All propounders of theories of knowledge since Kant have been influenced to a greater or lesser degree by the mistaken way he formulated the problem of knowledge. As a result of his a priorism he advanced the view that all objects given to us are our representations. Ever since, this view has been made the basic principle and starting point of practically all epistemological systems. The only thing we can establish as an immediate certainty is the principle that we are aware of our representations; this principle has become an almost universally accepted belief of philosophers. As early as 1792 G. E. Schulze maintained in his Aenesidemus 95 95. Gottlob Ernst Schulze (1761–1833), Aenesidemus, Helmstädt, 1792. that all our knowledge consists of mere representations, and that we can never go beyond our representations. Schopenhauer, 96On Schopenhauer, see note 34, above. with a characteristic philosophical fervor, puts forward the view that the enduring achievement of Kantian philosophy is the principle that the world is my representation. Eduard von Hartmann 97On von Hartmann, see note 4, above. finds this principle so irrefutable that in his book, Kritische Grundlegung des transzendentalen Realismus (Critical Basis of Transcendental Realism) he assumes that his readers, by critical reflection, have overcome the naive identification of the perceptual picture with the thing-in-itself, that they have convinced themselves of the absolute diversity of the subjective-ideal content of consciousness, given as perceptual object through the act of representing, and the thing existing by itself, independent both of the act of representing and of the form of consciousness; in other words, readers who have entirely convinced themselves that the totality of what is given us directly consists of our representations. 98Kritische Grundlegung, by Hartmann, Berlin 1875, Foreword, p. 10 of the German ed. In his final work on epistemology, Eduard von Hartmann did attempt to provide a foundation for this view. The validity of this in relation to a theory of knowledge free from presuppositions, will be discussed later. Otto Liebmann 99Liebmann, Zur Analysis, p. 28 ff. of the German ed. See note 28, above. claims that the principle: Consciousness cannot jump beyond itself must be the inviolable and foremost principle of any science of knowledge. Volkelt is of the opinion that the first and most immediate truth is: All our knowledge extends, to begin with, only as far as our representations he called this the most positive principle of knowledge, and considered a theory of knowledge to be eminently critical only if it considers this principle as the sole stable point from which to begin all philosophizing, and from then on thinks it through consistently. 100Kant's Erkenntnistheorie, Theory of Knowledge, Sec. 1. Other philosophers make other assertions the center of epistemology, e.g.: the essential problem is the question of the relation between thinking and existence, as well as the possibility of mediation between them, 101A. Dorner, Das menschliche Erkennen, usw., Human Cognition, Berlin, 1887. or again: How does that which exists become conscious? (Rehmke) etc. Kirchmann starts from two epistemological axioms: the perceived is and the contradictory is not. 102Julius Heinrich v. Kirchmann (1802–1884), Die Lehre vom Wissen, The Theory of Knowledge, Berlin, 1868. According to E. L. Fischer 103E. L. Fischer, Die Grundfragen der Erkenntnistheorie, Basic Questions of the Theory of Cognition, Mainz 1887, p. 385. knowledge consists in the recognition of something factual and real. He lays down this dogma without proof as does Göring, who maintains something similar: Knowledge always means recognizing something that exists; this is a fact that neither scepticism nor Kantian criticism can deny. 104C. Göring, System der kritischen Philosophie, System of Critical Philosophy, Leipzig, 1874, Part I, p. 257. The two latter philosophers simply lay down the law: This they say is knowledge, without judging themselves.
Even if these different assertions were correct, or led to a correct formulation of the problem, the place to discuss them is definitely not at the beginning of a theory of knowledge. For they all represent at the outset a quite specific insight into the sphere of knowledge. To say that my knowledge extends to begin with only as far as my representations, is to express a quite definite judgment about cognition. In this sentence I add a predicate to the world given to me, namely, its existence in the form of representation. But how do I know, prior to all knowledge, that the things given to me are representations?
Thus this principle ought not to be placed at the foundation of a theory of knowledge; that this is true is most easily appreciated by tracing the line of thought that leads up to it. This principle has become in effect a part of the whole modern scientific consciousness. The considerations which have led to it are to be found systematically and comprehensively summarized in Part I of Eduard von Hartmann's book, Das Grundproblem der Erkenntnistheorie (The Fundamental Problem of Epistemology). What is advanced there can thus serve as a kind of guide when discussing the reasons that led to the above assumption.
