因明入正理論疏 2.139

2.139

述曰：指不定相，狹因能立，通成寬狹兩宗，故雖同品而言定有非遍。寬因能立，唯成寬宗。今既以寬成狹，由此因便成共，共因不得成不共法。若有簡略，則便無失，故《理門》云：「諸有皆共，無簡別因。此唯於彼俱不相違，是疑因性。」此說共不定。諸有立因，於同、異品皆共有性，無有簡別，如聲常宗，所量性因二品皆有。然宗有二：一寬、二狹，如立聲無我名寬，聲外一切皆無我故；立聲無常為狹，除聲以外有常法故。因品亦二：所量所知所取等名寬，無有一法非所量等故；勤勇所作性等名狹，更有餘法非勤勇發、非所作故。若立其狹，常、無常宗，說前寬因，同、異二品因皆遍轉，故成不定。若望寬宗，其義可立，唯說狹因，可成狹宗，亦可成寬，異品無故，可成正因。如聲論師對勝論立「聲常為宗，耳心、心所所量性故，猶如聲性。」有此簡略，即便無失，故此與不共二不定差別，彼於一切品皆都無故。

Commentary: Indicating the characteristic of being indeterminate: a narrow reason capable of proving can establish both broad and narrow theses, so although it is present in the sapakṣa, it is said to be definitely existent without being pervasive. A broad reason capable of proving can only establish a broad thesis. Now, since one establishes a narrow [thesis] with a broad [reason], the reason becomes common, and a common reason cannot establish an uncommon property. If there is a qualification, then there will be no flaw; hence the Nyāyamukha states: 'Whatever is common to all lacks a distinguishing reason. Because this is not contradictory to both, it is the cause of doubt.' This speaks of the common indeterminate. Whatever reason one sets up that shares the property of being common to both sapakṣa and vipakṣa without distinction—just as in the thesis that sound is permanent, the reason 'being an object of valid cognition' is present in both classes. However, theses are of two kinds: first, broad; second, narrow. For instance, setting up 'sound is non-self' is called broad, because everything other than sound is non-self; setting up 'sound is impermanent' is narrow, because there are permanent phenomena apart from sound. The classes of reasons are also of two kinds: being an object of cognition, being knowable, being apprehendable, and the like are called broad, because there is no phenomenon that is not an object of cognition; being produced by effort, being artificial, and the like are called narrow, because there are other phenomena that are not produced by effort and not artificial. If one sets up a narrow thesis of permanence or impermanence and states the aforementioned broad reason, the reason pervades both sapakṣa and vipakṣa, and therefore becomes indeterminate. If viewed with respect to a broad thesis, the meaning could be established; if one only states a narrow reason, it can establish a narrow thesis and can also establish a broad one, and since it is absent in the vipakṣa, it can serve as a correct reason. For example, when a Śabda theorist sets up against a Vaiśeṣika: 'Sound is permanent, because it is an object of valid cognition by the ear-consciousness and its mental factors, just like the universal of sound (śabdatva).' With this qualification, there is no flaw. Therefore, this differs from the uncommon indeterminate, because the latter is completely absent from all classes.