Splitting of the psyche from the soma—the equivalent of repression in more sophisticated organization—is a retrogression employing archaic residues in setting up its defense organization. By contrast, psychosomatic integration is part of forward movement in development. If this is so, then psychosomatic illness may be classified according to two main developmental ideas: as a primary unintegrated state and as a later psychosomatic integration or 'indwelling' of the psyche in the soma. The latter achievement depends on the mother's adaptive capacity to re-enforce the infant's ego by supplying a 'reality in dependence'. In treatment we must take a unified view of the patient without going ahead of his capacity for integration. This includes the patient's need for separation of physical doctors and analyst, with the former preferably not too rigid in their application of medical theory. Two cases moving favorably in treatment—a case of anorexia nervosa and one of colitis doing less well—are reported.