I. Soul and Spirit in the Human Physical Constitution

In addition to the solid components, therefore, we must bear in mind the 'fluid' and also the 'air'. For the air that is within us, in regard to its organization and its differentiations, is an organism in the same sense as the solid organism, only it is gaseous, airy, and in motion. And finally, the warmth in us is not a uniform warmth extending over the whole human being, but is also delicately organized. As soon, however, as we begin to speak of the fluid organism which fills the same space that is occupied by the solid organism, we realize immediately that we cannot speak of this fluid organism in the earthly human without speaking of the etheric body which permeates this fluid organism and fills it with forces. The physical organism exists for itself, as it were; it is the physical body; in so far as we consider it in its entirety, we regard it, to begin with, as a solid organism. (blue) This is the physical body.