In this Lasker lecture to the Institute for Psychosomatic and Psychiatric Training and Research of the Michael Reese Hospital, Rioch points out the interrelation between the patient and observer which determines perception and communication. These qualities cannot be differentiated because what an observer sees the patient as perceiving are inferences decoded from messages the patient sends. The therapeutic problem involved is illustrated by case material from hospitalized schizophrenic patients, in which the difficulty in understanding and reaching the patient is shown. The view is offered that regardless of what precipitates the state of disturbed consciousness, one has to recognize the significance of the symbolic behavior and interpret it to the patient in terms of the present and immediate situation that makes him feel isolated from life.