I picked up this poem somewhere on the Internet which I think says a lot about silence.
______________________________________________________________________________________
When the Nazis came for the communists, I remained silent;
I was not a communist.
When they locked up the social democrats, I remained silent;
I was not a social democrat.
When they came for the trade unionists, I did not speak out;
I was not a trade unionist.
When they came for the Jews, I remained silent;
I wasn’t a Jew.
When they came for me,
there was no one left to speak out