Unfixed Zi Phase
The "Unfixed "Zi" Phase"( 活子時 huozishi ) is a term of Inner Alchemy ( 內丹 neidan ). "Zi" was not only a time in ancient China, but also a symbol of the beginning of things. The ancients matched the twelve Terrestrial Branches ( 地支 dizhi ) with the twelve Trigrams of Waxing and Waning ( 消息卦 xiaoxi gua ) in the Book of Changes ( 周易 zhouyi ) and supplemented them with the twenty-four solar terms to describe the changes throughout the year. In the calendric system of the Zhou dynasty, the Winter Solstice in the eleventh lunar month and the Zi hour matched and were signified by the Fu (return) trigram, which stands for the initial rising of the one-Yang on one hand, and the orientation of due north on the other hand. According to the principle of Oneness of Heaven and Man ( 天人合一 tianren heyi ), Daoist Inner Alchemists also use the Zi hour to indicate the initial emergence of the one-Yang. But this time is unfixed. It varies with one’s feelings. The Four-hundred-word Book of the Golden Elixir ( 金丹四百字 jindan sibai zi ) says, "the time of Fire Phases ( 火候 huohou ) is unfixed, and why must the Winter Solstice be fixed at the Zi hour?" That is to say, in Inner Alchemy cultivation, the Fire Phases cannot be fixed to a certain time, and the "Winter Solstice" in the human body (the initial emergence of the one-Yang) does not have to correspond rigidly to the "Zi" of the twelve Terrestrial Branches. It shows what "unfixed" means. Then how can one feel the "Unfixed "Zi" Phase"? Daoism believes that when the mind rests still, the body mechanism is activated spontaneously, and a stream of inner breath descends to the acupoint of perineum. In this case, a male's penis will erect, and a female will also feel comfortable and relaxed. These are indications of the "Unfixed "Zi" Phase" in body. If a practitioner has such feelings, he should collect elixirs and place them back to the Elixir Field ( 丹田 dantian ), and by refining them, transform the Essential Matter ( 精 jing ) into the Vital Breath ( 氣 qi ) according to the instructions of Inner Alchemy cultivation.