Chapter Nine: A Deeper Inquiry — What Question Is This Passage Ultimately Answering$1

I. The Purpose of the Xi Ci Zhuan

To understand the deep meaning of a passage, we must know what question drove its composition.

The Xi Ci Zhuan (upper and lower sections) is the most philosophically profound text within the Yi Zhuan. Unlike the Tuan Zhuan (Judgment Commentary) and Xiang Zhuan (Image Commentary), which explain hexagram by hexagram and line by line, it stands at a higher vantage point to discuss the fundamental principles of the Zhouyi as a book. The Xi Ci Zhuan may be said to answer the questions: "What is the Yi$2 Why does it work$3 How did it come into being$4"

The xiang and yao discussed in this chapter are the core of the answer to "What is the Yi$5" The Xi Ci Zhuan's author (whether the Master himself or his later disciples) here tells us:

The essence of the Yi consists of two complementary symbol systems — the xiang system and the yao system. The xiang system expresses the deep structures of the myriad things; the yao system expresses their processes of change. Together, they constitute a complete cognition-and-decision tool.

II. Why Are Two Systems Needed$6

This returns us to the distinction between ze and dong.

We might imagine: if the world contained only ze but no dong — that is, if things had deep structure but did not change — then xiang alone would suffice. A fixed structural diagram would be enough to describe the entire world.

But the world does contain dong — things change at every moment. A fixed xiang alone cannot capture the richness and directionality of change. Hence the need for yao — the need to introduce the dimensions of time and change atop the foundation of image.

Conversely, if the world contained only dong but no ze — things changing ceaselessly with no deep structure — then change would be chaotic and utterly beyond grasp or prediction. But in fact, though change is multitudinous and complex, it possesses an inner order (huitong), and this order is the manifestation of ze.

Therefore ze and dong, xiang and yao, are mutually presupposing and inseparable paired concepts. Xiang provides the structural framework for understanding change; yao displays the concrete pathways of change within that framework.

This is a supremely refined theoretical design whose philosophical depth is in no way inferior to any cognitive system produced by any civilization.

III. Reflections in Comparison with Ancient Greek Philosophy

If we extend our view to the field of comparative philosophy, we find that the xiang-yao dual framework established in this chapter of the Xi Ci Zhuan bears striking correspondences to certain core propositions of ancient Greek philosophy.

Heraclitus said, "Everything flows" (panta rhei). This corresponds to "the movements of all under heaven." Parmenides said, "Being is one, unmoving and unchanging." This corresponds to "the profundity of all under heaven."

In Greek philosophy, the opposition between Heraclitus and Parmenides is regarded as the fundamental tension of Western metaphysics — change versus eternity, the many versus the one, flux versus being. Plato attempted to reconcile this tension with the "Forms" (eidos): Forms are eternal and unchanging (ze), while the phenomenal world is in ceaseless flux (dong); Forms are manifest in phenomena through "participation."

But pre-Qin Chinese thought adopted a wholly different mode of reconciliation — not using abstract "Forms" to subsume change, but using xiang to capture profundity and yao to model movement, allowing both to coexist within the single structure of a hexagram. This reconciliation requires no positing of a "world of Forms" separate from phenomena; instead, it grasps the unity of structure and change directly within phenomena.

In this sense, the "ze-xiang / dong-yao" framework established in this chapter of the Xi Ci Zhuan is an epistemological construction more austere and more closely rooted in experience than Plato's "Theory of Forms," yet equally profound.