Here is a link to a review of an anthology of philosophers asking about the   
relationship of philosophy to the history of philosophy, which I found   
interesting and relevant to our own discussions about the economics/history   
of economics.    
  
http://ndpr.nd.edu/review.cfm?id=5962  
  
Though it doesn't come up in the review,  I have lately been   
thinking about another reason to study the history of economic   
thought.  Suppose one believes, as Hegel taught, that normative authority   
is *essentially* historical.  This means that the norms that govern   
economic practice today can only be justified, if at all, in virtue of   
their ability to resolve problems - "aporai" as the Continentals like to   
say -  that earlier methodological norms gave rise to.   We "make sense" of   
ourselves as economists only to the extent that we can  give such an   
historical account.  The suggestion is that economic methodology cannot but   
be historical.  
  
Kevin Quinn