What Is Yin and Yang? The Taiji and Yin-Yang in the I Ching

To read the I Ching, first understand yin and yang. They are the two most basic symbols that build every hexagram, and the fundamental way Chinese philosophy sees the world.

Yin and yang

Yang is active, firm, and bright, drawn as a solid line (—); yin is receptive, yielding, and dark, drawn as a broken line (- -). Everything — day and night, motion and rest, hard and soft — can be seen as an interplay of these two forces.

The taiji gives birth to the two forms

The Great Treatise says, “In change there is the taiji, which gives birth to the two forms.” The taiji is the undivided whole; it differentiates into yin and yang, which in turn produce the four images and the eight trigrams. The familiar taiji symbol — black and white curling together, each holding a seed of the other — captures this dynamic balance.

How yin and yang build a hexagram

Three yin or yang lines stack into a trigram; two trigrams combine into a six-line hexagram. So all sixty-four hexagrams are simply different arrangements of yin and yang — see the eight trigrams explained.

“One yin and one yang is the Way”

In the I Ching, yin and yang do not fight to destroy each other; they transform into one another, waxing and waning. To grasp how they turn is to grasp the way of change. Pure yang is The Creative, pure yin is The Receptive — the father and mother of all the hexagrams.