generally translated as “defensive qì,” and in modern Chinese medicine closely associated with the western concept of immunity, by practitioners of modern Chinese medicine. While the character wèi (衛) means “to defend,” the mental shorthand many practitioners accept from their training in modern Chinese medicine distorts the classical idea.
Wèi (衛) is one of the Three Qì, as mentioned in the opening passage of Sùwèn 3. These three qì are fundamental to, and indeed define, individual human life. Wèiqì (衛氣) is intrinsic and autonomic. It moves through the terrain of the skin and sinews — both external and internal. Wèiqì (衛氣) naturally profuses upward and outward through the còulǐ (腠理). One of its key functional movements is closing and opening: when wèiqì (衛氣) closes, it consolidates — gù (固), which protects the embodied spirit from ‘external pathogenic factors’ (xiéqì (邪氣)), and gathers yáng (陽). However, some disruptive influence (xiéqì (邪氣)) often enters, anyway. If the wèiqì (衛氣) is closed, one does not immediately release or expel the xiéqì (邪氣), which has entered. The best it can do is block further penetration, by closing even more forcefully. This gathers even more yáng (陽), which does not release outward, but instead becomes (pathological) heat. When wèiqì (衛氣) opens, it can effuse (fā (發)) freely, both spreading warmth and releasing out stagnation and the heat it generates, whether or not that stagnation is due to the accumulation of xiéqì (邪氣). However, this process of blocking xiéqì (邪氣) from penetrating through closure has been well recognized historically within Chinese Medicine; it is called shàoyáng (少陽), and while it effectively blocks the penetration of xiéqì (邪氣), it also blocks it from being released. Both the opening and closing of wèiqì (衛氣) are vitally important movements.« Back to Glossary Index