IV. The World as Perception

Physiology also shows that there is no question of a direct knowledge of what the objects cause to take place in our sense-organs. When the physiologist traces the processes in our bodies, he discovers that already in the sense organs, the effects of the external vibrations are modified in the most manifold ways. This can be seen most clearly in the case of the eye and ear. Both are very complicated organs which modify the external stimulus considerably before they conduct it to the corresponding nerve. From the peripheral end of the nerve the already modified stimulus is then led further to the brain. Here at last the central organs are stimulated in their turn. From this the conclusion is drawn that the external process must have undergone a series of transformations before it reaches consciousness. What goes on in the brain is connected by so many intermediate processes with the external process, that any similarity to the latter is unthinkable. What the brain ultimately transmits to the soul is neither external processes nor processes in the sense-organs, but only such as occur in the brain. But even these are not directly perceived by the soul; what we finally have in consciousness are not brain processes at all, but sensations. My sensation of red has absolutely no similarity to the process which occurs in the brain when I sense the red. The red is caused by the processes in the brain and appears again only as an effect of this in the soul. This is why Hartmann says:[^12] “What the subject perceives therefore is always only modifications of his own psychic states and nothing else.” When I have sensations, these are as yet far from being grouped into what I perceive as objects. For only single sensations can be transmitted to me by the brain. The sensations of hardness and softness are transmitted to me by the sense of touch, those of color and light by the sense of sight. Yet all these can be found united in one and the same object. The unification must, therefore, be caused by the soul itself; this means that the soul combines into bodies the separate sensations transmitted through the brain. My brain gives me separately and indeed along very different paths, the sensations of sight, touch and hearing, which the soul then combines into the representation “trumpet.” This last link (the representation of trumpet) is the very first process to enter my consciousness. In it can no longer be found anything of what is outside of me and originally made an impression on my senses. The external object has been entirely lost on the way to the brain and through the brain to the soul.