On the Function of Advanced Modalizing

Abstract The Lewisian account of modality based on counterpart theory suffers from the problems of advanced modalizing, where claims about spatiotemporally disunified entities are modalized. In this paper, I first discuss a strategy to bypass the problem, one which treats cases of advanced modalizing as cases of equivocation lying outside the scope of the translation. I then argue that the strategy does not satisfactorily generalize to the case of advanced modal claims involving abstract entities. This failure not only reveals the limitations of counterpart theory in handling abstracta, but also weakens the abductive argument for modal realism that posits it as a robust account of nominalism. Furthermore, advanced modalizing is an indispensable part of the Lewisian framework when doing metaphysics, since advanced modal claims made by Lewis himself strengthen his abductive argument for modal realism. Hence advanced modalizing plays a crucial role in the Lewisian project, and an account of advanced modalizing is needed for the Lewisian reduction of modality to succeed.