IN pursuance Of the aim which I had proposed to myself, as attainable in a degree commensurate with my own powers and with the present state of knowledge, I have consi dered Nature, in the two volumes Of the Cosmos which have already appeared, in a twofold point Of View. I have sought to represent her, first, in the pure Objectivity of external phaenomena, and, next, as the re?ex of the image received through the senses on the mirror of man's inner being, his ideas and feelings.