QUESTION: Is there a definitive statement proving that the bodhisattvas do not attain Buddhahood if the Two Vehicles do not attain it?

ANSWER: It is stated in the thirty-sixth fascicle of the Nirvana Sūtra: “A person who believes that people possess the Buddha-nature but that not necessarily all the people have it is called a man of insufficient faith.” If this is true, bodhisattvas in various pre-Lotus sūtras are all icchantika (a man without faith and virtue and without the possibility of attaining Buddhahood). These sūtras do not acknowledge the attainment of Buddhahood by the Two Vehicles as well as by the bodhisattvas. In this sense, as long as the attaining of Buddhahood by the Vehicles is not acknowledged, attaining Buddhahood by the bodhisattvas is not possible in the pre-Lotus sūtras preached during the first forty years or so.

Nizen Nijō Bosatsu Fu-sabutsu Ji, Never-Attaining Buddhahood by the Two Vehicles and Bodhisattvas in the Pre-Lotus Sūtras, Writings of Nichiren Shōnin, Doctrine 3, Page 220