Referential Understanding, Luck, and Knowledge of Reference

In some cases of communication, the hearer misunderstands the referential part of the speaker's utterance although she identifies the speaker's referent. What more is needed for referential understanding? One view is that the hearer must know what the speaker refers to. Against this view, this article argues that knowledge of reference is not necessary for referential understanding, because of differences between understanding and knowledge in the tolerance of luck. Whereas both referential understanding and knowledge are incompatible with one type of luck— intervening luck—referential understanding is less sensitive than knowledge to another type of luck— environmental luck.