Another way in which this conventionalism plays out is in the development of the apoha theory of concepts, which has important implications for how language functions. The term apoha means “exclusion.” This theory first presented in the work of fifth to sixth century CE philosopher Diṅnāga (see the entry on Dharmakīrti, and the discussion of the theory of apoha). The theory of exclusion is meant to explain how we can have conceptual connections (linguistic or otherwise) with the world even though, on this Buddhist view, reality is ultimately a series of unique, momentarily-existing, ineffable particulars. Without universals or qualities, the Buddhists have a difficulty explaining how talk of a “blue lotus,” for instance, is possible. Their ingenious solution, much debated after Diṅnāga, is to propose that we carve up the world conceptually by negation. Blueness is not a universal, but the exclusion of all non-blue particular things—it is to be “not non-blue.” How this theory works in detail is the subject of Dharmakīrti’s work (ca sixth to seventh century CE) and a whole host of later thinkers, such as Ratnakīrti (ca eleventh century CE). The philosopher of aesthetics Bhāmaha (ca sixth to seventh century CE) criticizes apoha in his Ornaments of Poetry (Kāvyālaṅkāra), but not with regard to any distinction between primary and secondary meaning. Rather, he argues that the sense of a word is positive, and that on apoha, Buddhists are assigning two capacities to words—exclusion and positive designation—when there is only one (KB). Mīmāṃsā and Nyāya philosophers likewise criticize apoha extensively on these and similar grounds.