To Reduce Fire
"To Reduce Fire"( 退符 tuifu ) is a term of the science of the Golden Elixir ( 金丹 jindan ). "Tui Fu", namely, "to reduce fire", is a way of controlling the Fire Phases ( 火候 huohou ) in opposition "Increasing Fire" ( 進火 jinhuo ). In the science of the Golden Elixir, "Fu" refers to the signs of the Hexagrammantic Lines ( 卦爻 guoyao ). Alchemists take the twelve Trigrams of Waxing and Waning ( 消息卦 xiaoxi gua ) (i.e., Fu, Lin, Tai, Dazhuang, Guai, Qian, Gou, Dun, Pi, Guan, Bo and Kun) in the Book of Changes ( 周易 zhouyi ) to be the indicators of changes in the Yin and Yang natures of Fire Phases. These twelve trigrams represent the principle of the increase and decrease of Yin and Yang. Among them, for the first six trigrams, Yang increases and Yin decreases; while for the last six trigrams, Yin increases and Yang decreases. Alchemists match the twelve trigrams with the twelve Terrestrial Branches ( 地支 dizhi ) to show the changes in Yin and Yang in the process of controlling Fire Phases. "To increase fire" is denoted by the first six trigrams, while "to decrease fire" is denoted by the last six trigrams; the former starts at the Zi hour, while the latter starts at the Wu hour. Yang decreases and Yin Increases after the Wu hour, so one should take care to make Yin dominate. But for Inner Alchemy, the hours of Zi and Wu are also flexible. What counts is not the fixed time, but the internal feelings of one’s own mind and spirit after the true breath activates. To understand "decreasing fire", one must pay attention to this point.