Truth and Science
GA 3
III. Epistemology Since Kant
[ 1 ] All epistemologists after Kant have been influenced to a greater or lesser extent by Kant’s flawed reasoning. Kant’s view (that all objects given to us are merely our mental representations) arises due to his a priori stance. His view consequently has been made the principle starting point of almost all epistemological systems. What is initially and immediately certain to us, he claims, is that we only know our mental pictures (Vorstellungen). This view has been believed almost universally by philosophers. As early as 1792, G. E. Schulze claimed in his Anesidemus 45Gottlob Ernst Schulze (1761–1833), Aenesidemus, Helmstädt, 1792. that mental pictures are all that we know, and that we can never go beyond them. Schopenhauer presents this same view with his own philosophical pathos, that the lasting attainment of Kant's philosophy is the view that the world is simply my own mental picture. Eduard von Hartmann finds this sentence so inviolable, that in his work Critical Foundations of Transcendental Realism he takes for granted that all his readers, by critical reflection, have freed themselves from the naive identification of their perceptual image with a thing-in-itself, and consider as evident that the seeming diversity of objects of observation in the act of mental picturing is a singular subjective-ideal content of consciousness, and consider as evident that something else exists in and of itself, independent of the form of consciousness. In other words, his readers are permeated by the conviction that the totality of what is immediately given to us consists of mental pictures (Vorstellungen).46Eduard von Hartmann, Kritische Grundlegung, Berlin 1875, Foreword, p. 10 of the German ed.
In his last epistemological publication, Hartmann tried to justify his view. Our further discussion will show how an unprejudiced epistemology must respond to this sort of justification. Otto Liebmann states as the sacrosanct supreme principle of all epistemology, “Consciousness cannot leap over itself.” 47Otto Liebmann, Zur Analysis, p. 28 ff. of the German ed Vokelt had the opinion that the first, most immediate truth is that "all our knowing extends initially only to our mental pictures, the positivistic principle of knowledge, and he only considers that theory of knowing as eminently critical which contains this principle, and then develops its consequences”.48Vokelt, Kant’s Erkenntnistheorie, section 1. Other philosophers put other claims at the forefront of epistemology, for example, that the real problem lies in the question of the relationship between thinking and existence, and the possibility of mediating between the two, or the question how a being becomes conscious.49J. Rehmke, Die Welt als Wahrnehmung und Begriff uns; Berlin 1880. Kirchmann 50Julius Heinrich v. Kirchmann (1802–1884), Die Lehre vom Wissen, The Theory of Knowledge, Berlin, 1868. starts from two epistemological axioms, “what is perceived is” and “the contradiction is not.51A. Dorner, Das menschliche Erkennen, usw., Human Cognition, Berlin, 1887. According to E. L. Fischer, cognition consists in the knowledge of something actual, real,52E. L. Fischer, Die Grundfragen der Erkenntnistheorie, Basic Questions of the Theory of Cognition, Mainz 1887, p. 385. and he leaves this dogma unexamined, just as does Göring, who claims something similar, “Knowing always means recognizing a being, and that is a fact which neither skepticism nor Kantian criticism can deny.” 53C. Göring, System der kritischen Philosophie, System of Critical Philosophy, Leipzig, 1874, Part I, p. 257. In the case of the last two, one simply decrees what knowing consists of, without asking by what right this can happen.
[ 2 ] Even if these various claims were correct or led to correct problems, they could not be discussed at the beginning of a theory of knowing, because, as very specific insights, they all already stand within the domain of knowing. When I say that my knowledge initially only extends to my ideas or mental pictures, that is a very specific cognitive judgment. Through this sentence a predicate is added to the world given to me, namely existence in the form of a mental picture. But above all, how am I supposed to know that the things given to me are mental pictures?
[ 3 ] We will best convince ourselves of the correctness of not placing this sentence at the forefront of epistemology if we follow the path that the human mind must take to get to it. Yet the phrase has become a part of modern scientific consciousness. The considerations that pushed it to the front can be found systematically and completely compiled in the first section of Eduard von Hartmann's Critical Foundation of Transcendental Realism.54Eduard von Hartmann, Kritische Grundlegung des transzendentalen Realismus; 2. Aufl. Berlin 1875, S.37. What has been put forward can therefore serve as a kind of guide, if one sets out to discuss all the reasons that could lead to that assumption. [ 4 ] These reasons are physical, psycho-physical, physiological, and specifically philosophical.
[ 5 ] A physicist tries to reach out through observation to actual events in our environment. When we, for instance, have a sensation of sound, a physicist conjectures that there is nothing in these actual happenings that has even the remotest similarity to what we simply perceive as sound. Outside, in the space surrounding us, only longitudinal vibrations of the bodies and the air can be found. From this it is concluded that what we call sound or tone in ordinary life is merely a subjective reaction of our organism to that wave movement. Likewise, one finds that light, color, and heat are all purely subjective. The varieties of color-scattering, light-refraction, light-wave-overlapping, and polarization teach us that the above-mentioned sensory qualities correspond to vibrations or waves moving in external space, which we feel compelled to attribute partly to bodies and partly to something immeasurably fine, elastic, and flowing in the atmosphere. Furthermore, due to certain phenomena in the physical world, the physicist is forced to give up the belief in the continuity of objects in space and to trace them back to systems of the smallest parts (molecules, atoms) whose sizes are immeasurably small in relation to their relative positions in space. From this he concludes that all effects of bodies on one-another work through empty space, which indicates forces acting over distances.55 t/n Physicists consider electromagnetic forces, gravitational forces, weak and strong nuclear forces, as well as quantum entanglement (EPR pairs). Physics believes it is justified in assuming that the effect of bodies on our sense of touch and warmth does not occur through direct contact, because there must always be a certain, albeit small, distance between the area of skin touching the body and the body itself. From this it follows that what we perceive, for example, as the hardness or warmth of the body, are only reactions of nerve endings that are sensitive to touch or heat, and heat, reacting to the molecular forces acting through empty space.
