It denies the subjectivity of whoever has to bear it, but reflects mirrorlike a threat on the subfectivy of whoever enacts it. Thus it may be considered as a primary defence reaction from a threatened identity. The experience of institutional life in psychiatry as well as the psychotherapies of subjects suffering from behaviour disorders are a priviledged place to study the latter one. Adolescence is a life stage most liable to expressions of violence due to the nature of the psychological changes that are imposed by puberty. Care should take into account such specificities of the psychological functioning of violent patients. The space for such care should be viewed as a figuration of the internal psychological space of the patient and its handling should be made a means to allow the relationships they need to become tolerable. Mediations and a concrete third function have a very special seat whithin such a handling.