Cleo Condoravdi

1 May, 2pm-3:30pm, LH 306

Detachment via Modus Ponens (factual detachment) faces well-known problems for conditionals with deontic modals. One class of conditionals where the validity of factual detachment has been contested are those conditioning on an agent’s preferences, known in the linguistic literature as anankastic conditionals and in the philosophical literature as hypothetical imperatives. This talk presents a semantics for such conditionals which validates detachment and then examines why detachment appears to fail when it does.

We claim that an endorsement component enters the interpretation of the modal in the conclusion, but, crucially, not that of the conditional premise. In the problematic cases, this endorsement component is at odds with what can be reasonably assumed about normal speakers, hence the unease assenting to the conclusion even when assenting to both premises. We argue that the source of the endorsement component is pragmatic, and that, therefore, these cases do not provide a reason to adopt a semantics for this type of conditional that invalidates Modus Ponens.

Kai Wehmeier

10 Apr, 2pm-3:30pm, LH 306

Orthodox approaches to formal semantics for modal operator languages, following Kripke and Kaplan, supplement the familiar compositional semantics embodied in the recursive definition of truth-at-a-world by a “postsemantics” that consists in identifying truth simpliciter with truth at the actual world. I will propose an alternative, Tarski-inspired approach that makes do without any appeal to a postsemantics. This Tarskian approach, I will argue, is superior to the orthodoxy on both empirical and methodological grounds, and has some remarkable philosophical consequences.