The final sentences of Maffeo Pantaleoni's obituary for Vilfredo Pareto are: Every great man has had to labour under the inconveniences created by Epigoni. These tend to the formation of "schools", more properly called obnoxious syndicates of fools. (Pantaleoni 1933, Economic Journal, vol.33, p590) As at least one historically important economist observed the formation of schools of thought and regarded them with considerable contempt, a relevant issue for historians is whether scientific progress should, or should not, be considered a defining characteristic for a school of thought. The answer may well depend on whether one's research methodology emphasizes the rational or sociological basis of scientific knowledge, so I think Matthias Klaes' suggestion (that a clear distinction be maintained between the historiographic and sociological approaches to this issue) is very sensible. Regards Michael McLure