissen Weise erklärlich werden sollen. Man strebt gegenüber dieser leblosen Natur nach möglichster Klarheit, nach durchsichtigen Begriffen. Und eine Folge dieses Strebens nach durchsichtigen Begriffen ist, daß man eigentlich am liebsten all dasjenige, was man da auf dem Gebiete der leblosen Natur in der Menschenumgebung hat, durchdringen möchte allüberall mit mathematischen Formeln. Man möchte die Tatsachen der Natur in die klaren mathematischen Formeln, in die durchsichtige Sprache der Mathematik bringen.

Es war im letzten Drittel des 19. Jahrhunderts, da glaubte man schon ganz nahe daran zu sein, eine mathematisch-mechanische Naturerklärung geben zu können, die gewissermaßen überallhin durchsichtig ist. Es blieb einem, ich möchte sagen, nur das kleine Pünktchen des Atoms. Man hat es wollen bis zum Kraftpunkt verdünnen, um seine Lage, seine Bewegungskräfte in mathematische Formeln zu bringen. Man glaubte dadurch sich sagen zu können: Ich blicke in die Natur; in Wirklichkeit blicke ich da in ein Gewebe von Kraftverhältnissen und Bewegungen, die ich durchaus mathematisch durchschauen kann. — Und es ist ja das Ideal der sogenannten astronomischen Naturerklärung entstanden, das im wesentlichen besagt: So wie man etwa in mathematischen Formeln die Verhältnisse unter den Himmelskörpern zum Ausdrucke bringt, so soll man im ganz Kleinen, gewissermaßen in diesem kleinen Kosmos der Atome und Moleküle, alles in durchsichtiger Mathematik berechnen können. Das war das Streben, das einen gewissen Höhepunkt erlangte - jetzt ist schon wieder dieser Höhepunkt überschritten — im letzten Drittel des 19. Jahrhunderts. Allein, diesem Streben nach dem mathematisch-durchsichtigen Weltenbilde steht etwas ganz anderes gegenüber, und das tritt sogleich hervor, wenn man die Ausdehnung dieses Strebens auf andere Gebiete als auf die der leblosen Natur herausbekommen will. Sie wissen, man hat ja auch versucht im Laufe des 19. Jahrhunderts, diese Anschauungsweise, dieses Streben nach durchsichtiger mathematischer Klarheit wenigstens teilweise hereinzubringen in die Erklärung des Lebendigen. Und während noch Kant gesagt hat, es werde sich niemals ein Newton finden, um in derselben Weise wie in die unorganische Natur auch in die Natur der Lebewesen Erklärung nach dem Ursachenprinzip hineinzubringen, konnte schon Haeckel sagen, daß dieser Newton in Darwin erstanden sei, daß da wirklich versucht worden ist, durch das Prinzip der Selektion gewissermaßen in durchsichtiger Weise zu zeigen, wie die Lebewesen sich entwickeln. Und nach einer ebensolchen Durchsichtigkeit, wenigstens an das mathematische Weltbild erinnernden Durchsichtigkeit, strebte man in allen Erklärungen, die heraufgingen bis zum Menschen. Und es war damit etwas erfüllt, was von einzelnen Naturforschern so ausgesprochen wurde, daß sie sagten: Das menschliche Kausalitätsbedürfnis gegenüber den Erscheinungen ist zunächst erfüllt, wenn man zu einer solchen durchsichtigen, klaren Anschauung kommt.

Nun steht aber eben alldem wieder etwas anderes gegenüber. Ich möchte sagen, 'Theorien über Theorien sind ausgedacht worden, um ein solches Weltbild, wie ich es eben jetzt charakterisiert habe, zu gewinnen. Und immer wieder und wiederum trat an die Seite derjenigen —- manchmal waren es dieselben, die sich zu gleicher Zeit ihre Opposition selber schufen -, es trat an die Seite derjenigen, welche nach einem solchen Weltbilde strebten, immer die andere Partei, die zeigte, wie ein solches Weltbild niemals wahre Erklärungen bringen könne, wie ein solches Weltbild niemals die menschlichen Erkenntnisbedürfnisse befriedigen könne. Auf der einen Seite wurde immer bewiesen, wie notwendig es ist, ein Weltbild in mathematischer Durchsichtigkeit zu erhalten, auf der andern Seite wurde bewiesen, daß ein solches Weltbild zum Beispiel ganz außerstande wäre, auch nur das einfachste Lebewesen irgendwie mit mathematischer Durchsichtigkeit gedanklich zu konstruieren, ja daß es selbst nicht imstande wäre, die organische Substanz irgendwie verstandesmäßig im Bilde zu konstruieren. Man möchte sagen: Immerfort wurde von dem einen ein Gewebe von Ideen gesponnen, um die Natur zu erklären, von dem andern, manchmal von demselben, wurde es wiederum aufgelöst.

