I argue that predicativism, the view that proper names are predicates, is a viable theory of the semantics of proper names given a certain hypothesis about the grammar of definiteness. Extant versions of predicativism hold that a singular name in argument position constitutes the predicative component of a covert definite description. I show that these versions cannot accommodate semantic and typological data, specifically: syntactic and semantic disparities between bare and non-bare occurrences of such names in English, the distinctive modal rigidity (...) displayed by names, as opposed to common noun definite descriptions, and cross-linguistic data that feature seemingly distinct determiners for names in argument position. I propose that predicativism needs to embrace a view of definite marking as complex, consisting of a definite article and a bindable, familiarity-tracking constituent, which I call _index_. I show that this view is empirically motivated and typologically attested. The resulting version of predicativism can accommodate elegantly the observed semantic data when coupled with language-specific morpho-phonological generalizations. I finally address criticisms of and alternatives to my version of predicativism. (shrink)