In East Asian commentaries on the Abhidharmakośa, the issue of the structure of the text has long been controversial. Commentators have discussed the issue, known in Japanese as sanbun-funbetsu 三分分別, in the context of the hermeneutics of Xuanzang’s translation of the Abhidharmakośa. However, Kaidō快道, a Japanese scholar-monk in the Edo period, declared a new theory on the textual history of the Abhidharmakośa in the sanbun-funbetsu controversy. In this paper, I clarify that, against the background of Kaidō’s theory, the value of the Xuanzang translation changed from that of an authoritative translation of the Abhidharmakośa to one of several sources to study the original text.
