Karen Lewis (Philos Stud, 158:313–342, 2012) argues that recognizing the importance of plans helps settle a debate regarding the semantics and pragmatics of indefinites. More specifically, Lewis argues against the dynamic approach (e.g., Kamp (In Groenendijk et al., Formal Methods in the Study of Language, pp. 277–322, Mathematics Center, Amsterdam, 1981), Heim (The semantics of definite and
... [Show full abstract] indefinite noun phrases, University of Massachusetts at Amherst, 1982), Groenendijk and Stokhof (Linguist Philos, 14:39–100, 1991), Kamp and Reyle (From Discourse to Logic, Kluwer, Dordrecht, 1993), and Asher and Lascarides (Logics of Conversation, Cambridge University Press, Cambridge, 2003)), according to which indefinite expressions are subject to a semantic Novelty condition. Drawing on data of the so-called summary uses, she claims that Novelty is best analyzed as a pragmatic, cancelable implicature. This chapter throws significant doubt on Lewis’ analysis. Not only is her objection in large part a misreading of dynamic semantics, but the proposed pragmatic account offers no real explanation of even the alleged counterexamples. Once we consider a wider range of linguistic phenomena involving indefinites, the verdict is on the side of the dynamic approach.