Geomantic omen, called geomantic omen theory in ancient times, is one of the five traditional physiognomy techniques. Feng Shui is a mysterious art with a long history in China. According to legend, its founder was Jiutian Xuan Nv, and the relatively perfect Feng Shui consultation originated in the Warring States Period. The core idea of Feng Shui is the harmony between man and nature. Early geomantic omen is mainly related to the site selection, orientation, construction methods and principles of palaces, houses, villages and cemeteries. Its original intention is to choose a suitable place.
Feng Shui takes qi as the source of all things, and thinks that the world has changed from nothing (not seeing qi) to existence (beginning of qi). Qi is the source, which distinguishes yin and yang (two instruments) and five substances (five elements): metal, wood, water, fire and earth. The ups and downs of these substances all have unchangeable laws (moderation and perseverance), and all have fortunes (good or bad, regret and meanness), which are all predictable.