These reasons are physical, psycho-physical, physiological, as well as philosophical. The physicist who observes phenomena that occur in our environment when, for instance, we perceive a sound, is led to conclude that these phenomena have not the slightest resemblance to what we directly perceive as sound. Out there in the space surrounding us, nothing is to be found except vibrations of material bodies and of air. It is concluded from this that what we ordinarily call sound or tone is solely a subjective reaction of our organism to those wave-like movements. Likewise it is found that light, color and heat are something purely subjective. The phenomena of color-diffraction, refraction, interference and polarization show that these sensations correspond to certain transverse vibrations in external space, which, so it is thought, must be ascribed partly to material bodies, partly to an infinitely fine elastic substance, the ether. Furthermore, because of certain physical phenomena, the physicist finds himself compelled to abandon the belief in the continuity of objects in space, and to analyze them into systems of minute particles (molecules, atoms) the size of which, in relation to the distance between them, is immeasurably small. Thus he concludes that material bodies affect one another across empty space, so that in reality force is exerted from a distance. The physicist believes he is justified in assuming that a material body does not affect our senses of touch and warmth by direct contact, because there must be a certain distance, even if very small, between the body and the place where it touches the skin. From this he concludes further that what we sense as the hardness or warmth of a body, for example, is only the reaction of the peripheral nerves of our senses of touch and warmth to the molecular forces of bodies which act upon them across empty space.
These considerations of the physicist are amplified by those of the psycho-physicist in the form of a science of specific sense-energies. J. Müller 105Johannes Müller (1801–1858), see note 32, above. has shown that each sense can be affected only in a characteristic manner which is conditioned by its structure, so that it always reacts in the same way to any external stimulus. If the optic nerve is stimulated, there is a sensation of light, whether the stimulus is in the form of pressure, electric current, or light. On the other hand, the same external phenomenon produces quite different sensations, according to which sense organ transmits it. This leads to the conclusion that there is only one kind of phenomenon in the external world, namely motion, and that the many aspects of the world which we perceive derive essentially from the reaction of our senses to this phenomenon. According to this view, we do not perceive the external world. itself, but merely the subjective sensations which it releases in us.
Thus physiology is added to physics. Physics deals with the phenomena occurring outside our organism to which our perceptions correspond; physiology aims to investigate the processes that occur in man's body when he experiences a certain sense impression. It shows that the epidermis is completely insensitive to external stimuli. In order to reach the nerves connected with our sense of touch on the periphery of the body, an external vibration must first be transmitted through the epidermis. In the case of hearing and vision the external motion is further modified through a number of organs in these sense-tools, before it reaches the corresponding nerve. These effects, produced in the organs at the periphery of the body, now have to be conducted through the nerve to the central organ, where sensations are finally produced through purely mechanical processes in the brain. It is obvious that the stimulus which acts on the sense organ is so changed through these modifications that there can be no similarity between what first affected the sense organs, and the sensations that finally arise in consciousness. The result of these considerations is summed up by Hartmann in the following words:
The content of consciousness consists fundamentally of the sensations which are the soul's reflex response to processes of movement in the uppermost part of the brain, and these have not the slightest resemblance to the molecular movements which called them into being.
If this line of thought is correct and is pursued to its conclusion, it must then be admitted that our consciousness does not contain the slightest element of what could be called external existence.
To the physical and physiological arguments against so-called naive realism Hartmann adds further objections which he describes as essentially philosophical. A logical examination of the first two objections reveals that in fact one can arrive at the above result only by first assuming the existence and interrelations of external things, as ordinary naive consciousness does, and then investigating how this external world enters our consciousness by means of our organism. We have seen that between receiving a sense impression and becoming conscious of a sensation, every trace of such an external world is lost, and all that remains in consciousness are our representations. We must therefore assume that our picture of the external world is built up by the soul, using the material of sensations. First of all, a spatial picture is constructed using the sensations produced by sight and touch, and sensations arising from the other senses are then added. When we are compelled to think of a certain complex of sensations as connected, we are led to the concept of matter, which we consider to be the carrier of sensations. If we notice that some sensations associated with a substance disappear, while others arise, we ascribe this to a change regulated by the causal laws in the world of phenomena. According to this view, our whole world-picture is composed of subjective sensations arranged by our own soul-activity. Hartmann says: Thus all that the subject perceives are modifications of its own soul-condition and nothing else. 106Hartmann's Grundproblem, p. 37 note 4, above).
