Stability: computing alternatives in conditional antecedents

Paolo Santorio, Leeds


Conditionals with disjunctive antecedents ("If A or B, C") seem to entail the two conditionals whose antecedents are the individual disjuncts ("If A, C" and "If B, C"); yet standard semantics for conditionals can't vindicate this entailment. Extant solutions to the problem take one of two routes:

  1. they derive a scalar implicature in conditional antecedents;
  2. they appeal to a non-boolean semantics for disjunction.
After showing that each of these options is problematic, I suggest a solution that exploits on a new algorithm for manipulating alternatives. The new algorithm, which is based on a notion that I call 'stability', is a descendant of the Sauerland/Fox innocent excludability algorithm, though crucially it does not rely on the exclusion of alternatives.