The most important of the three souls is fetal light, which is the source of human life. If the fetal light is dim, it means that people are not far from death. Shuang Ling is a source of wisdom. The traditional Zi Ling consists of a rain prefix, three mouths and a wizard, which vividly shows the essential meaning of "spirit": the communication between the wizard and heaven and earth. Therefore, the word spirit represents the talent given to human beings by God, and refreshing is the wisdom brought by life. In the end, ghosts decide who everyone will fall in love with in life.
The function of the "seven spirits" can be seen from the name. Swallowing thieves represents the human immune system and the ability to remove and devour foreign germs, while corpse dogs represent people's danger warning ability, removing dirt represents the human metabolism and discharging waste in the body, and smelly lungs represent the number of breaths in a person's life. Taoism believes that the total amount of breathing in a person's life is fixed, and smelly lungs are actually a symbol of the strength of cardiopulmonary function. Yin deficiency is a symbol of whether the reproductive system is healthy, while non-toxicity means that the mind controls the body and regulates the perception of cold and heat. The quality of sleep also depends on non-toxicity.
Three souls and seven spirits originate from Taoism, which advocates health and longevity, and Taoist practice also focuses on longevity, so the significance of three souls and seven spirits mainly lies in treating human diseases and prolonging life.