Utilising detailed clinical material from two analytic cases, this paper delineates a search to understand a difficult clinical situation in which the analyst's capacity to think and to analyse during the analytic hour are experienced as being paralysed by virulent, primarily unconscious, sadistic attacks on the part of the patient. The intensity of the counter-transference experience involving such attacks on the analyst's capacity to think left her feeling that the descriptive explanations of the mental processes involved (i.e. ‘perversion of communication’ and ‘projective identification’) fell short of helping to provide the understanding needed to overcome the analytic impasse. Investigation of Bion's concept of emotional knowing did provide understanding sufficient to resolve the analyst's experience of paralysis and thus overcome the threat to the analytic process.