For example, Nichiren says, 'There is nothing superior to sansho (three norms to be used for discrimination between right and wrong in religion), and thinking of Zenmui and Ichigyo who suffered onan (横難) oshi (横死), and the ways Kukai and Ennin died, I wonder how true practitioners of shobo (the true teachings of Buddha) could be like them' (in his "Kyogyosho gosho," Kyogyosho-writings or letters of superior) and so on, and denies founders of the Singon Sect and so forth.
たとえば、「一切は三証には如かず善無畏・一行が横難横死・空海・円仁が死去の有様・実に正法の行者是くの如くに有るべく候や」（教行証御書）などと述べて、真言宗などの祖師を否定している。