One of the main difficulties encountered in the study of psychology is the lack of exact definition in its terms. In psychopathology this difficulty is intensified and many authorities use the same term with widely varied meanings. This is especially noticeable with the term “perseveration.” Some writers restrict its use to describing a subsidiary symptom of apraxia or agnosia, and limit its application to the repetition of an already executed movement in the presence of desire to make a fresh movement. Others write of agnostic perseveration as being synonymous with ideational inertia, and define it as the persistence of an idea in the process of recognition. Woodworth (1) defines perseveration as recall seeming to occur without a stimulus, and considers that some undetected external stimulus is necessary. Dumville (2) holds that perseveration is much the same as retentiveness, and limits its meaning to spontaneous revival in the case only of intense experiences, tracing a close connection between perseveration and association.