Since the colonial era, environmental degradation in Fouta Djalon has been systematically described and denounced as a direct consequence of agropastoral practices. An extremely pessimistic scenario involving extensive farming practices, population increase, environmental degradation, and emigration has gradually emerged, without solid grounding in reality. Although regularly forecasted, the catastrophe is still to come. Elaboration of this crisis scenario is based on received ideas. These ideas have warped the initial diagnosis, led to an erroneous perception of local economic and social dynamics and of their potential for evolution, and ultimately account for the sometimes fantastic character of representations and predicted evolution of environmental dynamics. This misperception of reality is one cause of the low global efficacy of rural development programs.