Lecture XXVIII

If we study our sense organs as they are usually studied, we see that we have the possibility through the sense of smell of perceiving matter itself. Unless this fine substance were given off, man would be unable to smell. What takes place here is a connection with matter itself. The organ of taste is not connected with matter itself, but acts through a process of dissolving and perceiving its effect. Thus we can call taste a chemical sense, because it penetrates into the constitution of matter. The third sense that of sight, has nothing more to do with matter, for it only perceives pictures that are produced by matter. The fourth, the sense of touch, has still less to do with matter as such, for it only perceives attributes of the surroundings in connection with objects, such as warmth and cold; this is a state of matter which is no longer dependent on matter itself, but on what conditions surround it. Hearing is in no way dependent on the air, for we perceive only the oscillations, the vibrations of the air, something which stands in a quite external relationship to what is material. Matter, the air, is only the vehicle for the sound waves.