Exceptional cases are at odds with the typical : they stand out as bizarre and rare. What then could justify their systematic analysis? Elaborating the analytical distinction between anomalies, exceptions and outliers, this paper outlines three potential epistemic contributions of exceptional cases. First, exceptional cases reveal the limits of standard classification categories. In so doing, they problematize usual classificatory grids. Their input is critical. Second, exceptional cases point to new classes of objects. They acquire paradigmatic status when they exemplify the characteristic features of these new classes with utmost clarity. Third, exceptional cases magnify relational patterns that in more mundane contexts lack visibility. Here their contribution is heuristic. These three contributions become possible when we put at bay normative expectations of what should happen, and specify cases by reference to an analytical space of constitutive dimensions. To underscore the general significance of these observations, I draw on examples borrowed from different quarters of the social sciences: the sociology of organizations, ethnomethodology, comparative historical sociology and the history of science

Cet article éclaire trois contributions possibles du cas d’exception défini comme tout objet de considération qui se démarque et se distingue d’un cadre normatif, d’une thèse explicative ou d’une distribution fréquentielle. La contribution est critique lorsque le cas met en doute les fondements d’une taxonomie, le bien-fondé d’un énoncé prédictif ou celui d’une modélisation. Elle est paradigmatique dès lors que le cas exemplifie un ensemble de propriétés caractéristiques d’une classe empirique. Elle devient heuristique à partir du moment où le cas rend visible la logique de rapports restés jusqu’alors non documentés