Dieses Schauspiel — denn es war im Grunde genommen für den, der es unbefangen genug beobachten konnte, eine Art Schauspiel konnte man insbesondere in den letzten fünfzig Jahren innerhalb alles wissenschaftlichen Strebens und Arbeitens verfolgen. Man kann gerade, wenn man die ganze Last der Tatsache empfunden hat, daß gegenüber einer so ernsten Angelegenheit fortwährend ein Weben und Wiederauflösen stattfand, man kann demgegenüber die Frage aufwerfen: Ja, ist vielleicht nicht überhaupt alles Streben nach einer solchen begrifflichen Erklärung der Tatsachen etwas Unnötiges? Ist nicht vielleicht die richtige Antwort auf eine Frage, die sich aus alledem ergibt, diese, daß man einfach die Tatsachen für sich sprechen lassen soll, daß man beschreiben soll, was vorgeht in der Natur, und daß man auf Einzelheitenerklärung verzichten soll? Könnte es nicht vielleicht so sein, daß alle solche Erklärungen überhaupt nur eine Art Stecken-in-den-Kinderschuhen der Menschheitsentwickelung ist, daß die Menschheit in diesen Kinderschuhen wie nach einer Art Luxus hinstrebte, daß aber die reifgewordene Menschheit sich sagen müsse: Man muß überhaupt gar nicht streben nach solchen Erklärungen, man kommt mit solchen Erklärungen zu nichts, und man muß das Erklärungsbedürfnis einfach ausrotten. Es bedeutet die Reife des menschlichen Anschauens, solches Erklärungsbedürfnis auszurotten. - Warum denn nicht? Wir gewöhnen uns ja im späteren Alter auch das Spielen ab, warum sollte man sich denn nicht, wenn es berechtigt wäre, auch das Naturerklären einfach abgewöhnen?

Ich möchte sagen, solch eine Frage konnte schon auftauchen, als in einer ganz außerordentlich signifikanten Weise am 14. August 1872 in der zweiten Allgemeinen Sitzung der Versammlung Deutscher Naturforscher und Ärzte Du Bois-Reymond seine berühmte, heute noch berücksichtigenswerte Rede «Über die Grenzen des Naturerkennens» hielt. Trotzdem über diese Rede Du Bois-Reymonds, des bedeutenden Physiologen, so viel geschrieben worden ist, beachtet man nicht, daß mit ihr in einer gewissen Weise doch etwas gegeben ist, was einen Knotenpunkt in der modernen Weltanschauungsentwickelung bedeutet.

In der mittelalterlichen Scholastik war alles Denken, alle Ideenbildung der Menschheit hingeordnet nach der Anschauung, man könne dasjenige, was im weiten Reiche der Natur vorhanden ist, erklären durch gewisse Begriffe, aber man müsse haltmachen gegenüber dem Übersinnlichen. Das Übersinnliche müsse Gegenstand der Offenbarung sein. Das Übersinnliche soll dem Menschen so gegenüberstehen, daß er in dasselbe gar nicht eindringen wolle mit den Begriffen, die er sich über das Reich der Natur und des äußeren Menschendaseins mache. Da war eine Grenze gesetzt dem Erkennen nach der Seite des Übersinnlichen hin. Und in scharfer Weise betonte man, daß es eine solche Grenze geben müsse, daß es einfach im Menschenwesen und in der Welteneinrichtung liege, daß eine solche Grenze anerkannt werde. Von einer ganz andern Seite her erneuerte sich dieses Grenzesetzen durch solche Denker und Forscher wie Du Bois-Reymond. Sie waren nicht mehr Scholastiker, sie waren nicht mehr 'Theologen. Aber so wie der mittelalterliche Theologe aus seiner Denkweise heraus die Grenze gesetzt hat gegenüber dem Übersinnlichen, so standen diese Forscher und Denker vor den sinnlichen Tatsachen. In erster Linie gegenüber der äußeren Tatsachenwelt wurde diese Grenze geltend gemacht.

Zwei Begriffe waren es, die vor Du Bois-Reymonds geistigem Blick standen und von denen er sagt, sie geben die Grenze an, bis an welche die Naturforschung gelangen kann, über die sie aber nicht hinauskommen könne. Später hat er sie um fünf weitere Begriffe vermehrt in seiner Rede über «Die sieben Welträtsel», dazumal aber sprach er von den beiden Begriffen Materie und Bewußtsein. Er sagte: Indem wir die Naturtatsachen überblicken, sind wir gezwungen, solche Begriffe zu verwenden in der systematischen, in der gedanklichen Durchdringung, daß wir zum Schluß auf die Materie kommen. Aber was da eigentlich im Raume spukt, indem wir von Materie sprechen, das können wir niemals irgendwie erforschen. Wir müssen einfach den Begriff der Materie als einen dunklen Begriff aufnehmen. Wenn wir diesen dunklen Begriff der Materie aufnehmen, dann können wir unsere Rechnungsformeln ansetzen, dann können wir die Bewegung der Materie in diese Rechnungsformeln hineinbringen, dann wird uns die äußere Welt, wenn wir nur dieses, ich möchte sagen, dunkle Pünktchen millionen- und aber millionenmal darinnen haben, dann wird uns diese äußere Tatsachenwelt durchschaubar. Aber wir müssen doch annehmen, daß diese materielle Welt auch diejenige ist, die uns selbst zunächst leiblich aufbaut, die ihre Wirksamkeit in uns leiblich entfaltet, so daß durch diese leibliche Wirksamkeit in uns aufsteigt dasjenige, was zuletzt Empfindung und Bewußtsein wird. Wir stehen auf der einen Seite der Tatsachenwelt gegenüber, die uns nötigt, den Materiebegriff zu konstruieren, wir stehen auf der andern Seite uns selbst gegenüber, erfahren die Tatsache des Bewußtseins, beobachten die Bewußtseinserscheinungen, können ahnen, daß dasjenige, was wir in Materie annehmen, auch diesem Bewußtsein zugrunde liegt; aber wie aus diesen Bewegungen der Materie, wie aus diesen ganz leblosen, toten Bewegungen herauskommt dasjenige, was Bewußtsein ist, was schon die einfachste Empfindung ist, das ist niemals zu durchdringen. Das ist der andere Pol aller Ungewißheiten, aller Erkenntnisgrenzen, das Bewußstsein, ja schon die einfachste Empfindung,

