"observing emptiness;" the meditative practice in which one observes the lack of inherent nature in all things. The observation of the emptiness of all things， based on the Buddhist principle that all things arise through the process of dependent co-origination. A common Maha^ya^na explanation of the practice of the meditation on emptiness is that in which the two "hi^naya^na" practitioners （/sra^vaka and pratyekabuddha）， meditating on the emptiness of self 我空 succeed in overcoming the hindrances of defilement 烦恼障， while bodhisattvas， contemplating the emptiness of dharmas as well as the emptiness of self 我法二空， succeed in overcoming the hindrance of the known 所知障. ［二障义HPC 1.792c］Nakamura includes an explanation of Tiantai specific connotations of this tersm.