By substituting the collective representation concept (Durkheim, 1898) by the social representation one, Moscovici (Moscovici, 1961) has made possible the assumption that culture is not static, neither hermetic, nor homogeneous. He also pointed out the fact that a cultural plurality exists within modern societies. Otherwise, authors (Levy-Bruhl, 1921, Durkheim, 1898) had distinguished between modern and traditional societies. But observations made in the Tunisian context, suggest the assumption that plurality could be the survival of a traditional thinking in societies with modern institutions. More than that, this plurality would not be only a juxtaposition of several cultures but a particular reorganization of meanings. Otherwise, the exploration of antinomic structures in the Tunisian lay thinking, suggests that two different rationalities (traditional and modern) coexist in the social representation of fundamental notions that underpin modern societies (State, law, citizenship, private/public space…). These conclusions argue for a return of the notion of culture in social psychology and for taking into account Moscovici’s recommendation (2012) to consider social psychology as a psychology of culture, our culture.