The term regression as used in psychiatry may be defined as the re-living by an individual of his past, or part of it, in the present. Thus, in psychoanalytic therapy the patient may treat the analyst as he did one of his parents in his childhood, while in the dream of the normal person primitive tendencies and mechanisms of thought are revived. It should be noted, however, that regression is rarely or ever clear-cut or total. Although the patient reacts towards the psychoanalyst as he did in his childhood towards his father, yet at the same time he remains well aware of the analyst's true identity. Again, in the dream, although the underlying thoughts and feelings are related to childhood they are disguised and distorted by being mixed up with experiences of much later origin. In both the transference situation and the dream there is a ‘telescoping’ of the past into the present, a fusing of chronological levels, and a ‘condensation’ of experience.