While I agree with Anthony Waterman that it is desirable to read French   
to understand the history of economic thought in the 17th and 18th   
century, I do not think translating phrases from foreign languages is   
ever insulting.  After all, to understand the natural law background to   
18th century economic thought, a knowledge of Latin is essential and one   
of Greek quite useful.  For 14th-16th century thought, Italian should be   
added.  So few historians of economics have read Dutch that the Dutch   
contribution to economic thought is underappreciated.  And scholars who   
specialize in more modern economists but who have a passing interest in   
the 18th century might have put their efforts into German, Swedish or   
some other language.  It would be best for even those who wish to   
understand the history of economic thought in its canonical terms within   
Europe to read at least six and probably more languages, but I doubt   
that the majority of scholars who contribute to this list do. (This   
doesn't even make account for historians who wish to study economic   
thought outside of Europe and North America or non-canonical   
traditions.)   Translating foreign languages thus seems polite, because   
it does not exclude scholars with different skills from the discussion.    
If the original language is particularly crucial, then including the   
original language along with a translation seems the best solution, even   
if a little awkward.   
  
Best regards, and happy new year!  
  
Erik Thomson