Abstract
This paper develops a semantic solution to the puzzle of Free Choice
permission. The paper begins with a battery of impossibility results showing that
Free Choice is in tension with a variety of classical principles, including Disjunction
Introduction and the Law of Excluded Middle. Most interestingly, Free Choice
appears incompatible with a principle concerning the behavior of Free Choice under
negation, Double Prohibition, which says that Mary can’t have soup or salad implies
Mary can’t have soup and Mary can’t have salad. Alonso-Ovalle 2006 and others
have appealed to Double Prohibition to motivate pragmatic accounts of Free Choice.
Aher 2012, Aloni 2018, and others have developed semantic accounts of Free Choice
that also explain Double Prohibition.
This paper offers a new semantic analysis of Free Choice designed to handle the
full range of impossibility results involved in Free Choice. The paper develops the
hypothesis that Free Choice is a homogeneity effect. The claim possibly A or B
is defined only when A and B are homogenous with respect to their modal status,
either both possible or both impossible. Paired with a notion of entailment that is
sensitive to definedness conditions, this theory validates Free Choice while retaining
a wide variety of classical principles except for the transitivity of entailment. The
homogeneity hypothesis is implemented in two different ways, homogeneous alternative semantics and homogeneous dynamic semantics, with interestingly different
consequences.