GILDS-Lecture: Prof. Jean D'Aspremont on the underestimated complexity of customary international law

In law studies, it is usually taught that customary international law is characterized by two elements; state practice and opinio iuris. However, there are reasons to believe that this attribution does not do justice to the nature of customary international law, as Prof. Jean D'Aspremont impressively demonstrated in a guest lecture at the University of Graz, within the framework of the GILDS event series and in cooperation with ESIL. According to his explanation, the discourse concerning this topic is more complex than often claimed. In his lecture, he cited four observations that are not usually recognized and presented in this form. These concern, first, the often unrecognized modernity of the source of law in question; second, the qualification of a statement as a norm of customary international law; third, the need for a state of crisis in the discourse on customary international law; and fourth, the written nature of customary international law.

Prof. D'Aspremont also took the time to respond in detail to all of the questions of the plenary, as well as to lead a masterclass for PhD students of Austrian and Hungarian universities on the same day. The Institute of Public International Law of the University of Graz will follow the initiated cooperation and the lively discourse with great interest.