Teachings of the chan schools
Insisting on silent meditation as the most direct means of realizing the Buddha's experience of enlightenment, all chan schools in China rejected a formal and systematic study of Buddhist philosophy, derived from the scholastic traditions of India and cultivated especially at the principal Buddhist university-monastery of Nalanda. Instead, a distinctive type of dialogue discourse using statements expressed in metaphor and symbol came into existence during the course of the 8th century.
Personal conversations between students and teachers which seemed to provoke or demonstrate in a meaningful way various insights into dharma truths were transcribed for the benefit of other students. In the late Tang and early Song periods, various of these recorded dialogues were selected and codified into collections of gong an [koan], or "public cases," and, with the publication of additional elaborative commentary also expressed in metaphor and symbol, were by the 12th century used as the main method of instruction in probably all of the chan sects. Indeed, one can distinguish the Five Houses or chan schools during the Song period by the individual techniques developed by each to handle the study of koans. However, production of this discourse declined toward the end of the 13th century in China, the publication of Wumen Hukai's Wumen kuan [The Gateless Barrier] being the last major collection of koans with commentary to appear. We can therefore view the chan literature as a closed system of symbolic discourse, originating with the anecdotal teacher-student conversations of the early Tang and ending with the koan collections and commentaries ofthe late Song, a period lasting roughly six centuries.Although the original philosophic teachings of Buddhism are seldom mentioned explicitly in this uniquely Chinese discourse, they are nonetheless the substance underlying the statements involving sign and symbol. In other words, they are the meta-language upon which the discourse itself is based. Far from representing a rejection of traditional Buddhist philosophy, the chan literature is in reality a symbolic expression of it. Almost all chan statements originating with any sect or master point to one of three general Mahayana positions: the theory of emptiness (from the Prajna-paramita sutras and the Madhyamika literature); the theory of thusness (or non-duality); and the theory of tathagata-garbha, "buddha-matrix" or "buddha-essence," which has been commonly translated from Chinese into English as "Buddha-mind" or "Buddha-nature." Emptiness (sunyata) is the Mahayana Buddhist perception that all phenomena, physical and mental, are impermanent, and that none exist independently of others. However, this is understood not simply as a metaphysical statement about reality, but also and more importantly as an object of intuitive awareness: in other words, emptiness is additionally an experience, one which can be realized and actualized through meditation. The term "thusness" (tathata), often translated as "suchness" in English, appears first in the Prajna-paramita sutras. It refers to the way in which phenomena exist a priori, before conceptualizing, or any form of subject-object discrimination, occurs in relation to them. It is the inherent state of apparent reality viewed from the position of emptiness, or ultimate truth. When mental projections stop, phenomena exist in a state of self-identity, or sameness (samata). All things remain just as they are, in their basic condition of oneness or totality, called also non-duality. The term is used in different theoretical contexts by different Indian schools, including the Madhyamika, Vijnanavada and Yogacara, and is often mentioned in various of the later tantras. It is likewise a key teaching in Da sheng qi xin lun (Awakening of Faith in the Mahayana), a work which appeared around 550 and which had considerable impact on the development of Buddhist thought in China. The term tathagata-garbha, which I will translate here as Buddha-nature, appeared in a number of Indian sutras and sastras (sutra commentaries) between 250 and 400 CE. It means in Sanskrit either "embryonic Tathagata"—i.e., the Buddha who will appear—or it means "womb of the Tathagata"—where the Buddha will come from. It refers to the Buddha-essence in all sentient beings, the unrealized potential for enlightenment, which will enable the individual to give birth to Buddhahood. In Chinese, the term was originally translated as ru lai zang, but later as fo xing, after Chinese philosophical commentaries had begun to elaborate upon the concept, and from the latter we have received the translations "Buddha-mind" or "Buddha-nature" in English. In the 4th- and 5th-centuries, tathagata-garbha theory was incorporated into the Yogacara system by its leading theoreticians Maitreyanatha, Asanga and Vasubandhu. It is a key teaching in the Lankavatara sutra, which was very influential in the chan movement in the early 8th century, and it achieves especial prominence in the story of the recognition of the Sixth Patriarch's enlightenment, by his master, Hongren. The Indian Mahayana term expresses the idea that all sentient beings have within them the essence of Buddha-hood, and thus, by awakening bodhicitta, the mind of enlightenment, the ability to develop themselves into Buddhas. The Buddha-essence, the inner potential within everyone, becomes hidden by defilements, which obscure the perception of dharmakaya: the essence of the universe, the identity and unity of Buddha with everything that exists.
In chan, the tathagata-garbha concept takes on a dynamic, self-generative aspect: for Shitou Xiqian it is truly the source of all creation. The mirror is a constant metaphor for Buddha-nature; to practice Buddhism is to reveal the "luminous mirror-wisdom" within. Tathagata-garbha is also the basis for "the mind is Buddha" teaching of the Southern chan schools in the 8th century, referred to repeatedly by Shitou and Mazu.