This book's purpose is to trace how Rinsley has continued to extend and amend the basic thesis about borderline patients which was first offered in the seminal paper he co-authored with James Masterson in 1975. That paper, entitled "The Role of the Mother in the Genesis and Psychic Structure of the Borderline Personality" is republished here as Chapter 2. The thesis states that "the determining cause of the fixation of the borderline individual is found in the mother's withdrawal of her libidinal availability (i.e., of her libidinal supplies) as the child makes efforts toward separation-individuation during the rapprochement subphase; and further, that the fixation comes into