[ 6 ] These considerations of physicists are supplemented by those of psychophysicists,56t/n A psychophysicist is someone who deals with the relationship between a physical stimulus and the sensation and perception it produces. which find expression in the doctrine of specific sensory energies. J. Müller 57t/n Johannes Müller (1801–1858) has shown that every sense can only be affected in its own way, determined by its organization, and that it always reacts in the same way, whatever external impression is made on it. When the optic nerve is excited, we sense light, regardless of whether it is pressure or electric current or light that acts on the nerve. On the other hand, the same external stimuli produce completely different sensations, depending on how they are perceived by this or that sense. From this it has been concluded that there is only one type of process in the external world, namely movement, and that the diversity of the world we perceive is essentially a reaction of our senses to these processes. According to this view, we do not perceive the external world as such, but only the subjective feelings it triggers within us.
[ 7 ] In addition to the considerations of physics and psychophysicists, there are also those of physiologists. The former follows the phenomena that occur outside our organism and which correspond to our perceptions. Physiology seeks to explore the processes in people's own bodies that take place when certain sensory nerves are stimulated. Physiology teaches that the epidermis is completely insensitive to stimuli from the outside world. So, if the end-organs of our touch-sensitive nerves near the surface of the body are to be stimulated by the influences of the outside world, the vibrations or waves that lie outside our body must first propagate through the epidermis. In the auditory and visual senses, the external movement process is also modified by many organelles in the sensory apparatus before it reaches the auditory or visual nerves. This action on the end-organs is then conducted through the nerves to the central organ, and only there, from purely mechanical processes in the brain, the sensation is generated, is born.
It is quite clear that the sensory organ stimulation is converted on its way into the brain, so much so that every trace of resemblance between the first impact on the sensory system and the final sensation in awareness is obliterated. Hartmann summarizes this consideration in the following words, “This content of consciousness originally consists of sensations with which the soul reacts reflexively to the states of movement in its highest brain center, but which do not have the slightest resemblance to the molecular states of movement through which they are exercised”. [ 8 ] Anyone who thinks this train of thought through to the end must admit that if it is correct, not the slightest remnant of what can be called external existence would be contained in the content of our consciousness.
[ 9 ] To his physical and physiological objections to what he calls naive realism, Hartman adds what he calls purely philosophical objections. When we examine the first two objections logically, however, we notice that we can only really come to the result indicated if we start from the existence of and our connection to external things, just as ordinary naive consciousness assumes, and afterward examine how this external world can come into our awareness inside our bodily organization. We have seen that we lose every trace of such an external world on the way from the sensory impression to the entry into consciousness, and in the latter, in our awareness, nothing remains but our ideas, our mental pictures (Vorstellungen). We must therefore assume that our image of the external world is built by the soul based on sensations. First, a spatial picture of the world is constructed from the sensations of sight and touch, into which the sensations of the other senses are then inserted. If we find ourselves forced to think that a certain complex of sensations is coherent, we come to the concept of substance, which carries itself. If we notice that certain sensed qualities of a substance disappear as others appear, we attribute this to a change in the material world, regulated by the law of causality. According to this view, our entire worldview is made up of subjective sensory content, which is regulated by our own soul activity. Hartmann says, “The subject perceives only modifications of his own psychological states and nothing else.” 58Hartmann's Grundproblem, p. 37
[ 10 ] Let us now ask ourselves, how do we come to such a conclusion? The skeleton of the thought process is that if an external world exists, we do not perceive it as such, but rather transform it into a world of mental pictures through our organization. What we are dealing with here is a premise, that if pursued rigorously, cancels itself out. Is this line of thought a suitable basis for any conviction? Are we justified in viewing the world given to us as subjective conceptual content when this view necessarily leads to the assumption of naive consciousness, of naive realism? Our goal is to prove this assumption itself to be invalid. Can it be possible for an assertion to turn out to be false, and yet arrive at a proper conclusion? Well, that may happen, but the conclusion can never be regarded as proven in that way.
[ 11 ] The world view that accepts the reality of the world picture that is immediately given to us as something that cannot be questioned, and is self-evident, is usually called naive realism. The opposite, on the other hand, which considers this world view to be merely the content of our consciousness, is transcendental idealism. We can therefore also summarize the result of the previous considerations with the following words: transcendental idealism proves its correctness by operating with the means of naive realism, which it aims to refute.
Naive realism may be false, but its falseness is proven here only with the help of the false view itself. Anyone who keeps this in mind has no alternative but to leave the path taken here, and attempt to take up another view of the world. But should this be done on a trial basis, with luck, until we accidentally come across the right thing? Eduard von Hartmann has taken this path; he believes he has demonstrated the validity of his epistemological approach, for it explains world phenomena while others do not. According to him, individual world views struggle for existence, and the one that proves itself best is ultimately accepted as the winner. But such a procedure seems inadmissible to us, simply because there could easily be several hypotheses that lead to an equally satisfactory explanation of world phenomena. Therefore, we would rather stick to the above line of thought for refuting naive realism and see where specifically its deficiency lies.
Naive realism is the viewpoint from which all people start. For this reason alone, it is advisable to start the correction with it. If we understand what in it is defective, then we will be guided onto the right path with a completely different degree of certainty than if we simply try something randomly. [ 12 ] The subjectivism outlined above is based on mental processing of certain facts. It therefore presupposes, from an actual starting point, that correct convictions can be obtained through logical thinking (logical combination of certain observations). The right to apply our thinking in this way, however, is not examined from this point of view. And therein lies its weakness. While naive realism is based on the unexamined assumption that our perceived experience has objective reality, the characterized viewpoint above is based on the equally unexamined belief that one can arrive at scientifically justified convictions through the application of thinking. In contrast to naive realism, this point of view can be called naive rationalism. As a means of justifying this terminology, we would like to make a brief comment about the term “naive”. A. Doring seeks to define this concept more closely in his essay on the concept of naive realism.59A. Döring, article in Philosophische Monatshefte, Vol. XXVI, 1890, p. 390. publ. Heidelberg. He says about it, “The concept of naïveté describes, as it were, the zero point on the scale of reflection on one's own behavior. In terms of content, naïveté can certainly make the right decision, because it is indeed without reflection and therefore uncritical, but this lack of reflection and criticism only excludes the objective certainty of doing the right thing; it includes the possibility and danger of failing, but by no means the necessity of it. There is a naïveté of feeling and willing, as well as of imagining and thinking, in the broadest sense of the latter word, as well as a naïveté of the expressions of these inner states in contrast to the repression or modification of them brought about by considerations and reflection. Naïveté (at least consciously, not influenced by what is traditional, learned, and prescriptive) is in all areas what the root word nativus expresses, namely unconscious, impulsive, instinctive, demonic.”
