Yin and Yang

The Dao De Jing describes things as bearing yin and embracing yang. The Zhuangzi and the Xici commentary on the Zhouyi likewise use the interaction of the pair to speak about how things arise and transform. These passages do not make yin and yang two isolated substances: the relation between them is what explains generation in their respective arguments. The famous formulation in the Xici treats the alternation of one yin and one yang as the Dao.

Early Daoist texts extend this language beyond cosmology. The Taiping Jing applies yin and yang to heaven and earth, human affairs, rulership, and the seasons, arguing that neither side is self-sufficient. This is a religious account of order in nature and society, not a single physical law that can be tested by assigning every event to one of two fixed boxes.

The Zhouyi Cantong Qi uses paired imagery such as qian and kun, firmness and yielding, and male and female to articulate its account of alchemical transformation. The Chinese compilation also cites Ge Hong and later writers who connect yin-yang language with bodies and the making of things. Their uses share a vocabulary, yet the alchemical, cosmological, and social claims should not be treated as interchangeable explanations.

In Zhang Boduan's Wuzhen Pian, one qi differentiates into yin and yang, which are then discussed in relation to inner alchemy. The source connects this scheme with such pairs as heart and kidneys, nature and life, and with the triad jing, qi, and shen. These are correspondences within a transmitted religious model. They do not by themselves establish an anatomical map, a medical diagnosis, or a promised result from a practice.

The Chinese entry groups the major senses of yin and yang into four broad uses: formative qi in accounts of the world; vital processes described within the body; contrasting qualities such as firmness and softness or heat and cold; and evaluative or moral contrasts. Those uses overlap, but none can automatically substitute for another. Reading the surrounding passage is the best way to determine whether a particular author is discussing cosmology, ethics, alchemy, or a practical classification.