A magistrate from Pamiers, Vadier represented the Third Estate in 1789 and Ariège in the Convention. He joined the Committee of General Security in September 1793 and became a leading figure in the body responsible for surveillance, arrests and political investigations. In June 1794 he presented a report on Catherine Théot, an elderly visionary whose followers were accused of treating Robespierre as a divinely favoured figure. Coming soon after the Festival of the Supreme Being, the report’s mocking tone was widely understood as an attack on Robespierre. He supported Robespierre’s arrest on the 9th of Thermidor. Accused over his own conduct in 1795, Vadier went into hiding. Although later acquitted of involvement in the Babeuf conspiracy, he remained detained under an earlier deportation order. Released under the Consulate, he was exiled to Belgium in 1816 and died in Brussels in 1828.