Abstract
Cartographic studies have highlighted certain generalizations linked to functional hierarchies across languages. These generalizations may concern the order of functional elements, compatibilities and incompatibilities of occurrence, the recursive or non-recursive nature of positions, and so on. These descriptive generalizations immediately raise the question of explanation : can we reduce the observed states of affairs to plausible principles of the language faculty and their deductive interactions ? In this lecture, I would like to discuss two generalizations concerning topical and focal positions in the sentence periphery : 1. While topicals can be reiterated (with variation across languages), the focal position is typically unique ; 2. In languages where the co-occurrence of topical and focus is admitted, the order is typically Top>Foc. These properties can be deduced from a few simple assumptions about the nature of the interface principles governing the interpretation of topical and focal positions.
