In accordance with the early Chinese belief that in everything new meaning is derived from invisible qualities, the winter solstice represented the climax of Yin power, at which point the physical polarity must be reversed.
按照先民凡事從隱微中見新意的習慣，冬至既是陰氣到達極致，物極必反，因此也代表「冬至一陽生」。