How should an anthropologist respond to the demands of the mundane society ? As Anthropology is becoming an official discipline, demands coming from the civil society, firms and administration are growing. Specific sensitive circumstances, various tensions and stress not easily controlled lead institutions to look for new forms of understanding and governance. The status of the anthropologist is getting ambiguous in that context as the ethnologist becomes a social guide acting between different sources of power. How must the anthropologist be involved in the process to be studied ? We will try to show from our experience of being a go-between in a county council in the city of Lille how the anthropologist can find its proper footing. The communication with civil servants, citizen representatives and bureaucrats affects strongly the way the ethnologist looks at the social world, the context of its work and the meaning of the profession. The social demand claims a root in the current world, a reformulation of the memory in various distinct aspects : memory the experience, memory of local sites, memory of gestures. Genealogies, legitimation of underground sub-culture, values given to old things are emphasized. The political power amplifies this public interest given to memory but a major claim is hidden : a request for reconstructing the social link. If we look at numerous projects on the topic of memory, we could easily see that apart from museums, city councils support and create various projects on that subject. For example we can quote life stories of inhabitants living in a particular district, life stories of immigrants or narratives of a specific institutions. Our study about the memory of a district of Lille is related to that context. We start the study in 1998 by gathering participants coming the town council, scholars, local erudites, students that has been able to collect in the field various data and materials. The plurality of competence have permitted to reconstruct the itineraries and trajectories of the inhabitants, the major changes and the emergence of new social links in a modern city. The study has also permitted to see memory as a social construction situated in a frame of reference. Especially troublesome, memory is an ideological topic emerging from a specific political context. Memory entails different meaning and getting a dominant value perceived as linked both to citizenship and membership.