This article examines Zhanran’s discourse on “the Buddha-nature of insentient beings” and “non-duality of matter and mind” on the basis of his Shibuermen and Jingangpi. The theoretical foundation of Zhanran’s idea of the compatibility of Buddha-nature and Dharma-nature, and the contiguity of sentient beings and insentient beings lies to a large extent in the interdependence between mind and matter. For this reason, one can easily find in his concept of “the Buddha-nature of insentient beings” discussions on the relationship between matter and mind. In his Shibuermen, the notion of “non-duality of matter and mind” is given the first place, on which the rest “nine doors” are based, which underscores the importance of the aforesaid notion in his thoughts. In practice, the concept of “non-duality of matter and mind” sets in motion a return and a movement towards a worldview of “three thousand realms in a single moment of life,” in such a way as to put in place an expansive spiritual structure in our inner heart whereby we can arrive in a matter of an instant at the unfathomable spiritual realm of the union of mind and matter, as well as that of the ordinary man and the sage.
