 It is not ad hoc or unheard-of to claim that some kinds of content cannot be represented by a set of worlds—the set of worlds in which they are true. Some examples: to capture the content of indexical thoughts using “I” and “now”, we need the richer notion of a “centred world”—an ordered triple of a world, and individual and a time (see Lewis 1979). Gibbard (1990) proposes that the content of a normative judgement can be represented by a set of ordered pairs \(\langle w, n\rangle\) where w is a world and n is a set of norms. Moss (2018) argues that the contents of probability judgements are not propositions but sets of probability spaces. And Bacon (2018) argues that the contents of vague thoughts cannot be represented by a set of worlds. (He calls them propositions nevertheless—that is a verbal issue—but they are not propositions in the sense that is relevant here.)