Hart reviews the literature on identification and its relation to other problems of metapsychology. Some of the more important problems are: Is identification a bridge between narcissism and object love? Is it a method of mastering hate and ambivalence? Is it important in determining suicide or is loss of self esteem more so? Is it ambivalent only in its earlier phases of development and therefore dependent upon the libidinal development? What part does heredity play in the ability to form identifications? What part does the pleasure principal play in the two processes of introjection and projection inherent in the identification process? These questions are still to be answered by workers in the field.