Rhetorical calls for disciplinary unity and vision currently lack any grounding in historically informed analysis of Psychology's character and functions, while the historians of Psychology providing the material for such an analysis continue to remain marginalized. A framework for considering the issue is outlined in terms of a circuit reflexively linking the discipline ('Psychology') and its subject matter ('psychology'). This focuses on the psychologist role, the `inputs' from which Psychological ideas ultimately derive, and the disciplinary `outputs', which in turn affect psychology itself. Thus viewed, the prospects for disciplinary unity appear necessarily faint. The importance of history of Psychology, however, is clarified and reinforced. (The distinction between `Psychology'/ `Psychological' to refer to the discipline and `psychology'/'psychological' to refer to its subject matter is sustained throughout this paper.)