The scientific heritage of IHES
IHES explicitly drew inspiration from the model of the Institute for Advanced Study (IAS), founded in 1933. IHES adopted the main elements of its philosophy – a high-level institute that would offer complete freedom to a few researchers – as well as a number of traditions, such as serving tea every day, a practice conducive to conversations. In defending the model he wished to create, Léon Motchane emphasized the European nature of the Institute, which was being created at the same time as the European Economic Community (EEC).
When it was created in 1958, the Institute had no premises of its own. Early seminars were held in two rooms, lent by the Thiers Foundation in Paris. This did not hamper the development of the mathematics section. Physicists, on the other hand, were concerned about the Institute’s permanent location. They set out their preferences, at a meeting attended by renowned physicists who supported Léon Motchane’s project. Their request was for the Institute to be located close to an experimental center. Physics at IHES was indeed theoretical, but it could not be cut off from experimental physics. They suggested that the Institute be located close to the modern laboratories that had just been built in Orsay, where an outpost of the Paris Science Faculty had moved to, in the late 1950s. Léon Motchane purchased the “Bois-Marie” property in Bures-sur-Yvette from Charles Comar. IHES moved there in 1962.
IHES established relations with its mathematician and physicist neighbors, despite some reluctance from universities when it was created. The Institute extended invitations to the directors of the French National Scientific Research Center (CNRS) and of the Atomic Energy Commissariat (initial name of the CEA). Years later, IHES would become a founding member of Paris-Saclay University, from the latter’s creation in 2015. It now contributes to the University’s mathematical activity (with the Jacques Hadamard Mathematics Foundation and in hosting seconded mathematics professors from Orsay, for instance).
"Since my arrival at the IHES in January, I have learned more from conversations with Deligne than from talking with anyone else. Just today, for example, it was much more efficient for me to take the train from Paris to Bures in order to discuss a certain question with Deligne than it would have been for me to stay at my desk in Paris thinking about it ; as I had expected, Deligne had the techniques at his fingertips with which to give me a complete answer"
Letter from John Tate to Léon Motchane, March 15, 1968, when asked about the possibility of Deligne being recruited to IHES