Hartmann's concept of the 'autonomous ego functions' helps clarify some technical problems in analysis. The phrase refers to that part of the ego not involved in defensive processes. This 'conflictless sphere of the ego' deals with perceptions, memory, thinking, and reality testing—all those functions that ally themselves with the analyst to overcome resistances against treatment. From the point of view of this part of the ego, the analyst is an additional autonomous ego, more effective than the patient's own ego. This and other aspects of ego psychology have shifted the emphasis in technique, and provide a rationale that guides interpretation. Loewenstein suggests the phrase 'reconstruction upwards' to designate those interpretations in which the past is employed to understand recent events. Defense mechanisms operate against superego demands as well as id impulses.