The first step to understanding Taijiquan is that there are no absolutes. For example, in the concept of Jin (trained appropriate strength). Trying to find it in a quantitative way is futile. Jin once realised is an ever present entity within the body. Every principle in its appropriate state, jin can be brought forth instantly, whether in advance or retreat, for change from slow to fast, from soft to hard, from a great height to close to the ground... then it is said that you’re in the dao (on the right path of realisation).
Once you find the correct starting point, contain it, and with practice the body’s jin will become more and more subtle and indiscernible. In appearance the arms may look soft, but there’s heaviness under the elbows. The chest may look empty but the back is strong with a fully drawn bow. The waist and rib cavities may be flexible but they are securely held by the dantian. The body is compact and yet nimble. What is practised is a compound strength. Slow but not broken, fast but not dispersed.
