Just as every human being must once have listened only to the pure sound of the spoken word on a wholly sentient level in order to acquire the faculty of speaking, so also, in order to learn nature's language, the soul must once have been totally surrendered to the pure impressions of the senses. And just as with time the spoken word becomes a symbol for that which is signified by it, the consciousness turning to the latter and neglecting the actual sound-content of the word, so also in its intercourse with nature the soul, with its growing interest in the thing signified, turns its attention more and more away from the actual experiences of the senses.