Neidan 內丹 — Part II
Question
Where is the Original Cavity of Spirit (Ziqiao 紫竅) located?
Answer
It is situated at the Trikuta, the point between the eyebrows, extending inward to the center of the brain. Laozi called it the “Passage of Heaven and Earth” (Tiandi Men 天地門). Therefore, he advised practitioners to concentrate upon this center in order to realize the Self-Nature underlying all things.
Within this center resides a subtle point no larger than a grain of rice. It is the midpoint between Heaven and Earth within the human body, the Microcosm. It is the cavity of Prenatal Vitality (Xiantian Qi 先天氣).
Yet it is not sufficient merely to know its location, for the cavity itself does not include the wondrous Light of Original Nature (Benxing 本性), symbolized by the Circle and referred to by Confucius as Perfect Virtue (Ren 仁).
The Book of Changes (Yijing 易經) calls it the Limitless (Wuji 無極). The Buddha called it Perfect Enlightenment. Daoists refer to it as the Elixir of Immortality (Jindan 金丹), or Spiritual Light.