Starting from these sentences, we want the concept of being naive to be a little more precise. In every activity we carry out, two things come into consideration: the activity itself and a consideration of its consequences. We can be completely absorbed in the former without asking about the latter. This is the case when an artist fails to consider how his work affects others, but rather practices his art according to his own feelings and sensations. We call him naive. But there is a type of self-observation that considers the consequences of one's own actions, and which exchanges this awareness for naïveté, and knows exactly the scope and justification of what it is doing. We want to call this critical. We believe that this best captures the meaning of the term critical, as it has become established in philosophy with various degrees of clarity since Kant. Critical prudence is therefore the opposite of naïveté. We call behavior critical when it takes control of the laws of one's own activity, to learn about their safety and limits. Therefore, a theory of knowing, epistemology, can only be a critical science. Its object to a high degree is the subjective human activity of cognition,60t/n Cognition is the mental activity of acquiring understanding of sense perceptions and concepts. and what it wants to demonstrate are the laws of cognition. All naïveté must therefore be excluded from this science. It must see its strength precisely in the fact that it accomplishes what many practical minds boast that they have never done, namely "thinking about thinking."
III. Die Erkenntnistheorie nach Kant
[ 1 ] Von der fehlerhaften Fragestellung bei Kant sind nun alle nachfolgenden Erkenntnistheoretiker mehr oder weniger beeinflußt worden. Bei Kant tritt die Anschauung, daß alle uns gegebenen Gegenstände unsere Vorstellungen seien, als Resultat seines Apriorismus auf. Seither ist sie nun zum Grundsatze und Ausgangspunkte fast aller erkenntnistheoretischen Systeme gemacht worden. Was uns zunächst und unmittelbar als gewiß feststehe, sei einzig und allein der Satz, daß wir ein Wissen von unseren Vorstellungen haben; das ist zu einer fast allgemein geltenden Überzeugung der Philosophen geworden. G. E. Schulze behauptet bereits 1792 in seinem «Anesidemus», daß alle unsere Erkenntnisse bloße Vorstellungen seien, und daß wir über unsere Vorstellungen nie hinausgehen können. Schopenhauer vertritt mit dem ihm eigenen philosophischen Pathos die Ansicht. daß der bleibende Gewinn der Kantschen Philosophie die Ansicht sei, daß die Welt «meine Vorstellung» ist, Ed. v. Hartmann findet diesen Satz so unantastbar, daß er in seiner Schrift «Kritische Grundlegung des transzendentalen Realismus» überhaupt nur solche Leser voraussetzt, die sich von der naiven Identifikation ihres Wahrnehmungsbildes mit dem Dinge an sich kritisch losgerungen haben und sich die absolute Heterogeneität eines durch den Vorstellungsakt als subjektiv-idealen Bewußtseinsinhalts gegebenen Anschauungsobjekts und eines von dem Vorstellungsakt und der Form des Bewußtseins unabhängigen, an und für sich bestehenden Dinges zur Evidenz gebracht haben, d. i. solche, die von der Überzeugung durchdrungen sind, daß die Gesamtheit dessen, was uns unmittelbar gegeben ist, Vorstellungen seien. 16Hartmann, Kritische Grundlegung, Vorrede S.10. In seiner letzten erkenntnistheoretischen ??“In seiner letzten erkenntnistheoretischen Publikation“: Eduard von Hartmann, Transzendentaler Idealismus und Realismus mit besonderer Rücksicht auf das Kausalproblem; Zeitschrift für Philosophie und philosophische Kritik, Band 99, Leipzig 189 1, S. 18 3-209 Publikation sucht Hartmann diese seine Ansicht allerdings auch noch zu begründen. Wie sich eine vorurteilsfreie Erkenntnistheorie zu einer solchen Begründung stellen muß, werden unsere weiteren Ausführungen zeigen. Otto Liebmann spricht als sakrosankten obersten Grundsatz aller Erkenntnislehre den aus: «Das Bewußtsein kann sich selbst nicht überspringen.» 17Zur Analysis S.28 ff Volkelt hat das Urteil, daß die erste unmittelbarste Wahrheit die sei: «all unser Wissen erstrecke sich zunächst nur auf unsere Vorstellungen», das positivistische Erkenntnisprinzip genannt, und er betrachtet nur diejenige Erkenntnistheorie als «eminent kritisch», welche dieses «Prinzip, als das im Anfange des Philosophierens einzig Feststehende an die Spitze stellt und es dann konsequent durchdenkt. 18Volkelt, Kants Erkenntnistheorie § 1. Bei anderen Philosophen findet man wieder andere Behauptungen an die Spitze der Erkenntnistheorie gestellt, z. B. die, daß das eigentliche Problem derselben in der Frage bestehe nach dem Verhältnis zwischen Denken und Sein und der Möglichkeit einer Vermittlung zwischen beiden 19Dorner, Das menschliche Erkennen oder auch in der: wie wird das Seiende bewußt (Rehmke) usw. Kirchmann geht von zwei erkenntnistheoretischen Axiomen aus: «das Wahrgenommene ist»und «der Widerspruch ist nicht. 20Die Lehre vom Wissen. Nach E. L. Fischer besteht das Erkennen in dem Wissen von einem Tatsächlichen, Realen, 21Grundfragen S. 385. und er läßt dieses Dogma ebenso ungeprüft wie Göring, der ähnliches behauptet: «Erkennen heißt immer, ein Seiendes erkennen, das ist Tatsache, welche weder Skeptizismus noch Kantscher Kritizismus leugnen kann.» 22System S. 257. Bei den beiden letzteren wird einfach dekretiert: das ist Erkennen, ohne zu fragen, mit welchem Rechte denn dies geschehen kann.
