The Five Primordial Extremities, namely Taiyi, Tai Chu, Tai Shi, Tai Su, and Taiji, were the Daoist explanation for the progress of heaven, earth, and the universe.
According to historical records, there once had been rumors relating to them, corresponding to the great Daoist bodies cultivated by Daoist practitioners.
There were earlier and later stages among the Five Extremities, but no distinction between strength or weakness, each representing the profundities of different phases of the universe. All were the best root bone physiques for cultivation, yet none had appeared for many years, thus were rarely mentioned now.
Tai Chu, for instance, was formless and without substance, bringing forth the Innate Qi, undivided into Yin and Yang, with neither form nor quality.
From Taiyi, through Tai Chu, Tai Shi, Tai Su, and entering Taiji, Taiji split into Liangyi, and only then did Yin and Yang appear, the Four Symbols and Eight Trigrams revolving, thus giving birth to all things.