In bezug auf die beiden Fragen: Was ist Materie? Wie entsteht aus dem materiellen Geschehen das Bewußtsein? müssen wir als Naturforscher - so meinte Du Bois-Reymond — bekennen ein Ignorabimus, ein: Wir werden niemals wissen. — Das ist das moderne Gegenstück der mittelalterlichen Scholastik. Die mittelalterliche Scholastik stand vor der Grenze in die übersinnliche Welt hinein, die modernere Naturwissenschaft steht vor der Grenze, die da bezeichnet wird im wesentlichen doch durch die beiden Begriffe: Materie, die überall vorausgesetzt wird im Sinnlichen, aber in diesem Sinnlichen nicht gefunden werden kann, und Bewußtsein, von dem man annehmen will, daß es aus dem Sinnlichen entspringt, von dem man aber niemals begreifen kann, wie es aus diesem Sinnlichen entspringt.

Wenn man diesen Entwickelungsgang des neueren naturwissenschaftlichen Denkens überschaut, muß man sich dann nicht sagen: Die Naturforschung spinnt sich ja in ein gewisses Gewebe ein — außerhalb dieses Gewebes liegt die Welt. Denn da, wo Materie im Raume spukt, da ist doch schließlich die äußere Welt. Wenn man da nicht eindringen kann, so hat man eben keine Vorstellungen, die das Leben irgendwie beherrschen können. Im Menschen ist dieBewußtseinstatsache. Kommt man mit den Erklärungen, die man sich an der äußeren Natur bildet, dieser Bewußtseinstatsache bei? Man macht ja gerade vor dem Menschenleben halt mit allen Erklärungen, wie soll man denn dann zu Begriffen darüber kommen, wie der Mensch sich menschenwürdig ins Dasein hineinstellen könne, wenn man nicht begreift das Dasein, wenn man nicht begreift das Wesen des Menschen nach den Annahmen, die man sich über dieses Dasein macht?

Das wird uns gerade im Laufe dieses Kurses, wie ich glaube, mit aller Deutlichkeit ersichtlich werden, daß es die Ohnmacht der modernen naturwissenschaftlichen Denkweise ist, welche uns auch so ohnmächtig vor die soziale Begriffsbildung hingestellt hat. Man durchschaut heute noch nicht, welch wichtiger und wesentlicher Zusammenhang da besteht. Man durchschaut heute noch nicht, daß, als am 14. August 1872 Du Bois-Reymond in Leipzig ausgesprochen hat sein Ignorabimus, dieses Ignorabimus hingeworfen worden ist auch für alles soziale Denken, daß eigentlich dieses Ignorabimus geheißen hat: Wir wissen uns nicht zu helfen gegenüber dem wirklichen Leben, wir haben Schattenbegriffe, keine Wirklichkeitsbegriffe. — Und jetzt, fast fünfzig Jahre danach, verlangt die Welt von uns solche Begriffe. Wir müssen sie haben. Aus den Hörsälen, die im Grunde genommen noch immer unter der Wirkung dieses Ignorabimus arbeiten, können uns diese Begriffe, diese Impulse nicht kommen. Das ist die Kardinaltragik der Gegenwart. Da liegen die Fragen, die beantwortet werden müssen.

Wir wollen von den ersten Elementen zu einer solchen Antwort ausgehen, wollen uns vor allen Dingen die Frage vorlegen: Könnten wir nicht vielleicht als Menschen überhaupt etwas Gescheiteres tun, als die Natur erklären, wenn wir immer nach dem Muster, der Art der alten Penelope, in den letzten fünfzig Jahren namentlich, auf der einen Seite Theorien gesponnen haben, auf der andern Seite sie wiederum aufgelöst haben? Ja, wenn wir es könnten, wenn wir könnten ohne Gedanken dem Laufe der Natur gegenüberstehen! Das können wir aber nicht, insofern wir überhaupt Menschen sind und Menschen bleiben wollen. Wir müssen, indem wir denkend die Natur ergreifen, sie mit Begriffen und Ideen durchziehen. Warum müssen wir das?

Ja, meine sehr verehrten Anwesenden, das müssen wir, weil überhaupt nur daran unser Bewußtsein erwacht, weil wir nur dadurch bewußte menschliche Wesen werden. Wie wir im Grunde genommen jeden Morgen, wenn wir die Augen aufschließen, das Bewußtsein wiedererlangen an unseren Wechselbeziehungen mit der äußeren Welt, so war es auch im Entwickelungsgange der Menschheit. An dem Verkehr der Sinne, des Denkens mit dem äußeren Gange der Natur hat sich erst das Bewußtsein entzündet, ist erst das Bewußtsein so geworden, wie es jetzt ist. Die Tatsache des Bewußtseins sehen wir einfach historisch sich entwickeln an dem Sinnenverkehr des Menschen mit der äußeren Natur. Aus dem dumpfen, schläfrigen Kulturleben der Urweltzeiten entzündete sich das Bewußtsein an dem menschlichen Sinnenverkehr mit der äußeren Natur. Aber nun muß man dieses Entzünden des Bewußtseins, diesen Wechselverkehr des Menschen mit der äußeren Natur nur einmal unbefangen beobachten, und man wird finden, daß da etwas Eigentümliches im Menschen vorgeht. Wenn wir zurückschauen in unser Seelenleben, was da ist, entweder indem wir des Morgens aufwachen und vor dem Aufwachen noch drinnen verharren in der Dumpfheit des Traumbewußtseins, oder indem wir auf Urzustände der Menschheitsentwickelung, auf das auch fast traumhafte Bewußtsein dieser Urzeiten schauen, wenn wir das alles ins Auge fassen, was gewissermaßen zurückgeschoben ist in unserem Seelenleben hinter der an der Oberfläche liegenden Bewußtseinstatsache, die aus dem Sinnenverkehr mit der äußeren Natur entsteht, so finden wir eine Vorstellungswelt, wenig intensiv, bis zu Traumbildern abgeschwächt, mit unscharfen Konturen, die einzelnen Bilder ineinander verschwimmend. Das alles kann eine unbefangene Beobachtung feststellen. Diese geringe Intensität des Vorstellungslebens, diese Verschwommenheit in den Konturen, dieses Auseinanderschwimmen der einzelnen Vorstellungsbilder, es hört nicht anders auf, als daß wir erwachen zum völligen Sinnenverkehr mit der äußeren Natur. Wir müssen, um zu diesem Erwachen, das heißt, zum vollen Menschendasein zu kommen, jeden neuen Morgen erwachen zum Sinnenverkehr mit der Natur. Aber es mußte auch die ganze Menschheit vom dumpfen, traumhaften Urweltanschauen aus zu dem jetzigen klaren Vorstellen aus solcher Seelenwelt erst erwachen.

