This article elaborates on some of the key ideas that gave rise to and animated the International Commission on Intellectual Cooperation, a body which was among the last permanent organisations of the League of Nations. Although the Commission's efforts to cement intellectual relations among nations often went unappreciated, its proponents considered intellectual cooperation to be the very heart and soul of the League's Covenant. From the outset, the Commission sought to harmonise the world's various intellectual and cultural currents while maintaining respect for diversity. During its life, the Commission also became increasingly aware of the issue of its own cultural particularity and the vital need to incorporate perspectives and traditions other than those in which its origins lay. It was in grappling with these issues, and not just in pursuing its broader mandate, that the Commission can be said to be the forerunner of UNESCO.