What do the eight trigrams in the Book of Changes represent?

The eight trigrams are: Qian, Kun, Xun, Dui, Gen, Zhen, Li and Kan.

Qian represents heaven, Kun represents earth, Xun represents wind, Zhen represents thunder, Kan represents water, Li represents fire, Gen represents mountain and Dui represents lake.

Bagua is the basis of the Yixue system. The pre-Qin Yixue is mainly the "Three Yis", namely the Lianshan Yi of the Xia Dynasty, the Guizang of the Shang Dynasty, and the Zhouyi of the Zhou Dynasty. The Zhouyi that people in later generations are familiar with , which is divided into Yi Jing and Yi Zhuan.

Bagua represents early Chinese philosophical thought. In addition to divination and Feng Shui, its influence involves traditional Chinese medicine, martial arts, music, mathematics and other aspects.

Extended information:

The "gua" of Bagua is a knowing word, from Gui to divination. Gui refers to Tugui, who began to use clay to make pillars to measure the shadow of the sun. Bu means to measure. Li Hachigui measured the sun's shadow, that is, he summarized and recorded the observed sun's shadow from the four directions and four corners, which formed the image of Bagua.

The most basic unit of Bagua is Yao, which is mostly a special symbol describing the changes of the sun's shadow. There are two types of Yao: Yin and Yang. The Yang Yao represents sunlight and the Yin Yao represents moonlight. Each hexagram has three lines, representing the three talents of heaven, earth and man. The heavenly part of Sancai includes the movement of the entire celestial body and meteorological changes. These studies of astrology were called astronomy in ancient times.

Earth refers to the method of calculating the annual cycle by observing the sun's shadow, and using the principles of the earth to understand the entire process of growth and collection. The Ministry of Human Resources refers to the combination of astronomy, geography and personnel in order to produce and live according to these laws. The order of each hexagram is from bottom to top. The last horizontal line is called the first line, the middle line is called the second line, and the upper line is called the third line.

Reference: Baidu Encyclopedia - Bagua

Reference: Baidu Encyclopedia - Bagua Diagram