For example, during the early spring, the force of wood was in the ascendant; the sprouting of woody plants and a wide range of other natural and astronomical phenomena were explained by the dominance of the force of wood. As the season progressed, however, the power of fire would grow until it dominated. Then in midsummer, earth would become dominant; in autumn metal; in winter water; in spring wood once again. All of the regular phenomena of the natural world and many of those pertaining to the human world could be explained by the resonant power of the alternating forces.

from Zou Yan's work on the Five Natural Forces