Marcel Mauss (1872-1950), Durkheim's nephew, was a key figure among the Durkheimians and helped to found the distinctive French tradition in the social sciences at the start of the 20th century. He dominated the teaching of social anthropology in Paris between the Wars, however it is only recently that the breadth and freshness of his oeuvre is gaining wider appreciation. Having found inspiration in Mauss's texts for over twenty years, the author explores not only what he thought but also how his ideas can be developed and applied in new ways. Thus Durkheim and Mauss's notion of "primitive classification" often misunderstood, is well exemplified by Indo-European ideology as analysed by Georges Dumezil and current comparativists, and it is argued that this ancient ideology influenced the Durkheimian classification of "social facts".