QUDs, brevity, and the asymmetry of alternatives

Abstract

Exhaustivity is typically explained in terms of the exclusion of unmentioned alternatives. For this to work, the set of alternatives must be asymmetrical, lest both a proposition and its negation get excluded, yielding a contradiction (the Symmetry Problem). Since exhaustivity is regularly observed, these alternative sets must tend to be asymmetrical, and this requires an explanation. Existing explanations are based on considerations of brevity, but these run into certain problems. A new solution is proposed, explaining the asymmetry of alternatives in terms of the fact that discourse strategies with asymmetrical questions under discussion (Quds) are favored because they allow part of the answer to be communicated implicitly, namely as an exhaustivity implicature.