Wuji (無極) is the primordial state of non-being, a state of Nothingness and boundlessness or that which is without Bounds or Limits. Wuji like Tao, is and lies within all of the universe and in the human anatomy. It is the central definition to what Tao is in chapter one of the Tao Te Ching.
In Xiuzhen, Wuji or Dao is a state of Hunyuan Yiqi (混元一炁) in which Hunyuan is the Chinese equivalent of primordial, Yiqi is the one qi the original state of qi, together Hunyuan Yiqi is loosely the primordial qi. The state of Taiji is Xiantian Yiqi (先天一炁), or pre-birth qi. Note the word Qi (炁) differs to blood circulation in qigong.