Question: Who was a member of an international organization that was formed in 1957?
Sentence (from "The Movement of the Free Spirit"): The Movement of the Free Spirit: General Considerations and Firsthand Testimony Concerning Some Brief Flowerings of Life in the Middle Ages, the Renaissance and, Incidentally, Our Own Time (French: "Le mouvement du Libre-Esprit" ) is a 1986 book by former Situationist International (SI) member Raoul Vaneigem published in English in 1998 by Zone Books.
Relevant evidence: Yes