 Daoism represents the celestial realm as different systems of “heavens”, usually arranged hierarchically. In several cases, these domains are not only the residences of deities, but also correspond to degrees of priestly ordination and to inner spiritual states, and are associated with revelations of teachings and textual corpora. The existence of multiple systems reflects the development of the religion. Different traditions created their own systems in order to demonstrate that the respective methods derive from a superior celestial domain compared to those of other traditions, and therefore are more effective or grant access to a higher spiritual state.