Arecent Paper by Sears (1952) calls attention to an overall time trend in the design changes of various complicated stamped pottery styles in the southeastern United States. His analysis raises the question as to whether certain principles implied might not have more general application for the understanding of historical phenomena. A number of years ago I ventured a definition of what seemed to be a kind of entity in the history of aboriginal Peruvian ceramics. This was termed a “pottery tradition.”