Let us examine how this conviction is arrived at. The argument may be summarized as follows: If an external world exists then we do not perceive it as such, but through our organism transform it into a world of representations. When followed out consistently, this is a self-canceling assumption. In any case, can this argument be used to establish any conviction at all? Are we justified in regarding our given world-picture as a subjective content of representations, just because we arrive inevitably at this conclusion if we start from the assumption made by naive consciousness? After all, the aim was just to prove this assumption invalid. It should then be possible for an assertion to be wrong, and yet lead to a correct result. This can happen, but the result cannot then be said to have been proved by the assertion.
The view which accepts the reality of our directly given picture of the world as certain and beyond doubt, is usually called naive realism. The opposite view, which regards this world-picture as merely the content of our consciousness, is called transcendental idealism. Thus the preceding discussion could also be summarized as follows: Transcendental idealism demonstrates its truth by using the same premises as the naive realism which it aims to refute. Transcendental idealism is justified if naive realism is proved incorrect, but its incorrectness is only demonstrated by means of the incorrect view itself. Once this is realized there is no alternative but to abandon this path and to attempt to arrive at another view of the world. Does this mean proceeding by trial and error until we happen to hit on the right one? That is Hartmann's approach when he believes his epistemological standpoint established on the grounds that his view explains the phenomena, whereas others do not. According to him the various world-views are engaged in a sort of struggle for existence in which the fittest is ultimately accepted as victor. But the inconsistency of this procedure is immediately apparent, for there might well be other hypotheses which would explain the phenomena equally satisfactorily. For this reason we prefer to adhere to the above argument for the refuting of naive realism, and investigate precisely where its weakness lies. After all, naive realism is the viewpoint from which we all start. It is therefore the proper starting-point for a critical investigation. By recognizing its shortcomings we shall be led to the right path much more surely than by simply trusting to luck.
The subjectivism outlined above is based on the use of thinking for elaborating certain facts. This presupposes that, starting from certain facts, a correct conclusion can be obtained through logical thinking (logical combination of particular observations). But the justification for using thinking in this way is not examined by this philosophical approach. This is its weakness. While naive realism begins by assuming that the content of experience, as we perceive it, is an objective reality without examining if this is so, the standpoint just characterized sets out from the equally uncritical conviction that thinking can be used to arrive at scientifically valid conclusions. In contrast to naive realism, this view could be called naive rationalism. To justify this term, a brief comment on the concept of naive is necessary here. A. Döring 107A. Döring, article in Philosophische Monatshefte, Vol. XXVI, 1890, p. 390. publ. Heidelberg. Philosophical Monthly. tries to define this concept in his essay, Über den Begriff des naiven Realismus (Concerning the Concept of naive Realism). He says:
The concept 'naive' designates the zero point in the scale of reflection about one's own relation to what one is doing. A naive content may well be correct, for although it is unreflecting and therefore simply non-critical or uncritical, this lack of reflection and criticism excludes the objective assurance of truth, and includes the possibility and danger of error, yet by no means necessitates them. One can be equally naive in one's life of feeling and will, as in the life of representing and thinking in the widest sense; furthermore, one may express this inner life in a naive manner rather than repressing and modifying it through consideration and reflection. To be naive means not to be influenced, or at least not consciously influenced by tradition, education or rules; it means to be, in all spheres of life, what the root of the word: 'nativus' implies. i.e., unconscious, impulsive, instinctive, daimonic.
Starting from this, we will endeavor to define naive still more precisely. In all our activities, two things must be taken into account: the activity itself, and our knowledge of its laws. We may be completely absorbed in the activity without worrying about its laws. The artist is in this position when he does not reflect about the laws according to which he creates, but applies them, using feeling and sensitivity. We may call him naive. It is possible, however, to observe oneself, and enquire into the laws inherent in one's own activity, thus abandoning the naive consciousness just described through knowing exactly the scope of and justification for what one does. This I shall call critical. I believe this definition comes nearest to the meaning of this concept as it has been used in philosophy, with greater or lesser clarity, ever since Kant. Critical reflection then is the opposite of the naive approach. A critical attitude is one that comes to grips with the laws of its own activity in order to discover their reliability and limits. Epistemology can only be a critical science. For its object is an essentially subjective activity of man: cognition, and it wishes to demonstrate the laws inherent in cognition. Thus everything naive must be excluded from this science. Its strength must lie in doing precisely what many thinkers, inclined more toward the practical doing of things, pride themselves that they have never done, namely, think about thinking.