 There is a conception of propositions according to which they are sets of worlds (see, e.g., Stalnaker 1976). On such a conception, the truth-set of a proposition is the proposition itself, and issues about propositional existence remain: it may be held that propositions exist necessarily, or that their existence is in general world-relative. The first option seems intrinsically the most natural, and a proponent of the world-relative view will most naturally identify the existence-set of a proposition with its truth-set—or so it seems.