The brief outline of the accepted canon of psychology betrays the overriding weaknesses found in many modern histories of the discipline. Their continuities are provisory, and the assessments of influence incomplete or topical (as "x continued y's experiments"). These histories, in general, do not address the conceptual underpinnings of psychologists' works, but rather tend to trace back twentieth-century terminology and experiments to their roots. Even when they turn to intellectual history, they often overlook that terminology favored by the twentieth century was often peripheral to the core thought patterns of the nineteenth century in which it originated.¹