Greenberg and Mitchell (1983) have suggested that the drive/structure model and the relational/structure model are mutually exclusive models of psychic life. We regard their contribution as an invaluable one, which makes explicit the fundamental divergences in psychoanalytic theory. We have examined a derivative tendency in the field, for drive and relational theorists alike, to present psychic life as a dichotomy between inner experience and outer experience. We see a tendency to equate the drive model with unconscious motivation, and to the primacy of internal experience. There seems to be an equivalent tendency to equate the relational model with conscious perception and motivation, and to the primacy of external experience. We are advocating, for drive and relational theorists alike, greater focus on the process of intermediation between internal and external experience in the psychic life of the individual. Within the context of the drive model, precedent for such a focus is found in Freud's conception of the preconscious, an essential third dimension whose function was to mediate between the conscious and the unconscious. Within the context of the relational model, Winnicott's notion of potential space serves as a bridge between interior experience and external reality in the life of the individual. Finally, we have argued that by constructing three-part models of psychic life, these theorists have laid the groundwork for a synthetic theory. Though for Freud the drive state is primary, and for Winnicott the relationship between the infant and its environment (mother) is primary, each theorist posits an intermediating zone that fulfills a similar function in the psychic life of the individual. Whether we choose to call that zone the preconscious or potential space, its function is to translate bidirectionally between the infinitely dimensioned realm of interior, or unconscious, experience and the time-and space-bound realm of external, or conscious, experience. By highlighting the parallel constructs, we are not claiming to have created a synthesis between the theories. Our claim is that the eventual road to synthesis appears to reside in the direction of a movement away from the dichotomy between the primacy of inner or outer experience, and toward the common meeting ground of the primacy of an intermediating function.