IV. The World as Percept

I perceive the representation in my Self in the same sense as I perceive colour, sound, etc., in other objects. I am now also able to distinguish these other objects, which stand over against me, by the name of the outer world, whereas the contents of my percept of my Self form my inner world. The failure to recognize the true relation between representation and object has led to the greatest misunderstandings in modern philosophy. The fact that I perceive a change in my Self, that my Self undergoes a modification, has been thrust into the foreground, whilst the object which causes these modifications is altogether lost sight of. It has been said that we perceive, not objects, but only our representations. I know, so it is said, nothing of the table in itself, which is the object of my observation, but only of the changes which occur within me when I perceive a table. This view should not be confused with the Berkeleyan theory mentioned above. Berkeley maintains the subjective nature of my perceptual contents, but he does not say that I can know only my own representations. He limits my knowledge to my representations because, in his opinion, there are no objects outside the act of representing. What I take as a table no longer exists, according to Berkeley, when I cease to look at it. This is why Berkeley holds that our percepts are created directly by the omnipotence of God. I see a table because God causes this percept in me. For Berkeley therefore, nothing is real except God and human spirits. What we call the “world” exists only in spirits. What the naive man calls the outer world, or corporeal nature, is for Berkeley non-existent. This theory is confronted by the now predominant Kantian view which limits our knowledge of the world to our representations, not because of any conviction that nothing beyond these representations exists, but because it holds that we are so organized that we can experience only the changes of our own selves, not the things which cause these changes. This view concludes from the fact that I know only my representations, not that there is no reality independent of them, but only that the subject cannot have direct knowledge of such reality. The subject can merely “through the medium of its subjective thoughts imagine it, invent it, think it, cognize it, or perhaps even fail to cognize it.” (O. Liebmann, Zur Analysis der Wirklichkeit, p. 28.) This (Kantian) conception believes it gives expression to something absolutely certain, indeed immediately evident, without any proof. “The most fundamental principle which the philosopher must bring to clear consciousness, consists in the recognition that our knowledge, in the first instance, is limited to our representations. Our representations are all that we immediately experience, and just because we have immediate experience of them the most radical doubt cannot rob us of our knowledge of them. On the other hand, the knowledge which transcends my representations—taking representations here in the widest possible sense, so as to include all psychical processes—is not proof against doubt. Hence, at the very beginning of all philosophizing we must explicitly set down all knowledge which transcends representations as open to doubt.” These are the opening sentences of Volkelt's book on Kant's Theory of Knowledge. What is here put forward as an immediate and self-evident truth is, in reality, the conclusion of a line of argument which runs as follows. Naive common sense believes that things, just as we perceive them, exist also outside our consciousness. Physics, Physiology, and Psychology, however, seem to teach us that for our percepts our organization is necessary, and that, therefore, we cannot know anything about external objects except what our organization transmits to us. Our percepts are thus modifications of our organization, not things-in-themselves. This train of thought has, in fact, been characterized by Ed. von Hartmann as the one which leads necessarily to the conviction that we can have direct knowledge only of our own representations (cf. his Das Grundproblem der Erkenntnistheorie, pp. 16 – 40). Because outside our organisms we find vibrations of physical bodies and of air, which are perceived by us as sounds, it is concluded that what we call sound is nothing more than a subjective reaction of our organisms to these motions in the external world. Similarly, colour and heat are inferred to be merely modifications of our organisms. And, further, these two. kinds of percepts are held to be produced in us through processes in the external world which are utterly different from what we experience as heat or as colour. When these processes stimulate the nerves in the skin of my body, I have the subjective percept of heat; when they stimulate the optical nerve I perceive light and colour. Light, colour, and heat, then, are the reactions of my sensory nerves to external stimuli. Similarly, the sense of touch reveals to me, not the objects of the outer world, but only states of my own body. In the sense of modern Physics one could somehow think that bodies are composed of infinitely small particles called molecules, and that these molecules are not in direct contact with one another, but have definite intervals between them. Between them, therefore, is empty space. Across this space they act on one another by attraction and repulsion. If I put my hand on a body, the molecules of my hand by no means touch those of the body directly, but there remains a certain distance between body and hand, and what I experience as the body's resistance is nothing but the effect of the force of repulsion which its molecules exert on my hand. I am absolutely external to the body and perceive only its effects on my organism.