In this paper we propose a narrative hypothesis on the nature of language and a proto-discursive hypothesis on the origin of our communicative abilities. Our proposal is based on two assumptions. The first assumption, concerning the properties of language, is tied to the idea that global discourse coherence governs the origin of our communicative abilities as well the functioning of these abilities. The second assumption, concerning processing devices, is connected to the idea that the systems of spatial and temporal navigation are implicated in discourse coherence processing. Analysis of the relationship between these two assumptions allows us to integrate the model of language based on clues proposed by Sperber and Wilson with Relevance Theory with the discursive foundation of human communication. In this respect, our proposal can be considered as a tentative extension of Relevance Theory (both at the level of properties and the level of cognitive systems).