Centering Merits When Yin And Yang Join
“Centering Merits When Yin And Yang Join ” ( 合符行中 Hefu Xingzhong ) is a term of the science of the Golden Elixir ( 金丹 Jindan ). This term first appeared in the Three Ways Unified and Normalized of the Book of Changes ( 周易參同契 Zhouyi Cantongqi ). There is a phrase in the book, “centering merits when Yin And Yang join between the last day of a lunar month and the first day of the next one”. What’s important is the expression “when Yin And Yang join”, which signifies the combination of the two halves of a talisman. Then what does “centering merits” mean? Here “centering” implies the central place of earth, and the whole phrase means centralizing the inner vital breath in imitation of the fusion of the sun and the moon. It is also necessary to understand the expression “between the last day of a lunar month and the first day of the next one”. It refers to the time when Yin turns into Yang at midnight of the 30th day of the first lunar month. In the alchemical context, a day replaces a month. This expression therefore refers to the time “between the hour of Hai and the hour of Zi of a day”. The hour of Hai indicates ultimate Yin while the hour of Zi indicates the beginning of the birth of Yang. Hence the time “between the hour of Hai and the hour of Zi” is the moment of a day at which Yin changes into Yang. In the practice of Inner Alchemy ( 內丹 Neidan ), one should Collect Elixir Drugs ( 采藥 Caiyao ) and Increase Fire ( 進火 Jinhuo ) at this time. “Centering Merits When Yin And Yang Join” represents the doctrine of “Keeping to the Middle” ( 守中 Shouzhong ) elucidated in The Book of Dao and its Virtue ( 道德經 Daodejing ) by Laozi.