This paper should be a warning to all those who contest Freud's structural aspect of the human personality. Nunberg brilliantly applies the concept of ego, id and superego to some of the most important problems of the present psychology of the ego. Although at present science is not endowed with the means to measure the absolute energy of the ego, the author believes that the relative strength and weakness of the ego may be examined by scrutiny of typical situations. Thus, the quantitative relationship between the strength