At the École Normale Supérieure times were difficult as Paris was occupied by the German forces. However, mathematically it was an exciting time for Thom who was to be strongly influenced by Henri Cartan and the Bourbaki approach to mathematics.
Sa École Normale Supérieure beses ay mahirap bilang Paris ay ginagawa sa pamamagitan ng pwersa ng German. Gayunman, mathematically ito ay nakapupukaw ng isang oras para sa Thom na upang maging malakas naiimpluwensyahan ng Henri Cartan at ang Bourbaki diskarte sa matematika.