Das heißt, wir erwerben uns jene Klarheit des Vorstellens, jene scharfkonturierten Begriffe, die wir brauchen, um wach zu sein und mit wacher Seele die Umwelt zu verfolgen, wir brauchen das alles, um im vollen Sinne des Wortes Menschen zu sein. Aber wir können es nicht aus uns selbst herauszaubern. Wir können es zunächst nur aus unserem Sinnenverkehr mit der Natur gewinnen. Da kommen wir zu klaren, scharfkonturierten Begriffen. Da entwickeln wir etwas, was der Mensch entwickeln muß um seiner selbst willen, sonst würde sein Bewußtsein nicht erwachen. Es ist also nicht ein abstraktes Erklärungsbedürfnis, nicht dasjenige, was Menschen wie Du Bois-Reymond oder ähnliche ein Kausalbedürfnis nennen, sondern es ist das Bedürfnis, Mensch zu werden an der Naturbeobachtung, das uns hintreibt, Erklärungen zu suchen. Wir dürfen daher nicht sagen, wir können uns das Erklären abgewöhnen, wie wir uns das Kinderspielen abgewöhnen, denn damit würden wir bedeuten, daß wir nicht wollen im vollen Sinn des Wortes Menschen werden, daß heißt, uns so zum Erwachen bringen, wie wir erwachen müssen.

Aber dabei stellt sich etwas anderes heraus. Es stellt sich heraus, daß wir, indem wir zu solchen klaren Begriffen kommen, die wir an der Natur entwickeln, wir begrifflich, innerlich begrifflich verarmen. Unsere Begriffe werden klar, aber ihr Umfang wird arm. Und wenn wir uns dann besinnen, was wir erreicht haben durch diese klaren Begriffe, so ist es äußere mathematisch-mechanische Klarheit. Aber wir finden in dem, was so Klarheit geworden ist, nichts, was uns das Leben begreiflich erscheinen läßt. Wir sind gewissermaßen ins Licht gekommen, aber wir haben den Boden unter den Füßen verloren. Wir finden keine Begriffe, die uns das Leben, die uns das Bewußtsein selber irgendwie verbildlichen ließen. Mit der Klarheit, die wir um unserer Menschlichkeit willen erringen müssen, geht uns das Inhaltsvolle desjenigen verloren, wonach wir eigentlich gestrebt haben. Und wir sehen uns dann mit unseren Begriffen in der Natur um. Wir bilden klare Begriffe, die mechanistisch-mathematische Naturordnung. Wir bilden solche Begriffswelten wie die Deszendenztheorie und dergleichen. Wir streben nach Klarheit. Wir machen uns mit dieser Klarheit ein Weltbild. Aber in diesem Weltbild ist keine Möglichkeit, den Menschen, uns selbst, drinnen zu finden. Wir sind an unsere Oberfläche gekommen mit unseren Begriffen bis zum Verkehr mit der Natur. Wir kommen zur Klarheit, aber wir haben auf dem Wege den Menschen verloren. Wir gehen durch die Natur, wenden die mathematisch-mechanische Naturerklärung an, wir wenden die deszendenztheoretische Naturerklärung an, wir bilden allerlei biologische Begriffe aus, wir erklären die Natur, wir formen ein Naturbild - der Mensch kann nicht drinnen sein. Wir haben die Vollinhaltlichkeit, die wir zuerst hatten, verloren, und wir stehen so vor demjenigen Begriffe, den wir mit den, ich möchte sagen, allerausgedörrtesten Begriffen, mit den klarsten, aber ausgedörrtesten, leblosesten Begriffen formen können, wir stehen vor dem Materiebegriff. Und im Grunde genommen ist das Ignorabimus gegenüber dem Materiebegriff einfach das Bekenntnis: Ich habe mich zur Klarheit durchgerungen, ich habe mich zum vollen Erwachen des Bewußtseins durchgerungen, aber ich habe das Wesen des Menschen dabei in meinem Erkennen, in meinem Erklären, in meinem Erfassen verloren.

