Abstract: Our purpose will be an attempt to put into perspective the elements of a logic of transmission so that the transmission itself, as logical position in relation to knowledge or even more to non – knowledge. From a first point is the encounter with a patient, will be unfolded and articulated the question of otherness, that of instituting separation, position relative to a point of no knowledge. The knowledge is not there to hear their differences with misleading knowledge, as knowledge on the side of learned ignorance. Through clinical notes will be discussed accepting to be moved and transformed by a patient, the ability to ex- position in relation to the institution but to get out of the fascination generated by the statements of some patients. This sometimes invisible transmission from patients may question our know how of psychoanalyst but also our clinical know how of practitioner in institution and our responsibility.