 Subsequently, when in 1934 the Austrian government allied itself with the Nazi government in Germany, Neurath fled to the Netherlands. As a result, his local, Viennese, socialist Enlightenment project turned into an internationalist, intellectual and social-political project. He created the International Foundation for Visual Education in The Hague, with his assistants from Vienna, and spearheaded the International Unity of Science movement. The latter, inspired by a tradition culminating in the Enlightenment’s French Encyclopedists, launched the project of an Encyclopedia of Unified Science. Together with the pictorial languages, the scientific encyclopedia would promote scientific and social cooperation and progress at an international level. After Austria became part of the German Reich in 1938, even though living in the Netherlands, Neurath was considered a German citizen and a ‘half-Jew’ and he was not allowed to marry his ‘Aryan’ assistant Marie Reidemeister—after his second wife, Olga, had died in 1937. During this period, he travelled abroad, including the United States, where logical empiricism had become entangled with the Cold War political and intellectual debates and witch hunts (on the Cold War phase, see Reich 2005). Carnap and Charles Morris at the University of Chicago acted as his co-editors of the International Encyclopedia of Unified Science. New York leftist intellectuals hosted him as an intellectual and political ally. And his maternal first cousin Waldemar Kaempffert, influential editor for The New York Times and Popular Science, introduced him as an international reformer and visionary, praising his science-oriented intellectual, social and educational ideas, especially his contribution to unity of science and visual language (see Reisch 2019). After the Nazi invasion of the Netherlands in 1940, Otto Neurath and Marie Reidemeister fled to England, on the small Seaman’s Hope. After nine months in an internment camp they resumed activities related to the Isotype language and the unity of science. He died in Oxford on 22 December 1945 (on activities in the camp see Henning 2019; on activities after see Körber 2019 and Tuboly 2019).