Paul Brousse was active in the Jura Federation, a segment of the International Working Men's Association (IWMA), from the northwestern part of Switzerland and the Alscace. He helped edit the Bulletin de la Fèdèration Jurassienne, along with Peter Kropotkin. He was in contact with Gustave Brocher between 1877 and 1880, who became anarchist under Brousse's influence.

"Paul Brousse was then a young doctor, full of mental activity, uproarious, sharp, lively, ready to develop any idea with a geometrical logic to its utmost consequences; powerful in his criticisms of the state and state organization; finding enough time to edit two papers, in French and in German, to write scores of voluminous letters, to be the soul of a workmen's evening party; constantly active in organizing men, with the subtle mind of a true 'southerner.'"

--from Memoirs of a Revolutionist, Houghton Mifflin Company, Boston and New York, 1st ed., 1899.

From the Daily Bleed:
Paul Brousse lives (1844-1912). Member of the anarchist Jura Federation, helping James Guillaume publish its bulletin. Later became a socialist & electoral reformist, even stooping at the international congress in London, August 1886, with Jules Guesde, to vote for the expulsion of the anarchists. Consequently, his name is associated with the Socialist Party, reformism & vote-catching maneuvers.