Paul Gagnon, author of the article mentioned by CA Ely
in response to this post, was the lead staffer for the
Bradley Commission on History in the Schools, which
was run out of UCLA (depts. of hist. and ed., as I
recall).  The Commission's summary report is a
superb and pithy answer to the question.  And it
does not recycle the old saw about " . . . condemnded
to repeat . . ."  Highly recommended.
 
Matt Roth