What is the lesson learned in the book Friedrich by Hans Peter Richter?

Richter's work helps to explain why the Holocaust
happened.  Students of history are compelled to ask how the mass killing of over six
million people of one faith and millions of others could have been tolerated without any
real voice of dissent.  Richter's work helps to answer this in suggesting that in order
for such a terrible reality to be present, there has to be some level of complicity on
the part of its citizens.  Fritz's father, who becomes a member of the Nazi party in
order to enjoy the financial comforts for he and his family, rationalizes what the Nazis
do and others in the family allow it to happen.  Fritz's journalistic- like approach to
what is happening to Jewish people in Germany helps to bring light to the idea that when
citizens do not use the voice of dissent to bring out what is wrong with governmental
actions, they allow such travesties of justice and fairness to happen.  In the end, the
book shows that the citizens of "civilized Germany' ended up having responsibility for
what happened during the Holocaust.