Interpreting and Investigating the Chapter: 'The Sage Perceived the Profundities of the World' — The Primordial Code of *Xiang* and *Yao*
This paper deeply investigates the core proposition, 'The Sage perceived the profundity (Ze) of the world,' within the *Xi Ci Zhuan* (Commentary on the Appended Judgments) of the *Zhou Yi*, analyzing the original Pre-Qin semantics of 'Ze,' 'Xiang' (Image), and 'Yao' (Line). It focuses on explaining the cognitive leap of the Sage through 'looking up and observing down,' transforming deep textures (Ze) into external simulations (Xiang), and reveals the intrinsic connection between the 'Yao' and ancient ritual systems, thereby reconstructing the foundation of Yi learning theory.

I. The Deeper Meaning of "Observing Their Convergence and Connection" (Guān Qí Huì Tōng)
"Observing their convergence and connection" (guān qí huì tōng, 观其会通)—these four characters are exquisitely precise, encapsulating the core of the Yi's philosophy of change.
"Huì" means coming together, intersecting. "Tōng" means penetrating, achieving smooth passage. Used together, "huì tōng" refers to the points of intersection and channels of passage during the process of transformation.
All things in the world are moving (dòng), but dòng is not random or chaotic. Amidst infinite transformation, there are always certain crucial nodes—at these nodes, multiple threads of change converge (huì), forming channels that can be understood and grasped (tōng).
To use a metaphor: A great river flows ceaselessly (dòng), but there are always special places in the river—forks, confluences, sharp bends, drops. At these points, the direction and force of the current change significantly; these are the river's points of "huì tōng." A skilled hydraulic engineer does not need to know the trajectory of every drop of water; he only needs to grasp these crucial points of "huì tōng" to understand the law governing the entire river's movement, and thus utilize it.
Similarly, when the Sage "observes" the movements of the world, he is not trying to learn the details of every thing’s change at every moment (which is impossible), but rather attempting to grasp the critical junctures in the process of change—those crucial hubs where multiple forces converge and multiple trends pass through.