Although these are the techniques of practicing Tao in the Hou-tien, 10 understanding them is still necessary.
Whoever dissipates his vitality, spirit, and soul through ears and eyes is a commoner.
Whoever retrieves inward his vitality, spirit, and soul can become a Saint.
The practice of going with the flow dissipates. The practice of going against the flow retrieves. That is why Mencius said,