Factual detachment and speaker endorsement

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.