TWO CONCEPTIONS OF RATIONALITY IN GRICE'S THEORY OF IMPLICATURE 1

Conversational implicature has been considered by Grice as well as by post-Gricean and neoGricean approaches to linguistic communication as a “rational” matter. This paper explores why. The exploration will show that two distinct conceptions of rationality, “instrumental” and “argumentative” rationality, are at play in Grice’s thought, generating two different senses in which conversational implicature may be deemed to be rational, one based on its efficacy in maximizing understanding, the other on its so-called “calculability”. Instrumental rationality alone is cared for by both post- and neoGricean theories, but argumentative rationality plays a major role in Grice’s thought and may shed further light on his conception of conversational implicature.