Section 47.1
Yang
qi first emerges in the northeast and moves toward the south to assume its [dominant] position. It then circles westward and withdraws in the north, where it stores itself away for repose. Yin
qi first emerges in the southeast
1 and moves toward the north, where it likewise assumes its [dominant] position. It then circles westward and withdraws in the south, where it hides itself away for rest. Thus
yang takes the southern quarter as its position and the northern quarter as its repose;
yin takes the northern quarter as its position and the southern quarter as its retreat.
When yang arrives at its position, there is intense heating;
when yin arrives at its position, there is intense chilling.
When yang arrives at its repose, it withdraws and transforms in the earth;
when yin arrives at its retreat, it shuns accretion below.
Thus, what emerges and grows above in summer and withdraws and transforms below in winter is yang. What withdraws to guard vacuity belowground in summer and emerges to guard vacuity aboveground
2 in winter is yin.
Yang emerges from fullness and withdraws to fullness;
yin emerges from emptiness and withdraws to emptiness.
Heaven employs yang and does not employ yin. It loves accretion and abhors recision in this way. Thus, in the course of the year, yin and yang each emerge one at a time. [47/54/12–17]