Abstract
Through interviews with stone tailors and cabinet markers, we studied the nature of the treatment of the concept of symmetry. This study shows that the symmetries identified orient the craftsman’s gestures towards a large list of techniques relatively rooted. The gestures of a craftsman may come from teaching’s residue, contextual adaptation, knowledge or references to expertise. The entanglement of all these factors is such that we can give the concept of symmetry, a status that reflects all these influences: this means that the symmetry is not a familiar concept or a scientific concept, to use the terminology of Vygotsky, but rather refers to an intermediate concept that reflects all these influences, a concept that is "naturalized".