He made public profession of his republican principles as a schoolboy at the Lycée Charlemagne by refusing in 1867 to receive a prize at the Sorbonne from the hand of the Prince Imperial.
In 1885–1886, he was undersecretary for war in the Henri Brisson ministry, and he served in the cabinet of Émile Loubet (1892) as Minister of Marine and of the Colonies.
Resigning his portfolio, he continued to declare his conviction of Dreyfus's guilt and joined the nationalist group in the chamber of which he became one of its leaders.
[1] (He is portrayed in precisely the opposite way in the 1937 film The Life of Emile Zola in which he is depicted as the person who finally discovers the truth and demands the resignation of all those responsible for incriminating Dreyfus.)
[1] He had announced his intention of retiring from political life when he died at his country home near Flée (Sarthe) on September 25, 1905, aged 52.