Dissociation. The splitting of a personality into its component parts or complexes, characteristic of neurosis.
A dissociation is not healed by being split off, but by more complete disintegration. All the powers that strive for unity, all healthy desire for selfhood, will resist the disintegration, and in this way he will become conscious of the possibility of an inner integration, which before he had always sought outside himself. He will then find his reward in an undivided self.["Marriage as a Psychological Relationship," CW 17, pars. 334f.]
In the analysis of neurotic breakdowns, the aim is to make the conscious ego aware of autonomous complexes. This can be done both through reductive analysis and by objectifying them in the process of active imagination.
Every form of communication with the split-off part of the psyche is therapeutically effective. This effect is also brought about by the real or merely supposed discovery of the causes. Even when the discovery is no more than an assumption or a fantasy, it has a healing effect at least by suggestion if the analyst himself believes in it and makes a serious attempt to understand.[The Philosophical Tree," CW 13, par. 465.]