The Teachings of Shitou Xiqian

Shitou's teachings are seen in two sources: the biography and recorded sayings from the Song histories, and two long discursive poems which summarize his distinctive approach to chan practice. The numerous conversations with his students focus thematically on statements of emptiness, thusness (non-duality), and Buddha-nature (tathagata-garbha) theory. They conform generally to the mainstream chan literature disseminated during the Song period. The numerous references to Huineng and his temple in Cao Xi indicate a strong intention to conform to the lineage of the Southern School, which was in the process of establishing itself as the dominant chan movement during Shitou's lifetime. Repeated references to sutra study and mention of a work by the 5th-century Chinese dialectician Sengzhao show that Shitou had a strong knowledge of Buddhist literature and philosophy. Of great importance is Shitou's lengthy acknowledgment of "the mind is Buddha" teaching, which was also popular with other chan masters in the 8th century, being mentioned in the Record of Mazu as well as in the Platform Sutra. A direct statement of Buddha-nature theory, it identifies the human mind in its pristine or undefiled state as synonymous with the enlightened mind of Buddha.
Two longer poems attributed to Shitou present new perspectives to our understanding of his personality and career as a chan master. In the Grass Shack Song we see him newly arrived on South Mountain, living in the meditation hut he built for himself on top of a large flat rock. The poem is actually a restatement in Buddhist terms of a Taoist archetype, namely that of the hermit or "mountain sage" who has forsaken the conflicts and business of social existence to pursue a spiritual path. This is a common topos in Tang-period poetry, translated in this case to the realization of the universal Buddha-nature. The possibility of solitary meditation in a mountain wilderness seems to have largely disappeared with the gradual establishment of the chan monasteries and the increasing regimentation of monastic life, so we might think that the monks of the Song period may have looked back nostalgically to a more individualistic era. In any event, the poem's obvious enthusiasm for a do-it-yourself Buddhist lifestyle is, with the exception of Han Shan's Cold Mountain poems, quite unique in Buddhist literature, and also confirms the Sixth Patriarch's position that the real teacher resides within the individual mind and not necessarily within the walls of a monastery.
Shitou's other great poem, The Agreement of Difference and Unity, presents the teaching of li and shi, principle and phenomena, which originated in its Buddhist form with the masters of the Huayan school. Phenomena emerge from principle, the spiritual source, and are inseparable from it. One and many exist in a state of agreement, since neither may arise without the other. All creation derives from the interaction of principle with phenomena. In their interaction, not only the dual, polar forces of cosmic creation, but also all conceptual opposites are reconciled. Tacit to this conception is the assumption that, in traditional Buddhist terms, emptiness may be substituted for principle: since all phenomena are characterized by their emptiness or lack of substantial reality, and because emptiness is not cognizable apart from phenomenal existence, no inherent opposition can exist between them, or indeed between any other pair of conceptual opposites, since both sides are empty to begin with. Thus samsara and nirvana are one, and accordingly the worlds of enlightenment and non-enlightenment. Also tacit, in the context of Buddhist practice, is the conviction that the agreement of difference and unity may be intuitively experienced through the process of meditation.
Seen historically, Shitou's poem is an expression of allegiance to the Southern School, which became established almost exactly within his lifetime as the dominant school of chan. The poem opens with the lines, "The mind of India's great sage was quietly confided from west to east." We know that the idea of a direct mind-to-mind transmission between master and student was not a basic issue in chan teachings until Shenhui made it so by attacking the legitimacy of Shenxiu's dharma lineage, replacing it with the allegedly authentic transmission from Hongren to Huineng. This was clearly the core of Shenhui's attempt to discredit the Northern School; subsequently the belief in a direct mind-to-mind transmission from Sakyamuni Buddha downwards, not based in other words on just the written teachings of Buddha, became an inevitable and essential belief of the chan school, as ultimately and extensively documented in the "transmission of the lamp" chronicles of the Song period.
Shitou quotes the Platform Sutra almost directly when he states that in the Path (i.e., from the standpoint of ultimate truth), no differences exist between Southern or Northern ancestors. Numerous other obvious references exist in The Agreement of Difference and Unity as well and are listed here in Appendix 3, which provides an annotated version of the poem. If it is true that parts, if not all of the Platform Sutra originated not with Huineng, but with the disciples of Shenui during the time of Shitou's teaching career, it is certainly possible that Shitou, who with Mazu had a very large following of students and disciples, may have played a significant part in helping the Southern School achieve its prominence. In any event, The Agreement of Difference and Unity clearly indicates a strong desire to conform to the newly emerging teaching tradition.