Force in one direction alone holds nothing together. Only when two opposing forces pull at once in every joint does the body become an elastic unit under pre-tension. Wang Xiangzhai called this the “contending force” — and in 1939 declared it the secret of martial art, openly spoken.
Zheng Li means literally “contending” or “competing” force: simultaneous, mutually opposed pairs of force — between the parts of the body, and between body and surroundings. One pulls and presses mentally in two, later six directions at the same time; the tension of these opposites holds the body together as an elastic unit under pre-tension. Not tightening, but pre-tension: the forces cancel one another outwardly and at the same moment leave the body ready to answer in any direction.
“In movement, all the large and small joints always carry the two opposing forces — up and down, forward and back, or left and right; only then does one attain the Hunyuan force of the whole body.”
— Wang Xiangzhai, “The Right Path of Yiquan” (1928)Opposites acting at once and forming a unit: that is the body-mechanical version of yin/yang dialectics. Zheng Li is yin and yang as force — every direction has its counterpart. Yiquan keeps this dialectical structure (front ↔ back, song ↔ jin) and drops the cosmological elevation. In 1939 Wang still assigns the force to the Yijing and the five phases, only to add drily: “but in truth it is just one single contradictory force.”
The two terms are often run together, but they name different stages of the same thing: Zheng Li is the individual pairs of force, Hun Yuan Li is the state in which all six directions stand in balance at once.
The single pair of contending force: the head pulls up, the foot presses down. The arm presses forward, the shoulder holds back. Countable, nameable, trainable one at a time.
The whole-body force available in every direction. No preferred point of reference any more — a tyre full of high-pressure gas that answers any touch, wherever it is met.
The state in between has a name of its own: Liu Mian Zheng Li, the six-sided contending force — up ↔ down, front ↔ back, left ↔ right, all three axes at once. This state already is the Hunyuan force; there is no further step after it, only greater refinement.
The text recorded by Qi Zhidu in 1939 makes the contending force not only the core of the method but describes how it is built up — and Wang states expressly that he is giving something away here.
A single pair, usually the vertical one: the head lifted slightly, the foot pressed into the ground. Only this one pair of opposites is sought and held.
The three axes at once. Further main pairs join in: front knee ↔ rear hip, arm ↔ arm in embracing the balloon, wrists ↔ neck.
In every part of the body and on every plane at once — until there is spring everywhere. The pair stops being counted; it is the body’s resting state.
“At first you start from seeking two opposite forces … Once you have mastered two opposite forces, you can begin to seek them in all parts of the body and on all planes … that is the Hunyuan force.”
— Wang Xiangzhai, recorded by Qi Zhidu, 1939 (English translation: “At first you start from seeking two opposite forces …”)“Using the ‘contending forces’ should be natural. That is the true secret of martial art. I am revealing it here.”
— Wang Xiangzhai, 1939The manual of the lineage starts exactly here: first the vertical pair only — the head lifts slightly (“the crown hangs from a thread”), the sole presses into the ground. Only when this one pair holds reliably do the other axes join it. Whoever looks for six directions at once finds none.
For Newton, force exists only in pairs. Zheng Li covers both kinds of pair, and both obey action and reaction — the internal ones included. The decisive difference is not in the physics but in what the pair acts upon.
The contending force against the core of the earth and against the surroundings: the foot presses into the ground, the ground presses back. This pair acts on the body from outside — it accelerates the centre of mass and so actually delivers force.
The centre of mass movesThe co-contraction of the antagonists — the six-sided contending force inside the body. Outwardly this pair cancels exactly: the centre of mass does not move. What arises is joint stiffness and elastic pre-tension — the “ball”.
The body becomes firm and ready to answerThe earlier formula that internal Zheng Li is not action and reaction was imprecise: internal muscle and joint forces obey the third law as well. What is right is the distinction by effect — the external pair accelerates the centre of mass, the internal one stiffens the structure.
“Dachengquan uses contradictory relationships in the arms to reinforce peng and the whole-body connection. If these windings are not bound to the ground through the spine and the leg, they become mere outward appearances of force.”
— Mike Sigman, on “contradictory strength” from a neijia/taiji point of viewThat settles how the two kinds hang together: the internal counter-tension is fighting force only when it is bound to the ground through the spine and the leg — that is, when the internal pair hangs on the external one.
The sources name Zheng Li after whatever it contends with: the earth, the surroundings, one’s own body — and finally the release. Tap a form.
The foot presses down, the upright posture pulls up: contending force against gravity. Out of this pair comes rooting — the precondition for any force being delivered outward at all.
External force pairThe four stages of the method read as four verbs applied to the same contending force. The last step is the most surprising: Fa Li is not an increase of contending force but its deliberate, momentary collapse in one direction.
In the almost static standing post the pairs first come into being — in the Hunyuan posture as the six-sided contending force, “the body becomes one piece”.
Feeling for the force is what first makes the co-contraction perceptible, and at its highest level it leads to all six directions at once.
The test: does the contending force survive movement? Every Shili exercise carries the force along in its opposite direction as well.
The balance that has been built is deliberately given up for an instant — the sudden release of the stored six-sided tension.
“Nowhere on the body a point that is not a spring.”
— the classical formula for the target state, reached through the alternation of tension and relaxation