In Languedoc, sheep can be raised only if they are brought to summer pastures: this is a climatic necessity. And sheep are as indispensable in the plains as in the highlands. Transhumance has thus shaped the landscape, the paths, and human relations. In this context, the shepherd's knowledge has proved to be effective and pertinent. Today, questions are raised concerning the transmission of this knowledge in a global economy that does not necessarily need sheep, but is preoccupied by the biodiversity resulting from and saved by the traffic and the grazing of the flocks.