The Bidirectional Temporal Control Model of the Heavenly Stems and Five Phases
The other five-flavor model is the temporal model that pairs the Heavenly Stems with the Five Phases. The temporal five-flavor model no longer concerns itself with affinity in geometric directions, but instead focuses on the regulation of energetic fluctuations in all things by celestial timing and astronomical cycles. It folds the ten Heavenly Stems into five paired phases—Jia–Yi Wood, Bing–Ding Fire, Wu–Ji Earth, Geng–Xin Metal, and Ren–Gui Water—and presents a bidirectional control (Dual-Control) mechanism between time and the five flavors.
The temporal model contains two directions of control:
Forward control (celestial timing → plants): During a particular year or Heavenly-Stem period, its distinctive Three-Yin/Three-Yang and Five-Phase celestial-radiation characteristics directly modulate the internal chemical constituents of the plants, flowers, and fruits growing on the land that year, creating population-level biases in flavor.
Reverse control (medicinal flavor → the human system): By consciously selecting and taking medicines of particular flavors, people can precisely readjust and intervene in the body’s disrupted qi-dynamic fluctuations caused by abnormal celestial timing.
Along the temporal cycle of Five-Phase generation, each pair of Heavenly Stems governs one phase. Thus, in a Jia–Yi year or Jia–Yi day, for example, the dominant axis of external temporal energy is Wood. Teacher Jiang points out that this bidirectional-control model has a vast number of therapeutic applications in the “Great Treatise on the Utmost Truth” of the Suwen. When excessive Fire from celestial timing disrupts the body, taking a flavor assigned a particular function in the temporal model—such as salty flavor—can act like negative feedback in control theory and draw the body’s qi dynamics back toward equilibrium.
This is the underlying first principle of timing medication in classical formulas and regulating qi through flavor.