因明入正理論疏 2.26

2.26

述曰：下釋成義，顯異無體亦成三相，正因所攝。因明之法以無為宗，無能成立，有無皆異，即如論云「和合非實」。許六句中隨一攝故，如前五句。前破五句，體非實有，故得為喻。此中以無而成無故，應以有法而為異品，無其體故。還以無法而為異，云：諸是實者非六句攝，無其異體。若無為宗，有非能成，因無所依，喻無所立，故可有為異，異於無故。以有為宗，有為能成，順成有故，無非能立，因非能成，喻無所立，故有無並異，皆止濫故。無常之宗既是有體，所作瓶等有為能立。故於異品，若薩婆多立有體空為異，若經部等立以無體空為異，但止宗、因諸濫盡故，不要異喻必有所依。同喻能立，成有必有、成無必無，表詮、遮詮二種皆得。異喻不爾，有體、無體一向皆遮，性止濫故。故常言者，遮非無常宗；非所作言，表非所作因，不要常非作別詮二有體，意顯異喻通無體故。《理門論》云：「前是遮、詮，後唯止濫，由合及離比度義故。」前之同喻亦遮亦詮，由成無以無、成有以有故。後之異喻一向止濫，遮而不詮，由同喻合比度義故，由異喻離比度義故。彼復結云：「由是雖對不立實有太虛空等，而得顯示無有宗處無因義成。」古說聲無常，異喻如虛空。《理門》難云：「非異品中不顯無性，有所簡別能為譬喻。」謂於無常異品，應言：謂若是常，見非所作，如虛空等。正以常為異品，兼非所作，空為喻依。要此簡別，顯異品無，返顯有所作因，無常宗必隨逐。汝但云如空者，今返難云「非於異品不顯無宗及無因性。」即有簡別，故能為異喻。長讀文勢，義道亦遠。

The Commentary says: Below, he explains and establishes the meaning, showing that even if the vipakṣa lacks an ontological reality, it still fulfills the three characteristics [of a correct hetu] and is subsumed under a correct hetu. According to the method of hetuvidyā, when nonexistence is made the thesis (pratijñā), there is no [existent] capable of proving it, and both existence and nonexistence serve as the dissimilar. This is just like what the treatise says: "Inherence (samavāya) is not real, because it is admitted to be subsumed under any one of the six categories, like the preceding five categories." In refuting the first five categories, their ontological entity is not really existent, and hence they can serve as an example (dṛṣṭānta). In this case, because one establishes nonexistence by means of nonexistence, one ought to take an existent phenomenon as the dissimilar class (vipakṣa); yet because it lacks real being, one conversely takes a nonexistent phenomenon as the dissimilar, saying: "Whatever is real is not subsumed under the six categories," for which there is no separate dissimilar entity. If nonexistence is the thesis, existence cannot establish it: the hetu would have nothing to reside upon, and the dṛṣṭānta would have nothing to establish; hence an existent can serve as the dissimilar, because it is dissimilar to nonexistence. If existence is the thesis, an existent is capable of establishing it, because it is in concordance with establishing existence, while a nonexistent is incapable of establishing it, so the hetu could not establish it and the dṛṣṭānta would have nothing to establish; thus both existence and nonexistence are dissimilar, since both serve to preclude overextension. Since the thesis of "impermanence" has real entity, [things having] existence such as the productness of a jar and so forth can establish it. Therefore, regarding the dissimilar class, whether the Sarvāstivāda posits an existing space as the dissimilar, or the Sautrāntika and others posit a non-existing space as the dissimilar, it only serves to preclude all overextensions regarding the thesis and hetu; it is not required that the dissimilar example (vaidharmya-dṛṣṭānta) must have an ontological substratum. As for the similar example (sādharmya-dṛṣṭānta) which proves, establishing existence requires an existent, and establishing nonexistence requires a nonexistent; both affirmative designation (vidhi) and negative exclusion (apoha) are admissible. The dissimilar example is not so: whether having entity or lacking entity, it is uniformly and exclusively exclusionary, because its nature is to preclude overextension. Therefore, the word "eternal" excludes the thesis of non-impermanence; the words "non-product" express the exclusion of the hetu of productness—it does not require that "eternal" and "non-product" separately designate two existent entities, the intention being to show that the dissimilar example applies even to what lacks entity. The Nyāyamukha says: "The former involves exclusion and affirmative designation; the latter solely precludes overextension, because the meaning is inferred through application (anvaya) and negative exclusion (vyatireka)." The former similar example is both exclusionary and affirmational, because it establishes nonexistence by nonexistence, and establishes existence by existence. The latter dissimilar example is uniformly for precluding overextension, being exclusionary and not affirmational, because the meaning is inferred by the application of the similar example, and the meaning is inferred by the negative exclusion of the dissimilar example. That [treatise] further concludes: "Therefore, even when directed against [one who] does not accept absolute space and the like as real entities, it can still demonstrate that where the thesis is absent, the absence of the hetu is established." The ancients said: "Sound is impermanent; the dissimilar example is like empty space." The Nyāyamukha objected: "It is not that in the dissimilar class, without showing the absence of the nature, it could serve as an example having qualification." That is to say, regarding the dissimilar class to impermanence, one ought to say: "Whatever is eternal is seen to be non-produced, like empty space and so forth." Precisely taking "eternal" as the dissimilar class and combining it with "non-produced," space serves as the substratum of the example. This qualification is required to reveal the absence of the dissimilar class, which inversely reveals that where there is the hetu of being produced, the thesis of impermanence necessarily follows. As for your merely saying "like space," he now inversely objects: "It is not the case that in the dissimilar class one does not show the absence of the thesis and the absence of the hetu." That is to say, having qualification, it is therefore able to serve as a dissimilar example. When read with an extended syntax, the path of its meaning is profound.