二諦義 1.26

1.26

問：若為依二諦說四悉檀耶？解云：依第一義諦說第一義悉檀，依世諦說三悉檀。依第一義諦說，合而不開；依世諦說，開而不合，以依第一義諦還說第一義悉檀故合而不開，依世諦說三悉檀故開而不合也。

Question: In what manner are the four siddhāntas expounded based on the two truths? It is explained: Based on the ultimate truth, the ultimate-meaning siddhānta is expounded; based on the conventional truth, the [other] three siddhāntas are expounded. When expounded based on the ultimate truth, they are integrated rather than differentiated; when expounded based on the conventional truth, they are differentiated rather than integrated. Because, based on the ultimate truth, it is simply the ultimate-meaning siddhānta that is expounded, they are integrated rather than differentiated; because, based on the conventional truth, the three siddhāntas are expounded, they are differentiated rather than integrated.