 Each of the pramāṇavāda thinkers, including Śāntarakṣita, begin to address these questions with variations on a theory initiated by Dignāga and fine-tuned by Dharmakīrti and his followers, known as exclusion (apoha) theory. Dignāga’s response to the problem begins by claiming that language does not refer to universals, as one might presume a Buddhist would argue, but rather, through a negative process of exclusions or apoha, eliminates that which contradicts the referred object. Words talk about entities in so far as they are qualified by the negation of other things. Though nothing affirmative is said about reality, by use of exclusions, there is a relationship between concepts and particulars. Apoha or exclusions typically involves a double negation. Because in Buddhism the absence of something is a fiction in that absences are not caused and do not function, exclusions can be used to explain away universals as the referents of words. Because negations are fictions, this lightens the ontological commitment. A distinction is drawn between entities and pseudo-entities. Only particulars are real; negations are not real, but they are also not universals. Universals are positive or affirmative, whereas exclusions are negative. Dignāga’s position is explained quite succinctly by Bimal Matilal: