1 The ancient Daoists of China understood that heaven is a great universe, and a human being is a small universe. Heaven has four seasons and eight yearly solar terms;  a human being has four limbs and eight extraordinary channels. Heaven has its periodic cycles; in humans, there is the natural circulation of qi-and-blood, which is also a celestial cycle.
2 The human body utilizes the law of reciprocity to attune matter with nature. Through a process of spiritual and bodily tempering, one will eventually break through the constraints of the physical world. The transformation of qi causes wondrous transformation of body and spirit, bringing eternal life. Thus one enters the eternal spiritual realm of anthro-celestial union.
3 This is part of the spiritual civilization that was handed down by our ancestors. Furthermore, it shows that for the past 5,000 years, the Chinese people have believed that a spiritual world exists beyond the material world. Thus, I say that the highest realm of Chinese thought has always been anthro- celestial union.
4 The Chinese people say: “As an ideal form emerges in heaven; a physical form remains on Earth.” That is to say, first there is the spiritual world, and then there is the material world. The realm of anthro- celestial union is the spiritual world.
5 These ideas confirm that quiet sitting is related to the union between heaven and humanity.
6 From this we know that advanced cultivation of quiet sitting, at the very least, can prevent illness and extend life, bringing good health and longevity. It can probe the mysteries of the universe and the ultimate in human life. It lets man communicate with spirits and unveil revelations from heaven. It can prolong our stay on Earth to save this world and to discharge our affinities. Taken to its fullest, it can transcend the mundane and enter the sacred. It can give everlasting life and return us to oneness with nature.
An Academic Lecture, October 27, 1979
 The eight solar terms throughout the year are the beginning of spring, summer, autumn, and winter, spring and autumnal equinox, and summer and winter solstices.