The 1902 French educational reform opened up a debate about ways of teaching science. In 1904 Langevin gave a lecture at the Musée pédagogique entitled The Spirit of Scientific Education. Starting with a fierce critique of physics courses and textbooks used in secondary education, he rejected the separation between culture and technology and proposed a historical approach as an alternative to the dogmatic teaching of physics. Langevin valued the historical method to serve the promotion of atomism. He used history to legitimize atomism as a theoretical synthesis as powerful as rational mechanics. Sceptical chemists challenged his argument that atoms are no longer a hypothesis. Langevin also had to defeat a second opposition to atomism that came from the energeticists, who attempted to explain all phenomena in terms of energy relations and to dispense with the hypothesis of atoms. According to Langevin, energetics and mechanics were, despite their divergent positions, in the same camp. His historical insights are woven with a host of biological metaphors suggestion that science grows like a living organism.