- Possibilists or reformists, led by Paul Brousse and Jean Allemane, were collectivists like the Guesdists, but more nuanced in their views on the accession to power and the transformation of society, which they wished to be progressive.
With their Jacobin tradition, they were the most radical on the question of revolution, advocating “total action” leading to the establishment of a new socialist system.
- Cooperators, heirs to the ideas of Proudhon and Louis Blanc (who has since moved closer to the Radical Republicans), they are opposed to collectivism and violent action.
Contrary to Jean Jaurès, Jules Guesde thought the socialists should not ally with groups supporting bourgeois democracy.
In 1899, a debate raged among socialist groups about the participation of Alexandre Millerand in Pierre Waldeck-Rousseau's cabinet, which included the Marquis de Gallifet, best known for having directed the bloody repression during the Paris Commune.