This essay agrees that the two controversial characters on Slip 12 of the Hengxian 亙先 should be transcribed as “ ” and “ ,” and pronounced as “ji” 極. Secondly, with respect to six occurrences of the character “亙” (heng) on Slips 1-9 which Qiu Xigui 裘錫圭 reads as “極” (ji), this essay holds that in the end it should be read as “恆” (heng), and that the reading provided by Li Ling 李 零is acceptable. Therefore, that piece of bamboo slip writing can be named “恆 先” (Hengxian). Thirdly, “亙” (heng) and “亙先” (hengxian), or “恆” (heng) and “恆先” (hengxian), are two concepts, the latter of which is based on the former. “亙” (heng) is more fundamental and more important than “亙先” (hengxian). Scholars mostly equate “恆” (heng) with “恆先” (hengxian), and even regard “恆 先” as the prior expression of this concept. One can hardly say that this is correct. In the bamboo writing, “恆” (heng) actually refers to “tian dao” 天道 (heavenly dao), rather than “dao” in the Laozi. The so-called “恆先” (hengxian) suggests the very commencement of the genesis and evolvement of Heavenly dao, which is somewhat equivalent to “taishi” 太始 (grand commencement) in the Huainanzi 淮南子. Fourthly, in the Hengxian, “恆” (heng) implies objective and natural laws, while “極” (ji) suggests ought-to-be rules. “極” (ji) in the bamboo writing is actually informed by “恆” (heng).