Und wir wenden uns dann nach innen. Wir wenden uns von der Materie ab und schauen nun nach dem Inneren des Bewußtseins. Wir schauen, wie in diesem Inneren des Bewußtseins Vorstellungen verlaufen, Gefühle sich abspielen, wie Willensimpulse uns durchzucken. Wir beobachten das alles, und siehe da, wenn wir nun versuchen, jene Klarheit, die wir uns errungen haben an der äußeren Natur, da in unserer Selbstanschauung zu entfalten — es geht nicht. Wir schwimmen gewissermaßen in einem Elemente, das wir nicht zu wirklichen Konturen bringen können, das immer fort und fort verschwimmt. Die Klarheit, die wir gegenüber der äußeren Natur erstreben, sie läßt sich nicht anwenden auf unser Inneres. Wir sehen in den modernsten Bestrebungen, die auf dieses Innere gehen, in der englisch-amerikanischen Assoziations-Psychologie, wie man dasjenige, was man an Klarheit gewonnen hat an der Beobachtung der äußeren Natur, das Zusammen-sich-Assoziieren von Dingen und Vorgängen, wie man das anwenden will nach dem Muster von Hume, von Mill, von James und so weiter auf das Vorstellen, auf das Empfinden. Man überträgt die äußere Klarheit auf das Empfinden. Es geht nicht. Es ist so, wie wenn man die Gesetze des Fliegens anwenden wollte beim Schwimmen. Man kommt nicht in dem Element zurecht, in dem man sich nun zu bewegen hat. Die Assoziations-Psychologie kommt nicht zu einem wirklichen Konturieren, zur Klarheit gegenüber der Tatsache des Bewußtseins. Und selbst wenn man versucht, mit einer gewissen Nüchternheit, wie Herbart, das Rechnen, das solche Erfolge bringt im äußeren Naturwerden, nun auf das menschliche Vorstellen, auf die Seele anzuwenden: Man kann rechnen, aber die Rechnungen schweben in der Luft. Man kann keine Ansätze machen, weil die Rechnungsformeln nicht erfassen können dasjenige, was in der Seele eigentlich vorgeht. Während man den Menschen verloren hat an der äußeren Klarheit, findet man zwar den Menschen — das ist ja selbstverständlich, daß man den Menschen findet, wenn man ins Bewußtsein zurückkommt -, aber man kann jetzt mit der Klarheit nichts anfangen, denn man schwimmt wesenlos hin- und hergerissen in diesem Bewußtsein herum. Man findet den Menschen, aber man findet kein Bild des Menschen.

Das ist dasjenige, was präzise gefühlt worden ist, aber weniger präzise, sondern nur aus einem gewissen allgemeinen Gefühle gegenüber der modernen Naturforschung ausgesprochen worden ist im August 1872 von Du Bois-Reymond mit dem Ignorabimus. Im Grunde genommen will dieses Ignorabimus sagen: Wir haben uns in der historischen Menschheitsentwickelung auf der einen Seite zur Klarheit an der Natur gebracht und den Materiebegriff konstruiert. Wir haben in diesem Naturbilde den Menschen, das heißt, uns selbst verloren. Wir sehen wiederum zurück in unser Bewußtsein. Wir wollen dasjenige, was wir uns als das Bedeutsamste für die neuere Naturerklärung errungen haben, die Klarheit, da drinnen anwenden. Das Bewußtsein stößt diese Klarheit wieder aus. Diese mathematische Klarheit läßt sich nicht anwenden. Wir finden zwar den Menschen, aber unser Bewußtsein ist noch nicht stark genug, noch nicht intensiv genug, um diesen Menschen zu erfassen.

Man möchte wiederum mit einem Ignorabimus antworten. Das darf aber nicht sein, denn wir brauchen etwas anderes als ein Ignorabimus gegenüber den sozialen Forderungen der modernen Welt. Nicht in einer Einrichtung der Menschennatur, sondern einfach in dem gegenwärtigen Stande der historischen Menschheitsentwickelung liegt die Grenzbestimmung, zu der am 14. August 1872 Du Bois-Reymond mit seinem Ignorabimus gekommen ist. Wie ist über dieses Ignorabimus hinauszukommen? Das ist die große Frage. Sie muß beantwortet werden, nicht aus einem bloßen Erkenntnisbedürfnis heraus, sondern aus einem allgemeinsten Menschheitsbedürfnisse heraus. Und davon, wie man nach einer Antwort streben kann, wie man das Ignorabimus überwinden kann so, wie es überwunden werden muß von der Menschheitsentwickelung, davon soll der Kursus in seinem weiteren Verlaufe handeln.

First Lecture

The topic of this lecture series was not chosen out of any tradition of philosophical-academic study, for example because something epistemological or similar should be included in our lectures, but rather, I believe, out of an unbiased observation of the needs and demands of our time. For the next stage of human development, we need concepts, mental images, and, above all, impulses for social life. We need ideas whose realization will enable us to bring about social conditions that give people of all walks of life, classes, and so on, an existence that they consider humane. Today, even in the widest circles, we already speak of the fact that social renewal must come from the spirit. But in these widest circles, not everyone has a clear and distinct idea of what this means when they speak in this way. They do not ask themselves: Where are the mental images and ideas to come from that will enable us to establish a social economy that offers human beings a dignified existence? The educated part of humanity has been brought up since the last three or four centuries, but especially since the 19th century, on mental images and ideas — especially the part of humanity that has gone through academic studies — which have actually been shaped and matured by the newer scientific way of looking at things. Only in circles where people are engaged in activities other than natural science do people believe that natural science has little influence on these activities. However, it is easy to prove that even in modern, advanced theology, history, and jurisprudence, scientific concepts, that is, concepts that have been developed in scientific research over the last few centuries, have found their way into these fields, and that traditional concepts have been transformed in a certain way in accordance with these new concepts. One need only consider the course of new theological developments in the 19th century, for example, to see how, for example, Protestant theology arrived at its views on the personality of Jesus and the nature of Christ by having, as it were, in the background, the scientific concepts that it felt criticized it, the scientific concepts that it wanted to satisfy, that it did not want to sin against. And then came the other thing: the old, instinctive connections of social life gradually lost their tension in human existence. In the course of the 19th century, it became increasingly necessary to replace the instincts by which one class submitted to the orders of another, the instincts from which the newer parliamentary institutions with their results had emerged, with more or less conscious concepts. What could be called the transformation of the old social instincts into conscious concepts developed not only in the Marxist movement, but also in many other movements.

