Chengguan (738-839), the fourth patriarch of the Huayan tradition of Chinese Buddhism, formed and elaborated the theory of the four dharma-dhātus, i.e. the dharma-dhātu of phenomena, the dharma-dhātu of principle, the dharma-dhātu of the non-obstruction of phenomena and principle, the dharma-dhātu of the non-obstruction of phenomena and phenomena. With this invention he could synthesize two classical Huayan concepts, the nature origination, which explains the origination of phenomena from the Absolute, and the dharma-dhātu dependent arising, which depicts the interrelatedness of phenomena. Due to the increasing influence of Chan Buddhism, in Chengguan's teaching the four dharma-dhātus became closely associated with the Buddhist praxis, the meditation, and soterology, the bodhisattva path.