 Ineffability thus unpacks as a thorough mismatch between representations due to thought and language on the one hand and what there is on the other. For Buddhist Epistemologists this mismatch means that they cannot adopt unnuanced the predominant Brahmanical approach of vyākaraṇa, a grammatically oriented metaphysics in which genuine ontological features would be revealed by the features of Sanskrit grammar (such as case and gender accord between adjectives and nouns, connections between substantives via the genitive case, etc. Much of Dignāga’s philosophy of language is indeed an attempt to account for such Sanskrit grammatical phenomena, but without the realist baggage.) However, it also leads to a larger matter. The problem is that if the real world is composed only of particulars that are ineffable, it becomes difficult to see how language could nonetheless somehow refer to real things or ever be about entities in the world. The Buddhist Epistemologists are, in effect, to borrow an idea of Donald Davidson (1984), subscribers to a rigid separation between a conceptual scheme and a perceptual content free from the scheme’s additions and distortions, and their problem then becomes how to bridge that very scheme-content gap so that thought and language are still somehow about reality. To solve this problem of “aboutness” Dignāga had devised the theory of concepts, i.e., apoha (“exclusions”). Dharmakīrti reinterpreted this theory, once again, in terms of causal relations. Here are the broad  outlines.[36]