Abstract
Aristotle and Aquinas may have held that the things we believe and assert can have different truth-values at different times. Stoic logicians did; they held that there were “vacillating assertibles”—assertibles that are sometimes true and sometimes false. Frege and Russell endorsed the now widely accepted alternative, where the propositions believed and asserted are always specific with respect to time. This paper brings a new perspective to this question. We want to figure out what sorts of propositions speakers believe. Some philosophers have argued that we must take agents to believe temporalist propositions—propositions that are inspecific with respect to time—if we’re to explain the agent’s own thoughts and inferences. I’ll explore another strategy. I’ll focus on our ability to think and reason about the beliefs that other people have. I’ll suggest that an adequate account of that ability requires that we take others to believe some temporalist propositions. I also ask whether all propositions can be specific with respect to worlds, and close by exploring some general issues