In that text there’s question of the ritualisation’s importance in the family life, us cohesion’s and identity’s support. Those rituals stand up a paradoxical tendance between change and stability. In that point of view the adolescence is a key period. The therapeutic activity with families much use the family rituals (at least in systemic familiy therapy) and makes their modification thouks mediatory things, prescribing some rituals where they can be lacking or counter-rituals where they can be of use to a problematic stability.