四分律刪繁補闕行事鈔 1.52

1.52

Fourth: The intent in utilizing texts of the various schools. Clarifying the Vinaya Piṭaka comprehensively, it was originally truly one text; yet because capacity and awakening differed, various doctrines arose like mountains. Therefore, following their inclinations, they established their own schools, vying to extract texts of the Mahāsāṃgha to compile the canons of their single houses. Hence there came to be differing weights of lightness and heaviness, and divided paths of observance and transgression; existence and nonexistence appeared alternately, and abrogation and establishment became manifest by turns.