An influential anarchist movement based on syndicalist ideas is anarcho-syndicalism. The syndicalists viewed the factory committees as the true form of syndicalist organization, not unions. He organized an anarchist resistance group which included the exiled Russian syndicalist Volin. Mikhail Bakunin was the founder of the Spanish collectivist, syndicalist and internationalist workers' movement. They were followed by the major currents of social anarchism (collectivist, communist, and syndicalist). The extent to which syndicalist doctrine was a product of anarchism is debated. One of the more radical fascist syndicalist was the philosopher Ugo Spirito. De Leonism is a form of syndicalist Marxism developed by Daniel De Leon. The congress, however, revealed the irreconcilable differences between the syndicalist and the Bolshevik approach. In the syndicalist conception, unions played a dual role. Syndicalist movements that were not suppressed also declined. The Russian syndicalist movement was thereby defeated. Darlington cites the significance of the conscious intervention by syndicalist militants. Migration played a key role in spreading syndicalist ideas. It also exacerbated splits within the syndicalist camp.