A Truth-conditional Account of Free-choice Disjunction

Chapter Summary

In many languages, some uses of disjunction, often surprisingly, result in sentences that have a reading equivalent to that of certain conjunctions: these sentences have conjunctive force. In such a case, the word for or is sometimes said to express 'free choice' disjunction. Larson notes a puzzle about temporal comparatives such as the prepositions or subordinating conjunctions before and after. Conjunctive force is commonly found in disjunctions within the scope of existential modals. The approach to free-choice disjunction applies just as straightforwardly to existential modals as to comparatives. The core idea of Zimmermann's radical proposal is that natural language expressions such as or that are commonly taken to express the logician's inclusive (or even exclusive) disjunction truth-function, in fact do no such thing. Rather, natural-language "disjunctions" have the semantic structure of a conjunction of epistemic possibilities. Finally, some transitive psychological verbs pattern with modals is discussed.

Keywords: comparative adjectives; conjunctive force; existential modals; free-choice disjunction; free-choice operator; intensional transitive; Larson's puzzle; Zimmermann's analysis