He lost his professorship in 1867 along with his civic rights when he was condemned to fifteen months' imprisonment for his share in a secret society.
Returning to France under the government of Émile Ollivier he took an active share in the revolution of 4 September 1870 and became secretary of the commission of national defence.
[1] In the French National Assembly he sat on the extreme Left, consistently opposing the opportunist policy of successive governments.
Naquet, although he disapproved in principle of a second chamber, secured his election to the Senate of France in 1883 to pilot his measure through that body.
After Boulanger's suicide his political influence declined, and was further compromised by accusations (of which he was legally cleared) in connection with the Panama scandals.