This chapter addresses the relationship between international law and subject. More specifically, it engages with the question of which entities possess international legal personality. International lawyers respond to this question differently: examples range from those who believe that personality is an exclusive attribute of the state to those who ascribe personality to every participant in international legal discourse. As the chapter establishes, this difference is due to lawyers' many different opinions about the source of origin of international legal personality. Depending on whether lawyers belong to the camp of legal positivism, legal idealism or legal realism, they will insist that international legal personality is the result of an act of will and/or a recognized source of international law; that it derives from the ideal or ideal set for the international legal enterprise; or that it revolves around the participation of different entities in international decision-making processes.