[ 2 ] Selbst wenn diese verschiedenen Behauptungen richtig wären, oder zu richtigen Problemstellungen führten, könnten sie durchaus nicht am Anfange der Erkenntnistheorie zur Erörterung kommen. Denn sie stehen, als ganz bestimmte Einsichten, alle schon innerhalb des Gebietes des Erkennens. Wenn ich sage: mein Wissen erstreckt sich zunächst nur auf meine Vorstellungen, so ist das doch ein ganz bestimmtes Erkenntnisurteil. Ich füge durch diesen Satz der mir gegebenen Welt ein Prädikat bei, nämlich die Existenz in Form der Vorstellung. Woher aber soll ich vor allem Erkennen wissen, daß die mir gegebenen Dinge Vorstellungen sind?
[ 3 ] Wir werden uns von der Richtigkeit der Behauptung, daß dieser Satz nicht an die Spitze der Erkenntnistheorie gestellt werden darf, am besten überzeugen, wenn wir den Weg verfolgen, den der menschliche Geist nehmen muß, um zu ihm zu kommen. Der Satz ist fast ein Bestandteil des ganzen modernen wissenschaftlichen Bewußtseins geworden. Die Erwägungen, die dasselbe zu ihm hingedrängt haben, finden sich in ziemlicher Vollständigkeit systematisch zusammengestellt in dem 1. Abschnitt von Ed. v. Hartmanns Schrift: «Das Grundproblem der Erkenntnistheorie». Das in derselben Vorgebrachte kann somit als eine Art von Leitfaden dienen, wenn man sich zur Aufgabe macht, alle Gründe zu erörtern, die zu jener Annahme führen können.
[ 4 ] Diese Gründe sind physikalische, psycho-physische, physiologische und eigentlich philosophische.
[ 5 ] Der Physiker gelangt durch Beobachtung derjenigen Erscheinungen, die sich in unserer Umgebung abspielen, wenn wir z. B. eine Schallempfindung haben, zu der Annahme, daß in diesen Erscheinungen nichts liege, das mit dem auch nur die entfernteste Ähnlichkeit hätte, was wir unmittelbar als Schall wahrnehmen. Draußen, in dem uns umgebenden Raume, sind lediglich longitudinale Schwingungen der Körper und der Luft aufzufinden. Daraus wird gefolgert, daß das, was wir im gewöhnlichen Leben Schall oder Ton nennen, lediglich eine subjektive Reaktion unseres Organismus auf jene Wellenbewegung sei. Ebenso findet man , daß das Licht und die Farbe oder die Wärme etwas rein Subjektives sind. Die Erscheinungen der Farbenzerstreuung, der Brechung, Interferenz und Polarisation belehren uns, daß den obengenannten Empfindungsqualitäten im Außenraume gewisse transversale Schwingungen entsprechen, die wir teils den Körpern, teils einem unmeßbar feinen, elastischen Fluidum, dem Äther, zuzuschreiben uns veranlaßt fühlen. Ferner sieht sich der Physiker gezwungen, aus gewissen Erscheinungen in der Körperwelt den Glauben an die Kontinuität der Gegenstände im Raume aufzugeben und dieselben auf Systeme von kleinsten Teilen (Molekülen, Atomen) zurückzuführen, deren Größen im Verhältnisse zu ihren Entfernungen unmeßbar klein sind. Daraus wird geschlossen, daß alle Wirkung der Körper aufeinander durch den leeren Raum hindurch geschehe, somit eine wahre actio in distans sei. Die Physik glaubt sich berechtigt anzunehmen, daß die Wirkung der Körper auf unseren Tast- und Wärmesinn nicht durch unmittelbare Berührung geschehe, weil ja immer eine gewisse, wenn auch kleine, Entfernung zwischen der den Körper berührenden Hautstelle und diesem selbst da sein müsse. Daraus ergebe sich, daß das, was wir z.B. als Härte oder Wärme der Körper empfinden, nur Reaktionen unserer Tast- und Wärmenerven-Endorgane auf die durch den leeren Raum hindurch wirkenden Molekularkräfte der Körper seien.
[ 6 ] Als Ergänzung treten zu diesen Erwägungen des Physikers jene des Psycho-Physikers hinzu, die in der Lehre von den spezifischen Sinnes-Energien ihren Ausdruck finden. J. Müller hat gezeigt, daß jeder Sinn nur in der ihm eigentümlichen, durch seine Organisation bedingten Weise affiziert werden kann, und daß er immer in derselben Weise reagiert, was auch immer für ein äußerer Eindruck auf ihn ausgeübt wird. Wird der Sehnerv erregt, so empfinden wir Licht, gleichgültig, ob es Druck oder elektrischer Strom oder Licht ist, was auf den Nerv einwirkt. Andererseits erzeugen dieselben äußeren Vorgänge ganz verschiedene Empfindungen, je nachdem sie von diesem oder jenem Sinne perzipiert werden. Daraus hat man gefolgert, daß es nur eine Art von Vorgängen in der Außenwelt gebe, nämlich Bewegungen, und daß die Mannigfaltigkeit der von uns wahrgenommenen Welt wesentlich eine Reaktion unserer Sinne auf diese Vorgänge sei. Nach dieser Ansicht nehmen wir nicht die Außenwelt als solche wahr, sondern bloß die in uns von ihr ausgelösten, subjektiven Empfindungen.
