In contemporary Chinese Herbal Medicine education, herbs and herbal formulas are classified according to the Eight Methods. This organizational system poses a challenge for students learning Chinese Herbal Medicine because it is not integrated with the foundational principles of Chinese Medicine. Allow me to elaborate.
The system of placing herbs and herbal formulas in categories belongs to Cheng Zhong-Ling. He was a doctor during the Qing dynasty.
Cheng organized herbs and formulas into Eight methods. Most of us have learned these categories in our basic educations. They are:
Sweating, Vomiting, Draining Downward, Harmonizing, Warming, Clearing, Reducing, and Tonifying.
These categories are treatment methods and in clinic they are useful. Yet, they do not help us understand the herbs and formulas that we use. The categories not are organized according to the basics of Chinese Medicine.
The basics of Chinese Medicine are Yin and Yang, the Five agents of transformation or Five elements, and the Six climatic influences.
All herbs and herbal formulas need to be understood according to the basics of Chinese Medicine. So we need to the define herbs and formulas according to Yin and Yang, the Five elements or Six qi.
All herbs and herbal formulas must represent human physiology, pathology and treatments at the same time.
For example the most common herb Gui zhi, Cinnamomi cassiae ramulus is:
Gu zhi is a Yang and Yin herb. It is Yang because it warms and moves. It is Yin because it nourishes.
Gui zhi is a Wood, Fire and Water herb. It is Wood because it warms, moves, and nourishes Wood. It is a Fire herb because it warms, moves, and nourishes Fire. It is a Water herbs because it warms and moves Water.
Gui zhi is a Tai yang and Shao yin herb. It is a Tai yang herb because it warms the surface. It is a Shao yin herb because it warms the Heart and Kidneys. Tai yang and Shao yin are internal and external couples.
Describing herbs like this give us a general understanding of how gui zhi represents physiology and pathology.
This now makes it easier to understand why gui zhi is placed in the Sweating, Warming and Tonifying categories.
Next time you are learning a new herb look at the characteristics of the herb and try describing it according to Yin and Yang, Five elements, and Six qi. Then look at formulas that contain the herb and try to understand what the herb is doing in the formula.