The Five Elements (Metal, Wood, Water, Fire, Earth) originated from ancient observations of natural phenomena. During the Warring States period, the Yin-Yang philosopher Zou Yan systematized this into a comprehensive theory.
Zou Yan proposed the "Cycle of Five Virtues," using the principles of elemental generation and conquest to explain dynastic succession and historical cycles. By merging Yin-Yang with the Five Elements, he constructed a grand cosmological framework in which all phenomena operate through elemental interactions.
This theoretical foundation provided the core logic for later assigning elemental attributes to Ganzhi and calculating individual destiny. Without the Five Elements' generation and conquest cycles, there would be no BaZi (Four Pillars) astrology.