[ 7 ] Zu den Erwägungen der Physik treten auch noch jene der Physiologie. Jene verfolgt die außer unserem Organismus vor sich gehenden Erscheinungen, welche den Wahrnehmungen korrespondieren; diese sucht die Vorgänge im eigenen Leibe des Menschen zu erforschen, die sich abspielen, während in uns eine gewisse Sinnesqualität ausgelöst wird. Die Physiologie lehrt, daß die Epidermis gegen Reize der Außenwelt vollständig unempfindlich ist. Wenn also z. B. die Endorgane unserer Tastnerven an der Körperperipherie von den Einwirkungen der Außenwelt affiziert werden sollen, so muß der Schwingungsvorgang, der außerhalb unseres Leibes liegt, erst durch die Epidermis fortgepflanzt werden. Beim Gehör- und Gesichtssinne wird außerdem der äußere Bewegungsvorgang durch eine Reihe von Organen in den Sinneswerkzeugen verändert, bevor er an den Nerv herankommt. Diese Affektion der Endorgane muß nun durch den Nerv bis zum Zentralorgan geleitet werden, und hier erst kann sich das vollziehen, wodurch auf Grund von rein mechanischen Vorgängen im Gehirne die Empfindung erzeugt wird. Es ist klar, daß durch diese Umformungen, die der Reiz, der auf die Sinnesorgane ausgeübt wird, erleidet, derselbe so vollständig umgewandelt wird, daß jede Spur von Ahnlichkeit zwischen der ersten Einwirkung auf die Sinne und der zuletzt im Bewußtsein auftretenden Empfindung verwischt sein muß. Hartmann spricht das Ergebnis dieser Überlegung mit folgenden Worten aus: «Dieser Bewußtseinsinhalt besteht ursprünglich aus Empfindungen, mit welchen die Seele auf die Bewegungszustände ihres obersten Hirnzentrums reflektorisch reagiert, welche aber mit den molekularen Bewegungszuständen, durch welche sie ausgeübt werden, nicht die geringste Ähnlichkeit haben.»
[ 8 ] Wer diesen Gedankengang vollständig bis ans Ende durchdenkt, muß zugeben, daß, wenn er richtig ist, auch nicht der geringste Rest von dem, was man äußeres Dasein nennen kann, in unserem Bewußtseinsinhalt enthalten wäre.
[ 9 ] Hartmann fügt zu den physikalischen und physiologischen Einwänden gegen den sogenannten «naiven Realismus» noch solche, die er im eigentlichen Sinne philosophische nennt, hinzu. Bei einer logischen Durchmusterung der beiden ersten Einwände bemerken wir, daß wir im Grunde doch nur dann zu dem angezeigten Resultate kommen können, wenn wir von dem Dasein und dem Zusammenhange der äußeren Dinge, wie sie das gewöhnliche naive Bewußtsein annimmt, ausgehen und dann untersuchen, wie diese Außenwelt bei unserer Organisation in unser Bewußtsein kommen kann. Wir haben gesehen, daß uns jede Spur von einer solchen Außenwelt auf dem Wege vom Sinneseindruck bis zum Eintritt in das Bewußtsein verlorengeht, und in dem letzteren nichts als unsere Vorstellungen übrig bleiben. Wir müssen daher annehmen, daß jenes Bild der Außenwelt, das wir wirklich haben, von der Seele auf Grund des Empfindungsmaterials aufgebaut werde. Zunächst wird aus den Empfindungen des Gesichts- und des Tastsinns ein räumliches Weltbild konstruiert, in das dann die Empfindungen der übrigen Sinne eingefügt werden. Wenn wir uns gezwungen sehen, einen bestimmten Komplex von Empfindungen zusammenhängend zu denken, so kommen wir zum Begriffe der Substanz, die wir als Träger derselben ansehen. Bemerken wir, daß an einer Substanz Empfindungsqualitäten verschwinden und andere wieder auftauchen, so schreiben wir solches einem durch das Gesetz der Kausalität geregelten Wechsel in der Erscheinungswelt zu. So setzt sich, nach dieser Auffassung, unser ganzes Weltbild aus subjektivem Empfindungsinhalt zusammen, der durch die eigene Seelentätigkeit geordnet wird. Hartmann sagt: «Was das Subjekt wahrnimmt, sind also immer nur Modifikationen seiner eigenen psychischen Zustände und nichts anderes.» 23Das Grundproblem der Erkenntnistheorie, §. 37.
[ 10 ] Fragen wir uns nun: wie kommen wir zu einer solchen Überzeugung? Das Skelett des angestellten Gedankenganges ist folgendes: Wenn eine Außenwelt existiert, so wird sie von uns nicht als solche wahrgenommen, sondern durch unsere Organisation in eine Vorstellungswelt umgewandelt. Wir haben es hier mit einer Voraussetzung zu tun, die, konsequent verfolgt, sich selbst aufhebt. Ist dieser Gedankengang aber geeignet, irgendeine Überzeugung zu begründen? Sind wir berechtigt, das uns gegebene Weltbild deshalb als subjektiven Vorstellungsinhalt anzusehen, weil die Annahme des naiven Bewußtseins, strenge durchgedacht, zu dieser Ansicht führt? Unser Ziel ist ja doch, diese Annahme selbst als ungültig zu erweisen. Dann müßte es möglich sein, daß eine Behauptung sich als falsch erwiese und doch das Resultat, zu dem sie gelangt, ein richtiges sei. Das kann ja immerhin irgendwo vorkommen; aber nimmermehr kann dann das Resultat als aus jener Behauptung erwiesen angesehen werden.
[ 11 ] Man nennt gewöhnlich die Weltansicht, welche die Realität des uns unmittelbar gegebenen Weltbildes wie etwas nicht weiter Anzuzweifelndes, Selbstverständliches hinnimmt, naiven Realismus. Die entgegengesetzte dagegen, die dieses Weltbild bloß für unseren Bewußtseinsinhalt hält, transzendentalen Idealismus. Wir können somit auch das Ergebnis der vorangehenden Erwägungen mit folgenden Worten zusammenfassen: Der transzendentale Idealismus erweist seine Richtigkeit, indem er mit den Mitteln des naiven Realismus, dessen Widerlegung er anstrebt, operiert. Er ist berechtigt, wenn der naive Realismus falsch ist; aber die Falschheit wird nur mit Hilfe der falschen Ansicht selbst bewiesen. Wer sich dieses vor Augen bringt, für den bleibt nichts übrig, als den Weg zu verlassen, der hier eingeschlagen wird, um zu einer Weltansicht zu gelangen, und einen anderen zu gehen. Soll das aber, auf gut Glück, versuchsweise geschehen, bis wir zufällig auf das Rechte treffen? Ed. v. Hartmann ist allerdings dieser Ansicht, wenn er die Gültigkeit seines erkenntnistheoretischen Standpunktes damit dargetan zu haben glaubt, daß dieser die Welterscheinungen erklärt, während die anderen das nicht tun. Nach der Ansicht dieses Denkers nehmen die einzelnen Weltanschauungen eine Art von Kampf ums Dasein auf, und diejenige, welche sich in demselben am besten bewährt, wird zuletzt als Siegerin akzeptiert. Aber ein solches Verfahren scheint uns schon deshalb unstatthaft, weil es ja ganz gut mehrere Hypothesen geben könnte, die gleich befriedigend zur Erklärung der Welterscheinungen führen. Deshalb wollen wir uns lieber an den obigen Gedankengang zur Widerlegung des naiven Realismus halten und nachsehen, wo eigentlich sein Mangel liegt. Der naive Realismus ist doch diejenige Auffassung, von der alle Menschen ausgehen. Schon deshalb empfiehlt es sich, die Korrektur gerade bei ihm zu beginnen. Haben wir dann eingesehen, warum er mangelhaft sein muß, dann werden wir mit ganz anderer Sicherheit auf einen richtigen Weg geführt werden, als wenn wir einen solchen einfach auf gut Glück versuchen.
