All of the key concepts we will look at this chapter – Dao, qi, and Taiji, as well as the system of the Yi – remained at the core of Chinese metaphysics. They were used in a variety of ways to construct metaphysical systems of varying complexity, particularly through and in response to encounters with Buddhist philosophy.

The Huangdi Neijing (The Yellow Emperor’s Inner Classic) offers the most comprehensive definition of yinyang:

In this passage, yinyang is taken as a pattern embedded in the nature of all beings, thus providing the foundation for a coherent view of the world. This worldview weaves together human beings, heaven, and the Dao 道 (the way) in a way that creates a reality of dynamic wholeness pervaded by and mediated through the interaction of yin and yang. That is why yinyang is called the “net” (gangji) of the ten thousand things. The term gangji comes from the image of silk fabric. Gang 綱 is the main strand to which all other threads are attached, whereas ji 紀 represents the mesh of the other threads. Together, they show that the ten thousand things are tied to an interrelated net or web through yinyang. This chapter will explore this gangji through four of the most significant concepts in Chinese cosmology: Dao (the way), qi 氣 (vital energy), yi 易 (change/ease/constancy), and taiji 太極 (great ultimate).