Weak Uniqueness: The Only Difference Between Definites and Indefinites

We argue that predicative the is an identity function that is defined for predicates that satisfy weak uniqueness: if there is an F, then there is only one. Predicative definites do not presuppose existence, as evidenced by anti-uniqueness effects, for example the fact that ‘Scott is not the only author of Waverley’ implies that there is more than one author of Waverley. Separating the uniqueness and existence components of definites brings definites and indefinites closer together: The definite and indefinite articles are both argued to be identity functions on predicates, differing only in that the latter lacks the weak uniqueness presupposition. Furthermore, the meaning of argumental definites and indefinites can be derived from the predicative meanings using the same general mechanisms that introduce existence. Existence is generally at-issue with argumental indefinites and presupposed with argumental definites. However, we observe that anti-uniqueness effects arise with argumental definites as well, under conditions described in our ‘Dependence Generalization’. We take this to show that existence can be at-issue with argumental definites, and we derive the Dependence Generalization in terms of relevance to the question under discussion.