The eight trigrams (bagua) are the base images of Heaven, Lake, Fire, Thunder, Wind, Water, Mountain and Earth. Each is made of three lines, and stacking two of them builds the 64 hexagrams of the I Ching.
Eight images of nature
Qian (乾) is Heaven and strength, Kun (坤) Earth and receptivity, Zhen (震) Thunder and movement, Xun (巽) Wind and penetration. Kan (坎) is Water and danger, Li (離) Fire and clarity, Gen (艮) Mountain and stillness, Dui (兌) Lake and joy.
Each trigram extends beyond a single natural image to directions, family members, body parts and qualities. This web of symbols becomes the rich language of I Ching interpretation.
From eight trigrams to 64 hexagrams
Stack two of the eight trigrams and you get 8×8, that is 64 combinations. So knowing each trigram’s nature lets you naturally unpack the meaning that the upper and lower trigrams create together.
A hexagram with Heaven (Qian) above and Earth (Kun) below, versus the reverse, symbolizes an entirely different situation. Reading the relationship of top and bottom is the key to the 64 hexagrams.
Frequently asked
From Taiji, yin and yang divide, and stacking yin and yang three deep makes the eight trigrams. The trigrams are the basic language that divides the world into eight by combining the two forces of yin and yang.
Learning each trigram’s image and nature makes reading the 64 hexagrams far easier. Rather than rote memorizing, understand them through the image of the natural thing each represents and they settle in naturally.