In the early Tang Dynasty, the orthodox Consciousness-only thought which was transmitted from India by Xuanzang （602–664） had a completely different personality from the Dilun and Shelun Schools, which had been widely spread and deeply influenced by the thought of tathāgatagarbha. At the beginning of the introduction of Consciousness-only thought, there was a heated discussion in the Buddhist community between the theory that “All Sentient Beings Attain Supreme Enlightenment” and “Exclusion from Attaining Buddhahood,” that is, how to explain the One Buddhist Vehicle became the core issue of debate at that time. The Śrīmālādevīsiṃhanādasūtra played a noteworthy role, used by both camps as a representative sūtra which they eagerly cited. Yuance 円測 regarded the Śrīmālādevīsiṃhanādasūtra as holding that the One Vehicle was an expedient measure, with the Three Vehicles as the ultimate reality. Kuiji 窺基 believed that the same sūtra was the ultimate teaching,which presented the Four Vehicle as accomplishing ultimate reality, with the One Vehicle being an expedient measure. Fabao 法宝 regarded the Śrīmālādevīsiṃhanādasūtra as preaching the ultimate One Buddhist Vehicle, and Huiyuan 慧苑 criticized Fabao in his Nengxian zhongbian huiri lun 能顯中辺慧日論 （T. 1863）. It can be seen that the Śrīmālādevīsiṃhanādasūtra played an important role in the debate on the One Buddhist Vehicle in the early Tang Dynasty. How, then, did famous patriarchs at that time use the Śrīmālādevīsiṃhanādasūtra to argue for their own theories? This paper explores the position of the Śrīmālādevīsiṃhanādasūtra in the interpretations of the One Buddhist Vehicle, focused on the ideas of Yuance, Kuiji, Fabao and Huiyuan.
