“So, if we seek the laws of sculpture, we must realize that they are in fact the laws of our etheric body. The etheric body is above all a body of forces. Basically, everything in the etheric body is rhythm, a cyclical rhythm of movement or activity, and it has a spatial character only in as far as it inhabits the physical body. Occupying the physical body and extending, as it does, its activity and rhythmical play into this physical body.”
~Rudolf Steiner GA 275, Art as Seen in the Light of Mystery Wisdom, Dornach, 29 December 1914