By most accounts, people with a borderline personality disorder prove exceptionally difficult to treat. Divergent opinions abound about what, if anything, contributes to a positive outcome. Is it the quality of the relationship with the psychotherapist that is curative, in that the careful attunement of therapist to patient enables the development of a more secure attachment experience? Or is it the technical and structural parameters of the therapy--i.e., therapist neutrality, frame issues, and defensive operations combined with skillfully formulated and timely interventions? Taken together,...