SummaryThis contribution offers an evaluation of e contrario reasoning in which the interpretation of a legal rule is based on the context of the law system (contextual e contrario reasoning). A model is presented which will show all the explicit and implicit elements of the argument at work and will also point out how these distinct parts are interrelated. By questioning the content and justificatory power of these elements, the weak spots in the argument can be laid bare. It will (...) be argued that e contrario reasoning inevitably requires a dubious argumentative step, which renders the argument intrinsically weak. The model is applied to a European lawsuit on French cheese. (shrink)