[ 12 ] Der oben skizzierte Subjektivismus beruht auf einer denkenden Verarbeitung gewisser Tatsachen. Er setzt also voraus, daß, von einem tatsächlichen Ausgangspunkte aus, durch folgerichtiges Denken (logische Kombination bestimmter Beobachtungen) richtige Überzeugungen gewonnen werden können. Das Recht zu einer solchen Anwendung unseres Denkens wird aber auf diesem Standpunkt nicht geprüft. Und darin liegt seine Schwäche. Während der naive Realismus von der ungeprüften Annahme ausgeht, daß der von uns wahrgenommene Erfahrungsinhalt objektive Realität habe, geht der charakterisierte Standpunkt von der ebenfalls ungeprüften Überzeugung aus, daß man durch Anwendung des Denkens zu wissenschaftlich berechtigten Überzeugungen kommen könne. Im Gegensatz zum naiven Realismus kann man diesen Standpunkt naiven Rationalismus nennen. Um diese Terminologie zu rechtfertigen, möchten wir hier eine kurze Bemerkung über den Begriff des «Naiven»einschalten. A. Doring sucht diesen Begriff in seinem Aufsatze: «Über den Begriff des naiven Realismus»naher zu bestimmen. 24Philosophische Monatshefte Bd. XXVI, Heidelberg 1890, S. 390. Er sagt darüber: «Der Begriff der Naivität bezeichnet gleichsam den Nullpunkt auf der Skala der Reflektion über das eigene Verhalten. Inhaltlich kann die Naivität durchaus das Richtige treffen, denn sie ist zwar reflexionslos und eben darum kritiklos oder unkritisch, aber dies Fehlen der Reflexion und Kritik schließt nur die objektive Sicherheit des Richtigen aus; es schließt die Möglichkeit und Gefahr des Verfehlens, keineswegs die Notwendigkeit desselben in sich. Es gibt eine Naivität des Fühlens und Wollens, wie des Vorstellens und Denkens im weitesten Sinne des letzteren Wortes, ferner eine Naivität der Äußerungen dieser inneren Zustände im Gegensatz gegen die durch Rücksichten, Reflexion bewirkte Repression oder Modifikation derselben. Die Naivität ist, wenigstens bewußt, nicht beeinflußt vom Hergebrachten, Angelernten und Vorschriftsmäßigen, sie ist auf allen Gebieten, was das Stammwort nativus ausdrückt, das Unbewußte, Impulsive, Instinktive, Dämonische.»Wir wollen, von diesen Sätzen ausgehend, den Begriff des Naiven doch noch etwas präziser fassen. Bei aller Tätigkeit, die wir vollbringen, kommt zweierlei in Betracht: die Tätigkeit selbst und das Wissen um deren Gesetzmäßigkeit. Wir können in der ersten vollständig aufgehen, ohne nach der letzteren zu fragen. Der Künstler, der die Gesetze seines Schaffens nicht in reflexionsmäßiger Form kennt, sondern sie dem Gefühle, der Empfindung nach übt, ist in diesem Falle. Wir nennen ihn naiv. Aber es gibt eine Art von Selbstbeobachtung, die sich um die Gesetzlichkeit des eigenen Tuns fragt, und welche für die soeben geschilderte Naivität das Bewußtsein eintauscht, daß sie genau die Tragweite und Berechtigung dessen kennt, was sie vollführt. Diese wollen wir kritisch nennen. Wir glauben damit am besten den Sinn dieses Begriffes zu treffen, wie er sich seit Kant mit mehr oder minder klarem Bewußtsein in der Philosophie eingebürgert hat. Kritische Besonnenheit ist demnach das Gegenteil von Naivität. Wir nennen ein Verhalten kritisch, das sich der Gesetze der eigenen Tätigkeit bemächtigt, um deren Sicherheit und Grenzen kennen zu lernen. Die Erkenntnistheorie kann aber nur eine kritische Wissenschaft sein. Ihr Objekt ist ja ein eminent subjektives Tun des Menschen: das Erkennen, und was sie darlegen will, ist die Gesetzmäßigkeit des Erkennens. Von dieser Wissenschaft muß also alle Naivität ausgeschlossen sein. Sie muß gerade darinnen ihre Stärke sehen, daß sie dasjenige vollzieht, von dem sich viele aufs Praktische gerichtete Geister rühmen, es nie getan zu haben, nämlich das «Denken über das Denken».
