David - While Bob certainly did work that popularized, he also did 
scholarly work in the history of economic thought (and, with respect to 
Bruce's criteria list, also participated in the Society (maybe not as 
much as some of us would have liked, but some), trained students who 
contributed to the field, and promoted knowledge and appreciation of the 
history of thought).  But as I argued on this list previously (see 
http://www.eh.net/lists/archives/hes/oct-2003/0036.php ), Bob's work may 
be thought of as part of a tradition that "is 'legitimate' history of 
economics, and yet is infused with an implicit purpose (i.e., how can 
these ideas inform our understanding of actual economies)?"  (Of course, 
Bob did also believe that studying the history of thought was valuable 
in itself, for a number of reasons.) 
 
My post at that time was in response to a list editorial by Roy on "What 
defines a legitimate contribution to the history of economics" (see 
http://www.eh.net/HE/hes_list/Editorials/weintraub.php ), in which he 
argued that "In late twentieth-century departments of economics, all 
individuals who resort on occasion to modes of argument which employ 
historical devices or who in their work quote or comment on Keynes, 
Marx, Veblen, et al., are regarded by their economics departmental 
colleagues as de facto historians of economics; sometimes even those 
individuals believe themselves to be historians of economics if they 
quote or comment upon Keynes, Marx, Veblen, et al. I submit that such 
individuals should not be so regarded, and that their work, however 
valuable as economics, does not constitute a legitimate contribution to 
the history of economics." 
 
Mat