Yin and Yang陰陽

Polarity, the pairing of yin and yang, is the idea of seeing everything as two tendencies, one that reaches outward and one that draws inward. The words first named the sunlit and the shaded slopes of a hill, then widened to cover paired qualities of every kind, such as day and night or motion and rest. In this system each of the five elements is split again into a yang and a yin form, which yields the ten stems and the twelve branches. The heart of it is that neither side is better: the two turn into each other and lean on each other.

• 陰shade (Korean reading: eum)
• 陽sunlit side, sunshine (Korean reading: yang)

Shade and sunlight: a paired name for the side turned away from the sun and the side facing it.

The ten stems alternate in order, so the first, third, fifth, seventh, and ninth are yang and the rest are yin. Branches are also marked alternately from the Rat onward, but when sorting the Ten Gods this service follows the polarity of the main hidden stem. So the Rat and Horse branches, marked yang, are judged yin, and the Snake and Pig branches, marked yin, are judged yang. The polarity of the year stem, together with gender, sets whether the Luck Pillars run forward or backward.

Polarity is more useful for gauging which way the whole chart leans than for reading one character. Many yang characters are often read as moving first and showing yourself, and many yin characters as observing and consolidating. A chart heavy in yin is not taken as passive; it can be read as a strength for quiet preparation. Your results mark each character cell by surface class; main-stem polarity only separates indirect from direct Ten Gods.

The stem 丙 (Bing) is yang and 丁 (Ding) is yin. The branch 亥 (Hai) is yin on the surface, yet the yang 壬 (Ren) is its main hidden stem, so the Ten Gods treat it as yang. For a 庚午 (Geng Wu) birth year, the yang stem 庚 (Geng) sends a man's Luck Pillars forward and a woman's backward.

• A common idea

  The yang side is good and the yin side is bad.

  How we read it

  That idea comes from an old view that placed yang above yin. In this system the two are partners that turn into and lean on each other; this service separates them only as the side that shows and the side that holds, without ranking.

Using branch polarity only in the surface order flips indirect and direct Ten Gods roles in charts containing 子 (Zi), 午 (Wu), 巳 (Si), or 亥 (Hai). This service judges all four of these branches by the polarity of their main stems.