起信論疏筆削記 13.30

13.30

此三下，或問曰：「此四義中，何故染具說三、淨唯說一耶？」今此釋之。以染法本性自差別故、仗因託緣方得生故，須說三義。淨法一味雖分體用，用還同體，無別異故。仗託因緣者，於此三中無明是因，妄境是緣，妄心是因緣所起。本識、事識各有因緣，如前廣辨。體用無別者，但內熏為體，外熏為用。用合體時，非別外來，融同一味。故眾生心內之佛，還化自己眾生，故說一種。

"These three..." and so forth: Someone might ask: "Among these four meanings, why are three fully explained for defilement, while only one is explained for purity?" Now this is explained. Because defiled dharmas are by their original nature differentiated, and can arise only by relying on causes and depending on conditions, three meanings must be explained. Although the single flavor of pure dharmas is divided into essence and function, the function is still identical with the essence and has no difference. "Relying on and depending on causes and conditions": among these three, avidyā is the cause, deluded objects are the conditions, and the deluded mind is that which arises from causes and conditions. The fundamental consciousness and the worldly consciousness each have their causes and conditions, as broadly distinguished earlier. "Essence and function have no difference": internal perfuming is simply the essence, and external perfuming is the function. When function unites with essence, it does not come from outside separately; they fuse into a single flavor. Therefore, the Buddha within the mind of sentient beings turns back to transform sentient beings themselves; hence only one kind is spoken of.