[Amateurism in Geology: the French Reception of the Continental Drift Theory (1920-1950)].

At the beginning of the XXth century, Wegener proposed a theory – that of the roaming drift of the continents – unifying the rival theories of the Europeans and the Americans. As the work of a non-specialist who didn’t trouble himself with specific details, it raised numerous criticisms from specialists in various disciplines though others welcomed and supported it. Some even understood that despite its flaws, it started a new research program. Paradoxically, as regards its simplicity, nonspecialists – engineers, popularizers, secondary school teachers and even believers in para-sciences – gave it a favorable reception. Being amateurs, they continued to endorse it when specialists abandoned it.