Transformation of Yin and Yang

In given conditions, either Yin or Yang may transform into its opposite. In other words, Yin may be transformed into Yang and Yang into Yin.

If the waning-waxing of Yin and Yang is said to be a process of quantitative change, then that of their inter-transformation pertains to a qualitative change based on the quantitative change. Such a process is mostly a gradual one from quantitative to qualitative change.

Su Wen states: "Extreme Yin gives rise to Yang, while extreme Yang gives rise to Yin." and "Extreme cold brings on heat, while extreme heat brings on cold". This is termed "Things will develop in the opposite direction when they become extreme." Pathologically, the Yin syndromes can be transformed into Yang syndromes, and vice versa.

It must be pointed out that the decisive factor of the mutual transformation is the conditions, including internal and external conditions, without which such transformation will be by no means likely to occur. The relationship between Yin and Yang can be illustrated by Yin-Yang Diagram. In the diagram the white part indicates Yang, and the black part Yin.

The two are both opposite and complementary to each other. The white spot within Yin shows the Yang within Yin, while the black spot does Yin within Yang. Meanwhile, they contain the potential for inter-transformation and inter-wane-wax between Yin and Yang.