Illocutionary logic and discourse typology

Until now philosophy of language and linguistics has tended to analyze linguistic compe tence as the speakers' ability to use and understand single sentences without much taking into consideration their ability to contribute to conversations. Similarly, speech act theory tends to study isolated illocutionary acts performed by using sentences in single contexts of utterance. However, it is clear that speech acts are seldom performed alone in the use of language. On the contrary, speakers perform their illocutionary acts within entire discourses where they are most often in verbal interaction with other speakers who reply to them and perform in turn their own speech acts with the collective intention of conducting a certain type of conversation. Above all, the use of language is a social form of linguistic behaviour. It consists, in general, of ordered sequences of utterances made by several speakers who tend by their verbal interactions to achieve common goals such as discussing news, coordinating their joint action, negotiating or more simply exchanging greetings. Could we enrich current speech act theory so as to develop a more general but equally powerful theory of discourse? Could we make a reasoned typology of conver sations and analyze adequately their conditions of success and satisfaction? Recently, Searle (') expressed skepticism about the possibility of constructing such a theory of discourse. He has pointed out the main difficulties and left us with the challenge of carrying out such a project. The purpose of this article is to meet his challenge. I will enrich illocutionary logic (2) so as to con tribute to the foundations of the logic of discourse. For that purpose, I will analyze the logical structure of conversations such as descriptions, interviews, deliberations, consultations, regula tions, evaluations, protestations and eulogies, whose type is provided with a proper discursive goal. I think that ail intelligent discourses are composed of such types of conversation.