The bamboo slip essay Hengxian 恒先 is historically valuable because it serves to further the ontological understanding and comprehension of issues related to the existence of the universe from the perspective of Laozi’s Daoist thought. Hengxian explores important propositions such as how “Qi originated and activated itself” and “they came out of the same source but differed in nature” from several aspects. The idea that “Hengxian is ‘being’ without any definiteness” responds to the issue of the relationship of difference and identity of all things in the world, and thus examines the interdependent relationships between subjects and objects. It proposes that humans can further understand the existence of the universe through cognitive activities and practices such as “analysis and comparison” in which objective realities are checked. The issues discussed in Hengxian are consistent with Laozi’s Dao de jing, the works of Zhuangzi, Huangdi sijing 黄帝四经 (The Four Classics from the Emperor Yellow) and other Daoist works, and deserve significant attention.