A Doctrine Radical Enough to Include Plants

Chinese Tiantai teaching had already argued that buddha nature extends to insentient things, but medieval Japanese Tendai scholiasts pressed the claim to its most literal edge, holding that grasses and trees themselves attain buddhahood, not as a figure of speech about interconnection but as a doctrinal statement about what enlightenment already is. Jacqueline Stone's history of the doctrine traces its rise from roughly the eleventh century through material transmitted in oral and quasi secret lineage documents inside the Tendai school called kuden, teachings passed master to disciple and eventually written down, rather than through public treatise writing aimed at a wide readership. The doctrine's core distinction is between hongaku, original enlightenment, the buddhahood every being already possesses simply by existing, and shikaku, acquired enlightenment, the buddhahood reached through practice and realization understood as a process; hongaku thought increasingly treated the second as a derivative or even illusory restatement of a fact, original enlightenment, that never actually needed producing in the first place. Stone stresses this was not fringe speculation. It became the operating assumption behind mainstream medieval Tendai institutional teaching for several centuries.