At the age of 24, he wrote "Rogoshiki," where the thought of Confucianism, that of Taoism, and that of Buddhism were comparatively discussed, showing that what was taught popularly was not true (the title of "Rogoshiki" was later changed into "Sango shiiki," with the ten rhyme-based poems in the preface and at the end of the book revised).
24歳で儒教・道教・仏教の比較思想論でもある『聾瞽指帰（ろうごしいき）』を著して俗世の教えが真実でないことを示した（「聾瞽指帰」は、後に序文と巻末の十韻詩を改定、『三教指帰』（さんごうしいき）と改題されている）。