But what had entered social science, I would say, this favorite child of modern thinking? It was those concepts, namely conceptual forms, that had been developed in the natural sciences. And today we are faced with the big question: How far can we get with social effectiveness based on such concepts? And when we look at the turmoil in the world, when we consider all the hopelessness that results from the various attempts that are being made, from these ideas, from these concepts, we get a pretty grim picture. This raises the important question: What is the status of the concepts we have derived from natural science, which we now want to apply in life and which—as is already clearly evident in many areas—are actually being rejected by life itself? It is this vital question, this burning issue of our time, that has prompted me to choose this particular topic on the limits of natural knowledge and which will lead me to treat this topic in such a way that we can gain an overview of what natural science can and cannot do to contribute to a corresponding social order, and where we must turn in scientific research and in our worldview if we seriously want to address the demands of human existence, especially in our time.

What do we see when we look at the whole way of thinking within scientific circles and how all those who are influenced by these circles have learned to think? What do we see there? We see that the initial aim is to investigate the facts of nature in a transparent manner with the help of clear concepts, to edit them and bring them into a system. We see how attempts are made to systematically organize the facts of inanimate nature through the various sciences, mechanics, physics, chemistry, and so on, but also to penetrate them with certain concepts through which they are to become explainable to us in a certain way. In relation to this inanimate nature, the aim is to achieve the greatest possible clarity and transparent concepts. And a consequence of this striving for transparent concepts is that one would actually prefer to permeate everything in the realm of inanimate nature in the human environment with mathematical formulas. One would like to translate the facts of nature into clear mathematical formulas, into the transparent language of mathematics.

In the last third of the 19th century, people believed they were very close to being able to provide a mathematical-mechanical explanation of nature that was, so to speak, transparent everywhere. All that remained, I would say, was the tiny dot of the atom. People wanted to dilute it to the point of force in order to express its position and its forces of motion in mathematical formulas. They believed that this would enable them to say: I look at nature; in reality, I see a web of forces and movements that I can understand completely mathematically. — And this gave rise to the ideal of the so-called astronomical explanation of nature, which essentially says: just as one expresses the relationships between celestial bodies in mathematical formulas, so one should be able to calculate everything in transparent mathematics on a very small scale, in this small cosmos of atoms and molecules, so to speak. That was the aspiration that reached a certain peak—which has now been surpassed—in the last third of the 19th century. However, this aspiration for a mathematically transparent worldview is countered by something completely different, which immediately becomes apparent when one attempts to extend this aspiration to areas other than inanimate nature. As you know, attempts were made during the 19th century to introduce this view, this pursuit of transparent mathematical clarity, at least in part, into the explanation of living beings. And while Kant still said that there would never be a Newton who could explain the nature of living beings in the same way as inorganic nature according to the principle of causality, Haeckel was already able to say that this Newton had arisen in Darwin, that a real attempt had been made to show, through the principle of selection, in a transparent manner, how living beings develop. And all explanations that went up to man strove for the same transparency, at least a transparency reminiscent of the mathematical world view. And this fulfilled something that was expressed by individual natural scientists who said: The human need for causality in relation to phenomena is initially satisfied when one arrives at such a transparent, clear view.

Now, however, something else stands in opposition to all this. I would like to say, 'Theories about theories have been devised in order to arrive at a world view such as I have just characterized. And again and again, alongside those who strove for such a worldview, there was always another party—sometimes the same people who created their own opposition—who showed how such a worldview could never provide true explanations, how such a worldview could never satisfy human needs for knowledge. On the one hand, it was always proven how necessary it is to maintain a worldview with mathematical clarity; on the other hand, it was proven that such a worldview would be completely incapable, for example, of constructing even the simplest living being in any way with mathematical clarity, indeed that it would not even be capable of constructing organic substance in any way that could be understood by the intellect. One might say: one side constantly spun a web of ideas to explain nature, while the other side, sometimes the same side, unraveled it again.

This spectacle—for it was, in essence, a kind of spectacle that could be observed, especially in the last fifty years, within all scientific endeavor and work—could be observed by those who were impartial enough to observe it. Precisely when one has felt the full weight of the fact that, in the face of such a serious matter, there has been a constant weaving and unraveling, one can raise the question: Yes, is not perhaps all striving for such a conceptual explanation of facts something unnecessary? Is not perhaps the correct answer to a question that arises from all this that one should simply let the facts speak for themselves, that one should describe what is happening in nature, and that one should refrain from explaining details? Could it not perhaps be the case that all such explanations are merely a kind of infancy of human development, that humanity in this infancy strove for a kind of luxury, but that humanity, having matured, must now say to itself: One must not strive for such explanations at all; one gets nowhere with such explanations, and one must simply eradicate the need for explanations. It is a sign of maturity in human perception to eradicate such a need for explanations. - Why not? We do grow out of playing when we get older, so why shouldn't we simply grow out of explaining nature, if it is justified?

