What are the practices of going with and going against the flow?

Although these are the techniques of practicing Tao in the Hou-tien¹⁰,

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 “To practice Tao, one needs nothing

but to retrieve his lost heart.”

The technique of maintaining and nurturing one’s vitality, spirit and

soul is to keep tranquility in one’s heart and reflect one’s aureole inward. 

Through this process, the True Fire of li will descend.  By raising one’s

tongue to lightly touch the upper palate, his True Water of kan will

ascend through the glands in his mouth.  When there is enough True

Water, it is swallowed into Dan-tian (the root of human life or, literally,

the cavity of immortal embryo) in the abdomen.  Here is where the True

Water meets the True Fire from Ming-men (the door of life at the fifth joint

of the spine).  The True Water is then converted into Qi.  When the Qi and

soul are full, one can labour without feeling fatigue.  The Qi circulates in

the body by ascending along the spine and descending down in the front

continuously.  When vitality becomes full, one has no desire for lust. 

The vitality then is refined and transforms into Qi (spirit).  When the Qi

(spirit) is full, one has no appetite.  The Qi (spirit) then is refined and

transforms into the soul.  When the soul is full, one has no desire for sleep. 

Then the soul returns to the Void.  Once the soul returns to the Void, it is

bright and its presence permeates throughout the cosmos.  This is what

Taoism calls “turning the water mill”, Buddhism calls it “turning the

wheel of the Dharma” and Confucianism calls it “pervading the Truth

after the elimination of desires”.  This is the practice of going against

the flow.

The circulation of the Qi of the common ascends in the front and

descends in the back.  The circulation of the Qi of Saints descends

in the front and ascends in the back.  Aren’t the two exactly the opposite?