 He received his PhD in 1951 from the University of Paris.His thesis, titled "Espaces fibrés en sphères et carrés de Steenrod" ("Sphere bundles and Steenrod squares"), was written under the direction of Henri Cartan.The foundations of cobordism theory, for which he received the Fields Medal at the International Congress of Mathematicians in Edinburgh in 1958, were already present in his thesis.