Aufhebung des Jesuitenordens
The Suppression of the Society of Jesus in France obliged Grou to seek refuge first in Lorraine which was then ruled by the former Polish monarch Stanisław Leszczyński. He lived for several years at Pont-à-Mousson, where he made his final vows in 1765 or 1766. After the death of Leszczyński, the Jesuits were also banished from Lorraine. Grou moved next to the United Provinces of the Netherlands, where he continued to work on Greek philosophy. He later returned to Paris, where he took the alias of Leclaire and to all appearances functioned as a diocesan priest. He divided his time between his studies and religious duties. Initially, the Archbishop of Paris, Christophe de Beaumont, employed him to write on religion and granted him a temporary pension, which eventually ceased.