 Often the theses are run together. Nolan, Restall and West (2005) say, when introducing fictionalism, “The simplest fictionalist approach to a discourse takes certain claims in that discourse to be literally false, but nevertheless worth uttering in certain contexts, since the pretence that such claims are true is worthwhile for various theoretical purposes”. (The complication that they introduce is that some fictionalists may simply be agnostic about the relevant claims.) Zoltán Szabó (2001) says, “To be a fictionalist about Fs is to think that our naïve attitude toward F-discourse is only halfway correct: we are right in thinking that we use genuine singular terms that purport to refer to Fs, but wrong in thinking that they actually succeed in referring. In engaging in F-discourse we inadvertently slip into fictional talk”. One reason that the linguistic and ontological theses are often run together is that the linguistic thesis is often motivated by ontological concerns. For example, someone who is a nominalist might on that ground find herself attracted to fictionalism about mathematical discourse. 