by Eric Brand Today in clinic we were looking for Sang Ji Sheng on the shelf, and one of the students filling the formula couldn't remember whether it was classified as a wind-damp-dispelling medicinal or whether they should look for it on the yin-supplementing shelf. Actually, it could be easily placed on either shelf, and different books classify it differently. A similar situation is true for a number of medicinals. Chinese herbal medicine as we know it today has advanced gradually over the past 1800 years. Throughout much of Chinese medicine’s history, the body of available literature has been vast but rather difficult to navigate by modern standards. The idea of an index is relatively new, and often indexes in Chinese texts even today are not as useful as they could be. Other features of historical Chinese works, such as the traditional binding method and the lack of punctuation, made the ancient literature much harder to deal with. Certainly ancient doctors didn’t have the ability to do a simultaneous digital search of modern and classic texts when they wanted to research a topic.

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Over the course of the centuries, a variety of approaches have been used to classify medicinals. While the Chinese medical tradition was rich in its scope, the idea of using modern educational methods and an organizational style more effectively designed for teaching is relatively new. Organizing medicinals into categories based on their functions appears to be largely a prevalent trend only in modern times. Without a doubt, organizing medicinals by their actions makes the subject easier to teach and easier to learn. Nonetheless, because it is a relatively new phenomenon, there is not an absolute consensus on how each medicinal should be categorized. My horticulture teacher in college, a botanist by training, often remarked that the difficulty in classifying plants was compounded by the fact that “plants don’t read books.” They don’t fit nicely into the little boxes and categories that we like to use to organize them. In Chinese medicine, many medicinals do fit into categories relatively cleanly, but some do not. For example, no one would question the placement of Fu Zi (aconite) and Rou Gui (cinnamon bark) in the interior warming section, but Xi Xin (asarum) tends to be found in the interior-warming section in some books and the exterior-resolving section in other books. The assignment of medicinals to categories and the divisions in the categories themselves often differs slightly from one core textbook to the next. In ancient times, the earliest materia medicas grouped medicinals into “superior, middle, and inferior” substances, with the connotation that toxicity and medicinal potency were interrelated. Much of the historical literature uses the plant part or category of nature to group the medicinals (seeds, herbs, roots, insects, minerals, etc). A few historical books organize the medicinals by disease or other schemes, and some modern encyclopedic volumes list the medicinals by stroke order, basically the Chinese equivalent of an alphabetical listing as in a dictionary. The main modern method uses categories of function, such as blood-quickening medicinals, and some books break down the chapters into subchapters that differ from source to source. The categories (chapters) in a modern materia medica are largely consistent but some categories are prone to variance. The same can be said with medicinals. For example, Shi Gao (gypsum) is always found in the heat-clearing, fire-draining chapter, and we can always find a heat-clearing, fire-draining chapter in a materia medica textbook. But some books contain a vacuity-heat clearing subsection, while others do not. Below are some examples of single medicinals that are commonly found in different chapters in different books. This list is not comprehensive by any means, and it tends to reflect differences of opinion as to what the primary or most important action of a given medicinal is. Xi Xin (interior-warming vs. exterior-resolving) Sang Ji Sheng (wind-damp vs. supplementing) Gui Sui Bu (blood-quickening vs. supplementing) Bai Bian Dou (summerheat vs. supplementing) Chan Su (orifice-opening vs. external use chapter) Ma Qian Zi (blood-quickening vs. external) Niu Huang (heat-clearing vs. orifice-opening) Lu Dou (heat-clearing toxin-resolving vs. summerheat)