It may be a late response, but let me add this further contribution.

FIORITO LUCA AND WARREN J. SAMUELS (2006)
Robert Hoxie's Introductory Lecture on the Nature of the History of 
Political Economy
(1916): The History of Economic Thought as the History of Error
Research in the History of Economic Thought & Methodology v. 24C

The title is partly misleading, since Prof Samuels also offers a careful
reconstruction of the HES list discussion on the nature of the 
history of economic
thought which took place some five years ago.

Luca Fiorito