43. When we refer feelings to material conditions, we follow the natural tendency to translate the little known in terms of the better known, and employ the symbols Matter and Motion, because these furnish the intellect with images, i. e. definite and exact elements to operate with. In hearing a sound, there is nothing at all like “vibrations,” nothing like “aerial waves” and “neural processes,” given in that feeling; but on attempting to _explain_ it, we remove it from the sphere of Sensation to carry it into the sphere of Intellect, and we must change our symbols in changing our problem; here our only resource is to translate the subjective state into an _imaginable_ objective process, which can only be expressed in terms of Matter and Motion. What we _heard_ as Sound is then _seen_ as Vibration. When we are optically or mentally contemplating vibrations and neural processes, we are supplanting one source of feeling by another, translating an event in another set of symbols. But we can no more hear the sound in seeing the vibrations, than a blind man can see the fly in the amber which he feels with his fingers, or than we can feel the amber he holds, while we are only looking at it. The phrase “material conditions of Feeling” sometimes designates the objective aspect of the subjective process, and sometimes the agencies in the external medium which co-operate with the organism in the production of the feelings. In each case there is an attempt to explain a feeling by intelligible symbols. 44. The Animal probably never attempts such explanation; satisfied with the facts, it is careless of their factors. Man is never satisfied: is restless in the search after factors; and having found them, seeks factors of these factors; so that Lichtenberg felicitously calls him “_das rastlose Ursachenthier_”--“the animal untiring in the search for causes.” And thus sciences arise: we translate experiences into geometrical, physical, chemical, physiological, and psychological terms--different symbols of the different modes of apprehending phenomena.