Presuppositions and Implicatures in Counterfactuals

In this article, I propose a semantic account of temporally mismatched past subjunctive counterfactuals. The proposal consists of the following parts. First, I show that in cases of temporal mismatch, [past] cannot be interpreted inside the proposition where it occurs at surface structure. Instead, it must be interpreted as constraining the time argument of the accessibility relation. This has the effect of shifting the time of the evaluation of the conditional to some contextually salient past time. Second, I will propose specific felicity conditions (presuppositions) for subjunctive conditionals and I will argue that there is a strict correspondence between the time of evaluation in the truth conditions of a conditional and the time relevant for the felicity conditions. In other words, if the time relevant for the accessibility relation has been shifted to the past, then the conditional's presupposition will make reference to a past context. On the other hand, if no past is constraining the time argument of the accessibility relation, the conditional's felicity will make reference to the current (main) context. Third, I will argue that the intuition that the antecedent of mismatched counterfactuals is not true is a scalar implicature arising from a competition not between assertions but between presuppositions. Finally, I will investigate the repercussions of my proposal for the general theory of modality.