Tension = jĭn zhāng 紧张
Looseness = zhāng chí 松弛
The highest good is like water = shàng shàn ruò shuĭ 上善若水
Taiji is based on Yīn 阴 and Yáng 阳, the two opposing forces that balance each other. Yīn and Yáng are concepts from Daoism. The Daoists have a saying: “Shàng shàn ruò shuĭ 上善若水” which means, “Water treats all living things equally. It does not discriminate.” The character of water is that it goes where there is no resistance. If you don’t create resistance for it, it will flow quickly.
Qi is exactly the same. When you don’t resist, qi will flow. We create the tension and softness in our bodies. When we are tense, the Qi is compressed. As soon as we loosen and let go, Qi flows to where we are most loose. The energy goes where there is no tension. Energy is like water; it goes where there is the least resistance.
When we practice, we need to have this tension and looseness, but that tension is always created with two opposing points. It’s not just “holding tense” like a fist but rather like the tension created between two hands facing each other, feeling the tension between them without touching. And looseness is not simply being relaxed.
The whole body has tension and looseness, compression and expansion. During our Taiji practice, we move our body in a way that certain parts of the body are tensing while other parts are loosening and therefore Qi will flow toward the specific loosened part. In Qigong this is called Dăo Yĭn 导引 which means “guiding the energy” to where you want it.