["A little scourge of humanity". Notes on the term 'tic']

The assimilation by the medical community of terms belonging to current language is a rare phenomenon. The word 'tic' constitutes a remarkable exception to this rule. In this article, the author explores the origins and some historical and epistemological consequences of this case of osmosis between two different discourses, focusing on the attempts, by the XIX Century French medical community, to appropriate from common language and redefine both the term and the concept of 'tic'. Consequently, I highlight the substantial semantic shifts to which the term was subjected in the course of this dispute.