Paul Boghossian

An irrealist conception of a given region of discourse is the view that no real properties answer to the central predicates of the region in question. Any such conception emerges, invariably, as the result of the interaction of two forces. An account of the meaning of the central predicates, along with a conception of the sorts of property the world may contain, conspire to show that, if the predicates of the region are taken to express properties, their extensions would have to be deemed uniformly empty. The question then becomes whether the predicates are best understood as expressing properties, and hence as founded on error, or whether they ought to be understood along non-factualist lines.z Historically, irrealist models were developed primarily in connection with evaluative discourse, although as physicalism has flourished and as reductionist programs have failed, their application has been extended to many other domains. Indeed, it is one of the more influential suggestions in contemporary philosophy of mind that they apply even to ordinary belief/desire psychology. A correct understanding of the semantics and metaphysics of content-based psychology leaves us, so the proponents of the in-