 Suppose God (or nature) had linked our mental representations to just the right states of affairs in the way required by the realist. If so, this is a semantically significant fact. Anyone learning their native language would have to grasp these correspondences between sentences and states of affairs. How can they do this if even the competent speakers whom they seek to emulate cannot detect when these correspondences hold? In short, competence in one’s language would be impossible to acquire if realism were true [Dummett 1978, 1993; Wright 1993]. This is the Language Acquisition challenge.