The authors have studied in an unusual schizophrenic patient the pathological processes in ego function. Observations during psychotherapy indicated that schizophrenia causes a state in the ego that gives rise to unusual and frightening experiences. Defenses of the ego are 'reactive and represent a means of dealing with the breakdown of the ego'. The authors believe that 'psychotherapy in psychotic reactions must be primarily concerned with re-establishing the integrity of the ego'. They relate disturbances of auditory perception, body image, communication, and motility to concepts derived from psychoanalysis and from experiemental and genetic psychology.