And even though they have different names. They are not opposite but  complementary forces and just in  apparent opposition.  One of these energies precedes and promotes the other. They are not in opposition, they are set in opposition. And they make possible the circulation of the vital energy, which also receives the name of Qi in China. Instant Energy is a regulating force, which places in perfect balance the internal Ying and the external Yang.  By example : When a person is sick or weak is because the original energies of Ying and Yang are unbalanced. The energy of Mystic Healing Art, works as a regulator, such as the effect produced in a deep meditation.