This paper explores when and how the development of interpretations regarding the relationship between the Inherent Obstruction (自性障) mentioned in the Yuqi jing 瑜祇経 and the Infinitesimal Attachment (微細妄執) mentioned in the Hizōki 秘蔵記 occurred in annotated editions of the Yuqi jing in Shingon Esoteric Buddhism.
Jichiun 実運 (1105–1160) of Daigoji, a Shingon esoteric monk, introduced the concept of Infinitesimal Attachment into the interpretation of the Yuqi jing as an index for distinguishing whether or not inherent obstruction can become Vajrasattva and obtain mokṣa. However, Jichiun did not consider inherent obstruction and infinitesimal attachment to be the same.
The identification of inherent obstruction and infinitesimal attachment is likely to have been made for the first time by the later Shingon esoteric monks Jichigen 実賢 (1176–1249) and Dōhan 道範 (1179–1252).
However, not all Shingon scholars after Dōhan were influenced by Jichigen and Dōhan. In some cases, they developed their own doctrines, as did Yūban 宥範 (1270–1352), who belonged to the school based in Izu 伊豆流. This shows the diversity of Shingon Buddhism.
