Book 11, Part 7
CHAPTER 47
The Positions of Yin and Yang
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 southeast1 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 aboveground2 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]
 
  1.  This passage imagines yang as moving clockwise around the horizon. It emerges from the northeast and, after taking its dominant position in the south, continues to the west until it (implicitly) goes into hiding in the northwest, thus “resting” in the northern quadrant. Yin moves counterclockwise around the horizon circle. It emerges from the southeast, moves northward to its dominant position, and then continues westward, (implicitly) going into seclusion in the southwest and “retreating” in the southern quadrant.
  2.  Emending wei to di , based on the first part of the sentence.