The Yellow Emperor’s Inquiry: Understanding the Three Yin and Three Yang

The Yellow Emperor asked: “I have heard that the heavens are Yang, the earth is Yin, the sun is Yang, and the moon is Yin. The combination of full and hollow months completes a year of 360 days, corresponding to the human body. Now, I’ve heard that the three Yin and three Yang in the human body don’t match this count of cosmic Yin and Yang. Why is that?”

Qi Bo answered: “The scope of cosmic Yin and Yang is vast. Through further elaboration, it can extend from ten to a hundred, from a hundred to a thousand, from a thousand to ten thousand, and beyond, yet the fundamental principle remains the unity of opposing forces. Due to the heavens’ coverage and the earth’s support, all things are born. When below ground, they are in the Yin within Yin; when above ground, they are in the Yin within Yang. With Yang energy, things grow; with Yin energy, they take form. Thus, the birth of all things comes from spring warmth, their growth from summer heat, their harvest from autumn coolness, and their storage from winter cold. If the seasonal Yin and Yang lose order, climatic instability ensues, disrupting the natural cycles of growth and storage. These Yin and Yang principles also apply to humans and can be inferred.”

The Yellow Emperor said: “I would like to hear more about the interplay of the three Yin and three Yang.”

Qi Bo explained: “Facing south, the sage stands, with the front called Guang Ming and the back called Tai Chong. The meridian running through Tai Chong is Shao Yin. Above Shao Yin is the Tai Yang meridian, starting at the Zhi Yin point on the outer side of the small toe and ending at the Jing Ming point, as Tai Yang is the external aspect of Shao Yin, making it Yang within Yin. Considering the body’s vertical alignment, the upper body is Yang, called Guang Ming, and below it is Tai Yin. The meridian in front of Tai Yin is Yang Ming, starting at the Li Dui point next to the big toe, making it Yang within Yin as Yang Ming is the external aspect of Tai Yin. Jue Yin is internal, and Shao Yang is external, making the external aspect of Jue Yin the Shao Yang meridian, starting at the Qiao Yin point. Shao Yang is external to Jue Yin, making it lesser Yang within Yin. Therefore, separating the three Yang meridians, Tai Yang governs the exterior, Yang Ming the interior, and Shao Yang acts as the pivot between exterior and interior. However, these three are interconnected, forming one Yang.”

The Yellow Emperor said: “I would like to hear about the interplay of the three Yin.”

Qi Bo responded: “Externally is Yang, internally is Yin, so internal meridians are Yin meridians. The meridian in front of Shao Yin is Tai Yin, starting at the Yin Bai point on the big toe, making it Yin within Yin. Behind Tai Yin is Shao Yin, starting at the Yong Quan point on the sole, making it lesser Yin within Yin. In front of Shao Yin is Jue Yin, starting at the Da Dun point on the big toe, as two Yins converge without Yang, with Jue Yin being the innermost, making it the absolute Yin within Yin. Separating the three Yin meridians, Tai Yin governs the exterior, Jue Yin the interior, and Shao Yin is the pivot between exterior and interior. Yet, they work in harmony, forming one Yin. Yin and Yang energies circulate continuously, transmitting throughout the body, Qi moves internally, and form manifests externally, illustrating the unity and interplay of Yin and Yang, exterior and interior.”