Liu An

“ Though open on all sides, it contains the two cosmogonical Principles; it binds up the universe, while making manifest the sun, moon, and stars; it is thick as clay, and yet is watery; it is infinitesimally fine, and yet it can be subdivided; it makes mountains rise high and valleys sink low; it makes beasts to walk, birds to fly, the sun and moon to shine, the stars to move, the unicorn to come forth, and the phoenix to hover above us. ”

“ Tao roofs over the sky and is the foundation of the earth; it extends north, south, east, and west, stretching to the eight extreme points in those directions. Its height is beyond reach and its depth is unfathomable; it enfolds both the sky and the earth, and produces things which had been formless. It is like the flow of a spring, which starts bubbling up from nothing but gradually forms a volume of rushing muddy water which again gradually becomes clear. Therefore, if set vertically, it will block all the space between the sky and the earth ”