I would like to say that such a question could already have arisen when, in an extremely significant way, Du Bois-Reymond gave his famous speech “On the Limits of Natural Knowledge” on August 14, 1872, at the second general meeting of the Assembly of German Natural Scientists and Physicians. Despite the fact that so much has been written about this speech by Du Bois-Reymond, the eminent physiologist, it is not recognized that it represents, in a certain sense, a turning point in the development of the modern worldview.

In medieval scholasticism, all human thought and idea formation was based on the view that everything that exists in the vast realm of nature can be explained by certain concepts, but that one must stop short of the supernatural. The supernatural had to be the object of revelation. The supernatural was to stand before man in such a way that he did not even want to penetrate it with the concepts he had formed about the realm of nature and external human existence. A limit was set on knowledge of the supernatural. And it was emphatically stated that such a boundary must exist, that it was simply inherent in human nature and in the structure of the world that such a boundary be recognized. From a completely different angle, this setting of boundaries was renewed by thinkers and researchers such as Du Bois-Reymond. They were no longer scholastics, they were no longer “theologians.” But just as the medieval theologian, based on his way of thinking, set the boundary against the supersensible, so these researchers and thinkers stood before the sensory facts. This boundary was asserted primarily in relation to the external world of facts.

Two concepts stood before Du Bois-Reymond's intellectual gaze, and he said that they indicated the limits to which natural science could go, but beyond which it could not go. Later, he added five more concepts in his speech on “The Seven World Riddles,” but at that time he spoke of the two concepts of matter and consciousness. He said: "In surveying the facts of nature, we are compelled to use such concepts in systematic, intellectual analysis, that we finally arrive at matter. But what actually haunts space when we speak of matter, we can never explore in any way. We must simply accept the concept of matter as a dark concept. When we accept this obscure concept of matter, then we can apply our mathematical formulas, then we can incorporate the movement of matter into these mathematical formulas, then the external world, if we have this, I would say, obscure little dot millions and millions of times within it, then this external world of facts becomes transparent to us. But we must assume that this material world is also the one that initially builds us up physically, that unfolds its effectiveness in us physically, so that through this physical effectiveness in us, that which ultimately becomes sensation and consciousness rises up. On the one hand, we stand before the world of facts, which compels us to construct the concept of matter; on the other hand, we stand before ourselves, experience the fact of consciousness, observe the phenomena of consciousness, and can intuit that what we assume to be matter also underlies this consciousness. but how from these movements of matter, from these completely lifeless, dead movements, emerges that which is consciousness, that which is even the simplest sensation, is something that can never be fathomed. This is the other pole of all uncertainties, of all limits of knowledge, consciousness, even the simplest sensation.

With regard to the two questions: What is matter? How does consciousness arise from material events? we must, as natural scientists, admit — as Du Bois-Reymond said — an ignorabimus, a: We will never know. This is the modern counterpart of medieval scholasticism. Medieval scholasticism stood at the threshold of the supernatural world; modern natural science stands at the threshold that is essentially defined by two concepts: matter, which is assumed to be everywhere in the sensory world but cannot be found in it, and consciousness, which we assume to arise from the sensory world but can never understand how it arises from it.

When one surveys this course of development of modern scientific thinking, must one not say: Natural science weaves itself into a certain fabric—outside this fabric lies the world. For where matter haunts space, there is ultimately the external world. If one cannot penetrate it, one has no mental images that can somehow control life. In humans, there is the fact of consciousness. Can we come to terms with this fact of consciousness using the explanations we form about external nature? We stop short of human life with all our explanations, so how can we arrive at concepts about how human beings can establish themselves in existence in a humane way if we do not understand existence, if we do not understand the nature of human beings according to the assumptions we make about this existence?

I believe that in the course of this lecture it will become clear to us that it is the impotence of modern scientific thinking that has left us so powerless in the face of social conceptualization. Today we do not yet understand the important and essential connection that exists here. People still do not realize today that when Du Bois-Reymond pronounced his Ignorabimus in Leipzig on August 14, 1872, this Ignorabimus was also thrown down for all social thinking, that this Ignorabimus actually meant: We do not know how to help ourselves in the face of real life; we have shadow concepts, not concepts of reality. — And now, almost fifty years later, the world demands such concepts from us. We must have them. These concepts, these impulses, cannot come to us from the lecture halls, which are still essentially working under the influence of this Ignorabimus. That is the cardinal tragedy of the present. Therein lie the questions that must be answered.

We want to start from the first elements to arrive at such an answer, and above all we want to ask ourselves the question: Could we, as human beings, perhaps do something more intelligent than explain nature, if we have always followed the pattern, the manner of the ancient Penelope, especially in the last fifty years, spinning theories on the one hand and dissolving them on the other? Yes, if we could, if we could face the course of nature without thinking! But we cannot do that, insofar as we are human beings and want to remain human beings. By thinking about nature, we must permeate it with concepts and ideas. Why must we do that?

Yes, my dear friends, we must do so because it is the only way to awaken our consciousness, because it is the only way to become conscious human beings. Just as we regain consciousness every morning when we open our eyes through our interactions with the external world, so it was in the course of human development. It was through the interaction of the senses and thinking with the external course of nature that consciousness first ignited and became what it is today. We see the fact of consciousness developing historically in the interaction of the human senses with external nature. Out of the dull, sleepy cultural life of primeval times, consciousness was kindled by the human interaction of the senses with external nature. But now we must observe this kindling of consciousness, this interaction of man with external nature, impartially, and we will find that something peculiar is going on in man. When we look back into our soul life, either by waking up in the morning and remaining indoors in the dullness of dream consciousness, or by looking at the primordial states of human development, at the almost dreamlike consciousness of those primeval times, when we take in all that is, as it were, pushed back in our soul life behind the surface fact of consciousness that arises from our sensory interaction with external nature, we find a world of ideas that is not very intense, weakened to the point of dream images, with blurred contours, the individual images blurring into one another. All this can be observed impartially. This low intensity of the imaginative life, this blurring of contours, this drifting apart of the individual images of the imagination, ceases only when we awaken to complete communication with external nature through our senses. In order to achieve this awakening, that is, to attain full human existence, we must awaken every morning to commune with nature. But the whole of humanity also had to awaken from the dull, dreamlike view of the primeval world to the present clear imagination from such a soul world.

