Nan Jing, Chapter 69: Mother-Son Tonification and Reduction
In deficiency tonify the mother, in excess reduce the son: the five-phase method of point selection.
Nan Jing (难经)General Principles of Needling
ENGLISH TRANSLATION
The English is translated from the Chinese vernacular. The original text and its pinyin sit beneath each sentence in smaller type; hide them whenever you prefer to read the translation alone.
Question: The classic says, tonify the deficient, reduce the excessive, and where there is neither excess nor deficiency take it from the channel itself. What does this mean?
As for neither excess nor deficiency and taking it from the channel: the illness arises in the channel itself and was not struck by evil from another channel, so one takes from that channel; hence “take it from the channel”.
The sixty-ninth difficulty states the rule that governs five-phase point selection: in deficiency, tonify the mother; in excess, reduce the son. Applied to the channels, it means that a deficient channel is treated at the point corresponding to the phase that generates it, and an excess channel at the point corresponding to the phase it generates.
The rule has two forms, one within a single channel and one across channels, and the two do not always agree. Later authors argued about which was intended. Both are taught, and the disagreement itself is instructive about how classical formulas were received.
ANNOTATION
Mother and child (母子): in the five phases, what generates me is mother; what I generate is child.
Illness generated by the channel itself (正经自生病): disorder arising in the channel itself, not transmitted from another channel’s evil.
COMMENTARY
Mother-child tonification and reduction is the most refined use of the five transport points, and also the most easily reduced to formula. Remember that tonifying the mother and reducing the child is one line of thought in point selection; applied mechanically without regard to the whole pattern, it departs from the Nanjing’s intent. The line “neither full nor empty, take it by the channel” is precisely the guard against that rigidity.