This paper aims to examine the development of the discussions regarding whether to recognize the existence of the two vehicles in the writings of Zhizang 智蔵 (458-522) and Sengmin 僧旻 (467-527). By examining the fragments of works by Zhizang and Sengmin quoted in Sanlun 三論 (Three Treatises) literature, this study reveals how the two vehicles are interpreted as leading all sentient beings to attain buddhahood.
Although Zhizang initially recognized the concept of two vehicles, later he argued that two vehicles were just of nominal value, and their true essence was none other than the bodhisattva. While Sengmin accepted the two vehicles including the śrāvakas, he claimed that they later transformed and were incorporated in the Mahāyāna. Regardless of whether one accepts the two vehicles, based on the theory of equating the elimination of four abiding delusions as kleśa in the Mahāyāna with the elimination of delusion in regard to seeing reality and conceptual thinking as kleśa in the Hīnayāna, the arhat ranking system in the two vehicles practices was interpretated in such a way that the tenth stage of Huayan was converted to the seventh stage. Based on this view of Zhizang and Sengmin, while Jizang吉蔵 (549-623) formulated the theory of two types of śrāvakas dividing real-practice and provisional-practice, the point of contact in the stages of arhat and bodhisattva practice was reduced to ten stages of faith.