This paper aims at two issues. First, the theory of space is examined through an endangered pattern, the one of nomadic people in Sahara and Sahel region, so as to propose the hypothesis of mobile space which comes from a sort of «spontaneous geography». On the other hand, it shows the link beetween theory and doctrine which must be separated when hypothetic mobile space and spontaneous geography seam to point out the global flexibility of space not only linked with ultra-liberal capitalism reason. Mobility without the competition idea can be looked as a spatial fairness factor more efficient than places equality. A continuation will be proposed about the «space of contract».Ce texte vise deux objectifs. D'une part, il traite de la théorie ...