Abstract

The recent debate around scientific realism has taken an epistemic turn. The issue is no longer whether theoretical discourse is or is not assertoric (truth-valuable), nor whether theoretical discourse can be reduced to observational discourse. All sides of the present debate have left behind traditional instrumentalism and reductive empiricism. Instead, they endorse semantic realism which suggests that theoretical discourse (that is, statements about theoretical entities) should be understood literally and be taken to be assertoric and irreducible. In this setting, the philosophical reaction to realism challenges the grounds for the realists’ belief in the existence of the unobservable entities posited by theories and in the truth of the assertions made about them. This reaction can take different shapes. But the dominant one, coming from van Fraassen’s constructive empiricism, is that an empiricist cannot be rationally forced to be a scientific realist. In his view, an empiricist can understand scientific theories literally but remain agnostic as to the truth (or falsity) of their theoretical assertions. Besides, if an empiricist decides to accept a theory he accepts it not as true but as empirically adequate.