The concept of raison d’état (reason of state) is very popular in Poland, and it will apparently remain relevant as long as the Polish state exists. The idea is commonly used in official statements by politicians, political journalism, and in various government documents. Raison d’état is an ambiguous concept, which results from simplified and often popular opinions on what is and what is not the raison d’état. Conceptual chaos, intuitive judgments and notions appear to be the reason why political scientists are discouraged from systematized and in-depth studies on this political category. The paper is divided into three parts. The first part discusses definitions of raison d’état and the accompanying problems. The second one deals with the theoretical aspect covering the subjective, objective, temporal and spatial scopes of the concept. Two new definitions of raison d’état were mentioned which diminish the importance of the nation-state at the expense of international organizations. The third part presents methodological approaches in studies on raison d’état understood in two ways: as a system of vital interests of the state and as a category of political thought.