The aim of this paper is to propose a definition of the state of exception within the framework of the philosophy of law. The nature of the state of exception is both a legal and a political one. For this reason, it is a subject of inquiry in various disciplines. As a consequence of its hybrid character, state of exception is hard to define, which leads to definitional scepticism. As a criterial definition is impossible to reach, I believe that it should be replaced with a paradigmatic one. Such a definition should take into account the acquis of, among others, philosophy, history or political science, so that it may apply to different methodological approaches. In order to do so, I present the main definitional groups (state of exception as a normative fact, as a constitutional dictatorship, as a political fact, and as a legal void). Next, using the criteria that are common to all those definitions, I propose and analyse three constitutive elements of the state of emergency: a crisis, a suspension of ordinary laws, and a temporary character of this suspension. The definition I propose can help to assess whether a given state is a form of a state of exception. This is of a particular relevance as emergency laws are nowadays widely discussed in the context of terrorist threats.