Être d'humeur pour le cache-cache: le logicien et la définition.

My paper focuses on the work of Denis Miéville in the field of formal and informal logic, namely the status and value of definition. As we can notice by investigating Miéville's studies, there seems to be a certain fruitful tension between the way we normally understand the concept of definition within formal systems and the multiple uses of this knowledge tool in the field of argumentation and everyday discourse. The search for a common pattern across these different domains represents a noble endeavor, even if we would not reach a definitive answer on the matter. The fact that the scholars from Centre de Recherches Sémiologiques have devised a special model in order to make sense of any regular fragment of speech speaks volumes about the complexity of the task of explaining what takes place in a discursive universe which is very far from the clarity of formal systems. [ABSTRACT FROM AUTHOR]