III. The World as Illusion

There is no bridge for our knowledge that leads from motion to sensation. This is the credo of Du Bois-Reymond. From motion in the material world we cannot come into the psychical world of sensations. We know that sensation arises from matter in motion, but we do not know how this is possible. Also, in the world of motion we cannot go beyond motion. For our subjective perceptions we can point at certain forms of motions because we can infer the course of these motions from the process of our perceptions, but we have no conception of what it is that is moving outside in space. We say that matter moves. We follow its motions as we watch the reactions of our sensations, but as we do not observe the object in motion but only a subjective sign of it, we can never know what matter is. Du Bois-Reymond is of the opinion that we might be able to solve the riddle of sensation if the riddle of matter were disclosed. If we knew what matter is, we should probably also know how it produces sensations, but both riddles are inaccessible to our knowledge. Du Bois-Reymond meant to check those who wanted to go beyond this limit with the words, “Just let them try the only alternative that is left, namely, supra-naturalism, but be sure that science ends where supra-naturalism begins.”