Cross-temporal grounding

Cross-temporal grounding is a type of grounding whereby present facts about the past (for example that Caesar was alive) are explained in terms of past facts (for example that Caesar is alive) rather than in terms of other present facts. This paper lays the foundations for a theory of cross-temporal grounding. After introducing the general idea of a type of grounding connecting facts to past facts, we offer two arguments that past-directed facts require cross-temporal grounds—the ‘argument from intimacy’ and the ‘argument from past explanation’. We then go on to show that cross-temporal grounding statements can be understood as instances of a type of explanation which is perfectly legitimate and intelligible, even if somewhat unusual. Finally, we explain how the logic of grounding can be extended to accommodate cross-temporal grounding statements.