 On this understanding of realism, it is an error to identify realism with factualism, the view that sentences in some discourse or theory are to be construed literally as fact-stating ones. The anti-realist views discussed below are factualist about discourse describing certain contentious domains. Adopting a non-factualist or error-theoretic interpretation of some domain of discourse commits one to anti-realism about its entities. Factualism is thus a necessary condition for realism. But it is not sufficient. Verificationists such as Dummett reject the idea that something might exist without our being able to recognize its existence. They can be factualists about entities such as numbers and quarks while anti-realists about their nature since they deny any entities can exist mind-independently.