The three basic elements of China's ancient cosmology are heaven, earth and man. "Li Yun" said: "The husband's ceremony must take the sky as the sky, the land as the dish, and the ghosts and gods as the table." Ji Li is the crown of the five rites, that is, the ritual of sacrifice. In order to sacrifice gods and ghosts, the objects of sacrifice are divided into three categories: people and ghosts, gods and earth images. There are mainly ritual activities such as offering sacrifices to heaven and earth, the sun, the moon and the stars, ancestors, countries and ancestral temples.
Intense ceremonies are about sympathy, mourning and worry. "Li Zhouguan Chunzongbo" records: "Mourn the worries of the country with fierce ceremony, mourn the death with funeral ceremony, mourn the disaster with famine ceremony, mourn the disaster with hanging ceremony, mourn the defeat with ceremony, and mourn the chaos with funeral ceremony." It means mourning the country's crisis with fierce ceremonies, mourning death with funeral ceremonies, helping the epidemic of famine and epidemic diseases with famine ceremonies, mourning serious natural disasters and fire and water disasters with gifts, helping besieged and defeated allies with gifts, and sympathizing with neighboring countries suffering from domestic turmoil or chaos with gifts.
Military salute is about the etiquette of military activities. The king ruled the country by courtesy, making the world harmonious, and it is inevitable to encounter internal and external interference and even the threat of fire. "The Book of Rites and the Moon Order" records: "If you want to levy injustice, punish violence and slow down, be clear about likes and dislikes, and follow him away." Rites, pleasures and conquests are like two wheels of a car, which cannot be neglected.
Li is a ceremony to receive guests, that is, diplomatic exchanges between countries and ceremonial activities to receive guests. For example, the emperor made a pilgrimage by the vassal, was hired by the vassal envoy, was sent by the emperor to welcome the vassal, was paid tribute by the vassal envoys, and was given a banquet or envoy by the vassal. In addition, the meeting etiquette from princes to scholars is also a guest gift.
Li is a ceremony to receive guests, that is, diplomatic exchanges between countries and ceremonial activities to receive guests. For example, the emperor made a pilgrimage by the vassal, was hired by the vassal envoy, was sent by the emperor to welcome the vassal, was paid tribute by the vassal envoys, and was given a banquet or envoy by the vassal. In addition, the meeting etiquette from princes to scholars is also a guest gift.