Limiting himself to the history of the development of ego psychology in the work of Freud and some of his immediate precursors, Hartmann poses two questions. With what concepts did Freud begin his work? What evolutionary modifications in the concept of the ego were introduced? The idea of unconscious dynamic processes is found in Schopenhauer and Nietzsche, especially the latter. In the work of Meynert, whom Freud venerated, are found many close correspondences with analytic concepts of the ego. Freud differed from other profound thinkers in being a great clinician who could check theory against experience. The functions of defense early assumed major importance in the evolving conception of the ego. Absorption with other discoveries, however, led to postponement of Freud's expanding interest in ego psychology, later work on which was enriched by the new insights into the unconscious and the drives. A later emphasis, and one of crucial significance, is the biological function of the ego, which is the 'organ of centralized functional control'. Still later new ideas about anxiety