This means that we acquire the clarity of mental images, the sharply defined concepts that we need in order to be awake and to observe our environment with an alert soul. We need all of this in order to be human beings in the full sense of the word. But we cannot conjure it up out of ourselves. We can only gain it initially from our sensory interaction with nature. This is where we arrive at clear, sharply defined concepts. This is where we develop something that human beings must develop for their own sake, otherwise their consciousness would not awaken. It is therefore not an abstract need for explanation, not what people like Du Bois-Reymond or others call a causal need, but rather the need to become human through observation of nature that drives us to seek explanations. We cannot therefore say that we can wean ourselves off explaining things, as we wean ourselves off child's play, because that would mean that we do not want to become human beings in the full sense of the word, that is, to awaken ourselves as we must awaken.

But something else emerges in the process. It turns out that by arriving at such clear concepts, which we develop from nature, we become conceptually impoverished, internally conceptually impoverished. Our concepts become clear, but their scope becomes poor. And when we then reflect on what we have achieved through these clear concepts, it is external mathematical-mechanical clarity. But we find nothing in what has become clarity that makes life comprehensible to us. We have, so to speak, come into the light, but we have lost the ground beneath our feet. We find no concepts that allow us to somehow visualize life, consciousness itself. With the clarity that we must achieve for the sake of our humanity, we lose the substance of what we were actually striving for. And then we look around at nature with our concepts. We form clear concepts, the mechanistic-mathematical order of nature. We form conceptual worlds such as the theory of descent and the like. We strive for clarity. With this clarity, we create a worldview. But in this worldview, there is no possibility of finding human beings, ourselves, within it. We have reached our limits with our concepts in our interaction with nature. We have achieved clarity, but we have lost humanity along the way. We walk through nature, apply mathematical and mechanical explanations of nature, we apply the theory of descent to explain nature, we form all kinds of biological concepts, we explain nature, we form a picture of nature – but humanity cannot be part of it. We have lost the full content that we had at first, and we are thus faced with the concept that we can form with what I would call the most parched concepts, the clearest but most parched, lifeless concepts; we are faced with the concept of matter. And basically, ignorance of the concept of matter is simply the confession: I have struggled to achieve clarity, I have struggled to achieve full awakening of consciousness, but in doing so I have lost the essence of man in my understanding, in my explanation, in my comprehension.

And then we turn inward. We turn away from matter and now look into the inner life of consciousness. We observe how mental images flow within this inner life of consciousness, how feelings play out, how impulses of will flash through us. We observe all this, and lo and behold, when we now try to unfold in our self-contemplation the clarity we have achieved in external nature, it does not work. We are, as it were, swimming in an element that we cannot bring into real contours, that keeps blurring away. The clarity we strive for in relation to external nature cannot be applied to our inner nature. In the most modern endeavors that address this inner nature, in English-American association psychology, we see how the clarity gained from observing external nature is applied to the association of things and processes, as one would apply it according to the model of Hume, Mill, James, and so on, to imagination and feeling.the association of things and processes, how one wants to apply it according to the pattern of Hume, Mill, James, and so on, to imagination, to feeling. One transfers external clarity to feeling. It doesn't work. It's like trying to apply the laws of flying to swimming. You can't cope in the element in which you now have to move. Association psychology does not arrive at a real contour, at clarity with regard to the fact of consciousness. And even if one tries, with a certain sobriety, like Herbart, to apply arithmetic, which brings such success in external natural development, to human mental images, to the soul: one can calculate, but the calculations float in the air. One cannot make any attempts because the mathematical formulas cannot grasp what is actually going on in the soul. While one has lost the human being in external clarity, one does find the human being—it is only natural that one finds the human being when one returns to consciousness—but one cannot now do anything with this clarity, because one floats around in this consciousness, torn between two worlds. One finds the human being, but one finds no image of the human being.

This is what was felt precisely, but less precisely, and only expressed from a certain general feeling toward modern natural science in August 1872 by Du Bois-Reymond with the Ignorabimus. Basically, this Ignorabimus means: In the historical development of humanity, we have, on the one hand, brought ourselves to clarity about nature and constructed the concept of matter. In this image of nature, we have lost man, that is, ourselves. We look back into our consciousness. We want to apply what we have achieved as the most significant thing for the newer explanation of nature, namely clarity, to that which is within. Consciousness rejects this clarity. This mathematical clarity cannot be applied. We find human beings, but our consciousness is not yet strong enough, not yet intense enough to grasp these human beings.

One would like to respond again with an ignorabimus. But that cannot be, because we need something other than an ignorabimus in the face of the social demands of the modern world. It is not in the nature of human beings, but simply in the present state of historical human development that the limit was set which Du Bois-Reymond reached on August 14, 1872, with his ignorabimus. How can we move beyond this ignorabimus? That is the big question. It must be answered, not out of a mere need for knowledge, but out of a most general human need. And how we can strive for an answer, how we can overcome the ignorabimus as it must be overcome by human development, is what the course will deal with in its further course.