When Heaven and Earth first formed, chaos gave rise to two opposing forces: pure qi rose to become Heaven, and turbid qi sank to become Earth. Between them was a current of qi that neither rose nor fell, known as the One Qi of Mist and Rain. It belongs to neither Heaven nor Earth, is part of neither yin nor yang, and drifts beyond the Three Realms and Five Elements. It is the medium through which cause and effect flow in the world.
