Ontology After Folk Psychology; or, Why Eliminativists Should Be Mental Fictionalists

Abstract

Mental fictionalism holds that folk psychology should be regarded as a kind of fiction. The present version gives a Lewisian prefix semantics for mentalistic discourse, where roughly, a mentalistic sentence “p” is true iff “p” is deducible from the folk psycho-logical fiction. An eliminativist version of the view can seem self-refuting, but this charge is neutralized. Yet a different kind of "self-effacing” emerges: Mental fictionalism appears to be a mere “parasite” on a future science of cognition without contributing anything substantial. The paper then rebuts the objection, illustrating that prefix semantics resolves a lingering problem for eliminativism from Boghossian. The problem is that eliminativists seem unable to adopt realism about neuroscience, for such realism implies that neuroscientific statements represent reality accurately. However, a deflationary version of prefix semantics allows the eliminativist to draw an ontologically relevant distinction (roughly) between truths that have a storytelling prefix and those that do not. (Deflationism means there is no implication that the unprefixed sentences robustly represent reality). The over-arching lesson is that eliminativists need to approach ontology carefully so as to avoid self-refutation; however, prefix-semantical mental fictionalism provides the resources for them to do so.