Taiji, born of Wuji, is the potential for either dong (movement, dynamic) or jing (stillness, static). It is the mother ( the source) of yin and yang.
In dong (movement) yin and yang tend to fen (become separate and distinct), in jing (stillness) yin and yang tend to he (unite to become one).
Neither overextend nor fall short, fold (bend) and expand accordingly.
If your opponent is gang (hard) and I respond with rou (softness), it is called zou (moving away). When I am in a comfortable, advantageous position, it is called nian (adherence).
If the opponent moves quickly, then respond quickly; if the opponent moves slowly, then slow down with him.
There exist countless techniques and variations, but there is only basic principles behind all of them.
Zhao shou (familiarity with techniques) gradually leads to dong jin (understanding the use of jin = trained force), and from this understanding you can step-by-step grasp shenming. (The highest level of incredible skill seems like magic.) But if you do not practice long and hard enough, you will never understand it completely.
Let ding jin (the "pushing up" trained force to the top of your head) rise up effortlessly, and sink your qi to dan tian. Do not lean in any direction or on anything. Disappear suddenly, and reappear just as unexpectedly.
If you feel your opponent pushing harder on your left side, you should adjust your left side to be that much more xu (force using the mind as opposed to physical force); and vise versa for the right side. If he rises, then you should follow him to go higher. If he sinks down, then you should follow him to go lower. If he goes forward, then you should follow him to move backwards and increase the distance between the two of you. If he retreats, then you should follow him and propel him backwards quicker.
A feather cannot be added, and a fly cannot land. Do not let your opponent feel and know you, let you, and you alone be the one who knows your opponent. (first part means to have perfect balance with sensitivity)
Such is the path leading to heroic invincibility.
There are a great many types of martial arts. Although they may differ in their movements and techniques, none goes beyond the stronger beating the weaker, and the slower yielding to the quicker. The "strong beats the weak" and "the swift beats the slow" describe natural, inborn capabilities and responses, having little to do with high-level skills.
In examining the phrase "use a four-once force to lightly manipulate a thousand-pound force," it becomes obvious that this is not accomplished through physical strength alone. Look at the old man who can defend against a group of youth with ease, how can it be the result of swifter movements?!
Stand like a balance, and be lively and movable as a free-spinning wheel. Doing pianchen - sinking to one side, makes following possible. Being shuangzhong - double-weighted, causes stagnation.
In every instance where someone has spent many years practicing hard but still cannot use this skill well, being controlled and beaten by others, it is because this person has not really understood the sickness of shuangzhong.
If you want to avoid this kind of sickness (shuangzhong - double-weightedness), you have to understand yin and yang theory. Adherence (nian) is moving away (zou), and moving away is adherence. Yin never leaves the yang, and yang never leaves the yin. Only when you understand how to let yin and yang mutually aid and change one another can you say that you understand jin (dongjin) in TaijiQuan.
Once you understand the principle that shows dongjin, and have mastered how to do it, the more you practice, the more skilled you will become. If you think deeply and investigate every detail thoroughly, you will gradually reach a stage where you can move with complete freedom as your mind desires.
The main idea is to abandon your own will and follow your opponent. Most people err by giving up the near to seek the far.
It is said that an initial error of one inch can result in a deviation of a thousand miles. Practitioners must study and understand the principles very carefully. That is why this article is written.
The original note said: "This principle is passed down by Grandmaster Zhang Sanfeng of Wudang Mountain. Its purpose is to help all great people of the world to achieve health and longevity, so it is not only a martial arts skill, which is considered to be a low-level practice (in Daoist beliefs).