The part played by Needham and Unesco in History of Science was fundamental. The first proposal, May 1946, was an International Institute for the History of Science, which was transformed, November 1946, into the establishment of an International Union for the History of Science, besides the existing International Academy. Such an International Union, affiliated to ICSU, opened the possibility of to get financial support from Unesco.
Armando Cortesao was contracted by Unesco to build the Union in early 1947, and a History of Science section created in the Science department. Armando Cortesao was an exiled Portuguese, historian of science, member of this Academy. The official birth of the Union took place during the 5th ICHS (International Congress of History of Science), the first after the War, in Lausanne, October 1947.15 Unesco paid nearly the whole Union budget for the first two years, 1947 and 1948.
Later, Armando Cortesao moved to head another project, the Scientific and Cultural History of Mankind. He was replaced by Jean Pelseener, also member of the International Academy, in charge of the publication of a new journal "Archives Internationales d'Histoire des Sciences", to succeed to Archeion. The journal had a financial support from Unesco.
For Needham and Cortesao, History of Science has an important social function. It could bring into light that "there are few peoples and nations without any contribution, whether reduced or important, to the scientific patrimony of humankind". In opposition to narrow nationalisms, the History of Science has the possibility to contribute to the Unesco function, international understanding.
More, the History of Science is the irreplaceable tool to understand the social aspects of science, both ways. Therefore, the International Union established, right at the start, a special commission "history of the social relations of science", headed by Leon Rosenfeld and Samuel Lilley, both Marxists and friends of Needham. Unesco entrusted the commission with the redaction of a report on "social aspects of history of science", for which Samuel Lilley was the main redactor.16 The central thesis was that the contexts, whether economic, social, political, cultural) may stop or facilitate the scientific progress, but without changing its direction. This was not a very strong "externalism". The commission ceased to exist after 2 or 3 years, due to the situation of history of science in the 1950s.17
Attached to Needham's interest in History of Science, is the project to write a "Scientific and Cultural History of Mankind". This project had 3 initiators, Joseph Needham, Julian Huxley and Lucien Febvre. It was initially included in the Science Department programme (1947-48), then moved to the "Philosophy and Civilizations" Division.
The aim was to put into light the part played by science and technology in the history of civilizations, to put in the foreground the mutual dependency of all civilizations, the permanent exchanges and borrowings between cultures, etc. During the elaboration period, 1948 and 1949, a fascinating convergence existed between Needham and Febvre18 on the project aims, and therefore on the structure and the contents of this series of volumes. It was based upon the refusal of a positivist and chronological history, upon the refusal of a Eurocentric history: all civilizations were treated the same way, and it was refused to set up the Western civilization as the model and the final stage for a world civilization.