Paganism Syncretism and Popular Religious Culture in the Early Middle Ages : Observations on Method. The author describes few divergences between, on the one hand, research on religious culture in the history of mentalities, and, on the other hand, post-war German research on paganism and syncretism. He raises the question of whether the two lines of research can be integrated. Taking account of the fact that the stereotypicity of early medieval sources has given rise to serious doubts regarding the authenticity of their descriptions of paganism and syncretism the author suggests number of criteria that could be used to prove or argue that part of the material contained in these sources can reasonably be held to be authentic. Finally he considers the possibility of comparative investigation of the subject. By way of example he compares certain aspects of the christianization of occidental Europe in the Early Middle Ages and that of Peru in the 16th century.