Paul Boghossian

According to a very natural picture of rational belief, we aim to believe only what is true. However, as Bernard Williams used to say, the world does not just inscribe itself onto our minds. Rather, we have to try to figure out what is true from the evidence available to us. To do this, we rely on a set of epistemic rules that tell us in some general way what it would be most rational to believe under various epistemic circumstances. We reason about what to believe; and we do so by relying on a set of rules....

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-