At "Le Saulchoir" he was the teacher of Dominicans Yves Congar and Edward Schillebeeckx. In 1930 Chenu founded the "Institut d'Etudes Médiévales de Montréal." Chenu served as regent of studies at Le Saulchoir from 1932 to 1942, and was therefore very involved in the move of Le Saulchoir from Belgium to Étoilles, near Paris, in 1937. In 1937 Chenu privately issued a book entitled "Une école de théologie: le Saulchoir. "In February 1938 he was called to Rome and reprimanded for this work. Then, in February 1942, "Une école de théologie" was placed on the Vatican's "Index of Forbidden Books" because of its ideas about the role of historical studies in theology. He was removed as rector of Le Saulchoir. He would never again teach there. Friends got him a post at the École des Hautes Études in Paris, and he subsequently taught at the Sorbonne and the Institut catholique de Paris. In the late 1940s and early 1950s he became involved, as a friar-preacher, in the nascent worker-priest movement, and its attempts to evangelise the anti-clerical industrial suburbs of Paris. Eventually, in 1953, Chenu was among the French Dominicans disciplined by the Master of their Order, Suárez, supposedly to save them from worse treatment by the Vatican. He was expelled from Paris and moved to Rouen, only being allowed to return to the Dominican convent of Saint-Jacques in Paris in June 1962. According to Christoph F. Potworowski, for Chenu the incarnation is the means by which God acts within and on behalf of creation. Chenu was invited to be a "peritus", or expert, at the Roman Catholic Second Vatican Council (1962–65) where he was influential in the Pastoral Constitution on the Church in the Modern World ("Gaudium et spes"). Chenu was a forerunner of the "ressourcement" in theology that preceded the reforms of Vatican II. Chenu played a large role in the reappropriation of historic theological sources that led to the nouvelle théologie. In particular he promoted the return to Thomas Aquinas as a source, but rejected 19th century "modern scholastic" theology.