“Deviant Teachings”: The Tachikawa Lineage as a Moving Concept in Japanese Buddhism

In modern studies of esoteric Buddhism in medieval Japan, the so-called Tachikawa lineage has played a central role in defining heretical or heterodox practice. Founded in the early twelfth century, this minor and local lineage of the Shingon school underwent a series of transformations, eventually becoming a model for all heresies in Japan. In medieval Japan, the term “Tachikawa” was irredeemably associated with explicit sexual practices, especially in the writings of the Mt. Kōya monk Yūkai and his successors. These polemical critiques of Tachikawa as a deviant lineage and teaching developed into a tradition of textual study that sought to establish an orthodoxy in the Shingon school. This critique was later applied beyond the Shingon sectarian context to instances of heresy in the Jōdo Shin school and, eventually, Christianity. This heresiological process gradually resulted in a multilayered, “moving concept” of Japanese heresy, which came to fruition during the nineteenth century with the introduction of the Western ideas of religion and heresy.