III The theory of knowledge after Kant
[ 1 ] All subsequent epistemologists have been more or less influenced by Kant's erroneous questioning. In Kant, the view that all objects given to us are our conceptions appears as the result of his a priorism. Since then, it has become the principle and starting point of almost all epistemological systems. What is initially and immediately certain to us is solely the proposition that we have knowledge of our ideas; this has become an almost universally held conviction of philosophers. G. E. Schulze claimed as early as 1792 in his "Anesidemus" that all our knowledge is mere imagination and that we can never go beyond our imagination. Schopenhauer, with his own philosophical pathos, takes the view that the lasting gain of Kant's philosophy is the view that the world is "my imagination", Ed. v. Hartmann finds this sentence so inviolable that in his essay "Critical Foundation of Transcendental Realism" he presupposes only those readers at all who have critically freed themselves from the naive identification of their perceptual image with the thing in itself and have brought to evidence the absolute heterogeneity of an object of contemplation given by the act of representation as the subjective-ideal content of consciousness and of a thing existing in and for itself, independent of the act of representation and the form of consciousness, i.e. those who are convinced of the existence of a thing in and for itself. i.e. those who are imbued with the conviction that the totality of what is directly given to us are conceptions. 16Hartmann, Kritische Grundlegung, Preface p.10 . In his last epistemological ??"In seiner letzten erkenntnistheoretischen Publikation": Eduard von Hartmann, Transzendentaler Idealismus und Realismus mit besonderer Rücksicht auf das Kausalproblem; Zeitschrift für Philosophie und philosophische Kritik, Vol. 99, Leipzig 189 1, pp. 18 3-209 publication, however, Hartmann also seeks to justify this view. Our further remarks will show how an unprejudiced epistemology must approach such a justification. Otto Liebmann states the following as the sacrosanct supreme principle of all epistemology: "Consciousness cannot leap over itself." 17On Analysis p.28 ff Volkelt has called the judgment that the first most immediate truth is that "all our knowledge initially extends only to our ideas" the positivist principle of knowledge, and he regards as "eminently critical" only that epistemology which places this "principle at the head as the only fixed one at the beginning of philosophizing and then consistently thinks it through. 18Volkelt, Kants Erkenntnistheorie § 1. In other philosophers one finds other assertions placed at the head of epistemology, e.g. that the real problem of epistemology consists in the question of the relationship between thinking and being and the possibility of a mediation between the two 19Dorner, Das menschliche Erkennen or also in the question: how does the existing become conscious (Rehmke) etc. Kirchmann assumes two epistemological axioms: "what is perceived is" and "the contradiction is not. 20The doctrine of knowledge. According to E. L. Fischer, cognition consists in the knowledge of an actual, real thing, 21Fundamental Questions p. 385, and he leaves this dogma as unexamined as Göring, who claims something similar: "To cognize always means to recognize an existing thing, that is a fact which neither scepticism nor Kantian criticism can deny." 22System p. 257. The latter two simply decree: that is cognition, without asking by what right this can happen.
[ 2 ] Even if these various assertions were correct, or led to correct problems, they could not be discussed at the beginning of epistemology. For they are, as quite definite insights, all already within the realm of cognition. When I say: my knowledge initially extends only to my ideas, this is a very definite judgment of knowledge. Through this proposition I add a predicate to the world given to me, namely existence in the form of imagination. But how am I to know before all cognition that the things given to me are conceptions?
[ 3 ] We will best convince ourselves of the correctness of the assertion that this proposition must not be placed at the head of epistemology if we follow the path that the human mind must take in order to arrive at it. The proposition has become almost an integral part of the whole of modern scientific consciousness. The considerations that have pushed it towards it can be found in a fairly complete systematic compilation in the first section of Ed. v. Hartmann's work: "Das Grundproblem der Erkenntnistheorie". What is presented in it can thus serve as a kind of guide when one sets oneself the task of discussing all the reasons that can lead to that assumption.
[ 4 ] These reasons are physical, psycho-physical, physiological and actually philosophical.
[ 5 ] By observing the phenomena that take place in our environment, for example when we perceive sound, the physicist arrives at the assumption that there is nothing in these phenomena that bears even the remotest resemblance to what we directly perceive as sound. Outside, in the space surrounding us, there are only longitudinal vibrations of bodies and air. From this it is concluded that what we call sound or tone in ordinary life is merely a subjective reaction of our organism to that wave motion. Similarly, we find that light and color or heat are purely subjective. The phenomena of color dispersion, refraction, interference and polarization teach us that the above-mentioned qualities of sensation in outer space correspond to certain transverse vibrations which we feel compelled to attribute partly to bodies and partly to an immeasurably fine, elastic fluid, the ether. Furthermore, certain phenomena in the physical world force the physicist to abandon the belief in the continuity of objects in space and to attribute them to systems of the smallest parts (molecules, atoms) whose sizes are immeasurably small in relation to their distances. From this it is concluded that all action of bodies on each other takes place through empty space and is therefore a true actio in distans. Physics believes itself justified in assuming that the effect of bodies on our sense of touch and heat does not occur through direct contact, because there must always be a certain, albeit small, distance between the skin area touching the body and the body itself. This means that what we feel as hardness or warmth of the body, for example, are only reactions of our tactile and thermal nerve end organs to the molecular forces of the body acting through empty space.
[ 6 ] In addition to these considerations of the physicist, there are those of the psycho-physicist, which find their expression in the doctrine of specific sensory energies. J. Müller has shown that each sense can only be affected in the way peculiar to it, conditioned by its organization, and that it always reacts in the same way, whatever external impression is exerted on it. If the optic nerve is stimulated, we feel light, regardless of whether it is pressure or electric current or light that acts on the nerve. On the other hand, the same external processes produce quite different sensations depending on whether they are perceived by this or that sense. From this it has been concluded that there is only one kind of process in the external world, namely movement, and that the diversity of the world we perceive is essentially a reaction of our senses to these processes. According to this view, we do not perceive the external world as such, but merely the subjective sensations it triggers in us.
[ 7 ] In addition to the considerations of physics, there are also those of physiology. The former pursues the phenomena occurring outside our organism which correspond to our perceptions; the latter seeks to investigate the processes in man's own body which take place while a certain sensory quality is triggered in us. Physiology teaches that the epidermis is completely insensitive to stimuli from the outside world. If, for example, the end organs of our tactile nerves on the periphery of the body are to be affected by the influences of the outside world, the vibrational process, which lies outside our body, must first be propagated through the epidermis. In the case of the sense of hearing and sight, moreover, the external process of movement is modified by a series of organs in the sensory organs before it reaches the nerve. This affection of the end organs must now be conducted through the nerve to the central organ, and only here can that take place whereby sensation is produced on the basis of purely mechanical processes in the brain. It is clear that through these transformations which the stimulus exerted on the sense organs undergoes, it is so completely transformed that every trace of similarity between the first influence on the senses and the sensation which finally appears in consciousness must be obliterated. Hartmann expresses the result of this consideration in the following words: "This content of consciousness originally consists of sensations with which the soul reacts reflexively to the states of movement of its uppermost brain center, but which have not the slightest resemblance to the molecular states of movement through which they are exercised."
