Yin-Yang, Five Elements, Eight Trigrams, Meridians, San Chi, and Ba Gua.

The article focuses on the yin-yang theory as a foundational concept interconnected with the five elements, eight trigrams, meridians, san cai, and ba gua in Chinese philosophy. It explains yin and yang primarily through natural cycles of time—day and night, lunar phases, and seasons—where yang is associated with the sun, activity, and warmth, and yin with the earth, rest, and coolness. The ba gua diagram integrates these concepts with spatial directions and human physiology, illustrating how chi (energy) flows through meridians in the body in patterns reflecting yin-yang dynamics. The article also critiques alternative models like Ohsawa's centrifugal-centripetal framework, emphasizing that true yin-yang theory uniquely combines time and space and underpins traditional Chinese practices such as feng shui and traditional Chinese medicine.