This article describes, from the perspective of a participant in the process, the background of and rationale for the development of the Psychodynamic Diagnostic Manual (PDM), a classification system based on both long-standing clinical observation and recent empirical research. It was hoped that the PDM would compensate for some of the unintended negative consequences to practitioners and their clients of uncritical reliance on descriptive psychiatric taxonomies such as the Diagnostic and Statistical Manual of the American Psychiatric Association. A shared and motivating experience of the contributors to the PDM was dismay at how the dominance of a narrow, descriptive-psychiatry model has promoted the decline of the empirically sound and clinically valuable idiographic tradition, in which clients' difficulties are conceptualized in the context of their unique personalities, developmental challenges, and life contexts. Strengths and limitations of the new manual are discussed, as are ideas about its clinical utility.