Abstract

Standard definitions of validity are designed to preserve truth from the premises to the conclusion. However, it seems possible to construct arguments that contain sentences in the imperative mood. Such sentences are incapable of being true or false, so the standard definitions cannot capture the validity of these imperative arguments. Bernard Williams offers an argument that imperative inference is impossible: two imperatives will always have different permissive presuppositions, so a speaker will have to change his mind before uttering a second imperative, and so imperatives cannot ever be accumulated into a set of premises. I offer four objections to Williams’ argument: (1) Permissive presuppositions are analogous to conversational implicature, and so should be ignored when formulating imperative arguments. (2) There are other valid argument forms, which Williams does not consider, that do not suffer from different permissive presuppositions. (3) There are explanations for the change in permissive presuppositions in Williams’ example other than a change of mind, so the different permissive presuppositions do not have to prevent accumulation. Finally, (4) Williams accepts enough logical relations between imperatives (contradiction and a form of negation) for a definition of a valid imperative inference to follow naturally.