One thread of philosophy of language intersects, in at least a few places, with a thread of philosophical considerations about modality. Once we begin considering how to provide an account of understanding the meaning or intension of a predicate such as ‘is ψ’, we realize that we must consider possible circumstances or imaginary scenarios in which the use of `is ψ’ is appropriate. Simply put, one can only be said to understand completely the predicate `is ψ’ if one knows exactly when it is appropriate to use this predicate in conversation about actual or counterfactual situations. It should be of little surprise then, that philosophers often put to use possible worlds (however they’re to be understood) in the service of giving an account of intensions.
What is (or at least should be) more surprising is the epistemological tension between, on the one hand, using possible worlds to give an account of intensions of predicate terms which we take ourselves, prephilosophically, to understand, and, on the other hand, the notion that possible worlds should (somehow) be that which make true modal claims whether or not we have epistemic access to those worlds. Especially if we understand possible worlds as David Lewis does, our epistemic access to those worlds is problematic. But if the collection of worlds is to be used to explain the intension of predicate terms we take ourselves to understand, then it seems we must have some sort of epistemic access to them.
The substantial difficulties for a strategy of using possible worlds to provide a reductive account of modality if this account is to be satisfying in terms of modal epistemology are laid out elegantly by Scott Shalkowski in his “The Ontological Grounds of the Alethic Modality“. I won’t focus directly on these difficulties here, but rather pursue the relationship between modal concerns and an effort to give an account of intension for predicate terms. This post will be the first of four that each deal with some aspect of the connection between modality and an epistemology of the intensions of predicate terms.
By way of a sketch of the whole four post project, I assert in part II that a technical development of a “genuine” modal semantics given the background assumption that we have an antecedently meaningful language is unsatisfying in terms of shedding any light on that which underwrites the truth or falsity of modal claims because meaning is, by itself, shot-through with a modal aspect. To suppose that the terms of the modal language for which we wish to provide the semantics are already meaningful is to elide certain fundamental questions about modality. In part III, I assert that the view according to which a class of possible worlds is to account for the truth of modal claims makes an epistemology of intensions of predicate terms mysterious. Finally, in part IV, I hope to point to an account of understanding meaning that may offer some insight into modal epistemology while avoiding some of the difficulties faced by the accounts canvassed in parts II and III.