Besides creation of life and, depending on who you ask, the highest aim of life, sex also serves as a preserver of life. The sexual aspect of life force, qi, is qing essence. Cultivating and preserving qing essence isn't just a matter of selfish energy accumulation, though. It involves stimulating one's partner to the utmost heights of pleasure, without the male's succumbing to what the French call "the little death".

The process is known as "uniting yin and yang," laid out by Daoist experts bent on immortality. The text comes from the oldest known sexual tracts in China, from the second century BCE, unearthed in Changsha. The advice is much more edifying than anything you heard behind the Dairy Queen back in junior high, but far less explicit than anything you ‘stumble' onto in a day's internet surfing. Metaphoric terms are left to the reader's imagination.

This is the method for uniting yin and yang:

Clasp her hands and cross over to the outside of her wrists;

Stroke the elbow chambers;

Go beside the armpits;

Move up to the "stove frame";

Go to the "neck region";

Stroke the "receiving basket";

Cover the "encircling ring";

Descend to the "broken basin";

Pass over the "sweet wine ford";

Cross the" Bounding Sea";

Ascend "Mount Constancy";

Enter the "dark gate";

And mount the coital sinew.

By sucking her qing spirit upward, one can live forever and be coeval with heaven and earth. The coital sinew is the coital channel within the dark gate. If one is able to lay hold of and stroke it, this causes both bodies to be pleasurably nourished and joyfully radiant in a wonderful way. Although full of passion, do not act. Exchanging exhalations and embraces, carry out the dao of dalliance step by step.

This is the tao of dalliance:

First when her qi rises and her face becomes flushed, slowly exhale.

Second, when her nipples become hard and her nose perspires, slowly embrace her.

Third, when her tongue spreads and becomes lubricious, slowly press her.

Fourth, when secretions appear below and her thighs are damp, slowly take hold of her.

Fifth, when her throat is dry and she swallows saliva, slowly agitate her.

These are called the "signs of the five desires." When all of the signs manifest, then mount her. Stab upward, but do not penetrate, in order to stimulate qi. When the qiqi to dissipate and for her to become exhausted. Afterward, practice the ten movements, unite according to the ten postures, and combine the ten refinements. Uniting bodies after sunset, the qi extends to the "ancestral gate". Now observe the eight movements; listen to the five sounds, and examine the signs of the ten exhaustions.

The ten arousals begin with ten, then twenty, thirty, forty, fifty, sixty, seventy, eighty, ninety, and one hundred. Move in and out without reaching orgasm.

One arousal without orgasm makes the ears and eyes sharp and bright.

Two and the voice becomes clear.

Three and the skin is radiant.

Four and the back and flanks are strong.

Five and the buttocks and thighs become muscular.

Six and the "water course" flows.

Seven and one becomes sturdy and strong.

Eight and the pores are lustrous.

Nine and one achieves spiritual illumination.

Ten and the body endures.

These are the "ten movements":

The first is "roaming tiger".

The second is "cicada clinging".

The third is "measuring worm".

The fourth is "roe deer butting".

The fifth is "locust spreading".

The sixth is "monkey's squat".

The seventh is "toad in the moon".

The eighth is "rabbit bolts".

The ninth is "dragonflies".

The tenth is "fishes gobbling.

The ten refinements:

The first is up.

The second is down.

The third is to the left.

The fourth is to the right.

The fifth is rapidly.

The sixth is slowly.

The seventh is sparingly.

The eighth is frequently.

The ninth is shallow.

The tenth is deep.

The eight movements:

The first is clasping hands.

The second is straightening elbows.

The third is extending heels.

The fourth is hooking from the side.

The fifth is hooking from above.

The sixth is entwining thighs.

The seventh is calming the movement.

The eighth is quivering.

Clasping hands means that she desires contact with her belly. Straightening the elbows means that she desires her upper body to be rubbed and scratched. Extending heels means that penetrations is insufficient. Hooking from the side means that she wants her side rubbed.

Hooking from above means that she wants her lower body rubbed. Entwining thighs means that penetration is excessive. Calming the movement means that she desires shallow penetration. Quivering means that she wants to be held for a long time.

When she holds her breath, it means that she is experiencing inner urgency. When she pants it means that she feels intense joy. When she moans it means that the "jade pod" has penetrated and the pleasure begins. When she exhales it means that the sweetness is intense. When she grinds her teeth and her body quivers it means that she wants the man to continue for a long time.

In the evening the man's qing is strong; in the morning the woman's qing is concentrated. Using my qing to nourish the woman's qing, the anterior channels are all activated; and the skin, qi, and blood are stimulated. This opens closures and unblocks obstructions. The central treasury benefits from the circulation and becomes full. If when the qi begins to well up in the central extremity, one conceals the spirit, then spiritual illumination is attained.