Fairbairn's mature model of mind was developed over a period of time and was modified significantly as it developed. In contrast to some sympathetic commentators who have suggested changes, the author has been impressed by the untapped potential of the theory. There are two areas that he feels need clarification and explanation, which are the importance of the preconscious, so neglected in our literature, and its role in psychic growth. By looking closely at the topographic categories and the way that Fairbairn uses them, the author has developed a modified version of Fairbairn's original model, which has a crucial role for a structured preconscious. The preconscious now becomes both a crucial original aspect of the early self and a significant, descriptively unconscious, fulcrum for both psychic change and mature dependence.