The Summary of Physics Restored

20The division of the upper waters from the lower, expressed in sacred Genesis, seems to have been made by separating the subtle from the thick, and a tenuous, spirit-like part from a sooty body. This was the work of the luminous spirit proceeding from the divine word. For light, which is a fiery spirit, separated unlike things and drove the denser darkness downwards from the nearer, higher region. Gathering the matter of like nature, finer and closer to spirit, it kindled it into immortal light, like incombustible oil before the throne of divine majesty. This is the empyrean heaven, intermediate between the intelligible and material worlds, as though the horizon and boundary of both. It receives spiritual gifts from the higher world and communicates them to the next lower heaven, namely the middle one.