In depersonalization the ego and the external world appear changed and foreign. The defensive meaning of the symptom is to repudiate conscious recognition of threatening external events which the ego cannot tolerate. In Bird's clinical illustrations, the intolerable experiences all had to do with loss. The defensive mechanism of denial also is associated with ideas of castration and loss of love objects. The sense of reality being so intimately connected with sharp distinction between the self and the outer world, feelings of unreality represent a return to fusion with mother (loss of self). Through the sense of unreality Bird's patient reduced his fear of external objects, enabling him to maintain at least a partial relationship with them. Without this 'dilution', fear would necessitate total retreat from those objects.