Translated by Joshua Hehr
Through many years of teaching practice, I have come to realize that "Taiji above the head, Bagua embraced in the chest, Five Elements stepped upon with the feet" should be the true face of Taijiquan.
"Taiji above the head" refers to when practicing forms or push hands, the mind thinks of one stillness and one movement, never departing from Taiji's one yin and one yang. Mental thought must accord with yin-yang philosophy; violating it results in the error of double-weighting.
"Bagua embraced in the chest" refers to how Taijiquan's basic eight methods (namely peng, lu, ji, an, cai, lie, zhou, kao) correspond to the Bagua trigram symbols of yin-yang and empty-full. The relationships are: peng is Kan (☵), lu is Li (☲), ji is Zhen (☳), an is Dui (☱), cai is Qian (☰), lie is Kun (☷) (specifically referring to the dodging method), zhou is Gen (☶), kao is Xun (☴). The Taiji eight methods correspond to the eight directions, such as lu to the south, peng to the north, ji to the east, an to the west... The Taiji eight methods are both eight types of hand techniques, as well as eight types of training methods and eight types of force qualities.
"Five Elements stepped upon with the feet" refers to five types of footwork, namely advancing, retreating, looking left and gazing right, and central equilibrium. Advancing belongs to Water, retreating belongs to Fire, looking left belongs to Wood, gazing right belongs to Metal, and central equilibrium is Earth. Among these, central equilibrium is primary. Without central equilibrium there is nothing. One must always maintain one's own balance.
In summary, the hand movements of Taijiquan have eight directions; the foot movements have five steps. Bagua consists of Qian, Kan, Gen, Zhen, Xun, Li, Kun, and Dui. The changes of yin and yang in the upper, middle, and lower lines of the Bagua trigram symbols also correspond to the changes of empty and full in the upper, middle, and lower sections of the human body. Therefore it is said: "Taiji and Bagua are one family."
Appendix: "Year Rotation Diagram and Day Rotation Diagram" of the waxing and waning of yin and yang. (not pictured)