Traditional Chinese medicine believes that essence, qi, and spirit are the three treasures of the body and are the internal factors for disease prevention and longevity. Essence and qi are also the material basis of spirit.
When essence and qi are abundant, the spirit is flourishing; when essence and qi are deficient, the spirit becomes weak. The spirit is the external manifestation of the entire body's life activities, including one's mental state and thinking activities. The spirit holds a paramount position in the human body, and only with the presence of the spirit can all the phenomena of human life activities occur. Ancient health experts emphasized, "With a strong spirit, one can live longer." Here, a "strong spirit" refers to a healthy brain and spirit. Only with a healthy brain and spirit can one govern life activities, coordinate organs, control body movements, and have well-functioning sensory organs, maintaining a normal physiological balance between yin and yang. Therefore, it is said that having abundant essence, abundant qi, and a complete spirit is the foundation for health and longevity, and the key to regulating essence, qi, and spirit lies in nurturing the spirit.
Throughout history, medical practitioners, Taoist scholars, and health experts have placed great importance on mental cultivation and the role of psychological therapy in health preservation. They believe that the key to health preservation lies in eliminating distracting thoughts, maintaining a pure and focused mind, and following the principles of nature. By doing so, one can achieve the goal of health preservation. They believe that "those who properly nourish themselves do not strain their minds or exhaust their bodies. With a peaceful spirit and a harmonious form, how can misfortune and illness arise?" Renowned physician Shi Tianji composed a song called "Song for Dispelling Disease": "Some people are born with weak qi and blood, unable to enjoy a happy life without falling ill. When illness occurs, one should maintain a cheerful heart, and the illness will be dispelled. If the heart is troubled, no medicine will work. So, let us sing a joyful song, which is the elixir of eternal life."
