We have already seen that Saichō saw the Lotus Sūtra as the “direct path” or “great direct path,” over and against the Hossō view of enlightenment as requiring three incalculable aeons to achieve. He was not optimistic about most people actually realizing Buddhahood with this very body, a possibility he saw as open only to those who had reached the stage of partial realization, the fifth of the six stages of identity, which corresponds to the first abode or bhūmi in the fifty-seven stages of bodhisattva practice of the perfect teaching. The fifth stage of identity and the first abode both denote the point of transition from the level of an ordinary worldling (Prthag-jana, bonbu) bound by defilements to that of the sage (ārya-sattva, shō), who has eliminated all defilements except ignorance (mumyō-waku) and begun to experience true insight. Where the birth and death of the ordinary worldling is determined by karma (bundan shōji), that of the sage is chosen in accordance with his aspiration for enlightenment and intent to benefit others (hennyaku shōji). “Realizing Buddhahood with this very body” for Saichō thus referred to the partial enlightenment of those who had already made the transition from ordinary worldling to sage. However, he also maintained that, even in the case of deluded worldlings, through the power of the Lotus Sūtra the process of enlightenment could be vastly accelerated, being fulfilled in the next lifetime or at latest the lifetime after that. This concern, even on a theoretical level, with the possibility of Buddhahood for ordinary worldlings would eventually emerge as a major characteristic of Japanese Buddhism as a whole. (Page 32)
Original Enlightenment and the Transformation of Medieval Japanese Buddhism