To resolve Frege’s puzzle we must understand how cognitive agents grasp or conceive of individuals such that they may incorrectly grasp what there is. That requires positing mental files: mental representations of individuals in-and-of themselves (rather than in terms of their properties). The semantics of belief reports must have something to do with the psychology of believing, for it is in virtue of hearers’ understanding of the psychological states of the agent that hearers evaluate belief reports the way they do. If extant accounts of substitution failure are to be understood as bridging this gap they must be understood as requiring Fregean modes of presentation. But, Fregean modes of presentation are abstracta which we want to avoid a...