An analogy between States and international organizations has characterised the development of the law that applies to intergovernmental institutions on the international plane. That is best illustrated by the work of the International Law Commission on the treaties and responsibility of international organizations, where the Commission for the most part extended to organizations rules that had been originally devised for States. The talk will reflect on the foundations and limits of the assumption that the two main categories of international legal subjects are analogous for certain purposes, and discuss the elusive position that international organizations occupy in the international legal system. About the speaker: Fernando Lusa Bordin is a Thornely Fellow and Lecturer in Law at Sidney Sussex College and an Affiliated Lecturer at the University of Cambridge. His research focuses on topics of public international law, including law-making, international organizations and the intersection between international law and legal theory. He holds an LL.B. from the Federal University of Rio Grande do Sul (Brazil), an LL.M. from New York University, and a PhD from the University of Cambridge. He is a recipient of the Yorke Prize (University of Cambridge), Young Scholar Prize (International & Comparative Law Quarterly) and the Diploma of Public International Law (Hague Academy of International Law).