[ 8 ] Whoever thinks this train of thought through completely to the end must admit that, if it is correct, not even the slightest remnant of what can be called external existence would be contained in the content of our consciousness.
[ 9 ] Hartmann adds to the physical and physiological objections to so-called "naive realism" what he calls philosophical objections in the true sense of the word. In a logical examination of the first two objections, we notice that we can basically only arrive at the result indicated if we start from the existence and coherence of external things as assumed by ordinary naive consciousness and then examine how this external world can enter our consciousness in our organization. We have seen that every trace of such an external world is lost to us on the way from the sensory impression to the entry into consciousness, and in the latter nothing remains but our ideas. We must therefore assume that the image of the external world which we really have is built up by the soul on the basis of the material of sensation. First, a spatial picture of the world is constructed from the sensations of sight and touch, into which the sensations of the other senses are then inserted. If we find ourselves compelled to think of a certain complex of sensations as coherent, we arrive at the concept of substance, which we regard as its carrier. If we notice that sensory qualities in a substance disappear and others reappear, we attribute this to a change in the phenomenal world regulated by the law of causality. Thus, according to this view, our whole world picture is composed of subjective sensory content, which is ordered by our own soul activity. Hartmann says: "What the subject perceives are therefore always only modifications of his own mental states and nothing else." 23The fundamental problem of epistemology, §. 37.
[ 10 ] Let us now ask ourselves: how do we arrive at such a conviction? The skeleton of the train of thought is as follows: If an external world exists, it is not perceived by us as such, but is transformed by our organization into an imaginary world. We are dealing here with a presupposition which, if pursued consistently, cancels itself out. But is this train of thought suitable to justify any conviction? Are we entitled to regard the world view given to us as a subjective conceptual content because the assumption of naive consciousness, strictly thought through, leads to this view? After all, our aim is to prove this assumption itself to be invalid. Then it would have to be possible for an assertion to prove false and yet for the result to which it leads to be correct. This can always happen somewhere; but the result can then never be regarded as proven from that assertion.
[ 11 ] The view of the world that accepts the reality of the world view immediately given to us as something that cannot be doubted or taken for granted is usually called naive realism. The opposite view, on the other hand, which takes this world picture merely for the content of our consciousness, is called transcendental idealism. We can thus also summarize the result of the preceding considerations in the following words: Transcendental idealism proves its correctness by operating with the means of naive realism, which it strives to refute. It is justified if naive realism is false; but the falsity is only proven with the help of the false view itself. For anyone who realizes this, there is nothing left but to leave the path that is taken here in order to arrive at one view of the world and to take another. But should this be done on a trial and error basis until we happen to find what is right? Ed. v. Hartmann is of this opinion, however, when he believes that he has demonstrated the validity of his epistemological standpoint by the fact that it explains world phenomena, while the others do not. According to this thinker, the individual worldviews engage in a kind of battle for existence, and the one that proves itself best in this battle is ultimately accepted as the winner. But such a procedure seems inadmissible to us because there could well be several hypotheses that lead equally satisfactorily to the explanation of world phenomena. Therefore, we would rather stick to the above train of thought to refute naive realism and see where its shortcomings actually lie. After all, naïve realism is the view from which all people start. For this reason alone, it is advisable to begin the correction with it. Once we have realized why it must be flawed, we will be led onto the right path with a completely different degree of certainty than if we simply try to do so at random.
[ 12 ] The subjectivism outlined above is based on a thinking processing of certain facts. It therefore presupposes that, from an actual starting point, correct convictions can be obtained through logical thinking (logical combination of certain observations). However, the right to such an application of our thinking is not examined from this point of view. And therein lies its weakness. While naïve realism starts from the untested assumption that the content of experience perceived by us has objective reality, the characterized standpoint starts from the equally untested conviction that one can arrive at scientifically justified convictions through the application of thought. In contrast to naïve realism, this point of view can be called naïve rationalism. In order to justify this terminology, we would like to make a brief comment on the concept of the "naive". A. Doring attempts to define this concept more precisely in his essay "On the Concept of Naive Realism". 24Philosophische Monatshefte Vol. XXVI, Heidelberg 1890, p. 390. He says: "The concept of naivety denotes, as it were, the zero point on the scale of reflection on one's own behavior. In terms of content, naivety can certainly do the right thing, because although it is without reflection and therefore uncritical or uncritical, this lack of reflection and criticism only excludes the objective certainty of the right thing; it includes the possibility and danger of error, but by no means the necessity of it. There is a naivety of feeling and willing, as well as of imagining and thinking in the broadest sense of the latter word, furthermore a naivety of the expressions of these inner states in contrast to the repression or modification of them brought about by consideration and reflection. Naivety is, at least consciously, not influenced by the traditional, the learned and the prescribed, it is in all areas what the root word nativus expresses, the unconscious, the impulsive, the instinctive, the demonic. "Based on these sentences, we want to define the concept of the naive a little more precisely. In all activity that we accomplish, two things come into consideration: the activity itself and the knowledge of its lawfulness. We can be completely absorbed in the former without asking about the latter. The artist who does not know the laws of his work in a reflective form, but practises them according to feeling, according to sensation, is in this case. We call him naive. But there is a kind of self-observation that wonders about the legality of its own actions, and which exchanges the naivety just described for the awareness that it knows exactly the scope and justification of what it is doing. We want to call this critical. We believe this best captures the meaning of this term, as it has become naturalized in philosophy with more or less clear awareness since Kant. Critical prudence is therefore the opposite of naivety. We call a behavior critical that takes possession of the laws of its own activity in order to get to know their certainty and limits. However, epistemology can only be a critical science. After all, its object is an eminently subjective human activity: cognition, and what it wants to explain is the legality of cognition. All naivety must therefore be excluded from this science. It must see its strength precisely in the fact that it accomplishes that which many practical minds boast they have never done, namely "thinking about thinking".